1
|
Shimizu H, Hosseini-Alghaderi S, Woodcock SA, Baron M. Alternative mechanisms of Notch activation by partitioning into distinct endosomal domains. J Cell Biol 2024; 223:e202211041. [PMID: 38358349 PMCID: PMC10868400 DOI: 10.1083/jcb.202211041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/17/2023] [Accepted: 01/30/2024] [Indexed: 02/16/2024] Open
Abstract
Different membrane microdomain compositions provide unique environments that can regulate signaling receptor function. We identify microdomains on the endosome membrane of Drosophila endosomes, enriched in lipid-raft or clathrin/ESCRT-0, which are associated with Notch activation by distinct, ligand-independent mechanisms. Transfer of Notch between microdomains is regulated by Deltex and Suppressor of deltex ubiquitin ligases and is limited by a gate-keeper role for ESCRT complexes. Ubiquitination of Notch by Deltex recruits it to the clathrin/ESCRT-0 microdomain and enhances Notch activation by an ADAM10-independent/TRPML-dependent mechanism. This requirement for Deltex is bypassed by the downregulation of ESCRT-III. In contrast, while ESCRT-I depletion also activates Notch, it does so by an ADAM10-dependent/TRPML-independent mechanism and Notch is retained in the lipid raft-like microdomain. In the absence of such endosomal perturbation, different activating Notch mutations also localize to different microdomains and are activated by different mechanisms. Our findings demonstrate the interplay between Notch regulators, endosomal trafficking components, and Notch genetics, which defines membrane locations and activation mechanisms.
Collapse
Affiliation(s)
- Hideyuki Shimizu
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Samira Hosseini-Alghaderi
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Simon A. Woodcock
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Martin Baron
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Sollazzo G, Nikolouli K, Gouvi G, Aumann RA, Schetelig MF, Bourtzis K. Deep orange gene editing triggers temperature-sensitive lethal phenotypes in Ceratitis capitata. BMC Biotechnol 2024; 24:7. [PMID: 38302991 PMCID: PMC10835909 DOI: 10.1186/s12896-024-00832-x] [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: 10/06/2023] [Accepted: 01/17/2024] [Indexed: 02/03/2024] Open
Abstract
BACKGROUND The Mediterranean fruit fly, Ceratitis capitata, is a significant agricultural pest managed through area-wide integrated pest management (AW-IPM) including a sterile insect technique (SIT) component. Male-only releases increase the efficiency and cost-effectiveness of SIT programs, which can be achieved through the development of genetic sexing strains (GSS). The most successful GSS developed to date is the C. capitata VIENNA 8 GSS, constructed using classical genetic approaches and an irradiation-induced translocation with two selectable markers: the white pupae (wp) and temperature-sensitive lethal (tsl) genes. However, currently used methods for selecting suitable markers and inducing translocations are stochastic and non-specific, resulting in a laborious and time-consuming process. Recent efforts have focused on identifying the gene(s) and the causal mutation(s) for suitable phenotypes, such as wp and tsl, which could be used as selectable markers for developing a generic approach for constructing GSS. The wp gene was recently identified, and efforts have been initiated to identify the tsl gene. This study investigates Ceratitis capitata deep orange (Ccdor) as a tsl candidate gene and its potential to induce tsl phenotypes. RESULTS An integrated approach based on cytogenetics, genomics, bioinformatics, and gene editing was used to characterize the Ccdor. Its location was confirmed on the right arm of chromosome 5 in the putative tsl genomic region. Knock-out of Ccdor using CRISPR/Cas9-NHEJ and targeting the fourth exon resulted in lethality at mid- and late-pupal stage, while the successful application of CRISPR HDR introducing a point mutation on the sixth exon resulted in the establishment of the desired strain and two additional strains (dor 12del and dor 51dup), all of them expressing tsl phenotypes and presenting no (or minimal) fitness cost when reared at 25 °C. One of the strains exhibited complete lethality when embryos were exposed at 36 °C. CONCLUSIONS Gene editing of the deep orange gene in Ceratitis capitata resulted in the establishment of temperature-sensitive lethal mutant strains. The induced mutations did not significantly affect the rearing efficiency of the strains. As deep orange is a highly conserved gene, these data suggest that it can be considered a target for the development of tsl mutations which could potentially be used to develop novel genetic sexing strains in insect pests and disease vectors.
Collapse
Affiliation(s)
- Germano Sollazzo
- Insect Pest Control Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Friedensstrasse 1, Seibersdorf, 2444, Austria
- Institute for Insect Biotechnology, Department of Insect Biotechnology in Plant Protection, Justus-Liebig-University Gießen, Winchesterstr. 2, Gießen, 35394, Germany
- Present address: Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, Imperial College Road, London, SW7 2AZ, UK
| | - Katerina Nikolouli
- Insect Pest Control Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Friedensstrasse 1, Seibersdorf, 2444, Austria
| | - Georgia Gouvi
- Insect Pest Control Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Friedensstrasse 1, Seibersdorf, 2444, Austria
- Laboratory of Systems Microbiology and Applied Genomics, Department of Sustainable Agriculture, University of Patras, 2 G. Seferi St., Agrinio, 30100, Greece
- Present address: Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, South Kensington Campus, Imperial College Road, London, SW7 2AZ, UK
| | - Roswitha A Aumann
- Institute for Insect Biotechnology, Department of Insect Biotechnology in Plant Protection, Justus-Liebig-University Gießen, Winchesterstr. 2, Gießen, 35394, Germany
| | - Marc F Schetelig
- Institute for Insect Biotechnology, Department of Insect Biotechnology in Plant Protection, Justus-Liebig-University Gießen, Winchesterstr. 2, Gießen, 35394, Germany.
| | - Kostas Bourtzis
- Insect Pest Control Laboratory, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Friedensstrasse 1, Seibersdorf, 2444, Austria.
| |
Collapse
|
4
|
Emerging Lysosomal Functions for Photoreceptor Cell Homeostasis and Survival. Cells 2021; 11:cells11010060. [PMID: 35011622 PMCID: PMC8750961 DOI: 10.3390/cells11010060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 12/12/2022] Open
Abstract
Lysosomes are membrane-bound cell organelles that respond to nutrient changes and are implicated in cell homeostasis and clearance mechanisms, allowing effective adaptation to specific cellular needs. The relevance of the lysosome has been elucidated in a number of different contexts. Of these, the retina represents an interesting scenario to appreciate the various functions of this organelle in both physiological and pathological conditions. Growing evidence suggests a role for lysosome-related mechanisms in retinal degeneration. Abnormal lysosomal activation or inhibition has dramatic consequences on photoreceptor cell homeostasis and impacts extensive cellular function, which in turn affects vision. Based on these findings, a series of therapeutic methods targeting lysosomal processes could offer treatment for blindness conditions. Here, we review the recent findings on membrane trafficking, subcellular organization, mechanisms by which lysosome/autophagy pathway impairment affects photoreceptor cell homeostasis and the recent advances on developing efficient lysosomal-based therapies for retinal disorders.
Collapse
|
5
|
Pizette S, Matusek T, Herpers B, Thérond PP, Rabouille C. Hherisomes, Hedgehog specialized recycling endosomes, are required for high level Hedgehog signaling and tissue growth. J Cell Sci 2021; 134:268340. [PMID: 34028543 DOI: 10.1242/jcs.258603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/07/2021] [Indexed: 01/03/2023] Open
Abstract
In metazoans, tissue growth and patterning is partly controlled by the Hedgehog (Hh) morphogen. Using immuno-electron microscopy on Drosophila wing imaginal discs, we identified a cellular structure, the Hherisomes, which contain the majority of intracellular Hh. Hherisomes are recycling tubular endosomes, and their formation is specifically boosted by overexpression of Hh. Expression of Rab11, a small GTPase involved in recycling endosomes, boosts the size of Hherisomes and their Hh concentration. Conversely, increased expression of the transporter Dispatched, a regulator of Hh secretion, leads to their clearance. We show that increasing Hh density in Hherisomes through Rab11 overexpression enhances both the level of Hh signaling and disc pouch growth, whereas Dispatched overexpression decreases high-level Hh signaling and growth. We propose that, upon secretion, a pool of Hh triggers low-level signaling, whereas a second pool of Hh is endocytosed and recycled through Hherisomes to stimulate high-level signaling and disc pouch growth. Altogether, our data indicate that Hherisomes are required to sustain physiological Hh activity necessary for patterning and tissue growth in the wing disc.
Collapse
Affiliation(s)
- Sandrine Pizette
- Université Côte d'Azur, Centre National de la Recherche Scientifique (CNRS), Inserm, Institute of Biology-Valrose (iBV), 06108 Nice Cedex 2, France
| | - Tamás Matusek
- Université Côte d'Azur, Centre National de la Recherche Scientifique (CNRS), Inserm, Institute of Biology-Valrose (iBV), 06108 Nice Cedex 2, France
| | - Bram Herpers
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Pascal P Thérond
- Université Côte d'Azur, Centre National de la Recherche Scientifique (CNRS), Inserm, Institute of Biology-Valrose (iBV), 06108 Nice Cedex 2, France
| | - Catherine Rabouille
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands.,Hubrecht Institute/KNAW [Koninklijke Nederlandsee Akademie van Wetenschap (Dutch Royal Academy of Sciences)] and UMC Utrecht, 3584 CT Utrecht, The Netherlands.,Biological Sciences of Cells and Systems (BSBC) Department, UMC Groningen, 9713 AV Groningen, The Netherlands
| |
Collapse
|
6
|
Lv J, Wang Z, Qu Y, Zhu H, Zhu Q, Tong W, Bao L, Lv Q, Cong J, Li D, Deng W, Yu P, Song J, Tong WM, Liu J, Liu Y, Qin C, Huang B. Distinct uptake, amplification, and release of SARS-CoV-2 by M1 and M2 alveolar macrophages. Cell Discov 2021; 7:24. [PMID: 33850112 PMCID: PMC8043100 DOI: 10.1038/s41421-021-00258-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 03/11/2021] [Indexed: 01/17/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invades the alveoli, where abundant alveolar macrophages (AMs) reside. How AMs respond to SARS-CoV-2 invasion remains elusive. Here, we show that classically activated M1 AMs facilitate viral spread; however, alternatively activated M2 AMs limit the spread. M1 AMs utilize cellular softness to efficiently take up SARS-CoV-2. Subsequently, the invaded viruses take over the endo-lysosomal system to escape. M1 AMs have a lower endosomal pH, favoring membrane fusion and allowing the entry of viral RNA from the endosomes into the cytoplasm, where the virus achieves replication and is packaged to be released. In contrast, M2 AMs have a higher endosomal pH but a lower lysosomal pH, thus delivering the virus to lysosomes for degradation. In hACE2 transgenic mouse model, M1 AMs are found to facilitate SARS-CoV-2 infection of the lungs. These findings provide insights into the complex roles of AMs during SARS-CoV-2 infection, along with potential therapeutic targets.
Collapse
Affiliation(s)
- Jiadi Lv
- Department of Immunology and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College, Beijing 100005, China
| | - Zhenfeng Wang
- Department of Immunology and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College, Beijing 100005, China
| | - Yajin Qu
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Hua Zhu
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Qiangqiang Zhu
- Department of Immunology and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College, Beijing 100005, China
| | - Wei Tong
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Linlin Bao
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Qi Lv
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Ji Cong
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Dan Li
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Wei Deng
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Pin Yu
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China
| | - Jiangping Song
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, CAMS and Peking Union Medical College, Beijing 100005, China
| | - Wei-Min Tong
- Department of Pathology, Institute of Basic Medical Sciences, CAMS and Peking Union Medical College, Beijing 100005, China
| | - Jiangning Liu
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China.
| | - Yuying Liu
- Department of Immunology and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College, Beijing 100005, China. .,Clinical Immunology Center, CAMS, Beijing 100005, China.
| | - Chuan Qin
- NHC Key Laboratory of Human Disease Comparative Medicine, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, CAMS and Comparative Medicine Center, Peking Union Medical College, Beijing 100005, China.
| | - Bo Huang
- Department of Immunology and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College, Beijing 100005, China. .,Clinical Immunology Center, CAMS, Beijing 100005, China. .,Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
| |
Collapse
|
7
|
Chandran R, Kale G, Philippe JM, Lecuit T, Mayor S. Distinct actin-dependent nanoscale assemblies underlie the dynamic and hierarchical organization of E-cadherin. Curr Biol 2021; 31:1726-1736.e4. [PMID: 33607036 DOI: 10.1016/j.cub.2021.01.059] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 11/05/2020] [Accepted: 01/18/2021] [Indexed: 02/07/2023]
Abstract
Cadherins are transmembrane adhesion proteins required for the formation of cohesive tissues.1-4 Intracellular interactions of E-cadherin with the Catenin family proteins, α- and β-catenin, facilitate connections with the cortical actomyosin network. This is necessary for maintaining the integrity of cell-cell adhesion in epithelial tissues.5-11 The supra-molecular architecture of E-cadherin is an important feature of its adhesion function; cis and trans interactions of E-cadherin are deployed12-15 to form clusters, both in cis and trans.11,16-21 Studies in Drosophila embryo have also shown that Drosophila E-cadherin (dE-cad) is organized as finite-sized dynamic clusters that localize with actin patches at cell-cell junctions, in continuous exchange with the extra-junctional pool of dE-cad surrounding the clusters.11,19 Here, we use the ectopic expression of dE-cad in larval hemocytes, which lack endogenous dE-cad to recapitulate functional cell-cell junctions in a convenient model system. We find that, while dE-cad at cell-cell junctions in hemocytes exhibits a clustered trans-paired organization similar to that reported previously in embryonic epithelial tissue, extra-junctional dE-cad is also organized as relatively immobile nanoclusters as well as more loosely packed diffusive oligomers. Oligomers are promoted by cis interactions of the ectodomain, and their growth is counteracted by the activity of cortical actomyosin. Oligomers in turn promote assembly of dense nanoclusters that require cortical actomyosin activity. Thus, cortical actin activity remodels oligomers and generates nanoclusters. The requirement for dynamic actin in the organization of dE-cad at the nanoscale may provide a mechanism to dynamically tune junctional strength.
Collapse
Affiliation(s)
- Rumamol Chandran
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bellary Road, Bangalore 560065, India; Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Girish Kale
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bellary Road, Bangalore 560065, India
| | - Jean-Marc Philippe
- Aix Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Campus de Luminy Case 907, 13288 Marseille, France
| | - Thomas Lecuit
- Aix Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Campus de Luminy Case 907, 13288 Marseille, France; Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bellary Road, Bangalore 560065, India.
| |
Collapse
|
8
|
Lakatos Z, Lőrincz P, Szabó Z, Benkő P, Kenéz LA, Csizmadia T, Juhász G. Sec20 is Required for Autophagic and Endocytic Degradation Independent of Golgi-ER Retrograde Transport. Cells 2019; 8:cells8080768. [PMID: 31344970 PMCID: PMC6721519 DOI: 10.3390/cells8080768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 01/07/2023] Open
Abstract
Endocytosis and autophagy are evolutionarily conserved degradative processes in all eukaryotes. Both pathways converge to the lysosome where cargo is degraded. Improper lysosomal degradation is observed in many human pathologies, so its regulatory mechanisms are important to understand. Sec20/BNIP1 (BCL2/adenovirus E1B 19 kDa protein-interacting protein 1) is a BH3 (Bcl-2 homology 3) domain-containing SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptors) protein that has been suggested to promote Golgi-ER retrograde transport, mitochondrial fission, apoptosis and mitophagy in yeast and vertebrates. Here, we show that loss of Sec20 in Drosophila fat cells causes the accumulation of autophagic vesicles and prevents proper lysosomal acidification and degradation during bulk, starvation-induced autophagy. Furthermore, Sec20 knockdown leads to the enlargement of late endosomes and accumulation of defective endolysosomes in larval Drosophila nephrocytes. Importantly, the loss of Syx18 (Syntaxin 18), one of the known partners of Sec20, led to similar changes in nephrocytes and fat cells. Interestingly. Sec20 appears to function independent of its role in Golgi-ER retrograde transport in regulating lysosomal degradation, as the loss of its other partner SNAREs Use1 (Unconventional SNARE In The ER 1) and Sec22 or tethering factor Zw10 (Zeste white 10), which function together in the Golgi-ER pathway, does not cause defects in autophagy or endocytosis. Thus, our data identify a potential new transport route specific to lysosome biogenesis and function.
Collapse
Affiliation(s)
- Zsolt Lakatos
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
- Premium Postdoctoral Research Program, Hungarian Academy of Sciences, H-1117 Budapest, Hungary
| | - Zoltán Szabó
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Péter Benkő
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Lili Anna Kenéz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary.
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary.
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Ma P, Yun J, Deng H, Guo M. Atg1-mediated autophagy suppresses tissue degeneration in pink1/parkin mutants by promoting mitochondrial fission in Drosophila. Mol Biol Cell 2018; 29:3082-3092. [PMID: 30354903 PMCID: PMC6340213 DOI: 10.1091/mbc.e18-04-0243] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial dysfunction is considered a hallmark of multiple neurodegenerative diseases, including Parkinson’s disease (PD). The PD familial genes pink1 and parkin function in a conserved pathway that regulates mitochondrial function, including dynamics (fusion and fission). Mammalian cell culture studies suggested that the pink1/parkin pathway promotes mitophagy (mitochondrial autophagy). Mitophagy through mitochondrial fission and autolysosomal recycling was considered a quality control system at the organelle level. Whether defects in this quality control machinery lead to pathogenesis in vivo in PD remains elusive. Here, we found that elevating autophagy by atg1 overexpression can significantly rescue mitochondrial defects and apoptotic cell death in pink1 and parkin mutants in Drosophila. Surprisingly, the rescue effect relied both on the autophagy–lysosome machinery and on drp1, a mitochondrial fission molecule. We further showed that Atg1 promotes mitochondrial fission by posttranscriptional increase in the Drp1 protein level. In contrast, increasing fission (by drp1 overexpression) or inhibiting fusion (by knocking down mitofusin [mfn]) rescues pink1 mutants when lysosomal or proteasomal machinery is impaired. Taken together, our results identified Atg1 as a dual-function node that controls mitochondrial quality by promoting mitochondria fission and autophagy, which makes it a potential therapeutic target for treatment of mitochondrial dysfunction–related diseases, including PD.
Collapse
Affiliation(s)
- Peng Ma
- Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 20092, China
| | - Jina Yun
- Department of Neurology, Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, and California NanoSystems Institute at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Hansong Deng
- Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 20092, China.,Department of Neurology, Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, and California NanoSystems Institute at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| | - Ming Guo
- Department of Neurology, Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, and California NanoSystems Institute at UCLA, University of California, Los Angeles, Los Angeles, CA 90095
| |
Collapse
|
11
|
Cunningham PC, Waldeck K, Ganetzky B, Babcock DT. Neurodegeneration and locomotor dysfunction in Drosophila scarlet mutants. J Cell Sci 2018; 131:jcs.216697. [PMID: 30154211 DOI: 10.1242/jcs.216697] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 08/14/2018] [Indexed: 01/03/2023] Open
Abstract
Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons, resulting in progressive locomotor dysfunction. Identification of genes required for the maintenance of these neurons should help to identify potential therapeutic targets. However, little is known regarding the factors that render dopaminergic neurons selectively vulnerable to PD. Here, we show that Drosophila melanogaster scarlet mutants exhibit an age-dependent progressive loss of dopaminergic neurons, along with subsequent locomotor defects and a shortened lifespan. Knockdown of Scarlet specifically within dopaminergic neurons is sufficient to produce this neurodegeneration, demonstrating a unique role for Scarlet beyond its well-characterized role in eye pigmentation. Both genetic and pharmacological manipulation of the kynurenine pathway rescued loss of dopaminergic neurons by promoting synthesis of the free radical scavenger kynurenic acid (KYNA) and limiting the production of the free radical generator 3-hydroxykynurenine (3-HK). Finally, we show that expression of wild-type Scarlet is neuroprotective in a model of PD, suggesting that manipulating kynurenine metabolism may be a potential therapeutic option in treating PD.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
| | - Katherine Waldeck
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Barry Ganetzky
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Daniel T Babcock
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Parchure A, Vyas N, Mayor S. Wnt and Hedgehog: Secretion of Lipid-Modified Morphogens. Trends Cell Biol 2018; 28:157-170. [PMID: 29132729 PMCID: PMC6941938 DOI: 10.1016/j.tcb.2017.10.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 09/07/2017] [Accepted: 10/17/2017] [Indexed: 12/27/2022]
Abstract
Morphogens are signaling molecules produced by a localized source, specifying cell fate in a graded manner. The source secretes morphogens into the extracellular milieu to activate various target genes in an autocrine or paracrine manner. Here we describe various secreted forms of two canonical morphogens, the lipid-anchored Hedgehog (Hh) and Wnts, indicating the involvement of multiple carriers in the transport of these morphogens. These different extracellular secreted forms are likely to have distinct functions. Here we evaluate newly identified mechanisms that morphogens use to traverse the required distance to activate discrete paracrine signaling.
Collapse
Affiliation(s)
- Anup Parchure
- National Centre for Biological Sciences, Tata Institute of Fundamental Research and Institute for Stem Cell Science and Regenerative Medicine, Bangalore 560065, India; Current address: Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Neha Vyas
- St John's Research Institute, St John's National Academy of Health Sciences, Bangalore 560034, India.
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute of Fundamental Research and Institute for Stem Cell Science and Regenerative Medicine, Bangalore 560065, India.
| |
Collapse
|
14
|
Kamalesh K, Trivedi D, Toscano S, Sharma S, Kolay S, Raghu P. Phosphatidylinositol 5-phosphate 4-kinase regulates early endosomal dynamics during clathrin-mediated endocytosis. J Cell Sci 2017; 130:2119-2133. [PMID: 28507272 PMCID: PMC5536888 DOI: 10.1242/jcs.202259] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 05/09/2017] [Indexed: 12/19/2022] Open
Abstract
Endocytic turnover is essential for the regulation of the protein composition and function of the plasma membrane, and thus affects the plasma membrane levels of many receptors. In Drosophila melanogaster photoreceptors, photon absorption by the G-protein-coupled receptor (GPCR) rhodopsin 1 (Rh1; also known as NinaE) triggers its endocytosis through clathrin-mediated endocytosis (CME). We find that CME of Rh1 is regulated by phosphatidylinositol 5 phosphate 4-kinase (PIP4K). Flies lacking PIP4K show mislocalization of Rh1 on expanded endomembranes within the cell body. This mislocalization of Rh1 was dependent on the formation of an expanded Rab5-positive compartment. The Rh1-trafficking defect in PIP4K-depleted cells could be suppressed by downregulating Rab5 function or by selectively reconstituting PIP4K in the PI3P-enriched early endosomal compartment of photoreceptors. We also found that loss of PIP4K was associated with increased CME and an enlarged Rab5-positive compartment in cultured Drosophila cells. Collectively, our findings define PIP4K as a novel regulator of early endosomal homeostasis during CME.
Collapse
Affiliation(s)
- Kumari Kamalesh
- National Centre for Biological Sciences-TIFR, GKVK Campus, Bellary Road, Bangalore 560065, India.,Department of Biological Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Deepti Trivedi
- National Centre for Biological Sciences-TIFR, GKVK Campus, Bellary Road, Bangalore 560065, India
| | - Sarah Toscano
- Inositide Laboratory, Babraham Institute, Cambridge CB22 3AT, UK
| | - Sanjeev Sharma
- National Centre for Biological Sciences-TIFR, GKVK Campus, Bellary Road, Bangalore 560065, India
| | - Sourav Kolay
- National Centre for Biological Sciences-TIFR, GKVK Campus, Bellary Road, Bangalore 560065, India.,Manipal University, Madhav Nagar, Manipal, Karnataka 576104, India
| | - Padinjat Raghu
- National Centre for Biological Sciences-TIFR, GKVK Campus, Bellary Road, Bangalore 560065, India
| |
Collapse
|
15
|
Hanley J, Dhar DK, Mazzacuva F, Fiadeiro R, Burden JJ, Lyne AM, Smith H, Straatman-Iwanowska A, Banushi B, Virasami A, Mills K, Lemaigre FP, Knisely AS, Howe S, Sebire N, Waddington SN, Paulusma CC, Clayton P, Gissen P. Vps33b is crucial for structural and functional hepatocyte polarity. J Hepatol 2017; 66:1001-1011. [PMID: 28082148 PMCID: PMC5387182 DOI: 10.1016/j.jhep.2017.01.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/01/2016] [Accepted: 01/03/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND & AIMS In the normal liver, hepatocytes form a uniquely polarised cell layer that enables movement of solutes from sinusoidal blood to canalicular bile. Whilst several cholestatic liver diseases with defects of hepatocyte polarity have been identified, the molecular mechanisms of pathogenesis are not well defined. One example is arthrogryposis, renal dysfunction and cholestasis syndrome, which in most patients is caused by VPS33B mutations. VPS33B is a protein involved in membrane trafficking that interacts with RAB11A at recycling endosomes. To understand the pathways that regulate hepatocyte polarity better, we investigated VPS33B deficiency using a novel mouse model with a liver-specific Vps33b deletion. METHODS To assess functional polarity, plasma and bile samples were collected from Vps33b liver knockout (Vps33bfl/fl-AlfpCre) and control (Vps33bfl/fl) mice; bile components or injected substrates were quantitated by mass spectrometry or fluorometry. For structural analysis, livers underwent light and transmission electron microscopy. Apical membrane and tight junction protein localisation was assessed by immunostaining. Adeno-associated virus vectors were used for in vivo gene rescue experiments. RESULTS Like patients, Vps33bfl/fl-AlfpCre mice showed mislocalisation of ATP-binding cassette proteins that are specifically trafficked to the apical membrane via Rab11a-positive recycling endosomes. This was associated with retention of bile components in blood. Loss of functional tight junction integrity and depletion of apical microvilli were seen in knockout animals. Gene transfer partially rescued these defects. CONCLUSIONS Vps33b has a key role in establishing structural and functional aspects of hepatocyte polarity and may be a target for gene replacement therapy. LAY SUMMARY Hepatocytes are liver cells with tops and bottoms; that is, they are polarised. At their bottoms they absorb substances from blood. They then, at their tops, secrete these substances and their metabolites into bile. When polarity is lost, this directional flow of substances from blood to bile is disrupted and liver disease follows. In this study, using a new mouse model with a liver-specific mutation of Vps33b, the mouse version of a gene that is mutated in most patients with arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, we investigated how the Vps33b gene product contributes to establishing hepatocyte polarity. We identified in these mice abnormalities similar to those in children with ARC syndrome. Gene transfer could partly reverse the mouse abnormalities. Our work contributes to the understanding of VPS33B disease and hepatocyte polarity in general, and may point towards gene transfer mediated treatment of ARC liver disease.
Collapse
Affiliation(s)
- Joanna Hanley
- UCL Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Dipok Kumar Dhar
- Organ Transplantation Centre and Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia; MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Francesca Mazzacuva
- UCL Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Rebeca Fiadeiro
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Jemima J Burden
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Anne-Marie Lyne
- UCL Department of Statistical Science, University College London, London WC1E 6BT, UK
| | - Holly Smith
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | | | - Blerida Banushi
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Alex Virasami
- Histopathology Department, Camelia Botnar Laboratories, Great Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UK
| | - Kevin Mills
- UCL Institute of Child Health, University College London, London WC1N 1EH, UK
| | | | - A S Knisely
- Institut für Pathologie, Medizinische Universität Graz, 8036 Graz, Austria
| | - Steven Howe
- UCL Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Neil Sebire
- Histopathology Department, Camelia Botnar Laboratories, Great Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UK
| | - Simon N Waddington
- UCL Institute for Women's Health, University College London, London WC1E 6AU, UK; Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg 2193, South Africa
| | - Coen C Paulusma
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, 1105 BK Amsterdam, Netherlands
| | - Peter Clayton
- UCL Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Paul Gissen
- UCL Institute of Child Health, University College London, London WC1N 1EH, UK; MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Inherited Metabolic Disease Unit, Great Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UK.
| |
Collapse
|
16
|
Nemetschke L, Knust E. Drosophila Crumbs prevents ectopic Notch activation in developing wings by inhibiting ligand-independent endocytosis. Development 2016; 143:4543-4553. [DOI: 10.1242/dev.141762] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/21/2016] [Indexed: 12/13/2022]
Abstract
Many signalling components are apically restricted in epithelial cells, and receptor localisation and abundance is key for morphogenesis and tissue homeostasis. Hence, controlling apicobasal epithelial polarity is crucial for proper signalling. Notch is a ubiquitously expressed, apically localised receptor, which performs a plethora of functions; therefore, its activity has to be tightly regulated. Here, we show that Drosophila Crumbs, an evolutionarily conserved polarity determinant, prevents Notch endocytosis in developing wings through direct interaction between the two proteins. Notch endocytosis in the absence of Crumbs results in the activation of the ligand-independent, Deltex-dependent Notch signalling pathway, and does not require the ligands Delta and Serrate or γ-secretase activity. This function of Crumbs is not due to general defects in apicobasal polarity, as localisation of other apical proteins is unaffected. Our data reveal a mechanism to explain how Crumbs directly controls localisation and trafficking of the potent Notch receptor, and adds yet another aspect of Crumbs regulation in Notch pathway activity. Furthermore, our data highlight a close link between the apical determinant Crumbs, receptor trafficking and tissue homeostasis.
Collapse
Affiliation(s)
- Linda Nemetschke
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
| | - Elisabeth Knust
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
| |
Collapse
|
17
|
Jacomin AC, Fauvarque MO, Taillebourg E. A functional endosomal pathway is necessary for lysosome biogenesis in Drosophila. BMC Cell Biol 2016; 17:36. [PMID: 27852225 PMCID: PMC5112658 DOI: 10.1186/s12860-016-0115-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/05/2016] [Indexed: 12/21/2022] Open
Abstract
Background Lysosomes are the major catabolic compartment within eukaryotic cells, and their biogenesis requires the integration of the biosynthetic and endosomal pathways. Endocytosis and autophagy are the primary inputs of the lysosomal degradation pathway. Endocytosis is specifically needed for the degradation of membrane proteins whereas autophagy is responsible for the degradation of cytoplasmic components. We previously identified the deubiquitinating enzyme UBPY/USP8 as being necessary for lysosomal biogenesis and productive autophagy in Drosophila. Because UBPY/USP8 has been widely described for its function in the endosomal system, we hypothesized that disrupting the endosomal pathway itself may affect the biogenesis of the lysosomes. Results In the present study, we blocked the progression of the endosomal pathway at different levels of maturation of the endosomes by expressing in fat body cells either dsRNAs or dominant negative mutants targeting components of the endosomal machinery: Shibire, Rab4, Rab5, Chmp1 and Rab7. We observed that inhibition of endosomal trafficking at different steps in vivo is systematically associated with defects in lysosome biogenesis, resulting in autophagy flux blockade. Conclusion Our results show that the integrity of the endosomal system is required for lysosome biogenesis and productive autophagy in vivo. Electronic supplementary material The online version of this article (doi:10.1186/s12860-016-0115-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Anne-Claire Jacomin
- Université Grenoble-Alpes, F-38041, Grenoble, France.,CEA-DSV-iRTSV-BGE-Gen&Chem, 17, rue des Martyrs, 38054, Grenoble, Cedex 9, France.,INSERM, U1038, F-38054, Grenoble, France.,Present address: School of Life Sciences, University of Warwick, Coventry, UK
| | - Marie-Odile Fauvarque
- Université Grenoble-Alpes, F-38041, Grenoble, France. .,CEA-DSV-iRTSV-BGE-Gen&Chem, 17, rue des Martyrs, 38054, Grenoble, Cedex 9, France. .,INSERM, U1038, F-38054, Grenoble, France.
| | - Emmanuel Taillebourg
- Université Grenoble-Alpes, F-38041, Grenoble, France. .,CEA-DSV-iRTSV-BGE-Gen&Chem, 17, rue des Martyrs, 38054, Grenoble, Cedex 9, France. .,INSERM, U1038, F-38054, Grenoble, France.
| |
Collapse
|
18
|
Endocytosis of Wingless via a dynamin-independent pathway is necessary for signaling in Drosophila wing discs. Proc Natl Acad Sci U S A 2016; 113:E6993-E7002. [PMID: 27791132 DOI: 10.1073/pnas.1610565113] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Endocytosis of ligand-receptor complexes regulates signal transduction during development. In particular, clathrin and dynamin-dependent endocytosis has been well studied in the context of patterning of the Drosophila wing disc, wherein apically secreted Wingless (Wg) encounters its receptor, DFrizzled2 (DFz2), resulting in a distinctive dorso-ventral pattern of signaling outputs. Here, we directly track the endocytosis of Wg and DFz2 in the wing disc and demonstrate that Wg is endocytosed from the apical surface devoid of DFz2 via a dynamin-independent CLIC/GEEC pathway, regulated by Arf1, Garz, and class I PI3K. Subsequently, Wg containing CLIC/GEEC endosomes fuse with DFz2-containing vesicles derived from the clathrin and dynamin-dependent endocytic pathway, which results in a low pH-dependent transfer of Wg to DFz2 within the merged and acidified endosome to initiate Wg signaling. The employment of two distinct endocytic pathways exemplifies a mechanism wherein cells in tissues leverage multiple endocytic pathways to spatially regulate signaling.
Collapse
|
19
|
Riedel F, Gillingham AK, Rosa-Ferreira C, Galindo A, Munro S. An antibody toolkit for the study of membrane traffic in Drosophila melanogaster. Biol Open 2016; 5:987-92. [PMID: 27256406 PMCID: PMC4958275 DOI: 10.1242/bio.018937] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The use of Drosophila melanogaster as a model organism has been pivotal to understanding the developmental processes of metazoans. However, the use of flies for studying subcellular organization is hampered by a paucity of reliable reagents to label specific organelles. Here, we describe the generation of mouse monoclonal antibodies against a set of markers of the secretory and endocytic pathways, along with goat polyclonal antibodies against two Golgi proteins. We show that the monoclonal antibodies are highly specific and sufficiently sensitive to detect endogenous proteins in crude extracts by immunoblotting with little background staining. By immunofluorescence the major compartments of the membrane traffic system (including the endoplasmic reticulum, the Golgi, and early and late endosomes) are labeled by at least one antibody. Moreover, the antibodies can be used to label organelles in fly tissues including salivary glands and wing imaginal discs. We anticipate that these antibodies will provide a useful tool kit to facilitate the investigation of how the endomembrane system functions and varies in the diverse tissue types of metazoans. Summary: We report the generation and characterization of set of monoclonal and polyclonal antibodies for labeling the major compartments of the secretory and endocytic pathways in Drosophila melanogaster.
Collapse
Affiliation(s)
- Falko Riedel
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Alison K Gillingham
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Cláudia Rosa-Ferreira
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Antonio Galindo
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Sean Munro
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| |
Collapse
|
20
|
Gadila SKG, Kim K. Cargo trafficking from the trans-Golgi network towards the endosome. Biol Cell 2016; 108:205-18. [DOI: 10.1111/boc.201600001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/30/2016] [Accepted: 03/31/2016] [Indexed: 11/28/2022]
Affiliation(s)
| | - Kyoungtae Kim
- Department of Biology; Missouri State University; Springfield MO 65807 USA
| |
Collapse
|
21
|
Portela M, Parsons LM, Grzeschik NA, Richardson HE. Regulation of Notch signaling and endocytosis by the Lgl neoplastic tumor suppressor. Cell Cycle 2016; 14:1496-506. [PMID: 25789785 DOI: 10.1080/15384101.2015.1026515] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The evolutionarily conserved neoplastic tumor suppressor protein, Lethal (2) giant larvae (Lgl), plays roles in cell polarity and tissue growth via regulation of the Hippo pathway. In our recent study, we showed that in the developing Drosophila eye epithelium, depletion of Lgl leads to increased ligand-dependent Notch signaling. lgl mutant tissue also exhibits an accumulation of early endosomes, recycling endosomes, early-multivesicular body markers and acidic vesicles. We showed that elevated Notch signaling in lgl(-) tissue can be rescued by feeding larvae the vesicle de-acidifying drug chloroquine, revealing that Lgl attenuates Notch signaling by limiting vesicle acidification. Strikingly, chloroquine also rescued the lgl(-) overgrowth phenotype, suggesting that the Hippo pathway defects were also rescued. In this extraview, we provide additional data on the regulation of Notch signaling and endocytosis by Lgl, and discuss possible mechanisms by which Lgl depletion contributes to signaling pathway defects and tumorigenesis.
Collapse
Affiliation(s)
- Marta Portela
- a Cell Cycle and Development Laboratory; Research Division ; Peter MacCallum Cancer Centre ; Melbourne , Victoria , Australia
| | | | | | | |
Collapse
|
22
|
Ceramides And Stress Signalling Intersect With Autophagic Defects In Neurodegenerative Drosophila blue cheese (bchs) Mutants. Sci Rep 2015; 5:15926. [PMID: 26639035 PMCID: PMC4671070 DOI: 10.1038/srep15926] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/07/2015] [Indexed: 12/19/2022] Open
Abstract
Sphingolipid metabolites are involved in the regulation of autophagy, a degradative recycling process that is required to prevent neuronal degeneration. Drosophila blue cheese mutants neurodegenerate due to perturbations in autophagic flux, and consequent accumulation of ubiquitinated aggregates. Here, we demonstrate that blue cheese mutant brains exhibit an elevation in total ceramide levels; surprisingly, however, degeneration is ameliorated when the pool of available ceramides is further increased, and exacerbated when ceramide levels are decreased by altering sphingolipid catabolism or blocking de novo synthesis. Exogenous ceramide is seen to accumulate in autophagosomes, which are fewer in number and show less efficient clearance in blue cheese mutant neurons. Sphingolipid metabolism is also shifted away from salvage toward de novo pathways, while pro-growth Akt and MAP pathways are down-regulated, and ER stress is increased. All these defects are reversed under genetic rescue conditions that increase ceramide generation from salvage pathways. This constellation of effects suggests a possible mechanism whereby the observed deficit in a potentially ceramide-releasing autophagic pathway impedes survival signaling and exacerbates neuronal death.
Collapse
|
23
|
Parchure A, Vyas N, Ferguson C, Parton RG, Mayor S. Oligomerization and endocytosis of Hedgehog is necessary for its efficient exovesicular secretion. Mol Biol Cell 2015; 26:4700-17. [PMID: 26490120 PMCID: PMC4678025 DOI: 10.1091/mbc.e15-09-0671] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 10/14/2015] [Indexed: 12/14/2022] Open
Abstract
Hedgehog (Hh) is a secreted morphogen involved in both short- and long-range signaling necessary for tissue patterning during development. It is unclear how this dually lipidated protein is transported over a long range in the aqueous milieu of interstitial spaces. We previously showed that the long-range signaling of Hh requires its oligomerization. Here we show that Hh is secreted in the form of exovesicles. These are derived by the endocytic delivery of cell surface Hh to multivesicular bodies (MVBs) via an endosomal sorting complex required for transport (ECSRT)-dependent process. Perturbations of ESCRT proteins have a selective effect on long-range Hh signaling in Drosophila wing imaginal discs. Of importance, oligomerization-defective Hh is inefficiently incorporated into exovesicles due to its poor endocytic delivery to MVBs. These results provide evidence that nanoscale organization of Hh regulates the secretion of Hh on ESCRT-derived exovesicles, which in turn act as a vehicle for long-range signaling.
Collapse
Affiliation(s)
- Anup Parchure
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Neha Vyas
- Institute for Stem Cell Biology and Regenerative Medicine, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Charles Ferguson
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane St Lucia 4072, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane St Lucia 4072, Australia
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India Institute for Stem Cell Biology and Regenerative Medicine, Tata Institute of Fundamental Research, Bangalore 560065, India
| |
Collapse
|
24
|
Galmes R, ten Brink C, Oorschot V, Veenendaal T, Jonker C, van der Sluijs P, Klumperman J. Vps33B is required for delivery of endocytosed cargo to lysosomes. Traffic 2015; 16:1288-305. [DOI: 10.1111/tra.12334] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 12/23/2022]
Affiliation(s)
- Romain Galmes
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
- Present address: Institut Jacques Monod; CNRS, UMR7592, Université Paris Diderot; Sorbonne Paris Cité F-75013 Paris France
| | - Corlinda ten Brink
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Viola Oorschot
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
- Present address: Monash Micro Imaging; 15 Innovation Walk, Strip 1 Monash Biotechnology, Monash University; Clayton VIC 3800 Australia
| | - Tineke Veenendaal
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Caspar Jonker
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Peter van der Sluijs
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| | - Judith Klumperman
- Department of Cell Biology and Institute of Biomembranes; Center for Molecular Medicine, University Medical Center Utrecht; Heidelberglaan 100 3584CX Utrecht The Netherlands
| |
Collapse
|
25
|
Saha S, Prakash V, Halder S, Chakraborty K, Krishnan Y. A pH-independent DNA nanodevice for quantifying chloride transport in organelles of living cells. NATURE NANOTECHNOLOGY 2015; 10:645-51. [PMID: 26098226 DOI: 10.1038/nnano.2015.130] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 05/22/2015] [Indexed: 05/24/2023]
Abstract
The concentration of chloride ions in the cytoplasm and subcellular organelles of living cells spans a wide range (5-130 mM), and is tightly regulated by intracellular chloride channels or transporters. Chloride-sensitive protein reporters have been used to study the role of these chloride regulators, but they are limited to a small range of chloride concentrations and are pH-sensitive. Here, we show that a DNA nanodevice can precisely measure the activity and location of subcellular chloride channels and transporters in living cells in a pH-independent manner. The DNA nanodevice, called Clensor, is composed of sensing, normalizing and targeting modules, and is designed to localize within organelles along the endolysosomal pathway. It allows fluorescent, ratiometric sensing of chloride ions across the entire physiological regime. We used Clensor to quantitate the resting chloride concentration in the lumen of acidic organelles in Drosophila melanogaster. We showed that lumenal lysosomal chloride, which is implicated in various lysosomal storage diseases, is regulated by the intracellular chloride transporter DmClC-b.
Collapse
Affiliation(s)
- Sonali Saha
- National Centre for Biological Sciences, TIFR, GKVK, Bellary Road, Bangalore 560065, India
| | - Ved Prakash
- Department of Chemistry, University of Chicago, 929E, 57th Street, E305A, GCIS, Chicago, Illinois 60637, USA
| | - Saheli Halder
- National Centre for Biological Sciences, TIFR, GKVK, Bellary Road, Bangalore 560065, India
| | - Kasturi Chakraborty
- Department of Chemistry, University of Chicago, 929E, 57th Street, E305A, GCIS, Chicago, Illinois 60637, USA
| | - Yamuna Krishnan
- 1] National Centre for Biological Sciences, TIFR, GKVK, Bellary Road, Bangalore 560065, India [2] Department of Chemistry, University of Chicago, 929E, 57th Street, E305A, GCIS, Chicago, Illinois 60637, USA
| |
Collapse
|
26
|
Gupte TM. Mitochondrial Fragmentation Due to Inhibition of Fusion Increases Cyclin B through Mitochondrial Superoxide Radicals. PLoS One 2015; 10:e0126829. [PMID: 26000631 PMCID: PMC4441460 DOI: 10.1371/journal.pone.0126829] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 04/08/2015] [Indexed: 11/25/2022] Open
Abstract
During the cell cycle, mitochondria undergo regulated changes in morphology. Two particularly interesting events are first, mitochondrial hyperfusion during the G1-S transition and second, fragmentation during entry into mitosis. The mitochondria remain fragmented between late G2- and mitotic exit. This mitotic mitochondrial fragmentation constitutes a checkpoint in some cell types, of which little is known. We bypass the ‘mitotic mitochondrial fragmentation’ checkpoint by inducing fragmented mitochondrial morphology and then measure the effect on cell cycle progression. Using Drosophila larval hemocytes, Drosophila S2R+ cell and cells in the pouch region of wing imaginal disc of Drosophila larvae we show that inhibiting mitochondrial fusion, thereby increasing fragmentation, causes cellular hyperproliferation and an increase in mitotic index. However, mitochondrial fragmentation due to over-expression of the mitochondrial fission machinery does not cause these changes. Our experiments suggest that the inhibition of mitochondrial fusion increases superoxide radical content and leads to the upregulation of cyclin B that culminates in the observed changes in the cell cycle. We provide evidence for the importance of mitochondrial superoxide in this process. Our results provide an insight into the need for mitofusin-degradation during mitosis and also help in understanding the mechanism by which mitofusins may function as tumor suppressors.
Collapse
Affiliation(s)
- Tejas M. Gupte
- National Centre for Biological Sciences (NCBS-TIFR), UAS-GKVK campus, Bellary road, Bangalore, 560 065, Karnataka, India
- inStem, Institute for Stem Cell Biology and Regenerative Medicine, GKVK post, Bellary road, Bangalore, 560 065, Karnataka, India
- * E-mail:
| |
Collapse
|
27
|
Lee YM, Sun YH. Maintenance of glia in the optic lamina is mediated by EGFR signaling by photoreceptors in adult Drosophila. PLoS Genet 2015; 11:e1005187. [PMID: 25909451 PMCID: PMC4409299 DOI: 10.1371/journal.pgen.1005187] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 03/31/2015] [Indexed: 01/13/2023] Open
Abstract
The late onset of neurodegeneration in humans indicates that the survival and function of cells in the nervous system must be maintained throughout adulthood. In the optic lamina of the adult Drosophila, the photoreceptor axons are surrounded by multiple types of glia. We demonstrated that the adult photoreceptors actively contribute to glia maintenance in their target field within the optic lamina. This effect is dependent on the epidermal growth factor receptor (EGFR) ligands produced by the R1-6 photoreceptors and transported to the optic lamina to act on EGFR in the lamina glia. EGFR signaling is necessary and sufficient to act in a cell-autonomous manner in the lamina glia. Our results suggest that EGFR signaling is required for the trafficking of the autophagosome/endosome to the lysosome. The loss of EGFR signaling results in cell degeneration most likely because of the accumulation of autophagosomes. Our findings provide in vivo evidence for the role of adult neurons in the maintenance of glia and a novel role for EGFR signaling in the autophagic flux. Degeneration of the nervous system can be viewed as a failure to maintain cell survival or function in the nervous system. The late onset of neurodegeneration in humans indicates that the cell survival in the nervous system must be maintained throughout our lives. Neuronal survival is maintained by neurotrophic factors in adults; however, it is unclear whether glia survival is also maintained throughout adulthood. Here, we use the Drosophila visual system as a model to address the role played by adult neurons for the active maintenance of glia. We demonstrated that the adult photoreceptors secrete a signaling molecule, which is transported to the brain to act on the lamina glia and maintain its integrity. When this signaling pathway is blocked, the lamina glia undergoes a progressive and irreversible degeneration. The primary defect occurs in the trafficking from the late endosome and autophagosome to the lysosome. This defect leads to an accumulation of autophagosomes and subsequent cell degeneration as a result of autophagy. Our findings provide in vivo evidence for a novel aspect of the neuron-glia interaction and a novel role for EGFR signaling in regulating the maintenance and degeneration of the nervous system.
Collapse
Affiliation(s)
- Yuan-Ming Lee
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Institute of Genomic Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Y. Henry Sun
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Institute of Genomic Sciences, National Yang-Ming University, Taipei, Taiwan
- * E-mail:
| |
Collapse
|
28
|
Zlatic SA, Tornieri K, L'hernault SW, Faundez V. Metazoan cell biology of the HOPS tethering complex. CELLULAR LOGISTICS 2014; 1:111-117. [PMID: 21922076 DOI: 10.4161/cl.1.3.17279] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 07/18/2011] [Accepted: 07/20/2011] [Indexed: 01/09/2023]
Abstract
Membrane fusion with vacuoles, the lysosome equivalent of the yeast Saccharomyces cerevisiae, is among the best understood membrane fusion events. Our precise understanding of this fusion machinery stems from powerful genetics and elegant in vitro reconstitution assays. Central to vacuolar membrane fusion is the multi-subunit tether the HO motypic fusion and Protein Sorting (HOPS) complex, a complex of proteins that organizes other necessary components of the fusion machinery. We lack a similarly detailed molecular understanding of membrane fusion with lysosomes or lysosome-related organelles in metazoans. However, it is likely that fundamental principles of how rabs, SNAREs and HOPS tethers work to fuse membranes with lysosomes and related organelles are conserved between Saccharomyces cerevisiae and metazoans. Here, we discuss emerging differences in the coat-dependent mechanisms that govern HOPS complex subcellular distribution between Saccharomyces cerevisiae and metazoans. These differences reside upstream of the membrane fusion event. We propose that the differences in how coats segregate class C Vps/HOPS tethers to organelles and domains of metazoan cells are adaptations to complex architectures that characterize metazoan cells such as those of neuronal and epithelial tissues.
Collapse
Affiliation(s)
- Stephanie A Zlatic
- Graduate Program in Biochemistry, Cell and Developmental Biology; Emory University; Atlanta, GA USA
| | | | | | | |
Collapse
|
29
|
Solinger JA, Spang A. Loss of the Sec1/Munc18-family proteins VPS-33.2 and VPS-33.1 bypasses a block in endosome maturation in Caenorhabditis elegans. Mol Biol Cell 2014; 25:3909-25. [PMID: 25273556 PMCID: PMC4244200 DOI: 10.1091/mbc.e13-12-0710] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Evidence is presented for the existence of HOPS and CORVET tethering complexes in metazoans. A role is shown for the SM protein components of tethers in controlling the flux of material through the endosomal system. The end of the life of a transport vesicle requires a complex series of tethering, docking, and fusion events. Tethering complexes play a crucial role in the recognition of membrane entities and bringing them into close opposition, thereby coordinating and controlling cellular trafficking events. Here we provide a comprehensive RNA interference analysis of the CORVET and HOPS tethering complexes in metazoans. Knockdown of CORVET components promoted RAB-7 recruitment to subapical membranes, whereas in HOPS knockdowns, RAB-5 was found also on membrane structures close to the cell center, indicating the RAB conversion might be impaired in the absence of these tethering complexes. Unlike in yeast, metazoans have two VPS33 homologues, which are Sec1/Munc18 (SM)-family proteins involved in the regulation of membrane fusion. We assume that in wild type, each tethering complex contains a specific SM protein but that they may be able to substitute for each other in case of absence of the other. Of importance, knockdown of both SM proteins allowed bypass of the endosome maturation block in sand-1 mutants. We propose a model in which the SM proteins in tethering complexes are required for coordinated flux of material through the endosomal system.
Collapse
Affiliation(s)
- Jachen A Solinger
- Growth and Development, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Anne Spang
- Growth and Development, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| |
Collapse
|
30
|
Parsons LM, Portela M, Grzeschik NA, Richardson HE. Lgl regulates Notch signaling via endocytosis, independently of the apical aPKC-Par6-Baz polarity complex. Curr Biol 2014; 24:2073-2084. [PMID: 25220057 DOI: 10.1016/j.cub.2014.07.075] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 07/01/2014] [Accepted: 07/28/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND The Drosophila melanogaster junctional neoplastic tumor suppressor, Lethal-2-giant larvae (Lgl), is a regulator of apicobasal cell polarity and tissue growth. We have previously shown in the developing Drosophila eye epithelium that, without affecting cell polarity, depletion of Lgl results in ectopic cell proliferation and blockage of developmental cell death due to deregulation of the Hippo signaling pathway. RESULTS Here, we show that Notch signaling is increased in lgl-depleted eye tissue, independently of Lgl's function in apicobasal cell polarity. The upregulation of Notch signaling is ligand dependent and correlates with accumulation of cleaved Notch. Concomitant with higher cleaved Notch levels in lgl- tissue, early endosomes (Avalanche [Avl+]), recycling endosomes (Rab11+), early multivesicular bodies (Hrs+), and acidified vesicles, but not late endosomal markers (Car+ and Rab7+), accumulate. Colocalization studies revealed that Lgl associates with early to late endosomes and lysosomes. Upregulation of Notch signaling in lgl- tissue requires dynamin- and Rab5-mediated endocytosis and vesicle acidification but is independent of Hrs/Stam or Rab11 activity. Furthermore, Lgl regulates Notch signaling independently of the aPKC-Par6-Baz apical polarity complex. CONCLUSIONS Altogether, our data show that Lgl regulates endocytosis to restrict vesicle acidification and prevent ectopic ligand-dependent Notch signaling. This Lgl function is independent of the aPKC-Par6-Baz polarity complex and uncovers a novel attenuation mechanism of ligand-activated Notch signaling during Drosophila eye development.
Collapse
Affiliation(s)
- Linda M Parsons
- Cell Cycle and Development Laboratory, Research Division, Peter MacCallum Cancer Centre, 7 St. Andrew's Place, East Melbourne, Melbourne, VIC 3002, Australia; Department of Genetics, University of Melbourne, 1-100 Grattan Street, Parkville, Melbourne, VIC 3010, Australia
| | - Marta Portela
- Cell Cycle and Development Laboratory, Research Division, Peter MacCallum Cancer Centre, 7 St. Andrew's Place, East Melbourne, Melbourne, VIC 3002, Australia
| | - Nicola A Grzeschik
- Cell Cycle and Development Laboratory, Research Division, Peter MacCallum Cancer Centre, 7 St. Andrew's Place, East Melbourne, Melbourne, VIC 3002, Australia
| | - Helena E Richardson
- Cell Cycle and Development Laboratory, Research Division, Peter MacCallum Cancer Centre, 7 St. Andrew's Place, East Melbourne, Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Centre, 7 St. Andrew's Place, East Melbourne, Melbourne, VIC 3002, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, 1-100 Grattan Street, Parkville, Melbourne, VIC 3010, Australia; Department of Anatomy and Neuroscience, University of Melbourne, 1-100 Grattan Street, Parkville, Melbourne, VIC 3010, Australia.
| |
Collapse
|
31
|
Gupta GD, Dey G, MG S, Ramalingam B, Shameer K, Thottacherry JJ, Kalappurakkal JM, Howes MT, Chandran R, Das A, Menon S, Parton RG, Sowdhamini R, Thattai M, Mayor S. Population distribution analyses reveal a hierarchy of molecular players underlying parallel endocytic pathways. PLoS One 2014; 9:e100554. [PMID: 24971745 PMCID: PMC4074053 DOI: 10.1371/journal.pone.0100554] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 05/28/2014] [Indexed: 12/11/2022] Open
Abstract
Single-cell-resolved measurements reveal heterogeneous distributions of clathrin-dependent (CD) and -independent (CLIC/GEEC: CG) endocytic activity in Drosophila cell populations. dsRNA-mediated knockdown of core versus peripheral endocytic machinery induces strong changes in the mean, or subtle changes in the shapes of these distributions, respectively. By quantifying these subtle shape changes for 27 single-cell features which report on endocytic activity and cell morphology, we organize 1072 Drosophila genes into a tree-like hierarchy. We find that tree nodes contain gene sets enriched in functional classes and protein complexes, providing a portrait of core and peripheral control of CD and CG endocytosis. For 470 genes we obtain additional features from separate assays and classify them into early- or late-acting genes of the endocytic pathways. Detailed analyses of specific genes at intermediate levels of the tree suggest that Vacuolar ATPase and lysosomal genes involved in vacuolar biogenesis play an evolutionarily conserved role in CG endocytosis.
Collapse
Affiliation(s)
- Gagan D. Gupta
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Gautam Dey
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Swetha MG
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Balaji Ramalingam
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Khader Shameer
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Joseph Jose Thottacherry
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Joseph Mathew Kalappurakkal
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Mark T. Howes
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Ruma Chandran
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Anupam Das
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Sindhu Menon
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Robert G. Parton
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - R. Sowdhamini
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Mukund Thattai
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, UAS/GKVK Campus, Bangalore, India
| |
Collapse
|
32
|
Zhang J, Du J, Lei C, Liu M, Zhu AJ. Ubpy controls the stability of the ESCRT-0 subunit Hrs in development. Development 2014; 141:1473-9. [PMID: 24574010 DOI: 10.1242/dev.099564] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ubiquitylated developmental membrane signaling proteins are often internalized for endocytic trafficking, through which endosomal sorting complexes required for transport (ESCRT) act sequentially to deliver internalized cargos to lysosomes. The ESCRT function in endocytic sorting is well established; however, it is not fully understood how the sorting machinery itself is regulated. Here, we show that Ubiquitin isopeptidase Y (Ubpy) plays a conserved role in vivo in the homeostasis of an essential ESCRT-0 complex component Hrs. We find that, in the absence of Drosophila Ubpy, multiple membrane proteins that are essential components of important signaling pathways accumulate in enlarged, aberrant endosomes. We further demonstrate that this phenotype results from endocytic pathway defects. We provide evidence that Ubpy interacts with and deubiquitylates Hrs. In Ubpy-null cells, Hrs becomes ubiquitylated and degraded in lysosomes, thus disrupting the integrity of ESCRT sorting machinery. Lastly, we find that signaling proteins are enriched in enlarged endosomes when Hrs activity is abolished. Together, our data support a model in which Ubpy plays a dual role in both cargo deubiquitylation and the ESCRT-0 stability during development.
Collapse
Affiliation(s)
- Junzheng Zhang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Peking-Tsinghua Center for Life Sciences, College of Life Sciences, Peking University, Beijing 100871, China
| | | | | | | | | |
Collapse
|
33
|
Delahaye JL, Foster OK, Vine A, Saxton DS, Curtin TP, Somhegyi H, Salesky R, Hermann GJ. Caenorhabditis elegans HOPS and CCZ-1 mediate trafficking to lysosome-related organelles independently of RAB-7 and SAND-1. Mol Biol Cell 2014; 25:1073-96. [PMID: 24501423 PMCID: PMC3967972 DOI: 10.1091/mbc.e13-09-0521] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
As early endosomes mature, the SAND-1/CCZ-1 complex acts as a guanine nucleotide exchange factor (GEF) for RAB-7 to promote the activity of its effector, HOPS, which facilitates late endosome-lysosome fusion and the consumption of AP-3-containing vesicles. We show that CCZ-1 and the HOPS complex are essential for the biogenesis of gut granules, cell type-specific, lysosome-related organelles (LROs) that coexist with conventional lysosomes in Caenorhabditis elegans intestinal cells. The HOPS subunit VPS-18 promotes the trafficking of gut granule proteins away from lysosomes and functions downstream of or in parallel to the AP-3 adaptor. CCZ-1 also acts independently of AP-3, and ccz-1 mutants mistraffic gut granule proteins. Our results indicate that SAND-1 does not participate in the formation of gut granules. In the absence of RAB-7 activity, gut granules are generated; however, their size and protein composition are subtly altered. These observations suggest that CCZ-1 acts in partnership with a protein other than SAND-1 as a GEF for an alternate Rab to promote gut granule biogenesis. Point mutations in GLO-1, a Rab32/38-related protein, predicted to increase spontaneous guanine nucleotide exchange, specifically suppress the loss of gut granules by ccz-1 and glo-3 mutants. GLO-3 is known to be required for gut granule formation and has homology to SAND-1/Mon1-related proteins, suggesting that CCZ-1 functions with GLO-3 upstream of the GLO-1 Rab, possibly as a GLO-1 GEF. These results support LRO formation occurring via processes similar to conventional lysosome biogenesis, albeit with key molecular differences.
Collapse
Affiliation(s)
- Jared L Delahaye
- Department of Biology, Lewis & Clark College, Portland, OR 97219 Program in Biochemistry and Molecular Biology, Lewis & Clark College, Portland, OR 97219
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Balderhaar HJK, Ungermann C. CORVET and HOPS tethering complexes - coordinators of endosome and lysosome fusion. J Cell Sci 2013; 126:1307-16. [PMID: 23645161 DOI: 10.1242/jcs.107805] [Citation(s) in RCA: 351] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Protein and lipid transport along the endolysosomal system of eukaryotic cells depends on multiple fusion and fission events. Over the past few years, the molecular constituents of both fission and fusion machineries have been identified. Here, we focus on the mechanism of membrane fusion at endosomes, vacuoles and lysosomes, and in particular on the role of the two homologous tethering complexes called CORVET and HOPS. Both complexes are heterohexamers; they share four subunits, interact with Rab GTPases and soluble NSF attachment protein receptors (SNAREs) and can tether membranes. Owing to the presence of specific subunits, CORVET is a Rab5 effector complex, whereas HOPS can bind efficiently to late endosomes and lysosomes through Rab7. Based on the recently described overall structure of the HOPS complex and a number of in vivo and in vitro analyses, important insights into their function have been obtained. Here, we discuss the general function of both complexes in yeast and in metazoan cells in the context of endosomal biogenesis and maturation.
Collapse
Affiliation(s)
- Henning J kleine Balderhaar
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry Section, Barbarastrasse 13, 49076 Osnabrück, Germany
| | | |
Collapse
|
35
|
Tornieri K, Zlatic SA, Mullin AP, Werner E, Harrison R, L'hernault SW, Faundez V. Vps33b pathogenic mutations preferentially affect VIPAS39/SPE-39-positive endosomes. Hum Mol Genet 2013; 22:5215-28. [PMID: 23918659 DOI: 10.1093/hmg/ddt378] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in Vps33 isoforms cause pigment dilution in mice (Vps33a, buff) and Drosophila (car) and the neurogenic arthrogryposis, renal dysfunction and cholestasis syndrome in humans (ARC1, VPS33B). The later disease is also caused by mutations in VIPAS39, (Vps33b interacting protein, apical-basolateral polarity regulator, SPE-39 homolog; ARC2), a protein that interacts with the HOmotypic fusion and Protein Sorting (HOPS) complex, a tether necessary for endosome-lysosome traffic. These syndromes offer insight into fundamental endosome traffic processes unique to metazoans. However, the molecular and cellular mechanisms underlying these mutant phenotypes remain poorly understood. Here we investigate interactions of wild-type and disease-causing mutations in VIPAS39/SPE-39 and Vps33b by yeast two hybrid, immunoprecipitation and quantitative fluorescent microscopy. We find that although few mutations prevent interaction between VIPAS39/SPE-39 and Vps33b, some mutants fragment VIPAS39/SPE-39-positive endosomes, but all mutants alter the subcellular localization of Vps33b to VIPAS39/SPE-39-positive endosomes. Our data suggest that the ARC syndrome may result through impaired VIPAS39/SPE-39 and Vps33b-dependent endosomal maturation or fusion.
Collapse
|
36
|
Solinger JA, Spang A. Tethering complexes in the endocytic pathway: CORVET and HOPS. FEBS J 2013; 280:2743-57. [PMID: 23351085 DOI: 10.1111/febs.12151] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 01/10/2013] [Accepted: 01/23/2013] [Indexed: 12/21/2022]
Abstract
Endocytosis describes the processes by which proteins, peptides and solutes, and also pathogens, enter the cell. Endocytosed material progresses to endosomes. Genetic studies in yeast, worms, flies and mammals have identified a set of universally conserved proteins that are essential for early-to-late endosome transition and lysosome biogenesis, and for endolysosomal trafficking pathways, including autophagy. The two Vps-C complexes CORVET (class C core vacuole/endosome tethering) and HOPS (homotypic fusion and vacuole protein sorting) perform diverse biochemical functions in endocytosis: they tether membranes, interact with Rab GTPases, activate and proof-read SNARE assembly to drive membrane fusion, and possibly attach endosomes to the cytoskeleton. In addition, several of the CORVET and HOPS subunits have diversified in metazoans, and probably form additional specialized complexes to accomodate the higher complexity of trafficking pathways in these cells. Recent studies offer new insights into the complex relationships between CORVET and HOPS complexes and other factors of the endolysosomal pathway. Interactions with V-ATPase, the ESCRT machinery, phosphoinositides, the cytoskeleton and the Rab switch suggest an intricate cooperative network for endosome maturation. Accumulating evidence supports the view that endosomal tethering complexes implement a regulatory logic that governs endomembrane identity and dynamics.
Collapse
|
37
|
Pols MS, van Meel E, Oorschot V, ten Brink C, Fukuda M, Swetha MG, Mayor S, Klumperman J. hVps41 and VAMP7 function in direct TGN to late endosome transport of lysosomal membrane proteins. Nat Commun 2013; 4:1361. [PMID: 23322049 DOI: 10.1038/ncomms2360] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 12/05/2012] [Indexed: 12/18/2022] Open
Abstract
Targeted delivery of lysosome-associated membrane proteins is important for lysosome stability and function. Here we identify a pathway for transport of lysosome-associated membrane proteins directly from the trans-Golgi network to late endosomes, which exists in parallel to mannose 6-phosphate receptor and clathrin-dependent transport of lysosomal enzymes to early endosomes. By immunoelectron microscopy we localized endogenous LAMP-1 and -2 as well as LAMP-1-mGFP to non-coated, biosynthetic carriers at the trans-Golgi network and near late endosomes. These LAMP carriers were negative for mannose 6-phosphate receptor, adaptor-protein complex-1, secretory albumin and endocytic markers, but contained the homotypic fusion and protein sorting complex component hVps41 and the soluble N-ethylmaleimide-sensitive factor attachment protein receptors protein VAMP7. Knockdown of hVps41 or VAMP7 resulted in the accumulation of lysosome-associated membrane protein carriers, whereas knockdown of hVps39 or hVps18 did not, indicating that the effect of hVps41 is independent of CORVET/HOPS. Mannose 6-phosphate receptor carriers remained unaffected upon hVps41 or VAMP7 knockdown, implicating that hVps41 and VAMP7 are specifically involved in the fusion of trans-Golgi network-derived lysosome-associated membrane protein carriers with late endosomes.
Collapse
Affiliation(s)
- Maaike S Pols
- Department of Cell Biology, University Medical Centre Utrecht, AZU Room H02.313, Heidelberglaan 100, Utrecht 3584 CX, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Wei AH, Li W. Hermansky-Pudlak syndrome: pigmentary and non-pigmentary defects and their pathogenesis. Pigment Cell Melanoma Res 2012; 26:176-92. [DOI: 10.1111/pcmr.12051] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/16/2012] [Indexed: 10/27/2022]
Affiliation(s)
| | - Wei Li
- State Key Laboratory of Molecular Developmental Biology; Institute of Genetics & Developmental Biology; Chinese Academy of Sciences; Beijing; China
| |
Collapse
|
39
|
Smith H, Galmes R, Gogolina E, Straatman-Iwanowska A, Reay K, Banushi B, Bruce CK, Cullinane AR, Romero R, Chang R, Ackermann O, Baumann C, Cangul H, Cakmak Celik F, Aygun C, Coward R, Dionisi-Vici C, Sibbles B, Inward C, Ae Kim C, Klumperman J, Knisely AS, Watson SP, Gissen P. Associations among genotype, clinical phenotype, and intracellular localization of trafficking proteins in ARC syndrome. Hum Mutat 2012; 33:1656-64. [PMID: 22753090 PMCID: PMC3746110 DOI: 10.1002/humu.22155] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 06/12/2012] [Indexed: 12/31/2022]
Abstract
Arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome is a rare autosomal recessive multisystem disorder caused by mutations in vacuolar protein sorting 33 homologue B (VPS33B) and VPS33B interacting protein, apical-basolateral polarity regulator (VIPAR). Cardinal features of ARC include congenital joint contractures, renal tubular dysfunction, cholestasis, severe failure to thrive, ichthyosis, and a defect in platelet alpha-granule biogenesis. Most patients with ARC do not survive past the first year of life. We report two patients presenting with a mild ARC phenotype, now 5.5 and 3.5 years old. Both patients were compound heterozygotes with the novel VPS33B donor splice-site mutation c.1225+5G>C in common. Immunoblotting and complementary DNA analysis suggest expression of a shorter VPS33B transcript, and cell-based assays show that c.1225+5G>C VPS33B mutant retains some ability to interact with VIPAR (and thus partial wild-type function). This study provides the first evidence of genotype-phenotype correlation in ARC and suggests that VPS33B c.1225+5G>C mutation predicts a mild ARC phenotype. We have established an interactive online database for ARC (https://grenada.lumc.nl/LOVD2/ARC) comprising all known variants in VPS33B and VIPAR. Also included in the database are 15 novel pathogenic variants in VPS33B and five in VIPAR.
Collapse
Affiliation(s)
- Holly Smith
- Medical and Molecular Genetics, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, United Kingdom
- University College London Institute of Child Health, University College LondonLondon, United Kingdom
| | - Romain Galmes
- Department of Cell Biology, University Medical CenterUtrecht, the Netherlands
| | - Ekaterina Gogolina
- Medical Research Council Laboratory for Molecular Cell Biology, University College LondonLondon, United Kingdom
- University College London Institute of Child Health, University College LondonLondon, United Kingdom
- Medical School, Edinburgh UniversityEdinburgh, United Kingdom
| | - Anna Straatman-Iwanowska
- Medical Research Council Laboratory for Molecular Cell Biology, University College LondonLondon, United Kingdom
- University College London Institute of Child Health, University College LondonLondon, United Kingdom
| | - Kim Reay
- West Midlands Regional Genetics Laboratory, Birmingham Women's HospitalBirmingham, United Kingdom
| | - Blerida Banushi
- Medical and Molecular Genetics, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, United Kingdom
- University College London Institute of Child Health, University College LondonLondon, United Kingdom
| | - Christopher K Bruce
- Medical and Molecular Genetics, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, United Kingdom
| | - Andrew R Cullinane
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of HealthBethesda, Maryland
| | - Rene Romero
- Emory Children's Center Division of Gastroenterology, Hepatology, and NutritionAtlanta, Georgia
| | - Richard Chang
- Division of Metabolic Disorders, Children's Hospital of Orange CountyOrange, California
| | | | | | - Hakan Cangul
- Medical and Molecular Genetics, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, United Kingdom
| | | | - Canan Aygun
- Neonatology Unit, Mayis UniversitySamsun, Turkey
| | - Richard Coward
- Bristol Royal Hospital for Sick ChildrenBristol, United Kingdom
| | - Carlo Dionisi-Vici
- Division of Metabolism, Bambino Gesú Children's Hospital IRCCSRome, Italy
| | - Barbara Sibbles
- Erasmus University Medical Center, Sophia Children's HospitalRotterdam, the Netherlands
| | - Carol Inward
- Bristol Royal Hospital for Sick ChildrenBristol, United Kingdom
| | - Chong Ae Kim
- Department of Pediatrics, Instituto da Criança, University of Sao PauloSao Paulo, Brazil
| | - Judith Klumperman
- Department of Cell Biology, University Medical CenterUtrecht, the Netherlands
| | - A S Knisely
- Institute of Liver Studies/Histopathology, King's College HospitalLondon, United Kingdom
| | - Steven P Watson
- The Platelet Group, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, United Kingdom
| | - Paul Gissen
- Medical Research Council Laboratory for Molecular Cell Biology, University College LondonLondon, United Kingdom
- University College London Institute of Child Health, University College LondonLondon, United Kingdom
- Inherited Metabolic Diseases, Great Ormond Street HospitalLondon, United Kingdom
| |
Collapse
|
40
|
The VPS33B-binding protein VPS16B is required in megakaryocyte and platelet α-granule biogenesis. Blood 2012; 120:5032-40. [PMID: 23002115 DOI: 10.1182/blood-2012-05-431205] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Patients with platelet α or dense δ-granule defects have bleeding problems. Although several proteins are known to be required for δ-granule development, less is known about α-granule biogenesis. Our previous work showed that the BEACH protein NBEAL2 and the Sec1/Munc18 protein VPS33B are required for α-granule biogenesis. Using a yeast two-hybrid screen, mass spectrometry, coimmunoprecipitation, and bioinformatics studies, we identified VPS16B as a VPS33B-binding protein. Immunoblotting confirmed VPS16B expression in various human tissues and cells including megakaryocytes and platelets, and also in megakaryocytic Dami cells. Characterization of platelets from a patient with arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome containing mutations in C14orf133 encoding VPS16B revealed pale-appearing platelets in blood films and electron microscopy revealed a complete absence of α-granules, whereas δ-granules were observed. Soluble and membrane-bound α-granule proteins were reduced or undetectable, suggesting that both releasable and membrane-bound α-granule constituents were absent. Immunofluorescence microscopy of Dami cells stably expressing GFP-VPS16B revealed that similar to VPS33B, GFP-VPS16B colocalized with markers of the trans-Golgi network, late endosomes and α-granules. We conclude that VPS16B, similar to its binding partner VPS33B, is essential for megakaryocyte and platelet α-granule biogenesis.
Collapse
|
41
|
Rahman M, Haberman A, Tracy C, Ray S, Krämer H. Drosophila mauve mutants reveal a role of LYST homologs late in the maturation of phagosomes and autophagosomes. Traffic 2012; 13:1680-92. [PMID: 22934826 DOI: 10.1111/tra.12005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 08/28/2012] [Accepted: 08/28/2012] [Indexed: 01/05/2023]
Abstract
Chediak-Higashi syndrome (CHS) is a lethal disease caused by mutations that inactivate the lysosomal trafficking regulator protein (LYST). Patients suffer from diverse symptoms including oculocutaneous albinism, recurrent infections, neutropenia and progressive neurodegeneration. These defects have been traced back to over-sized lysosomes and lysosome-related organelles (LROs) in different cell types. Here, we explore mutants in the Drosophila mauve gene as a new model system for CHS. The mauve gene (CG42863) encodes a large BEACH domain protein of 3535 amino acids similar to LYST. This reflects a functional homology between these proteins as mauve mutants also display enlarged LROs, such as pigment granules. This Drosophila model also replicates the enhanced susceptibility to infections and we show a defect in the cellular immune response. Early stages of phagocytosis proceed normally in mauve mutant hemocytes but, unlike in wild type, late phagosomes fuse and generate large vacuoles containing many bacteria. Autophagy is similarly affected in mauve fat bodies as starvation-induced autophagosomes grow beyond their normal size. Together these data suggest a model in which Mauve functions to restrict homotypic fusion of different pre-lysosomal organelles and LROs.
Collapse
Affiliation(s)
- Mokhlasur Rahman
- Department of Neuroscience, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9111, USA
| | | | | | | | | |
Collapse
|
42
|
Sitaram A, Marks MS. Mechanisms of protein delivery to melanosomes in pigment cells. Physiology (Bethesda) 2012; 27:85-99. [PMID: 22505665 DOI: 10.1152/physiol.00043.2011] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vertebrate pigment cells in the eye and skin are useful models for cell types that use specialized endosomal trafficking pathways to partition cargo proteins to unique lysosome-related organelles such as melanosomes. This review describes current models of protein trafficking required for melanosome biogenesis in mammalian melanocytes.
Collapse
Affiliation(s)
- Anand Sitaram
- Cell and Molecular Biology Graduate Group, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | |
Collapse
|
43
|
Roy S, Short MK, Stanley ER, Jubinsky PT. Essential role of Drosophila black-pearl is mediated by its effects on mitochondrial respiration. FASEB J 2012; 26:3822-33. [PMID: 22700875 DOI: 10.1096/fj.11-193540] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Black-pearl (Blp) is a highly conserved, essential inner-mitochondrial membrane protein. The yeast Blp homologue, Magmas/Pam16, is required for mitochondrial protein transport, growth, and survival. Our purpose was to determine the role of Drosophila Blp in mitochondrial function, cell survival, and proliferation. To this end, we performed mitotic recombination in Drosophila melanogaster, RNAi-mediated knockdown, MitoTracker staining, measurement of reactive oxygen species (ROS), flow cytometry, electron transport chain complex assays, and hemocyte isolation from Drosophila larvae. Proliferation-defective, Blp-deficient Drosophila Schneider cells exhibited mitochondrial membrane depolarization, a 60% decrease in ATP levels, increased amounts of ROS (3.5-fold), cell cycle arrest, and activation of autophagy that were associated with a selective 65% reduction of cytochrome c oxidase activity. N-acetyl cysteine (NAC) rescued Blp-RNAi-treated cells from cell cycle arrest, indicating that increased production of ROS is the primary cause of the proliferation and survival defects in Blp-depleted cells. blp hypomorph larvae had a 35% decreased number of plasmatocytes with a 45% reduced active mitochondrial staining and their viability was increased 2-fold by administration of NAC, which blocked melanotic lesions. Loss of Blp decreases cytochrome c oxidase activity and uncouples oxidative phosphorylation, causing ROS production, which selectively affects mitochondria-rich plasmatocyte survival and function, leading to melanotic lesions in Blp-deficient flies.
Collapse
Affiliation(s)
- Soumit Roy
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | | | | |
Collapse
|
44
|
Gailite I, Egger-Adam D, Wodarz A. The phosphoinositide-associated protein Rush hour regulates endosomal trafficking in Drosophila. Mol Biol Cell 2011; 23:433-47. [PMID: 22160599 PMCID: PMC3268723 DOI: 10.1091/mbc.e11-02-0154] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Endocytosis regulates multiple cellular processes, including the protein composition of the plasma membrane, intercellular signaling, and cell polarity. We have identified the highly conserved protein Rush hour (Rush) and show that it participates in the regulation of endocytosis. Rush localizes to endosomes via direct binding of its FYVE (Fab1p, YOTB, Vac1p, EEA1) domain to phosphatidylinositol 3-phosphate. Rush also directly binds to Rab GDP dissociation inhibitor (Gdi), which is involved in the activation of Rab proteins. Homozygous rush mutant flies are viable but show genetic interactions with mutations in Gdi, Rab5, hrs, and carnation, the fly homologue of Vps33. Overexpression of Rush disrupts progression of endocytosed cargo and increases late endosome size. Lysosomal marker staining is decreased in Rush-overexpressing cells, pointing to a defect in the transition between late endosomes and lysosomes. Rush also causes formation of endosome clusters, possibly by affecting fusion of endosomes via an interaction with the class C Vps/homotypic fusion and vacuole protein-sorting (HOPS) complex. These results indicate that Rush controls trafficking from early to late endosomes and from late endosomes to lysosomes by modulating the activity of Rab proteins.
Collapse
Affiliation(s)
- Ieva Gailite
- Stammzellbiologie, Abteilung Anatomie und Zellbiologie, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | | | | |
Collapse
|
45
|
Kulkarni V, Khadilkar RJ, M. S. S, Inamdar MS. Asrij maintains the stem cell niche and controls differentiation during Drosophila lymph gland hematopoiesis. PLoS One 2011; 6:e27667. [PMID: 22110713 PMCID: PMC3215734 DOI: 10.1371/journal.pone.0027667] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Accepted: 10/21/2011] [Indexed: 02/02/2023] Open
Abstract
Several signaling pathways control blood cell (hemocyte) development in the Drosophila lymph gland. Mechanisms that modulate and integrate these signals are poorly understood. Here we report that mutation in a conserved endocytic protein Asrij affects signal transmission and causes aberrant lymph gland hematopoiesis. Mammalian Asrij (Ociad1) is expressed in stem cells of the blood vascular system and is implicated in several cancers. We found that Drosophila Asrij is a pan-hemocyte marker and localizes to a subset of endocytic vesicles. Loss of asrij causes hyperproliferation of lymph gland lobes coupled with increased hemocyte differentiation, thereby depleting the pool of quiescent hemocyte precursors. This co-relates with fewer Col+ cells in the hematopoietic stem cell niche of asrij mutants. Asrij null mutants also show excess specification of crystal cells that express the RUNX factor Lozenge (Lz), a target of Notch signaling. Asrij mutant lymph glands show increased N in sorting endosomes suggesting aberrant trafficking. In vitro assays also show impaired traffic of fluorescent probes in asrij null hemocytes. Taken together our data suggest a role for Asrij in causing increased Notch signaling thereby affecting hemocyte differentiation. Thus, conserved endocytic functions may control blood cell progenitor quiescence and differentiation.
Collapse
Affiliation(s)
- Vani Kulkarni
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Rohan J. Khadilkar
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Srivathsa M. S.
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Maneesha S. Inamdar
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
- * E-mail:
| |
Collapse
|
46
|
In vivo RNAi screen reveals neddylation genes as novel regulators of Hedgehog signaling. PLoS One 2011; 6:e24168. [PMID: 21931660 PMCID: PMC3169580 DOI: 10.1371/journal.pone.0024168] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 08/01/2011] [Indexed: 11/19/2022] Open
Abstract
Hedgehog (Hh) signaling is highly conserved in all metazoan animals and plays critical roles in many developmental processes. Dysregulation of the Hh signaling cascade has been implicated in many diseases, including cancer. Although key components of the Hh pathway have been identified, significant gaps remain in our understanding of the regulation of individual Hh signaling molecules. Here, we report the identification of novel regulators of the Hh pathway, obtained from an in vivo RNA interference (RNAi) screen in Drosophila. By selectively targeting critical genes functioning in post-translational modification systems utilizing ubiquitin (Ub) and Ub-like proteins, we identify two novel genes (dUba3 and dUbc12) that negatively regulate Hh signaling activity. We provide in vivo and in vitro evidence illustrating that dUba3 and dUbc12 are essential components of the neddylation pathway; they function in an enzyme cascade to conjugate the ubiquitin-like NEDD8 modifier to Cullin proteins. Neddylation activates the Cullin-containing ubiquitin ligase complex, which in turn promotes the degradation of Cubitus interruptus (Ci), the downstream transcription factor of the Hh pathway. Our study reveals a conserved molecular mechanism of the neddylation pathway in Drosophila and sheds light on the complex post-translational regulations in Hh signaling.
Collapse
|
47
|
Abstract
Inherited retinal degeneration in Drosophila has been explored for insights into similar processes in humans. Based on the mechanisms, I divide these mutations in Drosophila into three classes. The first consists of genes that control the specialization of photoreceptor cells including the morphogenesis of visual organelles (rhabdomeres) that house the visual signaling proteins. The second class contains genes that regulate the activity or level of the major rhodopsin, Rh1, which is the light sensor and also provides a structural role for the maintenance of rhabdomeres. Some mutations in Rh1 (NinaE) are dominant due to constitutive activity or folding defects, like autosomal dominant retinitis pigmentosa (ADRP) in humans. The third class consists of genes that control the Ca ( 2+) influx directly or indirectly by promoting the turnover of the second messenger and regeneration of PIP 2, or mediate the Ca ( 2+) -dependent regulation of the visual response. These gene products are critical for the increase in cytosolic Ca ( 2+ ) following light stimulation to initiate negative regulatory events. Here I will focus on the signaling mechanisms underlying the degeneration in norpA, and in ADRP-type NinaE mutants that produce misfolded Rh1. Accumulation of misfolded Rh1 in the ER triggers the unfolded protein response (UPR), while endosomal accumulation of activated Rh1 may initiate autophagy in norpA. Both autophagy and the UPR are beneficial for relieving defective endosomal trafficking and the ER stress, respectively. However, when photoreceptors fail to cope with the persistence of these stresses, a cell death program is activated leading to retinal degeneration.
Collapse
Affiliation(s)
- Bih-Hwa Shieh
- Department of Pharmacology, Center for Molecular Neuroscience and Vision Research Center, Vanderbilt University, Nashville, TN USA.
| |
Collapse
|
48
|
Swetha MG, Sriram V, Krishnan KS, Oorschot VMJ, ten Brink C, Klumperman J, Mayor S. Lysosomal membrane protein composition, acidic pH and sterol content are regulated via a light-dependent pathway in metazoan cells. Traffic 2011; 12:1037-55. [PMID: 21535339 DOI: 10.1111/j.1600-0854.2011.01214.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In metazoans, lysosomes are characterized by a unique tubular morphology, acidic pH, and specific membrane protein (LAMP) and lipid (cholesterol) composition as well as a soluble protein (hydrolases) composition. Here we show that perturbation to the eye-color gene, light, results in impaired lysosomal acidification, sterol accumulation, altered endosomal morphology as well as compromised lysosomal degradation. We find that Drosophila homologue of Vps41, Light, regulates the fusion of a specific subset of biosynthetic carriers containing characteristic endolysosomal membrane proteins, LAMP1, V0-ATPase and the cholesterol transport protein, NPC1, with the endolysosomal system, and is then required for the morphological progression of the multivesicular endosome. Inhibition of Light results in accumulation of biosynthetic transport intermediates that contain these membrane cargoes, whereas under similar conditions, endosomal delivery of soluble hydrolases, previously shown to be mediated by Dor, the Drosophila homologue of Vps18, is not affected. Unlike Dor, Light is recruited to endosomes in a PI3P-sensitive fashion wherein it facilitates fusion of these biosynthetic cargoes with the endosomes. Depletion of the mammalian counterpart of Light, hVps41, in a human cell line also inhibits delivery of hLAMP to endosomes, suggesting an evolutionarily conserved pathway in metazoa.
Collapse
Affiliation(s)
- M G Swetha
- National Centre for Biological Sciences, Bangalore, India
| | | | | | | | | | | | | |
Collapse
|
49
|
Yonamine I, Bamba T, Nirala NK, Jesmin N, Kosakowska-Cholody T, Nagashima K, Fukusaki E, Acharya JK, Acharya U. Sphingosine kinases and their metabolites modulate endolysosomal trafficking in photoreceptors. ACTA ACUST UNITED AC 2011; 192:557-67. [PMID: 21321100 PMCID: PMC3044112 DOI: 10.1083/jcb.201004098] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Alterations in sphingosine kinase activity change the degradation rates of Rhodopsin and the transient receptor potential (TRP) channel by lysosomes and can result in retinal degeneration. Internalized membrane proteins are either transported to late endosomes and lysosomes for degradation or recycled to the plasma membrane. Although proteins involved in trafficking and sorting have been well studied, far less is known about the lipid molecules that regulate the intracellular trafficking of membrane proteins. We studied the function of sphingosine kinases and their metabolites in endosomal trafficking using Drosophila melanogaster photoreceptors as a model system. Gain- and loss-of-function analyses show that sphingosine kinases affect trafficking of the G protein–coupled receptor Rhodopsin and the light-sensitive transient receptor potential (TRP) channel by modulating the levels of dihydrosphingosine 1 phosphate (DHS1P) and sphingosine 1 phosphate (S1P). An increase in DHS1P levels relative to S1P leads to the enhanced lysosomal degradation of Rhodopsin and TRP and retinal degeneration in wild-type photoreceptors. Our results suggest that sphingosine kinases and their metabolites modulate photoreceptor homeostasis by influencing endolysosomal trafficking of Rhodopsin and TRP.
Collapse
Affiliation(s)
- Ikuko Yonamine
- Program in Gene Function and Expression, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Yamada K, Fuwa TJ, Ayukawa T, Tanaka T, Nakamura A, Wilkin MB, Baron M, Matsuno K. Roles of Drosophila Deltex in Notch receptor endocytic trafficking and activation. Genes Cells 2011; 16:261-72. [DOI: 10.1111/j.1365-2443.2011.01488.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|