1
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Wisner SR, Chlebowski M, Mandal A, Mai D, Stein C, Petralia RS, Wang YX, Drerup CM. An initial HOPS-mediated fusion event is critical for autophagosome transport initiation from the axon terminal. Autophagy 2024:1-22. [PMID: 38899385 DOI: 10.1080/15548627.2024.2366122] [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: 12/03/2023] [Accepted: 06/05/2024] [Indexed: 06/21/2024] Open
Abstract
In neurons, macroautophagy/autophagy is a frequent and critical process. In the axon, autophagy begins in the axon terminal, where most nascent autophagosomes form. After formation, autophagosomes must initiate transport to exit the axon terminal and move toward the cell body via retrograde transport. During retrograde transport these autophagosomes mature through repetitive fusion events. Complete lysosomal cargo degradation occurs largely in the cell body. The precipitating events to stimulate retrograde autophagosome transport have been debated but their importance is clear: disrupting neuronal autophagy or autophagosome transport is detrimental to neuronal health and function. We have identified the HOPS complex as essential for early autophagosome maturation and consequent initiation of retrograde transport from the axon terminal. In yeast and mammalian cells, HOPS controls fusion between autophagosomes and late endosomes with lysosomes. Using zebrafish strains with loss-of-function mutations in vps18 and vps41, core components of the HOPS complex, we found that disruption of HOPS eliminates autophagosome maturation and disrupts retrograde autophagosome transport initiation from the axon terminal. We confirmed this phenotype was due to loss of HOPS complex formation using an endogenous deletion of the HOPS binding domain in Vps18. Finally, using pharmacological inhibition of lysosomal proteases, we show that initiation of autophagosome retrograde transport requires autophagosome maturation. Together, our data demonstrate that HOPS-mediated fusion events are critical for retrograde autophagosome transport initiation through promoting autophagosome maturation. This reveals critical roles for the HOPS complex in neuronal autophagy which deepens our understanding of the cellular pathology of HOPS-complex linked neurodegenerative diseases.Abbreviations: CORVET: Class C core vacuole/endosome tethering; gRNA: guide RNA; HOPS: homotypic fusion and protein sorting; pLL: posterior lateral line; Vps18: VPS18 core subunit of CORVET and HOPS complexes; Vps41: VPS41 subunit of HOPS complex.
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Affiliation(s)
- Serena R Wisner
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Madison Chlebowski
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Amrita Mandal
- National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Don Mai
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Chris Stein
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Ronald S Petralia
- Advanced Imaging Core, National Institute of Deafness and Other Communication Disorders, NIH, Bethesda, MD, USA
| | - Ya-Xian Wang
- Advanced Imaging Core, National Institute of Deafness and Other Communication Disorders, NIH, Bethesda, MD, USA
| | - Catherine M Drerup
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA
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2
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Shvarev D, König C, Susan N, Langemeyer L, Walter S, Perz A, Fröhlich F, Ungermann C, Moeller A. Structure of the endosomal CORVET tethering complex. Nat Commun 2024; 15:5227. [PMID: 38898033 PMCID: PMC11187117 DOI: 10.1038/s41467-024-49137-9] [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: 11/09/2023] [Accepted: 05/24/2024] [Indexed: 06/21/2024] Open
Abstract
Cells depend on their endolysosomal system for nutrient uptake and downregulation of plasma membrane proteins. These processes rely on endosomal maturation, which requires multiple membrane fusion steps. Early endosome fusion is promoted by the Rab5 GTPase and its effector, the hexameric CORVET tethering complex, which is homologous to the lysosomal HOPS. How these related complexes recognize their specific target membranes remains entirely elusive. Here, we solve the structure of CORVET by cryo-electron microscopy and revealed its minimal requirements for membrane tethering. As expected, the core of CORVET and HOPS resembles each other. However, the function-defining subunits show marked structural differences. Notably, we discover that unlike HOPS, CORVET depends not only on Rab5 but also on phosphatidylinositol-3-phosphate (PI3P) and membrane lipid packing defects for tethering, implying that an organelle-specific membrane code enables fusion. Our data suggest that both shape and membrane interactions of CORVET and HOPS are conserved in metazoans, thus providing a paradigm how tethering complexes function.
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Affiliation(s)
- Dmitry Shvarev
- Department of Biology/Chemistry, Structural Biology Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Caroline König
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Nicole Susan
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Lars Langemeyer
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany
| | - Stefan Walter
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany
| | - Angela Perz
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Florian Fröhlich
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany
- Department of Biology/Chemistry, Bioanalytical Chemistry Section, Osnabrück University, 49076, Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology/Chemistry, Biochemistry Section, Osnabrück University, 49076, Osnabrück, Germany.
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany.
| | - Arne Moeller
- Department of Biology/Chemistry, Structural Biology Section, Osnabrück University, 49076, Osnabrück, Germany.
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, 49076, Osnabrück, Germany.
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3
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van der Beek J, de Heus C, Sanza P, Liv N, Klumperman J. Loss of the HOPS complex disrupts early-to-late endosome transition, impairs endosomal recycling and induces accumulation of amphisomes. Mol Biol Cell 2024; 35:ar40. [PMID: 38198575 PMCID: PMC10916860 DOI: 10.1091/mbc.e23-08-0328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/22/2023] [Accepted: 01/05/2024] [Indexed: 01/12/2024] Open
Abstract
The multisubunit HOPS tethering complex is a well-established regulator of lysosome fusion with late endosomes and autophagosomes. However, the role of the HOPS complex in other stages of endo-lysosomal trafficking is not well understood. To address this, we made HeLa cells knocked out for the HOPS-specific subunits Vps39 or Vps41, or the HOPS-CORVET-core subunits Vps18 or Vps11. In all four knockout cells, we found that endocytosed cargos were trapped in enlarged endosomes that clustered in the perinuclear area. By correlative light-electron microscopy, these endosomes showed a complex ultrastructure and hybrid molecular composition, displaying markers for early (Rab5, PtdIns3P, EEA1) as well as late (Rab7, CD63, LAMP1) endosomes. These "HOPS bodies" were not acidified, contained enzymatically inactive cathepsins and accumulated endocytosed cargo and cation-independent mannose-6-phosphate receptor (CI-MPR). Consequently, CI-MPR was depleted from the TGN, and secretion of lysosomal enzymes to the extracellular space was enhanced. Strikingly, HOPS bodies also contained the autophagy proteins p62 and LC3, defining them as amphisomes. Together, these findings show that depletion of the lysosomal HOPS complex has a profound impact on the functional organization of the entire endosomal system and suggest the existence of a HOPS-independent mechanism for amphisome formation.
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Affiliation(s)
- Jan van der Beek
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Cecilia de Heus
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Paolo Sanza
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Nalan Liv
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Judith Klumperman
- Center for Molecular Medicine, University Medical Center Utrecht, Institute of Biomembranes, Utrecht University, 3584 CX Utrecht, The Netherlands
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4
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Nicolson S, Manning JA, Lim Y, Jiang X, Kolze E, Dayan S, Umargamwala R, Xu T, Sandow JJ, Webb AI, Kumar S, Denton D. The Drosophila ZNRF1/2 homologue, detour, interacts with HOPS complex and regulates autophagy. Commun Biol 2024; 7:183. [PMID: 38360932 PMCID: PMC10869362 DOI: 10.1038/s42003-024-05834-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 01/18/2024] [Indexed: 02/17/2024] Open
Abstract
Autophagy, the process of elimination of cellular components by lysosomal degradation, is essential for animal development and homeostasis. Using the autophagy-dependent Drosophila larval midgut degradation model we identified an autophagy regulator, the RING domain ubiquitin ligase CG14435 (detour). Depletion of detour resulted in increased early-stage autophagic vesicles, premature tissue contraction, and overexpression of detour or mammalian homologues, ZNRF1 and ZNRF2, increased autophagic vesicle size. The ablation of ZNRF1 or ZNRF2 in mammalian cells increased basal autophagy. We identified detour interacting proteins including HOPS subunits, deep orange (dor/VPS18), Vacuolar protein sorting 16A (VPS16A), and light (lt/VPS41) and found that detour promotes their ubiquitination. The detour mutant accumulated autophagy-related proteins in young adults, displayed premature ageing, impaired motor function, and activation of innate immunity. Collectively, our findings suggest a role for detour in autophagy, likely through regulation of HOPS complex, with implications for healthy aging.
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Affiliation(s)
- Shannon Nicolson
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
| | - Jantina A Manning
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
| | - Yoon Lim
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
| | - Xin Jiang
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
| | - Erica Kolze
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, 5001, Australia
| | - Sonia Dayan
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
| | - Ruchi Umargamwala
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
| | - Tianqi Xu
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia
| | - Jarrod J Sandow
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, 3052, Australia
| | - Sharad Kumar
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia.
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, 5001, Australia.
| | - Donna Denton
- Centre for Cancer Biology, University of South Australia, Adelaide, SA, 5001, Australia.
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5
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Terawaki S, Vasilev F, Moriwaki T, Otomo T. HOPS, CORVET and newly-identified Hybrid tethering complexes contribute differentially towards multiple modes of endocytosis. Sci Rep 2023; 13:18734. [PMID: 37907479 PMCID: PMC10618185 DOI: 10.1038/s41598-023-45418-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/19/2023] [Indexed: 11/02/2023] Open
Abstract
Vesicular transport driven by membrane trafficking systems conserved in eukaryotes is critical to cellular functionality and homeostasis. It is known that homotypic fusion and vacuole protein sorting (HOPS) and class C core endosomal vacuole tethering (CORVET) interact with Rab-GTPases and SNARE proteins to regulate vesicle transport, fusion, and maturation in autophagy and endocytosis pathways. In this study, we identified two novel "Hybrid" tethering complexes in mammalian cells in which one of the subunits of HOPS or CORVET is replaced with the subunit from the other. Substrates taken up by receptor-mediated endocytosis or pinocytosis were transported by distinctive pathways, and the newly identified hybrid complexes contributed to pinocytosis in the presence of HOPS, whereas receptor-mediated endocytosis was exclusively dependent on HOPS. Our study provides new insights into the molecular mechanisms of the endocytic pathway and the function of the vacuolar protein sorting-associated (VPS) protein family.
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Affiliation(s)
- Seigo Terawaki
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Filipp Vasilev
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Takahito Moriwaki
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan
| | - Takanobu Otomo
- Department of Molecular and Genetic Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan.
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6
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Coppola V, Marino I, Warnken U, Falchi M, Pasquini L, Biffoni M, De Maria R, Haas TL. The autophagic protein FYCO1 controls TNFRSF10/TRAIL receptor induced apoptosis and is inactivated by CASP8 (caspase 8). Autophagy 2023; 19:2733-2751. [PMID: 37418591 PMCID: PMC10472876 DOI: 10.1080/15548627.2023.2229656] [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: 05/13/2022] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 07/09/2023] Open
Abstract
Apoptosis is a tightly controlled cell death program executed by proteases, the so-called caspases. It plays an important role in tissue homeostasis and is often dysregulated in cancer. Here, we identified FYCO1, a protein that promotes microtubule plus end-directed transport of autophagic and endosomal vesicles as a molecular interaction partner of activated CASP8 (caspase 8). The absence of FYCO1 sensitized cells to basal and TNFSF10/TRAIL-induced apoptosis by receptor accumulation and stabilization of the Death Inducing Signaling Complex (DISC). Loss of FYCO1 resulted in impaired transport of TNFRSF10B/TRAIL-R2/DR5 (TNF receptor superfamily member 10b) to the lysosomes in TNFSF10/TRAIL-stimulated cells. More in detail, we show that FYCO1 interacted via its C-terminal GOLD domain with the CCZ1-MON1A complex, which is necessary for RAB7A activation and for the fusion of autophagosomal/endosomal vesicles with lysosomes. We demonstrated that FYCO1 is a novel and specific CASP8 substrate. The cleavage at aspartate 1306 resulted in the release of the C-terminal GOLD domain, inactivating FYCO1 function, and allowing for the progression of apoptosis. Furthermore, the lack of FYCO1 resulted in a stronger and prolonged formation of the TNFRSF1A/TNF-R1 signaling complex. Thus, FYCO1 limits the ligand-induced and steady-state signaling of TNFR-superfamily members, providing a control mechanism that fine-tunes both apoptotic and inflammatory answers.Abbreviations: AP: affinity purification; CHX: cycloheximide; co-IP: co-immunoprecipitation; CRISPR: clustered regularly interspaced short palindromic repeats; DISC: death-inducing signaling complex; DR: death receptors; doxy: doxycycline; GEF: guanine nucleotide exchange factor; ind: inducible; KD: knockdown; KO: knockout; MS: mass spectrometry; shRNA: short hairpin RNA; siRNA: small interfering RNA; TIP: two-step co-immunoprecipitation; WB: western blot.
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Affiliation(s)
- Valeria Coppola
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, RM, Italy
| | - Ilaria Marino
- Department of Translational Medicine and Surgery, Università Cattolica Del Sacro Cuore, Rome, RM, Italy
| | - Uwe Warnken
- Functional Proteomic Analysis, German Cancer Research Center (DKFZ), Heidelberg, BW, Germany
- Clinical Cooperation Unit Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, BW, Germany
| | | | - Luca Pasquini
- Servizio Tecnico Scientifico Grandi Strumentazioni E Core Facilities – FAST, Rome, RM, Italy
| | - Mauro Biffoni
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, RM, Italy
| | - Ruggero De Maria
- Department of Translational Medicine and Surgery, Università Cattolica Del Sacro Cuore, Rome, RM, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, RM, Italy
| | - Tobias Longin Haas
- Department of Translational Medicine and Surgery, Università Cattolica Del Sacro Cuore, Rome, RM, Italy
- Section of Immunotherapy, IIGM-Italian Institute for Genomic Medicine, Candiolo, TO, Italy
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7
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Del Vecchio M, Amado L, Cogan AP, Meert E, Rosseels J, Franssens V, Govers SK, Winderickx J, Montoro AG. Multiple tethers of organelle contact sites are involved in α-synuclein toxicity in yeast. Mol Biol Cell 2023; 34:ar84. [PMID: 37074954 PMCID: PMC10398879 DOI: 10.1091/mbc.e23-01-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/20/2023] Open
Abstract
The protein α-synuclein (α-syn) is one of the major factors linked to Parkinson's disease, yet how its misfolding and deposition contribute to the pathology remains largely elusive. Recently, contact sites among organelles were implicated in the development of this disease. Here, we used the budding yeast Saccharomyces cerevisiae, in which organelle contact sites have been characterized extensively, as a model to investigate their role in α-syn cytotoxicity. We observed that lack of specific tethers that anchor the endoplasmic reticulum to the plasma membrane resulted in cells with increased resistance to α-syn expression. Additionally, we found that strains lacking two dual-function proteins involved in contact sites, Mdm10 and Vps39, were resistant to the expression of α-syn. In the case of Mdm10, we found that this is related to its function in mitochondrial protein biogenesis and not to its role as a contact site tether. In contrast, both functions of Vps39, in vesicular transport and as a tether of the vacuole-mitochondria contact site, were required to support α-syn toxicity. Overall, our findings support that interorganelle communication through membrane contact sites is highly relevant for α-syn-mediated toxicity.
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Affiliation(s)
- Mara Del Vecchio
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
- Department of Biology, Microbial Systems Cell Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Lucia Amado
- Department of Biology/Chemistry, Cellular Communication Laboratory, Osnabrück University, 49076 Osnabrück, Germany
| | - Alexandra P. Cogan
- Department of Biology/Chemistry, Cellular Communication Laboratory, Osnabrück University, 49076 Osnabrück, Germany
| | - Els Meert
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Joelle Rosseels
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Vanessa Franssens
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Sander K. Govers
- Department of Biology, Microbial Systems Cell Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Joris Winderickx
- Department of Biology, Functional Biology Laboratory, KU Leuven, 3001 Heverlee, Belgium
| | - Ayelén González Montoro
- Department of Biology/Chemistry, Cellular Communication Laboratory, Osnabrück University, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück, 49076 Osnabrück, Germany
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8
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Shelke GV, Williamson CD, Jarnik M, Bonifacino JS. Inhibition of endolysosome fusion increases exosome secretion. J Cell Biol 2023; 222:e202209084. [PMID: 37213076 PMCID: PMC10202829 DOI: 10.1083/jcb.202209084] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 02/04/2023] [Accepted: 03/17/2023] [Indexed: 05/23/2023] Open
Abstract
Exosomes are small vesicles that are secreted from cells to dispose of undegraded materials and mediate intercellular communication. A major source of exosomes is intraluminal vesicles within multivesicular endosomes that undergo exocytic fusion with the plasma membrane. An alternative fate of multivesicular endosomes is fusion with lysosomes, resulting in degradation of the intraluminal vesicles. The factors that determine whether multivesicular endosomes fuse with the plasma membrane or with lysosomes are unknown. In this study, we show that impairment of endolysosomal fusion by disruption of a pathway involving the BLOC-one-related complex (BORC), the small GTPase ARL8, and the tethering factor HOPS increases exosome secretion by preventing the delivery of intraluminal vesicles to lysosomes. These findings demonstrate that endolysosomal fusion is a critical determinant of the amount of exosome secretion and suggest that suppression of the BORC-ARL8-HOPS pathway could be used to boost exosome yields in biotechnology applications.
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Affiliation(s)
- Ganesh Vilas Shelke
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Chad D. Williamson
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Michal Jarnik
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Juan S. Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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9
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Wang L, Wang T, Wen S, Song R, Zou H, Gu J, Liu X, Bian J, Liu Z, Yuan Y. Puerarin Prevents Cadmium-Induced Neuronal Injury by Alleviating Autophagic Dysfunction in Rat Cerebral Cortical Neurons. Int J Mol Sci 2023; 24:ijms24098328. [PMID: 37176033 PMCID: PMC10179714 DOI: 10.3390/ijms24098328] [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: 02/26/2023] [Revised: 04/23/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Autophagic dysfunction is one of the main mechanisms of cadmium (Cd)-induced neurotoxicity. Puerarin (Pue) is a natural antioxidant extracted from the medicinal and edible homologous plant Pueraria lobata. Studies have shown that Pue has neuroprotective effects in a variety of brain injuries, including Cd-induced neuronal injury. However, the role of Pue in the regulation of autophagy to alleviate Cd-induced injury in rat cerebral cortical neurons remains unclear. This study aimed to elucidate the protective mechanism of Pue in alleviating Cd-induced injury in rat cerebral cortical neurons by targeting autophagy. Our results showed that Pue alleviated Cd-induced injury in rat cerebral cortical neurons in vitro and in vivo. Pue activates autophagy and alleviates Cd-induced autophagic blockade in rat cerebral cortical neurons. Further studies have shown that Pue alleviates the Cd-induced inhibition of autophagosome-lysosome fusion, as well as the inhibition of lysosomal degradation. The specific mechanism is related to Pue alleviating the inhibition of Cd on the expression levels of the key proteins Rab7, VPS41, and SNAP29, which regulate autophagosome-lysosome fusion, as well as the lysosome-related proteins LAMP2, CTSB, and CTSD. In summary, these results indicate that Pue alleviates Cd-induced autophagic dysfunction in rat cerebral cortical neurons by alleviating autophagosome-lysosome fusion dysfunction and lysosomal degradation dysfunction, thereby alleviating Cd-induced neuronal injury.
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Affiliation(s)
- Li Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Tao Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Shuangquan Wen
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Ruilong Song
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Hui Zou
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Jianhong Gu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Xuezhong Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Jianchun Bian
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Zongping Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Yan Yuan
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
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10
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Liv N, Fermie J, Ten Brink CBM, de Heus C, Klumperman J. Functional characterization of endo-lysosomal compartments by correlative live-cell and volume electron microscopy. Methods Cell Biol 2023; 177:301-326. [PMID: 37451771 DOI: 10.1016/bs.mcb.2022.12.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Fluorescent biosensors are valuable tools to monitor protein activities and the functional state of organelles in live cells. However, the information provided by fluorescent microscopy (FM) is mostly limited in resolution and lacks ultrastructural context information. Protein activities are confined to organelle zones with a distinct membrane morphology, which can only be seen by electron microscopy (EM). EM, however, intrinsically lacks information on protein activities. The lack of methods to integrate these two imaging modalities has hampered understanding the functional organization of cellular organelles. Here we introduce "functional correlative microscopy" (functional CLEM) to directly infer functional information from live cells to EM with nanometer resolution. We label and visualize live cells with fluorescent biosensors after which they are processed for EM and imaged using a volume electron microscopy technique. Within a single dataset we correlate hundreds of fluorescent spots enabling quantitative analysis of the functional-ultrastructural data. We employ our method to monitor essential functional parameters of late endo-lysosomal compartments, i.e., pH, calcium, enzyme activities and cholesterol content. Our data reveal a steep functional difference in enzyme activity between late endosomes and lysosomes and unexpectedly high calcium levels in late endosomes. The presented CLEM workflow is compatible with a large repertoire of probes and paves the way for large scale functional studies of all types of cellular structures.
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Affiliation(s)
- Nalan Liv
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
| | - Job Fermie
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands; Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands
| | - Corlinda B M Ten Brink
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Cecilia de Heus
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Judith Klumperman
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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11
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Abstract
Cargo delivery from one compartment to the next relies on the fusion of vesicles with different cellular organelles in a process that requires the concerted action of tethering factors. Although all tethers act to bridge vesicle membranes to mediate fusion, they form very diverse groups as they differ in composition, and in their overall architecture and size, as well as their protein interactome. However, their conserved function relies on a common design. Recent data on class C Vps complexes indicates that tethers play a significant role in membrane fusion beyond vesicle capturing. Furthermore, these studies provide additional mechanistic insights into membrane fusion events and reveal that tethers should be considered as key players of the fusion machinery. Moreover, the discovery of the novel tether FERARI complex has changed our understanding of cargo transport in the endosomal system as it has been shown to mediate 'kiss-and-run' vesicle-target membrane interactions. In this Cell Science at a Glance and the accompanying poster, we compare the structure of the coiled-coil and the multisubunit CATCHR and class C Vps tether families on the basis of their functional analogy. We discuss the mechanism of membrane fusion, and summarize how tethers capture vesicles, mediate membrane fusion at different cellular compartments and regulate cargo traffic.
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Affiliation(s)
| | - Anne Spang
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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12
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CP204L Is a Multifunctional Protein of African Swine Fever Virus That Interacts with the VPS39 Subunit of the Homotypic Fusion and Vacuole Protein Sorting Complex and Promotes Lysosome Clustering. J Virol 2023; 97:e0194322. [PMID: 36722971 PMCID: PMC9972913 DOI: 10.1128/jvi.01943-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Virus replication depends on a complex interplay between viral and host proteins. In the case of African swine fever virus (ASFV), a large DNA virus, only a few virus-host protein-protein interactions have been identified to date. In this study, we demonstrate that the ASFV protein CP204L interacts with the cellular homotypic fusion and protein sorting (HOPS) protein VPS39, blocking its association with the lysosomal HOPS complex, which modulates endolysosomal trafficking and promotes lysosome clustering. Instead, CP204L and VPS39 are targeted to virus factories and localized at the periphery of the virus DNA replication sites. Furthermore, we show that loss of VPS39 reduces the levels of virus proteins synthesized in the early phase of infection and delays ASFV replication but does not completely inhibit it. Collectively, these results identify a novel virus-host protein interaction that modulates host membrane rearrangement during infection and provide evidence that CP204L is a multifunctional protein engaged in distinct steps of the ASFV life cycle. IMPORTANCE African swine fever virus (ASFV) was first identified over a hundred years ago. Since then, much effort has been made to understand the pathogenesis of ASFV. However, the specific roles of many individual ASFV proteins during the infection remain enigmatic. This study provides evidence that CP204L, one of the most abundant ASFV proteins, modulates endosomal trafficking during virus infection. Through protein-protein interaction, CP204L prevents the recruitment of VPS39 to the endosomal and lysosomal membranes, resulting in their accumulation. Consequently, CP204L and VPS39 become sequestered in the ASFV replication and assembly site, known as the virus factory. These results uncover a novel function of viral protein CP204L and extend our understanding of complex interaction between virus and host.
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13
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Targeting VPS41 induces methuosis and inhibits autophagy in cancer cells. Cell Chem Biol 2023; 30:130-143.e5. [PMID: 36708709 DOI: 10.1016/j.chembiol.2023.01.002] [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: 04/16/2022] [Revised: 11/09/2022] [Accepted: 01/09/2023] [Indexed: 01/28/2023]
Abstract
The homotypic fusion and vacuole protein sorting (HOPS) complex mediates membrane trafficking involved in endocytosis, autophagy, lysosome biogenesis, and phagocytosis. Defects in HOPS subunits are associated with various forms of cancer, but their potential as drug targets has rarely been examined. Here, we identified vacuolar protein sorting-associated protein 41 homolog (VPS41), a subunit of the HOPS complex, as a target of methyl 2,4-dihydroxy-3-(3-methyl-2-butenyl)-6-phenethylbenzoate (DMBP), a natural small molecule with preferable anticancer activity. DMBP induced methuosis and inhibited autophagic flux in cancer cells by inhibiting the function of VPS41, leading to the restrained fusion of late endosomes and autophagosomes with lysosomes. Moreover, DMBP effectively inhibited metastasis in a mouse metastatic melanoma model. Collectively, the current work revealed that targeting VPS41 would provide a valuable method of inhibiting cancer proliferation through methuosis.
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14
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Making bubbles: Targeting VPS41 induces vacuolization and methuosis. Cell Chem Biol 2023; 30:127-129. [PMID: 36800990 DOI: 10.1016/j.chembiol.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
In this issue of Cell Chemical Biology, Liu et al. describe the natural product DMBP as the first tool compound for VPS41. Treatment with DMBP induced vacuolization and methuosis and inhibited autophagic flux in lung and pancreatic cancer cell lines, validating VPS41 as a potential therapeutic target.
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15
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Schleinitz A, Pöttgen LA, Keren-Kaplan T, Pu J, Saftig P, Bonifacino JS, Haas A, Jeschke A. Consecutive functions of small GTPases guide HOPS-mediated tethering of late endosomes and lysosomes. Cell Rep 2023; 42:111969. [PMID: 36640308 PMCID: PMC10018218 DOI: 10.1016/j.celrep.2022.111969] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 10/12/2022] [Accepted: 12/20/2022] [Indexed: 01/06/2023] Open
Abstract
The transfer of endocytosed cargoes to lysosomes (LYSs) requires HOPS, a multiprotein complex that tethers late endosomes (LEs) to LYSs before fusion. Many proteins interact with HOPS on LEs/LYSs. However, it is not clear whether these HOPS interactors localize to LEs or LYSs or how they participate in tethering. Here, we biochemically characterized endosomes purified from untreated or experimentally manipulated cells to put HOPS and interacting proteins in order and to establish their functional interdependence. Our results assign Rab2a and Rab7 to LEs and Arl8 and BORC to LYSs and show that HOPS drives LE-LYS fusion by bridging late endosomal Rab2a with lysosomal BORC-anchored Arl8. We further show that Rab7 is absent from sites of HOPS-dependent tethering but promotes fusion by moving LEs toward LYSs via dynein. Thus, our study identifies the topology of the machinery for LE-LYS tethering and elucidates the role of different small GTPases in the process.
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Affiliation(s)
| | | | - Tal Keren-Kaplan
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jing Pu
- Department of Molecular Genetics and Microbiology, and Autophagy, Inflammation, and Metabolism, Center of Biomedical Research Excellence, University of New Mexico, Albuquerque, NM 87131, USA
| | - Paul Saftig
- Biochemical Institute, University of Kiel, 24118 Kiel, Germany
| | - Juan S Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Albert Haas
- Cell Biology Institute, University of Bonn, 53121 Bonn, Germany.
| | - Andreas Jeschke
- Cell Biology Institute, University of Bonn, 53121 Bonn, Germany.
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16
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Miller AN, Houlihan PR, Matamala E, Cabezas-Bratesco D, Lee GY, Cristofori-Armstrong B, Dilan TL, Sanchez-Martinez S, Matthies D, Yan R, Yu Z, Ren D, Brauchi SE, Clapham DE. The SARS-CoV-2 accessory protein Orf3a is not an ion channel, but does interact with trafficking proteins. eLife 2023; 12:e84477. [PMID: 36695574 PMCID: PMC9910834 DOI: 10.7554/elife.84477] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/25/2023] [Indexed: 01/26/2023] Open
Abstract
The severe acute respiratory syndrome associated coronavirus 2 (SARS-CoV-2) and SARS-CoV-1 accessory protein Orf3a colocalizes with markers of the plasma membrane, endocytic pathway, and Golgi apparatus. Some reports have led to annotation of both Orf3a proteins as viroporins. Here, we show that neither SARS-CoV-2 nor SARS-CoV-1 Orf3a form functional ion conducting pores and that the conductances measured are common contaminants in overexpression and with high levels of protein in reconstitution studies. Cryo-EM structures of both SARS-CoV-2 and SARS-CoV-1 Orf3a display a narrow constriction and the presence of a positively charged aqueous vestibule, which would not favor cation permeation. We observe enrichment of the late endosomal marker Rab7 upon SARS-CoV-2 Orf3a overexpression, and co-immunoprecipitation with VPS39. Interestingly, SARS-CoV-1 Orf3a does not cause the same cellular phenotype as SARS-CoV-2 Orf3a and does not interact with VPS39. To explain this difference, we find that a divergent, unstructured loop of SARS-CoV-2 Orf3a facilitates its binding with VPS39, a HOPS complex tethering protein involved in late endosome and autophagosome fusion with lysosomes. We suggest that the added loop enhances SARS-CoV-2 Orf3a's ability to co-opt host cellular trafficking mechanisms for viral exit or host immune evasion.
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Affiliation(s)
| | | | - Ella Matamala
- Physiology Institute and Millennium Nucleus of Ion Channel-Associated Diseases, Universidad Austral de ChileValdiviaChile
| | - Deny Cabezas-Bratesco
- Physiology Institute and Millennium Nucleus of Ion Channel-Associated Diseases, Universidad Austral de ChileValdiviaChile
| | - Gi Young Lee
- Department of Biology, University of PennsylvaniaPhiladelphiaUnited States
| | | | | | | | | | - Rui Yan
- Janelia Research CampusAshburnUnited States
| | - Zhiheng Yu
- Janelia Research CampusAshburnUnited States
| | - Dejian Ren
- Department of Biology, University of PennsylvaniaPhiladelphiaUnited States
| | - Sebastian E Brauchi
- Janelia Research CampusAshburnUnited States
- Physiology Institute and Millennium Nucleus of Ion Channel-Associated Diseases, Universidad Austral de ChileValdiviaChile
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17
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Wen QX, Luo B, Xie XY, Zhou GF, Chen J, Song L, Liu Y, Xie SQ, Chen L, Li KY, Xiang XJ, Chen GJ. AP2S1 regulates APP degradation through late endosome-lysosome fusion in cells and APP/PS1 mice. Traffic 2023; 24:20-33. [PMID: 36412210 PMCID: PMC10107530 DOI: 10.1111/tra.12874] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 09/08/2022] [Accepted: 11/14/2022] [Indexed: 11/23/2022]
Abstract
AP2S1 is the sigma 2 subunit of adaptor protein 2 (AP2) that is essential for endocytosis. In this study, we investigated the potential role of AP2S1 in intracellular processing of amyloid precursor protein (APP), which contributes to the pathogenesis of Alzheimer disease (AD) by generating the toxic β-amyloid peptide (Aβ). We found that knockdown or overexpression of AP2S1 decreased or increased the protein levels of APP and Aβ in cells stably expressing human full-length APP695, respectively. This effect was unrelated to endocytosis but involved lysosomal degradation. Morphological studies revealed that silencing of AP2S1 promoted the translocalization of APP from RAB9-positive late endosomes (LE) to LAMP1-positive lysosomes, which was paralleled by the enhanced LE-lysosome fusion. In support, silencing of vacuolar protein sorting-associated protein 41 (VPS41) that is implicated in LE-lyso fusion prevented AP2S1-mediated regulation of APP degradation and translocalization. In APP/PS1 mice, an animal model of AD, AAV-mediated delivery of AP2S1 shRNA in the hippocampus significantly reduced the protein levels of APP and Aβ, with the concomitant APP translocalization, LE-lyso fusion and the improved cognitive functions. Taken together, these data uncover a LE-lyso fusion mechanism in APP degradation and suggest a novel role for AP2S1 in the pathophysiology of AD.
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Affiliation(s)
- Qi-Xin Wen
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Biao Luo
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Xiao-Yong Xie
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Gui-Feng Zhou
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Jian Chen
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Li Song
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Yue Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Shi-Qi Xie
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Long Chen
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Kun-Yi Li
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Xiao-Jiao Xiang
- Department of Nuclear Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Guo-Jun Chen
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Major Neurological and Mental Disorders, Chongqing Key Laboratory of Neurology, Chongqing, China.,Institute for Brain Science and Disease, Chongqing Medical University, Chongqing, China
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18
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De Mazière A, van der Beek J, van Dijk S, de Heus C, Reggiori F, Koike M, Klumperman J. An optimized protocol for immuno-electron microscopy of endogenous LC3. Autophagy 2022; 18:3004-3022. [PMID: 35387562 PMCID: PMC9673964 DOI: 10.1080/15548627.2022.2056864] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
MAP1LC3/LC3 (microtubule associated protein 1 light chain 3) is widely used as marker of autophagic compartments at different stages of maturation. Electron microscopy (EM) combined with immunolabeling is the only technique that can reveal the ultrastructural identity of LC3-labeled compartments. However, immuno-EM of endogenous LC3 proteins has proven difficult. Here, we test a panel of commercially available antibodies and apply different labeling conditions to present an optimized procedure for LC3 immuno-EM. Using ultrathin cryosections and protein A-colloidal gold or gold enhancement labeling, we localize endogenous LC3 in starved cells or tissues in the presence or absence of the proton pump inhibitor bafilomycin A1. We localize LC3 to early and late stage autophagic compartments that can be classified by their morphology. By on-section correlative light-electron microscopy (CLEM) we show that comparable fluorescent LC3-positive puncta can represent different autophagic intermediates. We also show that our approach is sufficiently robust to label endogenous LC3 simultaneously with other lysosomal and autophagy markers, LAMP1 or SQSTM1/p62, and can be used for quantitative approaches. Thus, we demonstrate that bafilomycin A1 treatment from 2.5 up to 24 h does not inhibit fusion between autophagosomes and lysosomes, but leads to the accumulation of LC3-positive material inside autolysosomes. Together, this is the first study presenting an extensive overview of endogenous LC3 localization at ultrastructural resolution without the need for cell permeabilization and using a commercially available antibody. This provides researchers with a tool to study canonical and non-canonical roles of LC3 in native conditions.Abbreviations: BafA1: bafilomycin A1; BSA: bovine serum albumin; BSA-c: acetylated BSA; BSA5: BSA conjugated to 5-nm gold particles; CLEM: correlative light-electron microscopy; EGFP: enhanced green fluorescent protein; EM: electron microscopy; FBS: fetal bovine serum; FSG: fish skin gelatin; GA: glutaraldehyde; IF: immunofluorescence; LAMP1: lysosomal associated membrane protein 1; LC3s: LC3 proteins; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; ON: overnight; PAG: protein A-conjugated gold particles; PAG1-3: PAG5, PAG10, PAG15, protein A conjugated to 1-3-, 5-, 10-, or 15-nm gold particles; PB: Sorensen's phosphate buffer; PBS: phosphate-buffered saline; PFA: paraformaldehyde; RT: room temperature.
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Affiliation(s)
- Ann De Mazière
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Jan van der Beek
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Suzanne van Dijk
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Cecilia de Heus
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells & Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Masato Koike
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands,CONTACT Judith Klumperman Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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19
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Miller AN, Houlihan PR, Matamala E, Cabezas-Bratesco D, Lee GY, Cristofori-Armstrong B, Dilan TL, Sanchez-Martinez S, Matthies D, Yan R, Yu Z, Ren D, Brauchi SE, Clapham DE. The SARS-CoV-2 accessory protein Orf3a is not an ion channel, but does interact with trafficking proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.09.02.506428. [PMID: 36263072 PMCID: PMC9580380 DOI: 10.1101/2022.09.02.506428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The severe acute respiratory syndrome associated coronavirus 2 (SARS-CoV-2) and SARS-CoV-1 accessory protein Orf3a colocalizes with markers of the plasma membrane, endocytic pathway, and Golgi apparatus. Some reports have led to annotation of both Orf3a proteins as a viroporin. Here we show that neither SARS-CoV-2 nor SARS-CoV-1 form functional ion conducting pores and that the conductances measured are common contaminants in overexpression and with high levels of protein in reconstitution studies. Cryo-EM structures of both SARS-CoV-2 and SARS-CoV-1 Orf3a display a narrow constriction and the presence of a basic aqueous vestibule, which would not favor cation permeation. We observe enrichment of the late endosomal marker Rab7 upon SARS-CoV-2 Orf3a overexpression, and co-immunoprecipitation with VPS39. Interestingly, SARS-CoV-1 Orf3a does not cause the same cellular phenotype as SARS-CoV-2 Orf3a and does not interact with VPS39. To explain this difference, we find that a divergent, unstructured loop of SARS-CoV-2 Orf3a facilitates its binding with VPS39, a HOPS complex tethering protein involved in late endosome and autophagosome fusion with lysosomes. We suggest that the added loop enhances SARS-CoV-2 Orf3a ability to co-opt host cellular trafficking mechanisms for viral exit or host immune evasion.
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20
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Molecular Mechanism and Regulation of Autophagy and Its Potential Role in Epilepsy. Cells 2022; 11:cells11172621. [PMID: 36078029 PMCID: PMC9455075 DOI: 10.3390/cells11172621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/14/2022] [Accepted: 08/22/2022] [Indexed: 01/18/2023] Open
Abstract
Autophagy is an evolutionally conserved degradation mechanism for maintaining cell homeostasis whereby cytoplasmic components are wrapped in autophagosomes and subsequently delivered to lysosomes for degradation. This process requires the concerted actions of multiple autophagy-related proteins and accessory regulators. In neurons, autophagy is dynamically regulated in different compartments including soma, axons, and dendrites. It determines the turnover of selected materials in a spatiotemporal control manner, which facilitates the formation of specialized neuronal functions. It is not surprising, therefore, that dysfunctional autophagy occurs in epilepsy, mainly caused by an imbalance between excitation and inhibition in the brain. In recent years, much attention has been focused on how autophagy may cause the development of epilepsy. In this article, we overview the historical landmarks and distinct types of autophagy, recent progress in the core machinery and regulation of autophagy, and biological roles of autophagy in homeostatic maintenance of neuronal structures and functions, with a particular focus on synaptic plasticity. We also discuss the relevance of autophagy mechanisms to the pathophysiology of epileptogenesis.
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21
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Lu A. Endolysosomal cholesterol export: More than just NPC1. Bioessays 2022; 44:e2200111. [PMID: 35934896 DOI: 10.1002/bies.202200111] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/22/2022] [Accepted: 07/26/2022] [Indexed: 11/07/2022]
Abstract
NPC1 plays a central role in cholesterol egress from endolysosomes, a critical step for maintaining intracellular cholesterol homeostasis. Despite recent advances in the field, the full repertoire of molecules and pathways involved in this process remains unknown. Emerging evidence suggests the existence of NPC1-independent, alternative routes. These may involve vesicular and non-vesicular mechanisms, as well as release of extracellular vesicles. Understanding the underlying molecular mechanisms that bypass NPC1 function could have important implications for the development of therapies for lysosomal storage disorders. Here we discuss how cholesterol may be exported from lysosomes in which NPC1 function is impaired.
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Affiliation(s)
- Albert Lu
- Departament de Biomedicina, Unitat de Biologia Cellular, Facultat de Medicina i Ciències de la Salut, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
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22
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Anderson J, Walker G, Pu J. BORC-ARL8-HOPS ensemble is required for lysosomal cholesterol egress through NPC2. Mol Biol Cell 2022; 33:ar81. [PMID: 35653304 PMCID: PMC9582633 DOI: 10.1091/mbc.e21-11-0595-t] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/16/2022] [Accepted: 05/24/2022] [Indexed: 11/11/2022] Open
Abstract
Lysosomes receive extracellular and intracellular cholesterol and redistribute it throughout the cell. Cholesterol egress from lysosomes is critical for cholesterol homeostasis, and its failure underlies the pathogenesis of genetic disorders such as Niemann-Pick C (NPC) disease. Here we report that the BLOC one-related complex (BORC)-ARL8-homotypic fusion and protein sorting (HOPS) ensemble is required for egress of free cholesterol from lysosomes and for storage of esterified cholesterol in lipid droplets. Depletion of BORC, ARL8, or HOPS does not alter the localization of the lysosomal transmembrane cholesterol transporter NPC1 to degradative compartments but decreases the association of the luminal transporter NPC2 and increases NPC2 secretion. BORC-ARL8-HOPS depletion also increases lysosomal degradation of cation-independent (CI)-mannose 6-phosphate (M6P) receptor (MPR), which normally sorts NPC2 to the endosomal-lysosomal system and then is recycled to the trans-Golgi network. These defects likely result from impaired HOPS-dependent fusion of endosomal-lysosomal organelles and an uncharacterized function of HOPS in CI-MPR recycling. Our study demonstrates that the BORC-ARL8-HOPS ensemble is required for cholesterol egress from lysosomes by enabling CI-MPR-dependent trafficking of NPC2 to the endosomal-lysosomal system.
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Affiliation(s)
- Jacob Anderson
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, NM 87131
- Autophagy, Inflammation, and Metabolism Center of Biomedical Research Excellence, University of New Mexico, Albuquerque, NM 87131
| | - Gerard Walker
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Jing Pu
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, NM 87131
- Autophagy, Inflammation, and Metabolism Center of Biomedical Research Excellence, University of New Mexico, Albuquerque, NM 87131
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Fermie J, de Jager L, Foster HE, Veenendaal T, de Heus C, van Dijk S, ten Brink C, Oorschot V, Yang L, Li W, Müller WH, Howes S, Carter AP, Förster F, Posthuma G, Gerritsen HC, Klumperman J, Liv N. Bimodal endocytic probe for three-dimensional correlative light and electron microscopy. CELL REPORTS METHODS 2022; 2:100220. [PMID: 35637912 PMCID: PMC9142762 DOI: 10.1016/j.crmeth.2022.100220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 02/04/2022] [Accepted: 04/26/2022] [Indexed: 12/03/2022]
Abstract
We present a bimodal endocytic tracer, fluorescent BSA-gold (fBSA-Au), as a fiducial marker for 2D and 3D correlative light and electron microscopy (CLEM) applications. fBSA-Au consists of colloidal gold (Au) particles stabilized with fluorescent BSA. The conjugate is efficiently endocytosed and distributed throughout the 3D endolysosomal network of cells and has an excellent visibility in both fluorescence microscopy (FM) and electron microscopy (EM). We demonstrate that fBSA-Au facilitates rapid registration in several 2D and 3D CLEM applications using Tokuyasu cryosections, resin-embedded material, and cryoelectron microscopy (cryo-EM). Endocytosed fBSA-Au benefits from a homogeneous 3D distribution throughout the endosomal system within the cell, does not obscure any cellular ultrastructure, and enables accurate (50-150 nm) correlation of fluorescence to EM data. The broad applicability and visibility in both modalities makes fBSA-Au an excellent endocytic fiducial marker for 2D and 3D (cryo)CLEM applications.
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Affiliation(s)
- Job Fermie
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, the Netherlands
| | - Leanne de Jager
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - Helen E. Foster
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Cambridge, UK
| | - Tineke Veenendaal
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Cecilia de Heus
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Suzanne van Dijk
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Corlinda ten Brink
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Viola Oorschot
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Lin Yang
- Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Wei Li
- Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Wally H. Müller
- Microbiology, Department of Biology, Utrecht University, Utrecht, the Netherlands
| | - Stuart Howes
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - Andrew P. Carter
- Medical Research Council Laboratory of Molecular Biology, Division of Structural Studies, Cambridge, UK
| | - Friedrich Förster
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | - George Posthuma
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Hans C. Gerritsen
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, the Netherlands
| | - Judith Klumperman
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Nalan Liv
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
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24
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Loginov SV, Fermie J, Fokkema J, Agronskaia AV, De Heus C, Blab GA, Klumperman J, Gerritsen HC, Liv N. Correlative Organelle Microscopy: Fluorescence Guided Volume Electron Microscopy of Intracellular Processes. Front Cell Dev Biol 2022; 10:829545. [PMID: 35478966 PMCID: PMC9035751 DOI: 10.3389/fcell.2022.829545] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 03/04/2022] [Indexed: 01/19/2023] Open
Abstract
Intracellular processes depend on a strict spatial and temporal organization of proteins and organelles. Therefore, directly linking molecular to nanoscale ultrastructural information is crucial in understanding cellular physiology. Volume or three-dimensional (3D) correlative light and electron microscopy (volume-CLEM) holds unique potential to explore cellular physiology at high-resolution ultrastructural detail across cell volumes. However, the application of volume-CLEM is hampered by limitations in throughput and 3D correlation efficiency. In order to address these limitations, we describe a novel pipeline for volume-CLEM that provides high-precision (<100 nm) registration between 3D fluorescence microscopy (FM) and 3D electron microscopy (EM) datasets with significantly increased throughput. Using multi-modal fiducial nanoparticles that remain fluorescent in epoxy resins and a 3D confocal fluorescence microscope integrated into a Focused Ion Beam Scanning Electron Microscope (FIB.SEM), our approach uses FM to target extremely small volumes of even single organelles for imaging in volume EM and obviates the need for post-correlation of big 3D datasets. We extend our targeted volume-CLEM approach to include live-cell imaging, adding information on the motility of intracellular membranes selected for volume-CLEM. We demonstrate the power of our approach by targeted imaging of rare and transient contact sites between the endoplasmic reticulum (ER) and lysosomes within hours rather than days. Our data suggest that extensive ER-lysosome and mitochondria-lysosome interactions restrict lysosome motility, highlighting the unique capabilities of our integrated CLEM pipeline for linking molecular dynamic data to high-resolution ultrastructural detail in 3D.
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Affiliation(s)
- Sergey V. Loginov
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, Netherlands
| | - Job Fermie
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, Netherlands
- Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Jantina Fokkema
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, Netherlands
| | - Alexandra V. Agronskaia
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, Netherlands
| | - Cilia De Heus
- Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Gerhard A. Blab
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, Netherlands
| | - Judith Klumperman
- Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Hans C. Gerritsen
- Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, Netherlands
| | - Nalan Liv
- Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
- *Correspondence: Nalan Liv,
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25
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Fang Z, Méresse S. Endomembrane remodeling and dynamics in Salmonella infection. MICROBIAL CELL (GRAZ, AUSTRIA) 2022; 9:24-41. [PMID: 35127930 PMCID: PMC8796136 DOI: 10.15698/mic2022.02.769] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/08/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022]
Abstract
Salmonellae are bacteria that cause moderate to severe infections in humans, depending on the strain and the immune status of the infected host. These pathogens have the particularity of residing in the cells of the infected host. They are usually found in a vacuolar compartment that the bacteria shape with the help of effector proteins. Following invasion of a eukaryotic cell, the bacterial vacuole undergoes maturation characterized by changes in localization, composition and morphology. In particular, membrane tubules stretching over the microtubule cytoskeleton are formed from the bacterial vacuole. Although these tubules do not occur in all infected cells, they are functionally important and promote intracellular replication. This review focuses on the role and significance of membrane compartment remodeling observed in infected cells and the bacterial and host cell pathways involved.
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Affiliation(s)
- Ziyan Fang
- Aix Marseille University, CNRS, INSERM, CIML, Marseille, France
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26
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Single-phagosome imaging reveals that homotypic fusion impairs phagosome degradative function. Biophys J 2022; 121:459-469. [PMID: 34968424 PMCID: PMC8822610 DOI: 10.1016/j.bpj.2021.12.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/01/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023] Open
Abstract
Immune cells degrade internalized pathogens in vesicle compartments called phagosomes. Many intracellular bacteria induce homotypic phagosome fusion to survive in host cells, but the fusion interaction between phagosomes and its consequence for phagosome function have scarcely been studied. Here, we characterize homotypic fusion between phagosomes in macrophages and identify how such interactions impact the degradative capacity of phagosomes. By developing a series of particle sensors for measuring biochemical changes of single phagosomes, we show that phagosomes undergo stable fusion, transient "kiss-and-run" fusion, or both in succession. Super-resolution three-dimensional fluorescence microscopy revealed that stably fused phagosomes are connected by membrane "necks" with submicron-sized fusion pores. Furthermore, we demonstrate that, after stable fusion, phagosomes have leaky membranes and thereby impaired degradative functions. Our findings, based on phagosomes that contain synthetic particles, illustrate that homotypic fusion is not exclusive to phagosomes that encapsulate pathogens, as previously believed. The physical process of homotypic fusion is alone sufficient to perturb the degradative functions of phagosomes.
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27
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Zhao J, Lu W, Ren Y, Fu Y, Martens YA, Shue F, Davis MD, Wang X, Chen K, Li F, Liu CC, Graff-Radford NR, Wszolek ZK, Younkin SG, Brafman DA, Ertekin-Taner N, Asmann YW, Dickson DW, Xu Z, Pan M, Han X, Kanekiyo T, Bu G. Apolipoprotein E regulates lipid metabolism and α-synuclein pathology in human iPSC-derived cerebral organoids. Acta Neuropathol 2021; 142:807-825. [PMID: 34453582 PMCID: PMC8500881 DOI: 10.1007/s00401-021-02361-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/31/2021] [Accepted: 08/17/2021] [Indexed: 12/25/2022]
Abstract
APOE4 is a strong genetic risk factor for Alzheimer's disease and Dementia with Lewy bodies; however, how its expression impacts pathogenic pathways in a human-relevant system is not clear. Here using human iPSC-derived cerebral organoid models, we find that APOE deletion increases α-synuclein (αSyn) accumulation accompanied with synaptic loss, reduction of GBA levels, lipid droplet accumulation and dysregulation of intracellular organelles. These phenotypes are partially rescued by exogenous apoE2 and apoE3, but not apoE4. Lipidomics analysis detects the increased fatty acid utilization and cholesterol ester accumulation in apoE-deficient cerebral organoids. Furthermore, APOE4 cerebral organoids have increased αSyn accumulation compared to those with APOE3. Carrying APOE4 also increases apoE association with Lewy bodies in postmortem brains from patients with Lewy body disease. Our findings reveal the predominant role of apoE in lipid metabolism and αSyn pathology in iPSC-derived cerebral organoids, providing mechanistic insights into how APOE4 drives the risk for synucleinopathies.
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Affiliation(s)
- Jing Zhao
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Center for Regenerative Medicine, Neuroregeneration Laboratory, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Wenyan Lu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Center for Regenerative Medicine, Neuroregeneration Laboratory, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Yingxue Ren
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Yuan Fu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Yuka A Martens
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Center for Regenerative Medicine, Neuroregeneration Laboratory, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Francis Shue
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Mary D Davis
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Center for Regenerative Medicine, Neuroregeneration Laboratory, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Xue Wang
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Kai Chen
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Fuyao Li
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | | | | | - Steven G Younkin
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - David A Brafman
- School of Biological & Health Systems Engineering, Arizona State University, Tempe, AZ, 85287, USA
| | - Nilüfer Ertekin-Taner
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Department of Neurology, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Yan W Asmann
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Ziying Xu
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center At San Antonio, San Antonio, TX, 78229, USA
| | - Meixia Pan
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center At San Antonio, San Antonio, TX, 78229, USA
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center At San Antonio, San Antonio, TX, 78229, USA
- Department of Medicine, University of Texas Health Science Center At San Antonio, San Antonio, TX, 78229, USA
| | - Takahisa Kanekiyo
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Center for Regenerative Medicine, Neuroregeneration Laboratory, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA.
- Center for Regenerative Medicine, Neuroregeneration Laboratory, Mayo Clinic, Jacksonville, FL, 32224, USA.
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28
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Fountain A, Inpanathan S, Alves P, Verdawala MB, Botelho RJ. Phagosome maturation in macrophages: Eat, digest, adapt, and repeat. Adv Biol Regul 2021; 82:100832. [PMID: 34717137 DOI: 10.1016/j.jbior.2021.100832] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 11/30/2022]
Abstract
Phagocytosis is a dynamic process that requires an intricate interplay between phagocytic receptors, membrane lipids, and numerous signalling proteins and their effectors, to coordinate the engulfment of a bound particle. These particles are diverse in their physico-chemical properties such as size and shape and include bacteria, fungi, apoptotic cells, living tumour cells, and abiotic particles. Once engulfed, these particles are enclosed within a phagosome, which undergoes a striking transformation referred to as phagosome maturation, which will ultimately lead to the processing and degradation of the enclosed particulate. In this review, we focus on recent advancements in phagosome maturation in macrophages, highlighting new discoveries and emerging themes. Such advancements include identification of new GTPases and their effectors and the intricate spatio-temporal dynamics of phosphoinositides in governing phagosome maturation. We then explore phagosome fission and recycling, the emerging role of membrane contact sites, and delve into mechanisms of phagosome resolution to recycle and reform lysosomes. We further illustrate how phagosome maturation is context-dependent, subject to the type of particle, phagocytic receptors, the phagocytes and their state of activation during phagocytosis. Lastly, we discuss how phagosomes serve as signalling platforms to help phagocytes adapt to their environmental conditions. Overall, this review aims to cover recent findings, identify emerging themes, and highlight current challenges and directions to improve our understanding of phagosome maturation in macrophages.
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Affiliation(s)
- Aaron Fountain
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada; Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada
| | - Subothan Inpanathan
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada; Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada
| | - Patris Alves
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada; Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada
| | - Munira B Verdawala
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada
| | - Roberto J Botelho
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada; Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, M5B2K3, Canada.
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29
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Molecular mechanisms of mammalian autophagy. Biochem J 2021; 478:3395-3421. [PMID: 34554214 DOI: 10.1042/bcj20210314] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/19/2021] [Accepted: 07/28/2021] [Indexed: 02/06/2023]
Abstract
The ubiquitin-proteasome pathway (UPP) and autophagy play integral roles in cellular homeostasis. As part of their normal life cycle, most proteins undergo ubiquitination for some form of redistribution, localization and/or functional modulation. However, ubiquitination is also important to the UPP and several autophagic processes. The UPP is initiated after specific lysine residues of short-lived, damaged or misfolded proteins are conjugated to ubiquitin, which targets these proteins to proteasomes. Autophagy is the endosomal/lysosomal-dependent degradation of organelles, invading microbes, zymogen granules and macromolecules such as protein, carbohydrates and lipids. Autophagy can be broadly separated into three distinct subtypes termed microautophagy, chaperone-mediated autophagy and macroautophagy. Although autophagy was once thought of as non-selective bulk degradation, advancements in the field have led to the discovery of several selective forms of autophagy. Here, we focus on the mechanisms of primary and selective mammalian autophagy pathways and highlight the current knowledge gaps in these molecular pathways.
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30
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Davis LJ, Bright NA, Edgar JR, Parkinson MDJ, Wartosch L, Mantell J, Peden AA, Luzio JP. Organelle tethering, pore formation and SNARE compensation in the late endocytic pathway. J Cell Sci 2021; 134:268392. [PMID: 34042162 PMCID: PMC8186482 DOI: 10.1242/jcs.255463] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 04/14/2021] [Indexed: 11/24/2022] Open
Abstract
To provide insights into the kiss-and-run and full fusion events resulting in endocytic delivery to lysosomes, we investigated conditions causing increased tethering and pore formation between late endocytic organelles in HeLa cells. Knockout of the soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) VAMP7 and VAMP8 showed, by electron microscopy, the accumulation of tethered lysosome-associated membrane protein (LAMP)-carrier vesicles around multivesicular bodies, as well as the appearance of ‘hourglass’ profiles of late endocytic organelles attached by filamentous tethers, but did not prevent endocytic delivery to lysosomal hydrolases. Subsequent depletion of the SNARE YKT6 reduced this delivery, consistent with it compensating for the absence of VAMP7 and VAMP8. We also investigated filamentous tethering between multivesicular bodies and enlarged endolysosomes following depletion of charged multi-vesicular body protein 6 (CHMP6), and provide the first evidence that pore formation commences at the edge of tether arrays, with pore expansion required for full membrane fusion. Summary: Endocytic delivery to lysosomes by kiss and run/membrane fusion entails pore formation commencing at the edge of tether arrays, and demonstrates SNARE redundancy and compensation.
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Affiliation(s)
- Luther J Davis
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Nicholas A Bright
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - James R Edgar
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Michael D J Parkinson
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Lena Wartosch
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Judith Mantell
- School of Biochemistry, University of Bristol, Medical Sciences Building, University Walk, Bristol BS81TD, UK.,Wolfson Bioimaging Facility, University of Bristol, Medical Sciences Building, University Walk, Bristol BS81TD, UK
| | - Andrew A Peden
- Department of Biomedical Science & Centre for Membrane Interactions and Dynamics (CMIAD), The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - J Paul Luzio
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
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31
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van der Welle REN, Jobling R, Burns C, Sanza P, van der Beek JA, Fasano A, Chen L, Zwartkruis FJ, Zwakenberg S, Griffin EF, ten Brink C, Veenendaal T, Liv N, van Ravenswaaij‐Arts CMA, Lemmink HH, Pfundt R, Blaser S, Sepulveda C, Lozano AM, Yoon G, Santiago‐Sim T, Asensio CS, Caldwell GA, Caldwell KA, Chitayat D, Klumperman J. Neurodegenerative VPS41 variants inhibit HOPS function and mTORC1-dependent TFEB/TFE3 regulation. EMBO Mol Med 2021; 13:e13258. [PMID: 33851776 PMCID: PMC8103106 DOI: 10.15252/emmm.202013258] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/19/2021] [Accepted: 02/22/2021] [Indexed: 11/09/2022] Open
Abstract
Vacuolar protein sorting 41 (VPS41) is as part of the Homotypic fusion and Protein Sorting (HOPS) complex required for lysosomal fusion events and, independent of HOPS, for regulated secretion. Here, we report three patients with compound heterozygous mutations in VPS41 (VPS41S285P and VPS41R662* ; VPS41c.1423-2A>G and VPS41R662* ) displaying neurodegeneration with ataxia and dystonia. Cellular consequences were investigated in patient fibroblasts and VPS41-depleted HeLa cells. All mutants prevented formation of a functional HOPS complex, causing delayed lysosomal delivery of endocytic and autophagic cargo. By contrast, VPS41S285P enabled regulated secretion. Strikingly, loss of VPS41 function caused a cytosolic redistribution of mTORC1, continuous nuclear localization of Transcription Factor E3 (TFE3), enhanced levels of LC3II, and a reduced autophagic response to nutrient starvation. Phosphorylation of mTORC1 substrates S6K1 and 4EBP1 was not affected. In a C. elegans model of Parkinson's disease, co-expression of VPS41S285P /VPS41R662* abolished the neuroprotective function of VPS41 against α-synuclein aggregates. We conclude that the VPS41 variants specifically abrogate HOPS function, which interferes with the TFEB/TFE3 axis of mTORC1 signaling, and cause a neurodegenerative disease.
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Affiliation(s)
- Reini E N van der Welle
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Rebekah Jobling
- Department of PediatricsDivision of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenUniversity of TorontoTorontoONCanada
| | - Christian Burns
- Department of Biological SciencesDivision of Natural Sciences and MathematicsUniversity of DenverDenverCOUSA
| | - Paolo Sanza
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Jan A van der Beek
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Alfonso Fasano
- Edmond J. Safra Program in Parkinson’s DiseaseMorton and Gloria Shulman Movement Disorders ClinicToronto Western Hospital, UHNTorontoONCanada
- Division of NeurologyUniversity of TorontoTorontoONCanada
- Krembil Brain InstituteTorontoONCanada
- Center for Advancing Neurotechnological Innovation to Application (CRANIA)TorontoONCanada
| | - Lan Chen
- Department of Biological SciencesDivision of Natural Sciences and MathematicsUniversity of DenverDenverCOUSA
| | - Fried J Zwartkruis
- Section Molecular Cancer ResearchCenter for Molecular MedicineUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Susan Zwakenberg
- Section Molecular Cancer ResearchCenter for Molecular MedicineUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Edward F Griffin
- Department of Biological SciencesThe University of AlabamaTuscaloosaALUSA
- Department of NeurologyCenter for Neurodegeneration and Experimental TherapeuticsNathan Shock Center for Basic Research in the Biology of AgingUniversity of Alabama at Birmingham School of MedicineBirminghamALUSA
| | - Corlinda ten Brink
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Tineke Veenendaal
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Nalan Liv
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | | | - Henny H Lemmink
- Department of GeneticsUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
| | - Rolph Pfundt
- Department of Human GeneticsRadboud University Medical CenterNijmegenThe Netherlands
| | - Susan Blaser
- Department of Diagnostic ImagingHospital for Sick ChildrenTorontoONCanada
| | - Carolina Sepulveda
- Edmond J. Safra Program in Parkinson’s DiseaseMorton and Gloria Shulman Movement Disorders ClinicToronto Western Hospital, UHNTorontoONCanada
- Division of NeurologyUniversity of TorontoTorontoONCanada
| | - Andres M Lozano
- Krembil Brain InstituteTorontoONCanada
- Center for Advancing Neurotechnological Innovation to Application (CRANIA)TorontoONCanada
- Department of NeurosurgeryToronto Western Hospital, UHNTorontoONCanada
- University of TorontoTorontoONCanada
| | - Grace Yoon
- Department of PediatricsDivision of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenUniversity of TorontoTorontoONCanada
| | | | - Cedric S Asensio
- Department of Biological SciencesDivision of Natural Sciences and MathematicsUniversity of DenverDenverCOUSA
| | - Guy A Caldwell
- Department of Biological SciencesThe University of AlabamaTuscaloosaALUSA
- Department of NeurologyCenter for Neurodegeneration and Experimental TherapeuticsNathan Shock Center for Basic Research in the Biology of AgingUniversity of Alabama at Birmingham School of MedicineBirminghamALUSA
| | - Kim A Caldwell
- Department of Biological SciencesThe University of AlabamaTuscaloosaALUSA
- Department of NeurologyCenter for Neurodegeneration and Experimental TherapeuticsNathan Shock Center for Basic Research in the Biology of AgingUniversity of Alabama at Birmingham School of MedicineBirminghamALUSA
| | - David Chitayat
- Department of PediatricsDivision of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenUniversity of TorontoTorontoONCanada
- The Prenatal Diagnosis and Medical Genetics ProgramDepartment of Obstetrics and GynecologyUniversity of TorontoTorontoONCanada
| | - Judith Klumperman
- Section Cell BiologyCenter for Molecular MedicineInstitute of BiomembranesUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
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Davegårdh C, Säll J, Benrick A, Broholm C, Volkov P, Perfilyev A, Henriksen TI, Wu Y, Hjort L, Brøns C, Hansson O, Pedersen M, Würthner JU, Pfeffer K, Nilsson E, Vaag A, Stener-Victorin E, Pircs K, Scheele C, Ling C. VPS39-deficiency observed in type 2 diabetes impairs muscle stem cell differentiation via altered autophagy and epigenetics. Nat Commun 2021; 12:2431. [PMID: 33893273 PMCID: PMC8065135 DOI: 10.1038/s41467-021-22068-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 02/25/2021] [Indexed: 02/02/2023] Open
Abstract
Insulin resistance and lower muscle quality (strength divided by mass) are hallmarks of type 2 diabetes (T2D). Here, we explore whether alterations in muscle stem cells (myoblasts) from individuals with T2D contribute to these phenotypes. We identify VPS39 as an important regulator of myoblast differentiation and muscle glucose uptake, and VPS39 is downregulated in myoblasts and myotubes from individuals with T2D. We discover a pathway connecting VPS39-deficiency in human myoblasts to impaired autophagy, abnormal epigenetic reprogramming, dysregulation of myogenic regulators, and perturbed differentiation. VPS39 knockdown in human myoblasts has profound effects on autophagic flux, insulin signaling, epigenetic enzymes, DNA methylation and expression of myogenic regulators, and gene sets related to the cell cycle, muscle structure and apoptosis. These data mimic what is observed in myoblasts from individuals with T2D. Furthermore, the muscle of Vps39+/- mice display reduced glucose uptake and altered expression of genes regulating autophagy, epigenetic programming, and myogenesis. Overall, VPS39-deficiency contributes to impaired muscle differentiation and reduced glucose uptake. VPS39 thereby offers a therapeutic target for T2D.
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Affiliation(s)
- Cajsa Davegårdh
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Johanna Säll
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Anna Benrick
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- School of Health Sciences, University of Skövde, Skövde, Sweden
| | - Christa Broholm
- Diabetes and Bone-metabolic Research Unit, Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
| | - Petr Volkov
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Alexander Perfilyev
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Tora Ida Henriksen
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Yanling Wu
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Line Hjort
- Diabetes and Bone-metabolic Research Unit, Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
- Department of Obstetrics, Rigshospitalet, Copenhagen, Denmark
| | - Charlotte Brøns
- Diabetes and Bone-metabolic Research Unit, Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
| | - Ola Hansson
- Genomics, Diabetes and Endocrinology Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
- Finnish Institute of Molecular Medicine, University of Helsinki, Helsinki, Finland
| | - Maria Pedersen
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - Klaus Pfeffer
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Emma Nilsson
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden
| | - Allan Vaag
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | | | - Karolina Pircs
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, Lund University, Lund, Sweden
| | - Camilla Scheele
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Charlotte Ling
- Epigenetics and Diabetes Unit, Department of Clinical Sciences, Lund University Diabetes Centre, Lund University, Scania University Hospital, Malmö, Sweden.
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Simon-Vecsei Z, Sőth Á, Lőrincz P, Rubics A, Tálas A, Kulcsár PI, Juhász G. Identification of New Interactions between Endolysosomal Tethering Factors. J Mol Biol 2021; 433:166965. [PMID: 33781757 DOI: 10.1016/j.jmb.2021.166965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 02/28/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
Proper functioning of the precisely controlled endolysosomal system is essential for maintaining the homeostasis of the entire cell. Tethering factors play pivotal roles in mediating the fusion of different transport vesicles, such as endosomes or autophagosomes with each other or with lysosomes. In this work, we uncover several new interactions between the endolysosomal tethering factors Rabenosyn-5 (Rbsn) and the HOPS and CORVET complexes. We find that Rbsn binds to the HOPS/CORVET complexes mainly via their shared subunit Vps18 and we mapped this interaction to the 773-854 region of Vps18. Based on genetic rescue experiments, the binding between Rbsn and Vps18 is required for endosomal transport and is dispensable for autophagy. Moreover, Vps18 seems to be important for β1 integrin recycling by binding to Rbsn and its known partner Vps45.
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Affiliation(s)
- Zsófia Simon-Vecsei
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.
| | - Ármin Sőth
- 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; Premium Postdoctoral Research Program, Eötvös Loránd Research Network, Budapest, Hungary
| | - András Rubics
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - András Tálas
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Péter István Kulcsár
- Institute of Enzymology, Research Centre for Natural Sciences, 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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Gonzalez-Latapi P, Marotta N, Mencacci NE. Emerging and converging molecular mechanisms in dystonia. J Neural Transm (Vienna) 2021; 128:483-498. [DOI: 10.1007/s00702-020-02290-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/13/2020] [Indexed: 02/06/2023]
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Miao G, Zhao H, Li Y, Ji M, Chen Y, Shi Y, Bi Y, Wang P, Zhang H. ORF3a of the COVID-19 virus SARS-CoV-2 blocks HOPS complex-mediated assembly of the SNARE complex required for autolysosome formation. Dev Cell 2020; 56:427-442.e5. [PMID: 33422265 PMCID: PMC7832235 DOI: 10.1016/j.devcel.2020.12.010] [Citation(s) in RCA: 223] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/29/2020] [Accepted: 12/11/2020] [Indexed: 02/07/2023]
Abstract
Autophagy acts as a cellular surveillance mechanism to combat invading pathogens. Viruses have evolved various strategies to block autophagy and even subvert it for their replication and release. Here, we demonstrated that ORF3a of the COVID-19 virus SARS-CoV-2 inhibits autophagy activity by blocking fusion of autophagosomes/amphisomes with lysosomes. The late endosome-localized ORF3a directly interacts with and sequestrates the homotypic fusion and protein sorting (HOPS) component VPS39, thereby preventing HOPS complex from interacting with the autophagosomal SNARE protein STX17. This blocks assembly of the STX17-SNAP29-VAMP8 SNARE complex, which mediates autophagosome/amphisome fusion with lysosomes. Expression of ORF3a also damages lysosomes and impairs their function. SARS-CoV-2 virus infection blocks autophagy, resulting in accumulation of autophagosomes/amphisomes, and causes late endosomal sequestration of VPS39. Surprisingly, ORF3a from the SARS virus SARS-CoV fails to interact with HOPS or block autophagy. Our study reveals a mechanism by which SARS-CoV-2 evades lysosomal destruction and provides insights for developing new strategies to treat COVID-19.
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Affiliation(s)
- Guangyan Miao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Hongyu Zhao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Yan Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Mingming Ji
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Yong Chen
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Yi Shi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Yuhai Bi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Peihui Wang
- Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Ji'nan, Shandong 250012, P.R. China
| | - Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
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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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Shi HB, Chen N, Zhu XM, Su ZZ, Wang JY, Lu JP, Liu XH, Lin FC. The casein kinase MoYck1 regulates development, autophagy, and virulence in the rice blast fungus. Virulence 2020; 10:719-733. [PMID: 31392921 PMCID: PMC8647852 DOI: 10.1080/21505594.2019.1649588] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Casein kinases are serine/threonine protein kinases that are evolutionarily conserved in yeast and humans and are involved in a range of important cellular processes. However, the biological functions of casein kinases in the fungus Magnaporthe oryzae, the causal agent of destructive rice blast disease, are not characterized. Here, two casein kinases, MoYCK1 and MoHRR25, were identified and targeted for replacement, but only MoYCK1 was further characterized due to the possible nonviability of the MoHRR25 deletion mutant. Disruption of MoYCK1 caused pleiotropic defects in growth, conidiation, conidial germination, and appressorium formation and penetration, therefore resulting in reduced virulence in rice seedlings and barley leaves. Notably, the MoYCK1 deletion triggered quick lipidation of MoAtg8 and degradation of the autophagic marker protein GFP-MoAtg8 under nitrogen starvation conditions, in contrast to the wild type, indicating that autophagy activity was negatively regulated by MoYck1. Furthermore, we found that HOPS (homotypic fusion and vacuolar protein sorting) subunit MoVps41, a putative substrate of MoYck1, was co-located with MoAtg8 and positively required for the degradation of MoAtg8-PE and GFP-MoAtg8. In addition, MoYCK1 is also involved in the response to ionic hyperosmotic and heavy metal cation stresses. Taken together, our results revealed crucial roles of the casein kinase MoYck1 in regulating development, autophagy and virulence in M. oryzae.
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Affiliation(s)
- Huan-Bin Shi
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China.,b State Key Laboratory of Rice Biology, China National Rice Research Institute , Hangzhou , China
| | - Nan Chen
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Xue-Ming Zhu
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Zhen-Zhu Su
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Jiao-Yu Wang
- c State Key Laboratory for Quality and Safety of Agro-products, Institute of Plant Protection Microbiology, Zhejiang Academy of Agricultural Science , Hangzhou , China
| | - Jian-Ping Lu
- d College of Life Sciences, Zhejiang University , Hangzhou , China
| | - Xiao-Hong Liu
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Fu-Cheng Lin
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
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38
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Targeting the Early Endosome-to-Golgi Transport of Shiga Toxins as a Therapeutic Strategy. Toxins (Basel) 2020; 12:toxins12050342. [PMID: 32456007 PMCID: PMC7290323 DOI: 10.3390/toxins12050342] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 02/07/2023] Open
Abstract
Shiga toxin (STx) produced by Shigella and closely related Shiga toxin 1 and 2 (STx1 and STx2) synthesized by Shiga toxin-producing Escherichia coli (STEC) are bacterial AB5 toxins. All three toxins target kidney cells and may cause life-threatening renal disease. While Shigella infections can be treated with antibiotics, resistance is increasing. Moreover, antibiotic therapy is contraindicated for STEC, and there are no definitive treatments for STEC-induced disease. To exert cellular toxicity, STx, STx1, and STx2 must undergo retrograde trafficking to reach their cytosolic target, ribosomes. Direct transport from early endosomes to the Golgi apparatus is an essential step that allows the toxins to bypass degradative late endosomes and lysosomes. The essentiality of this transport step also makes it an ideal target for the development of small-molecule inhibitors of toxin trafficking as potential therapeutics. Here, we review the recent advances in understanding the molecular mechanisms of the early endosome-to-Golgi transport of STx, STx1, and STx2, as well as the development of small-molecule inhibitors of toxin trafficking that act at the endosome/Golgi interface.
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39
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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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40
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Ba Q, Raghavan G, Kiselyov K, Yang G. Whole-Cell Scale Dynamic Organization of Lysosomes Revealed by Spatial Statistical Analysis. Cell Rep 2019; 23:3591-3606. [PMID: 29925001 DOI: 10.1016/j.celrep.2018.05.079] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 04/14/2018] [Accepted: 05/23/2018] [Indexed: 01/22/2023] Open
Abstract
In eukaryotic cells, lysosomes are distributed in the cytoplasm as individual membrane-bound compartments to degrade macromolecules and to control cellular metabolism. A fundamental yet unanswered question is whether and, if so, how individual lysosomes are organized spatially to coordinate and integrate their functions. To address this question, we analyzed their collective behavior in cultured cells using spatial statistical techniques. We found that in single cells, lysosomes maintain non-random, stable, yet distinct spatial distributions mediated by the cytoskeleton, the endoplasmic reticulum (ER), and lysosomal biogenesis. Throughout the intracellular space, lysosomes form dynamic clusters that significantly increase their interactions with endosomes. Cluster formation is associated with local increases in ER spatial density but does not depend on fusion with endosomes or spatial exclusion by mitochondria. Taken together, our findings reveal whole-cell scale spatial organization of lysosomes and provide insights into how organelle interactions are mediated and regulated across the entire intracellular space.
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Affiliation(s)
- Qinle Ba
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Guruprasad Raghavan
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Ge Yang
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Department of Computational Biology, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
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41
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Selyunin AS, Hutchens S, McHardy SF, Mukhopadhyay S. Tamoxifen blocks retrograde trafficking of Shiga toxin 1 and 2 and protects against lethal toxicosis. Life Sci Alliance 2019; 2:2/3/e201900439. [PMID: 31243048 PMCID: PMC6599968 DOI: 10.26508/lsa.201900439] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/18/2022] Open
Abstract
This study reports an unexpected role of late endosome–lysosome fusion in early endosome-to-Golgi trafficking of Shiga toxins and identifies tamoxifen to be a potent inhibitor of Shiga toxicosis. Shiga toxin 1 (STx1) and 2 (STx2), produced by Shiga toxin–producing Escherichia coli, cause lethal untreatable disease. The toxins invade cells via retrograde trafficking. Direct early endosome-to-Golgi transport allows the toxins to evade degradative late endosomes. Blocking toxin trafficking, particularly at the early endosome-to-Golgi step, is appealing, but transport mechanisms of the more disease-relevant STx2 are unclear. Using data from a genome-wide siRNA screen, we discovered that disruption of the fusion of late endosomes, but not autophagosomes, with lysosomes blocked the early endosome-to-Golgi transport of STx2. A subsequent screen of clinically approved lysosome-targeting drugs identified tamoxifen (TAM) to be a potent inhibitor of the trafficking and toxicity of STx1 and STx2 in cells. The protective effect was independent of estrogen receptors but dependent on the weak base property of TAM, which allowed TAM to increase endolysosomal pH and alter endosomal dynamics. Importantly, TAM treatment enhanced survival of mice injected with a lethal dose of STx1 or STx2. Thus, it may be possible to repurpose TAM for treating Shiga toxin–producing E. coli infections.
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Affiliation(s)
- Andrey S Selyunin
- Division of Pharmacology and Toxicology, College of Pharmacy; Institute for Cellular and Molecular Biology; and Institute for Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Steven Hutchens
- Division of Pharmacology and Toxicology, College of Pharmacy; Institute for Cellular and Molecular Biology; and Institute for Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Stanton F McHardy
- Center for Innovative Drug Discovery, Department of Chemistry, University of Texas San Antonio, San Antonio, TX, USA
| | - Somshuvra Mukhopadhyay
- Division of Pharmacology and Toxicology, College of Pharmacy; Institute for Cellular and Molecular Biology; and Institute for Neuroscience, The University of Texas at Austin, Austin, TX, USA
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Lőrincz P, Kenéz LA, Tóth S, Kiss V, Varga Á, Csizmadia T, Simon-Vecsei Z, Juhász G. Vps8 overexpression inhibits HOPS-dependent trafficking routes by outcompeting Vps41/Lt. eLife 2019; 8:45631. [PMID: 31194677 PMCID: PMC6592680 DOI: 10.7554/elife.45631] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/13/2019] [Indexed: 01/31/2023] Open
Abstract
Two related multisubunit tethering complexes promote endolysosomal trafficking in all eukaryotes: Rab5-binding CORVET that was suggested to transform into Rab7-binding HOPS. We have previously identified miniCORVET, containing Drosophila Vps8 and three shared core proteins, which are required for endosome maturation upstream of HOPS in highly endocytic cells (Lőrincz et al., 2016a). Here, we show that Vps8 overexpression inhibits HOPS-dependent trafficking routes including late endosome maturation, autophagosome-lysosome fusion, crinophagy and lysosome-related organelle formation. Mechanistically, Vps8 overexpression abolishes the late endosomal localization of HOPS-specific Vps41/Lt and prevents HOPS assembly. Proper ratio of Vps8 to Vps41 is thus critical because Vps8 negatively regulates HOPS by outcompeting Vps41. Endosomal recruitment of miniCORVET- or HOPS-specific subunits requires proper complex assembly, and Vps8/miniCORVET is dispensable for autophagy, crinophagy and lysosomal biogenesis. These data together indicate the recruitment of these complexes to target membranes independent of each other in Drosophila, rather than their transformation during vesicle maturation.
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Affiliation(s)
- Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.,Premium Postdoctoral Research Program, Hungarian Academy of Sciences, Budapest, Hungary
| | - Lili Anna Kenéz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Sarolta Tóth
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Viktória Kiss
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Ágnes Varga
- 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
| | - Zsófia Simon-Vecsei
- 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, Hungarian Academy of Sciences, Szeged, Hungary
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van der Beek J, Jonker C, van der Welle R, Liv N, Klumperman J. CORVET, CHEVI and HOPS – multisubunit tethers of the endo-lysosomal system in health and disease. J Cell Sci 2019; 132:132/10/jcs189134. [DOI: 10.1242/jcs.189134] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
ABSTRACT
Multisubunit tethering complexes (MTCs) are multitasking hubs that form a link between membrane fusion, organelle motility and signaling. CORVET, CHEVI and HOPS are MTCs of the endo-lysosomal system. They regulate the major membrane flows required for endocytosis, lysosome biogenesis, autophagy and phagocytosis. In addition, individual subunits control complex-independent transport of specific cargoes and exert functions beyond tethering, such as attachment to microtubules and SNARE activation. Mutations in CHEVI subunits lead to arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, while defects in CORVET and, particularly, HOPS are associated with neurodegeneration, pigmentation disorders, liver malfunction and various forms of cancer. Diseases and phenotypes, however, vary per affected subunit and a concise overview of MTC protein function and associated human pathologies is currently lacking. Here, we provide an integrated overview on the cellular functions and pathological defects associated with CORVET, CHEVI or HOPS proteins, both with regard to their complexes and as individual subunits. The combination of these data provides novel insights into how mutations in endo-lysosomal proteins lead to human pathologies.
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Affiliation(s)
- Jan van der Beek
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Caspar Jonker
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Reini van der Welle
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
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Sharma G, Guardia CM, Roy A, Vassilev A, Saric A, Griner LN, Marugan J, Ferrer M, Bonifacino JS, DePamphilis ML. A family of PIKFYVE inhibitors with therapeutic potential against autophagy-dependent cancer cells disrupt multiple events in lysosome homeostasis. Autophagy 2019; 15:1694-1718. [PMID: 30806145 DOI: 10.1080/15548627.2019.1586257] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
High-throughput screening identified 5 chemical analogs (termed the WX8-family) that disrupted 3 events in lysosome homeostasis: (1) lysosome fission via tubulation without preventing homotypic lysosome fusion; (2) trafficking of molecules into lysosomes without altering lysosomal acidity, and (3) heterotypic fusion between lysosomes and autophagosomes. Remarkably, these compounds did not prevent homotypic fusion between lysosomes, despite the fact that homotypic fusion required some of the same machinery essential for heterotypic fusion. These effects varied 400-fold among WX8-family members, were time and concentration dependent, reversible, and resulted primarily from their ability to bind specifically to the PIKFYVE phosphoinositide kinase. The ability of the WX8-family to prevent lysosomes from participating in macroautophagy/autophagy suggested they have therapeutic potential in treating autophagy-dependent diseases. In fact, the most potent family member (WX8) was 100-times more lethal to 'autophagy-addicted' melanoma A375 cells than the lysosomal inhibitors hydroxychloroquine and chloroquine. In contrast, cells that were insensitive to hydroxychloroquine and chloroquine were also insensitive to WX8. Therefore, the WX8-family of PIKFYVE inhibitors provides a basis for developing drugs that could selectively kill autophagy-dependent cancer cells, as well as increasing the effectiveness of established anti-cancer therapies through combinatorial treatments. Abbreviations: ACTB: actin beta; Baf: bafilomycin A1; BECN1: beclin 1; BODIPY: boron-dipyrromethene; BORC: BLOC-1 related complex; BRAF: B-Raf proto-oncogene, serine/threonine kinase; BSA: bovine serum albumin; CTSD: cathepsin D; CQ: chloroquine; DNA: deoxyribonucleic acid; EC50: half maximal effective concentration; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFP: green fluorescent protein; HCQ: hydroxychloroquine; HOPS complex: homotypic fusion and protein sorting complex; Kd: equilibrium binding constant; IC50: half maximal inhibitory concentration; KO: knockout; LAMP1: lysosomal associated membrane protein 1; MAP1LC3A: microtubule associated protein 1 light chain 3 alpha; MES: 2-(N-morpholino)ethanesulphonic acid; MTOR: mechanistic target of rapamycin kinase; μM: micromolar; NDF: 3-methylbenzaldehyde (2,6-dimorpholin-4-ylpyrimidin-4-yl)hydrazine;NEM: N-ethylmaleimide; NSF: N-ethylmaleimide sensitive factor; PBS: phosphate-buffered saline; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; PIP4K2C: phosphatidylinositol-5-phosphate 4-kinase type 2 gamma; PtdIns3P: phosphatidylinositol 3-phosphate; PtdIns(3,5)P2: phosphatidylinositol 3,5-biphosphate; RFP: red fluorescent protein; RPS6: ribosomal protein S6; RPS6KB1: ribosomal protein S6 kinase B1; SQSTM1: sequestosome 1; TWEEN 20: polysorbate 20; V-ATPase: vacuolar-type H+-translocating ATPase; VPS39: VPS39 subunit of HOPS complex; VPS41: VPS41 subunit of HOPS complex; WWL: benzaldehyde [2,6-di(4-morpholinyl)-4-pyrimidinyl]hydrazone; WX8: 1H-indole-3-carbaldehyde [4-anilino-6-(4-morpholinyl)-1,3,5-triazin-2-yl]hydrazine; XBA: N-(3-chloro-4-fluorophenyl)-4,6-dimorpholino-1,3,5-triazin-2-amine hydrochloride; XB6: N-(4-ethylphenyl)-4,6-dimorpholino-1,3,5-triazin-2-amine hydrochloride.
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Affiliation(s)
- Gaurav Sharma
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Carlos M Guardia
- Cell Biology and Neurobiology Branch, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Ajit Roy
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Alex Vassilev
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Amra Saric
- Cell Biology and Neurobiology Branch, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Lori N Griner
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Juan Marugan
- Division of Pre-Clinical Innovation, NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health , Rockville , MD , USA
| | - Marc Ferrer
- Division of Pre-Clinical Innovation, NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, National Institutes of Health , Rockville , MD , USA
| | - Juan S Bonifacino
- Cell Biology and Neurobiology Branch, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Melvin L DePamphilis
- Division of Developmental Biology, National Institute of Child Health & Human Development, National Institutes of Health , Bethesda , MD , USA
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45
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Steinauer A, LaRochelle JR, Knox SL, Wissner RF, Berry S, Schepartz A. HOPS-dependent endosomal fusion required for efficient cytosolic delivery of therapeutic peptides and small proteins. Proc Natl Acad Sci U S A 2019; 116:512-521. [PMID: 30610181 PMCID: PMC6329960 DOI: 10.1073/pnas.1812044116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Protein therapeutics represent a significant and growing component of the modern pharmacopeia, but their potential to treat human disease is limited because most proteins fail to traffic across biological membranes. Recently, we discovered a class of cell-permeant miniature proteins (CPMPs) containing a precisely defined, penta-arginine (penta-Arg) motif that traffics readily to the cytosol and nucleus of mammalian cells with efficiencies that rival those of hydrocarbon-stapled peptides active in animals and man. Like many cell-penetrating peptides (CPPs), CPMPs enter the endocytic pathway; the difference is that CPMPs containing a penta-Arg motif are released efficiently from endosomes, while other CPPs are not. Here, we seek to understand how CPMPs traffic from endosomes into the cytosol and what factors contribute to the efficiency of endosomal release. First, using two complementary cell-based assays, we exclude endosomal rupture as the primary means of endosomal escape. Next, using an RNA interference screen, fluorescence correlation spectroscopy, and confocal imaging, we identify VPS39-a gene encoding a subunit of the homotypic fusion and protein-sorting (HOPS) complex-as a critical determinant in the trafficking of CPMPs and hydrocarbon-stapled peptides to the cytosol. Although CPMPs neither inhibit nor activate HOPS function, HOPS activity is essential to efficiently deliver CPMPs to the cytosol. CPMPs localize within the lumen of Rab7+ and Lamp1+ endosomes and their transport requires HOPS activity. Overall, our results identify Lamp1+ late endosomes and lysosomes as portals for passing proteins into the cytosol and suggest that this environment is prerequisite for endosomal escape.
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Affiliation(s)
- Angela Steinauer
- Department of Chemistry, Yale University, New Haven, CT 06520-8107
| | - Jonathan R LaRochelle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103
| | - Susan L Knox
- Department of Chemistry, Yale University, New Haven, CT 06520-8107
| | | | - Samuel Berry
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114
| | - Alanna Schepartz
- Department of Chemistry, Yale University, New Haven, CT 06520-8107;
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520-8103
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46
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Pascual L, Yan J, Pujol M, Monforte AJ, Picó B, Martín-Hernández AM. CmVPS41 Is a General Gatekeeper for Resistance to Cucumber Mosaic Virus Phloem Entry in Melon. FRONTIERS IN PLANT SCIENCE 2019; 10:1219. [PMID: 31632432 PMCID: PMC6781857 DOI: 10.3389/fpls.2019.01219] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/04/2019] [Indexed: 05/19/2023]
Abstract
Melon production is often compromised by viral diseases, which cannot be treated with chemicals. Therefore, the use of genetic resistances is the main strategy for generating crops resistant to viruses. Resistance to Cucumber mosaic virus (CMV) in melon is scarcely described in few accessions. Until recently, the only known resistant accessions were Freeman's Cucumber and PI 161375, cultivar Songwhan Charmi (SC). Resistance to CMV in melon is recessive and generally oligogenic and quantitative. However, in SC, the resistance to CMV strains of subgroup II is monogenic, depending only on one gene, cmv1, which is able to stop CMV movement by restricting the virus to the bundle sheath cells and preventing a systemic infection. This restriction depends on the viral movement protein (MP). Chimeric viruses carrying the MP of subgroup II strains, like the strain LS (CMV-LS), are restricted in the bundle sheath cells, whereas those carrying MP from subgroup I, like the strain FNY (CMV-FNY), are able to overcome this restriction. cmv1 encodes a vacuolar protein sorting 41 (CmVPS41), a protein involved in the transport of cargo proteins from the Golgi to the vacuole through late endosomes. We have analyzed the variability of the gene CmVPS41 in a set of 52 melon accessions belonging to 15 melon groups, both from the spp melo and the spp agrestis. We have identified 16 different haplotypes, encoding 12 different CmVPS41 protein variants. Challenging members of all haplotypes with CMV-LS, we have identified nine new resistant accessions. The resistance correlates with the presence of two mutations, either L348R, previously found in the accession SC and present in other three melon genotypes, or G85E, present in Freeman's Cucumber and found also in four additional melon genotypes. Moreover, the new resistant accessions belong to three different melon horticultural groups, Conomon, Makuwa, and Dudaim. In the new resistant accessions, the virus was able to replicate and move cell to cell, but was not able to reach the phloem. Therefore, resistance to phloem entry seems to be a general strategy in melon controlled by CmVPS41. Finally, the newly reported resistant accessions broaden the possibilities for the use of genetic resistances in new melon breeding strategies.
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Affiliation(s)
- Laura Pascual
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
| | - Jinqiang Yan
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
| | - Marta Pujol
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, Bellaterra, Barcelona, Spain
| | - Antonio J. Monforte
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universitat Politècnica de València (UPV)-Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Belén Picó
- COMAV, Institute for the Conservation and Breeding of Agricultural Biodiversity, Universitat Politècnica de València (UPV), Camino de Vera s/n, Valencia, Spain
| | - Ana Montserrat Martín-Hernández
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, C/Vall Moronta, Edifici CRAG, Bellaterra (Cerdanyola del Vallés), Barcelona, Spain
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, Bellaterra, Barcelona, Spain
- *Correspondence: Ana Montserrat Martín-Hernández,
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Lund VK, Madsen KL, Kjaerulff O. Drosophila Rab2 controls endosome-lysosome fusion and LAMP delivery to late endosomes. Autophagy 2018; 14:1520-1542. [PMID: 29940804 PMCID: PMC6135592 DOI: 10.1080/15548627.2018.1458170] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Rab2 is a conserved Rab GTPase with a well-established role in secretory pathway function and phagocytosis. Here we demonstrate that Drosophila Rab2 is recruited to late endosomal membranes, where it controls the fusion of LAMP-containing biosynthetic carriers and lysosomes to late endosomes. In contrast, the lysosomal GTPase Gie/Arl8 is only required for late endosome-lysosome fusion, but not for the delivery of LAMP to the endocytic pathway. We also find that Rab2 is required for the fusion of autophagosomes to the endolysosomal pathway, but not for the biogenesis of lysosome-related organelles. Surprisingly, Rab2 does not rely on HOPS-mediated vesicular fusion for recruitment to late endosomal membranes. Our work suggests that Drosophila Rab2 is a central regulator of the endolysosomal and macroautophagic/autophagic pathways by controlling the major heterotypic fusion processes at the late endosome.
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Affiliation(s)
- Viktor Karlovich Lund
- a Department of Neuroscience, The Faculty of Health Sciences , University of Copenhagen , Copenhagen , Denmark
| | - Kenneth Lindegaard Madsen
- a Department of Neuroscience, The Faculty of Health Sciences , University of Copenhagen , Copenhagen , Denmark
| | - Ole Kjaerulff
- a Department of Neuroscience, The Faculty of Health Sciences , University of Copenhagen , Copenhagen , Denmark
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48
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Fermie J, Liv N, Ten Brink C, van Donselaar EG, Müller WH, Schieber NL, Schwab Y, Gerritsen HC, Klumperman J. Single organelle dynamics linked to 3D structure by correlative live-cell imaging and 3D electron microscopy. Traffic 2018; 19:354-369. [PMID: 29451726 DOI: 10.1111/tra.12557] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 02/13/2018] [Accepted: 02/13/2018] [Indexed: 01/05/2023]
Abstract
Live-cell correlative light-electron microscopy (live-cell-CLEM) integrates live movies with the corresponding electron microscopy (EM) image, but a major challenge is to relate the dynamic characteristics of single organelles to their 3-dimensional (3D) ultrastructure. Here, we introduce focused ion beam scanning electron microscopy (FIB-SEM) in a modular live-cell-CLEM pipeline for a single organelle CLEM. We transfected cells with lysosomal-associated membrane protein 1-green fluorescent protein (LAMP-1-GFP), analyzed the dynamics of individual GFP-positive spots, and correlated these to their corresponding fine-architecture and immediate cellular environment. By FIB-SEM we quantitatively assessed morphological characteristics, like number of intraluminal vesicles and contact sites with endoplasmic reticulum and mitochondria. Hence, we present a novel way to integrate multiple parameters of subcellular dynamics and architecture onto a single organelle, which is relevant to address biological questions related to membrane trafficking, organelle biogenesis and positioning. Furthermore, by using CLEM to select regions of interest, our method allows for targeted FIB-SEM, which significantly reduces time required for image acquisition and data processing.
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Affiliation(s)
- Job Fermie
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Section Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Corlinda Ten Brink
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Elly G van Donselaar
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Wally H Müller
- Section Cryo-EM, Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Nicole L Schieber
- Electron Microscopy Core Facility, EMBL Heidelberg, Heidelberg, Germany
| | - Yannick Schwab
- Electron Microscopy Core Facility, EMBL Heidelberg, Heidelberg, Germany
| | - Hans C Gerritsen
- Section Molecular Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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49
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Molecular hypotheses to explain the shared pathways and underlying pathobiological causes in catatonia and in catatonic presentations in neuropsychiatric disorders. Med Hypotheses 2018. [DOI: 10.1016/j.mehy.2018.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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50
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Mackie TD, Kim BY, Subramanya AR, Bain DJ, O'Donnell AF, Welling PA, Brodsky JL. The endosomal trafficking factors CORVET and ESCRT suppress plasma membrane residence of the renal outer medullary potassium channel (ROMK). J Biol Chem 2018; 293:3201-3217. [PMID: 29311259 PMCID: PMC5836112 DOI: 10.1074/jbc.m117.819086] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 01/02/2018] [Indexed: 11/06/2022] Open
Abstract
Protein trafficking can act as the primary regulatory mechanism for ion channels with high open probabilities, such as the renal outer medullary (ROMK) channel. ROMK, also known as Kir1.1 (KCNJ1), is the major route for potassium secretion into the pro-urine and plays an indispensable role in regulating serum potassium and urinary concentrations. However, the cellular machinery that regulates ROMK trafficking has not been fully defined. To identify regulators of the cell-surface population of ROMK, we expressed a pH-insensitive version of the channel in the budding yeast Saccharomyces cerevisiae We determined that ROMK primarily resides in the endoplasmic reticulum (ER), as it does in mammalian cells, and is subject to ER-associated degradation (ERAD). However, sufficient ROMK levels on the plasma membrane rescued growth on low-potassium medium of yeast cells lacking endogenous potassium channels. Next, we aimed to identify the biological pathways most important for ROMK regulation. Therefore, we used a synthetic genetic array to identify non-essential genes that reduce the plasma membrane pool of ROMK in potassium-sensitive yeast cells. Genes identified in this screen included several members of the endosomal complexes required for transport (ESCRT) and the class-C core vacuole/endosome tethering (CORVET) complexes. Mass spectroscopy analysis confirmed that yeast cells lacking an ESCRT component accumulate higher potassium concentrations. Moreover, silencing of ESCRT and CORVET components increased ROMK levels at the plasma membrane in HEK293 cells. Our results indicate that components of the post-endocytic pathway influence the cell-surface density of ROMK and establish that components in this pathway modulate channel activity.
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Affiliation(s)
| | - Bo-Young Kim
- the Department of Physiology, University of Maryland at Baltimore, Baltimore, Maryland 21201
| | - Arohan R Subramanya
- the Departments of Medicine and Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
- the Medicine and Research Services, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania 15240, and
| | - Daniel J Bain
- Geology and Environmental Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Allyson F O'Donnell
- the Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282
| | - Paul A Welling
- the Department of Physiology, University of Maryland at Baltimore, Baltimore, Maryland 21201
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