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Lachuer H, Le L, Lévêque-Fort S, Goud B, Schauer K. Spatial organization of lysosomal exocytosis relies on membrane tension gradients. Proc Natl Acad Sci U S A 2023; 120:e2207425120. [PMID: 36800388 PMCID: PMC9974462 DOI: 10.1073/pnas.2207425120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 12/17/2022] [Indexed: 02/18/2023] Open
Abstract
Lysosomal exocytosis is involved in many key cellular processes but its spatiotemporal regulation is poorly known. Using total internal reflection fluorescence microscopy (TIRFM) and spatial statistics, we observed that lysosomal exocytosis is not random at the adhesive part of the plasma membrane of RPE1 cells but clustered at different scales. Although the rate of exocytosis is regulated by the actin cytoskeleton, neither interfering with actin or microtubule dynamics by drug treatments alters its spatial organization. Exocytosis events partially co-appear at focal adhesions (FAs) and their clustering is reduced upon removal of FAs. Changes in membrane tension following a hypo-osmotic shock or treatment with methyl-β-cyclodextrin were found to increase clustering. To investigate the link between FAs and membrane tension, cells were cultured on adhesive ring-shaped micropatterns, which allow to control the spatial organization of FAs. By using a combination of TIRFM and fluorescence lifetime imaging microscopy (FLIM), we revealed the existence of a radial gradient in membrane tension. By changing the diameter of micropatterned substrates, we further showed that this gradient as well as the extent of exocytosis clustering can be controlled. Together, our data indicate that the spatial clustering of lysosomal exocytosis relies on membrane tension patterning controlled by the spatial organization of FAs.
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Affiliation(s)
- Hugo Lachuer
- Institut Curie, Paris Sciences et Lettres Research University, CNRS UMR 144 Cell Biology and Cancer, 75005Paris, France
| | - Laurent Le
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay91405, Orsay, France
| | - Sandrine Lévêque-Fort
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay91405, Orsay, France
| | - Bruno Goud
- Institut Curie, Paris Sciences et Lettres Research University, CNRS UMR 144 Cell Biology and Cancer, 75005Paris, France
| | - Kristine Schauer
- Institut Curie, Paris Sciences et Lettres Research University, CNRS UMR 144 Cell Biology and Cancer, 75005Paris, France
- Tumor Cell Dynamics Unit, Inserm U1279 Gustave Roussy Institute, Université Paris-Saclay, Villejuif94800, France
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2
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Li G, Huang D, Li P, Yuan X, Yarotskyy V, Li PL. Regulation of exosome release by lysosomal acid ceramidase in coronary arterial endothelial cells: Role of TRPML1 channel. CURRENT TOPICS IN MEMBRANES 2022; 90:37-63. [PMID: 36368874 PMCID: PMC9842397 DOI: 10.1016/bs.ctm.2022.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Lysosomal acid ceramidase (AC) has been reported to determine multivesicular body (MVB) fate and exosome secretion in different mammalian cells including coronary arterial endothelial cells (CAECs). However, this AC-mediated regulation of exosome release from CAECs and associated underlying mechanism remain poorly understood. In the present study, we hypothesized that AC controls lysosomal Ca2+ release through TRPML1 channel to regulate exosome release in murine CAECs. To test this hypothesis, we isolated and cultured CAECs from WT/WT and endothelial cell-specific Asah1 gene (gene encoding AC) knockout mice. Using these CAECs, we first demonstrated a remarkable increase in exosome secretion and significant reduction of lysosome-MVB interaction in CAECs lacking Asah1 gene compared to those cells from WT/WT mice. ML-SA1, a TRPML1 channel agonist, was found to enhance lysosome trafficking and increase lysosome-MVB interaction in WT/WT CAECs, but not in CAECs lacking Asah1 gene. However, sphingosine, an AC-derived sphingolipid, was able to increase lysosome movement and lysosome-MVB interaction in CAECs lacking Asah1 gene, leading to reduced exosome release from these cells. Moreover, Asah1 gene deletion was shown to substantially inhibit lysosomal Ca2+ release through suppression of TRPML1 channel activity in CAECs. Sphingosine as an AC product rescued the function of TRPML1 channel in CAECs lacking Asah1 gene. These results suggest that Asah1 gene defect and associated deficiency of AC activity may inhibit TRPML1 channel activity, thereby reducing MVB degradation by lysosome and increasing exosome release from CAECs. This enhanced exosome release from CAECs may contribute to the development of coronary arterial disease under pathological conditions.
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Affiliation(s)
- Guangbi Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Dandan Huang
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Pengyang Li
- Division of Cardiology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Xinxu Yuan
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Viktor Yarotskyy
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States.
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3
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Parveen S, Khamari A, Raju J, Coppolino MG, Datta S. Syntaxin 7 contributes to breast cancer cell invasion by promoting invadopodia formation. J Cell Sci 2022; 135:275829. [PMID: 35762511 DOI: 10.1242/jcs.259576] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 05/12/2022] [Indexed: 12/15/2022] Open
Abstract
Invasion in various cancer cells requires coordinated delivery of signaling proteins, adhesion proteins, actin-remodeling proteins and proteases to matrix-degrading structures called invadopodia. Vesicular trafficking involving SNAREs plays a crucial role in the delivery of cargo to the target membrane. Screening of 13 SNAREs from the endocytic and recycling route using a gene silencing approach coupled with functional assays identified syntaxin 7 (STX7) as an important player in MDA-MB-231 cell invasion. Total internal reflection fluorescence microscopy (TIRF-M) studies revealed that STX7 resides near invadopodia and co-traffics with MT1-MMP (also known as MMP14), indicating a possible role for this SNARE in protease trafficking. STX7 depletion reduced the number of invadopodia and their associated degradative activity. Immunoprecipitation studies revealed that STX7 forms distinct SNARE complexes with VAMP2, VAMP3, VAMP7, STX4 and SNAP23. Depletion of VAMP2, VAMP3 or STX4 abrogated invadopodia formation, phenocopying what was seen upon lack of STX7. Whereas depletion of STX4 reduced MT1-MMP level at the cell surfaces, STX7 silencing significantly reduced the invadopodia-associated MT1-MMP pool and increased the non-invadosomal pool. This study highlights STX7 as a major contributor towards the invadopodia formation during cancer cell invasion. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Sameena Parveen
- Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Bhopal 462066, India
| | - Amrita Khamari
- Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Bhopal 462066, India
| | - Jyothikamala Raju
- Thazhathemalayil House, Thodupuzha East PO, Keerikode, Kerala 685585, India
| | - Marc G Coppolino
- Department of Molecular and Cellular Biology, University of Guelph, Ontario N1G 2W1, Canada
| | - Sunando Datta
- Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Bhopal 462066, India
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4
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Barber CN, Goldschmidt HL, Ma Q, Devine LR, Cole RN, Huganir RL, Raben DM. Identification of Synaptic DGKθ Interactors That Stimulate DGKθ Activity. Front Synaptic Neurosci 2022; 14:855673. [PMID: 35573662 PMCID: PMC9095502 DOI: 10.3389/fnsyn.2022.855673] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/16/2022] [Indexed: 01/16/2023] Open
Abstract
Lipids and their metabolic enzymes are a critical point of regulation for the membrane curvature required to induce membrane fusion during synaptic vesicle recycling. One such enzyme is diacylglycerol kinase θ (DGKθ), which produces phosphatidic acid (PtdOH) that generates negative membrane curvature. Synapses lacking DGKθ have significantly slower rates of endocytosis, implicating DGKθ as an endocytic regulator. Importantly, DGKθ kinase activity is required for this function. However, protein regulators of DGKθ's kinase activity in neurons have never been identified. In this study, we employed APEX2 proximity labeling and mass spectrometry to identify endogenous interactors of DGKθ in neurons and assayed their ability to modulate its kinase activity. Seven endogenous DGKθ interactors were identified and notably, synaptotagmin-1 (Syt1) increased DGKθ kinase activity 10-fold. This study is the first to validate endogenous DGKθ interactors at the mammalian synapse and suggests a coordinated role between DGKθ-produced PtdOH and Syt1 in synaptic vesicle recycling.
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Affiliation(s)
- Casey N. Barber
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Hana L. Goldschmidt
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Qianqian Ma
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lauren R. Devine
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Robert N. Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Richard L. Huganir
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Daniel M. Raben
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States,*Correspondence: Daniel M. Raben,
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5
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Kaur H, Richardson E, Kamra K, Dacks JB. Molecular evolutionary analysis of the SM and SNARE vesicle fusion machinery in ciliates shows concurrent expansions in late secretory machinery. J Eukaryot Microbiol 2022; 69:e12919. [PMID: 35460134 DOI: 10.1111/jeu.12919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 03/25/2022] [Accepted: 04/15/2022] [Indexed: 11/30/2022]
Abstract
Protists in the phylum Ciliophora possess a complex membrane-trafficking system, including osmoregulatory Contractile Vacuoles and specialized secretory organelles. Molecular cell biological investigations in Tetrahymena thermophila have identified components of the protein machinery associated with the secretory organelles, mucocysts. The Qa-SNARE Syn7lp plays a role in mucocyst biogenesis as do subunits of the CORVET tethering complex (specifically Vps8). Indeed, Tetrahymena thermophila possesses expanded gene complements of several CORVET components, including Vps33 which is also a Sec1/Munc18 (SM) protein that binds Qa-SNAREs. Moreover, the Qa-SNAREs in Paramecium tetraurelia have been localized to various endomembrane organelles. Here, we use comparative genomics and phylogenetics to determine the evolutionary history of the SM and Qa-SNARE proteins across the Ciliophora. We identify that the last ciliate common ancestor possessed the four SM proteins and six Qa-SNAREs common to eukaryotes, including the uncommonly retained Syntaxin 17. We furthermore identify independent expansion of these protein families in several ciliate classes, including concurrent expansions of the SM protein-Qa SNARE partners Sec1:SynPM in the oligohymenophorean ciliates lineage, consistent with novel Contractile Vacuole specific innovations. Overall, these data are consistent with SM proteins and Qa-SNAREs being a common set of components for endomembrane modulation in the ciliates.
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Affiliation(s)
- Harpreet Kaur
- Department of Zoology, University of Delhi, Delhi, India.,Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.,Ciliate Biology Lab, SGTB Khalsa College, University of Delhi, Delhi, India
| | - Elisabeth Richardson
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Komal Kamra
- Ciliate Biology Lab, SGTB Khalsa College, University of Delhi, Delhi, India
| | - Joel B Dacks
- Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Department of Life Sciences, The Natural History Museum, London, UK
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6
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Portilla Y, Mulens-Arias V, Paradela A, Ramos-Fernández A, Pérez-Yagüe S, Morales MP, Barber DF. The surface coating of iron oxide nanoparticles drives their intracellular trafficking and degradation in endolysosomes differently depending on the cell type. Biomaterials 2022; 281:121365. [PMID: 35038611 DOI: 10.1016/j.biomaterials.2022.121365] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/15/2021] [Accepted: 01/04/2022] [Indexed: 12/13/2022]
Abstract
Magnetic nanoparticles (MNPs) are potential theranostic tools that are biodegraded through different endocytic pathways. However, little is known about the endolysosomal network through which MNPs transit and the influence of the surface coating in this process. Here, we studied the intracellular transit of two MNPs with identical iron oxide core size but with two distinct coatings: 3-aminopropyl-trietoxysilane (APS) and dimercaptosuccinic acid (DMSA). Using endolysosomal markers and a high throughput analysis of the associated proteome, we tracked the MNPs intracellularly in two different mouse cell lines, RAW264.7 (macrophages) and Pan02 (tumor cells). We did not detect differences in the MNP trafficking kinetics nor in the MNP-containing endolysosome phenotype in Pan02 cells. Nonetheless, DMSA-MNPs transited at slower rate than APS-MNPs in macrophages as measured by MNP accumulation in Rab7+ endolysosomes. Macrophage DMSA-MNP-containing endolysosomes had a higher percentage of lytic enzymes and catalytic proteins than their APS-MNP counterparts, concomitantly with a V-type ATPase enrichment, suggesting an acidic nature. Consequently, more autophagic vesicles are induced by DMSA-MNPs in macrophages, enhancing the expression of iron metabolism-related genes and proteins. Therefore, unlike Pan02 cells, the MNP coating appears to influence the intracellular trafficking rate and the endolysosome nature in macrophages. These results highlight how the MNP coating can determine the nanoparticle intracellular fate and biodegradation in a cell-type bias.
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Affiliation(s)
- Yadileiny Portilla
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Vladimir Mulens-Arias
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain; Current address: Integrative Biomedical Materials and Nanomedicine Lab, Department of Experimental and Health Sciences (DCEXS), Pompeu Fabra University, PRBB, Carrer Doctor Aiguader 88, 08003, Barcelona, Spain
| | - Alberto Paradela
- Proteomics Facility, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Antonio Ramos-Fernández
- Proteomics Facility, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - Sonia Pérez-Yagüe
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain
| | - M Puerto Morales
- Department of Energy, Environment and Health, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, 28049, Madrid, Spain
| | - Domingo F Barber
- Department of Immunology and Oncology and Nanobiomedicine Initiative, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049, Madrid, Spain.
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7
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Zhang L, Liu W, Zhang X, Li L, Wang X. Southern rice black-streaked dwarf virus hijacks SNARE complex of its insect vector for its effective transmission to rice. MOLECULAR PLANT PATHOLOGY 2021; 22:1256-1270. [PMID: 34390118 PMCID: PMC8435234 DOI: 10.1111/mpp.13109] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/22/2021] [Accepted: 06/25/2021] [Indexed: 05/03/2023]
Abstract
Vesicular trafficking is an important dynamic process that facilitates intracellular transport of biological macromolecules and their release into the extracellular environment. However, little is known about whether or how plant viruses utilize intracellular vesicles to their advantage. Here, we report that southern rice black-streaked dwarf virus (SRBSDV) enters intracellular vesicles in epithelial cells of its insect vector by engaging VAMP7 and Vti1a proteins in the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex. The major outer capsid protein P10 of SRBSDV was shown to interact with VAMP7 and Vti1a of the white-backed planthopper and promote the fusion of vesicles into a large vesicle, which finally fused with the plasma membrane to release virions from midgut epithelial cells. Downregulation of the expression of either VAMP7 or Vti1a did not affect viral entry and accumulation in the gut, but significantly reduced viral accumulation in the haemolymph. It also did not affect virus acquisition, but significantly reduced the virus transmission efficiency to rice. Our data reveal a critical mechanism by which a plant reovirus hijacks the vesicle transport system to overcome the midgut escape barrier in vector insects and provide new insights into the role of the SNARE complex in viral transmission and the potential for developing novel strategies of viral disease control.
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Affiliation(s)
- Lu Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Wenwen Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Xiaowan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Li Li
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Xifeng Wang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
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8
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Gu J, Geng M, Qi M, Wang L, Zhang Y, Gao J. The role of lysosomal membrane proteins in glucose and lipid metabolism. FASEB J 2021; 35:e21848. [PMID: 34582051 DOI: 10.1096/fj.202002602r] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/11/2021] [Accepted: 07/26/2021] [Indexed: 11/11/2022]
Abstract
Lysosomes have long been regarded as the "garbage dump" of the cell. More recently, however, researchers have revealed novel roles for lysosomal membranes in autophagy, ion transport, nutrition sensing, and membrane fusion and repair. With active research into lysosomal membrane proteins (LMP), increasing evidence has become available showing that LMPs are inextricably linked to glucose and lipid metabolism, and this relationship represents mutual influence and regulation. In this review, we summarize the roles of LMPs in relation to glucose and lipid metabolism, and describe their roles in glucose transport, glycolysis, cholesterol transport, and lipophagy. The role of transport proteins can be traced back to the original discoveries of GLUT8, NPC1, and NPC2, which were all found to have significant roles in the pathways involved in glucose and lipid metabolism. CLC-5 and SIDT2-knockout animals show serious phenotypic disorders of metabolism, and V-ATPase and LAMP-2 have been found to interact with proteins related to glucose and lipid metabolism. These findings all emphasize the critical role of LMPs in glycolipid metabolism and help to strengthen our understanding of the independent and close relationship between LMPs and glycolipid metabolism.
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Affiliation(s)
- Jing Gu
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
| | - Mengya Geng
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Mengxiang Qi
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Lizhuo Wang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Yao Zhang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Jialin Gao
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
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9
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Mori Y, Takenaka KI, Fukazawa Y, Takamori S. The endosomal Q-SNARE, Syntaxin 7, defines a rapidly replenishing synaptic vesicle recycling pool in hippocampal neurons. Commun Biol 2021; 4:981. [PMID: 34408265 PMCID: PMC8373932 DOI: 10.1038/s42003-021-02512-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 08/02/2021] [Indexed: 12/12/2022] Open
Abstract
Upon the arrival of repetitive stimulation at the presynaptic terminals of neurons, replenishment of readily releasable synaptic vesicles (SVs) with vesicles in the recycling pool is important for sustained neurotransmitter release. Kinetics of replenishment and the available pool size define synaptic performance. However, whether all SVs in the recycling pool are recruited for release with equal probability and speed is unknown. Here, based on comprehensive optical imaging of various presynaptic endosomal SNARE proteins in cultured hippocampal neurons, all of which are implicated in organellar membrane fusion in non-neuronal cells, we show that part of the recycling pool bearing the endosomal Q-SNARE, syntaxin 7 (Stx7), is preferentially mobilized for release during high-frequency repetitive stimulation. Recruitment of the SV pool marked with an Stx7-reporter requires actin polymerization, as well as activation of the Ca2+/calmodulin signaling pathway, reminiscent of rapidly replenishing SVs characterized previously in calyx of Held synapses. Furthermore, disruption of Stx7 function by overexpressing its N-terminal domain selectively abolished this pool. Thus, our data indicate that endosomal membrane fusion involving Stx7 forms rapidly replenishing vesicles essential for synaptic responses to high-frequency repetitive stimulation, and also highlight functional diversities of endosomal SNAREs in generating distinct exocytic vesicles in the presynaptic terminals. Yasunori Mori et al. find that a subset of neurotransmitter-bearing synaptic vesicles are marked for release by the endosomal Q-SNARE protein Stx7. They show that Stx7 function is necessary for the rapid replenishment of synaptic vesicles that is needed to sustain synaptic transmission during high-frequency stimulation.
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Affiliation(s)
- Yasunori Mori
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan. .,Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan.
| | - Koh-Ichiro Takenaka
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Yugo Fukazawa
- Division of Brain Structure and Function, Research Center for Child Mental Development, Life Science Innovation Center, School of Medical Science, University of Fukui, Fukui, Japan
| | - Shigeo Takamori
- Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan.
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10
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Davis LJ, Bright NA, Edgar JR, Parkinson MDJ, Wartosch L, Mantell J, Peden AA, Luzio JP. Organelle tethering, pore formation and SNARE compensation in the late endocytic pathway. J Cell Sci 2021; 134:268392. [PMID: 34042162 PMCID: PMC8186482 DOI: 10.1242/jcs.255463] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 04/14/2021] [Indexed: 11/24/2022] Open
Abstract
To provide insights into the kiss-and-run and full fusion events resulting in endocytic delivery to lysosomes, we investigated conditions causing increased tethering and pore formation between late endocytic organelles in HeLa cells. Knockout of the soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) VAMP7 and VAMP8 showed, by electron microscopy, the accumulation of tethered lysosome-associated membrane protein (LAMP)-carrier vesicles around multivesicular bodies, as well as the appearance of ‘hourglass’ profiles of late endocytic organelles attached by filamentous tethers, but did not prevent endocytic delivery to lysosomal hydrolases. Subsequent depletion of the SNARE YKT6 reduced this delivery, consistent with it compensating for the absence of VAMP7 and VAMP8. We also investigated filamentous tethering between multivesicular bodies and enlarged endolysosomes following depletion of charged multi-vesicular body protein 6 (CHMP6), and provide the first evidence that pore formation commences at the edge of tether arrays, with pore expansion required for full membrane fusion. Summary: Endocytic delivery to lysosomes by kiss and run/membrane fusion entails pore formation commencing at the edge of tether arrays, and demonstrates SNARE redundancy and compensation.
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Affiliation(s)
- Luther J Davis
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Nicholas A Bright
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - James R Edgar
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Michael D J Parkinson
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Lena Wartosch
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Judith Mantell
- School of Biochemistry, University of Bristol, Medical Sciences Building, University Walk, Bristol BS81TD, UK.,Wolfson Bioimaging Facility, University of Bristol, Medical Sciences Building, University Walk, Bristol BS81TD, UK
| | - Andrew A Peden
- Department of Biomedical Science & Centre for Membrane Interactions and Dynamics (CMIAD), The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - J Paul Luzio
- Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
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11
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Zhang C, Miyagishima KJ, Dong L, Rising A, Nimmagadda M, Liang G, Sharma R, Dejene R, Wang Y, Abu-Asab M, Qian H, Li Y, Kopera M, Maminishkis A, Martinez J, Miller S. Regulation of phagolysosomal activity by miR-204 critically influences structure and function of retinal pigment epithelium/retina. Hum Mol Genet 2020; 28:3355-3368. [PMID: 31332443 DOI: 10.1093/hmg/ddz171] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/04/2019] [Accepted: 07/09/2019] [Indexed: 12/13/2022] Open
Abstract
MicroRNA-204 (miR-204) is expressed in pulmonary, renal, mammary and eye tissue, and its reduction can result in multiple diseases including cancer. We first generated miR-204-/- mice to study the impact of miR-204 loss on retinal and retinal pigment epithelium (RPE) structure and function. The RPE is fundamentally important for maintaining the health and integrity of the retinal photoreceptors. miR-204-/- eyes evidenced areas of hyper-autofluorescence and defective photoreceptor digestion, along with increased microglia migration to the RPE. Migratory Iba1+ microglial cells were localized to the RPE apical surface where they participated in the phagocytosis of photoreceptor outer segments (POSs) and contributed to a persistent build-up of rhodopsin. These structural, molecular and cellular outcomes were accompanied by decreased light-evoked electrical responses from the retina and RPE. In parallel experiments, we suppressed miR-204 expression in primary cultures of human RPE using anti-miR-204. In vitro suppression of miR-204 in human RPE similarly showed abnormal POS clearance and altered expression of autophagy-related proteins and Rab22a, a regulator of endosome maturation. Together, these in vitro and in vivo experiments suggest that the normally high levels of miR-204 in RPE can mitigate disease onset by preventing generation of oxidative stress and inflammation originating from intracellular accumulation of undigested photoreactive POS lipids. More generally, these results implicate RPE miR-204-mediated regulation of autophagy and endolysosomal interaction as a critical determinant of normal RPE/retina structure and function.
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Affiliation(s)
- Congxiao Zhang
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and Disease, National Eye Institute, National Institutes of Health, Bethesda, MD USA
| | - Kiyoharu J Miyagishima
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and Disease, National Eye Institute, National Institutes of Health, Bethesda, MD USA
| | - Lijin Dong
- Genetic Engineering Facility, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Aaron Rising
- Ophthalmic Genetics and Visual Function Branch, Unit on Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Malika Nimmagadda
- Ophthalmic Genetics and Visual Function Branch, Unit on Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Genqing Liang
- Ophthalmic Genetics and Visual Function Branch, Unit on Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ruchi Sharma
- Ophthalmic Genetics and Visual Function Branch, Unit on Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Roba Dejene
- Ophthalmic Genetics and Visual Function Branch, Unit on Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yuan Wang
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and Disease, National Eye Institute, National Institutes of Health, Bethesda, MD USA
| | - Mones Abu-Asab
- Section of Histopathology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Megan Kopera
- Genetic Engineering Facility, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Arvydas Maminishkis
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and Disease, National Eye Institute, National Institutes of Health, Bethesda, MD USA
| | - Jennifer Martinez
- Inflammation and Autoimmunity, National Institute of Environmental Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Sheldon Miller
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and Disease, National Eye Institute, National Institutes of Health, Bethesda, MD USA
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12
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Stefaniak S, Wojtyla Ł, Pietrowska-Borek M, Borek S. Completing Autophagy: Formation and Degradation of the Autophagic Body and Metabolite Salvage in Plants. Int J Mol Sci 2020; 21:E2205. [PMID: 32210003 PMCID: PMC7139740 DOI: 10.3390/ijms21062205] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/18/2020] [Accepted: 03/20/2020] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an evolutionarily conserved process that occurs in yeast, plants, and animals. Despite many years of research, some aspects of autophagy are still not fully explained. This mostly concerns the final stages of autophagy, which have not received as much interest from the scientific community as the initial stages of this process. The final stages of autophagy that we take into consideration in this review include the formation and degradation of the autophagic bodies as well as the efflux of metabolites from the vacuole to the cytoplasm. The autophagic bodies are formed through the fusion of an autophagosome and vacuole during macroautophagy and by vacuolar membrane invagination or protrusion during microautophagy. Then they are rapidly degraded by vacuolar lytic enzymes, and products of the degradation are reused. In this paper, we summarize the available information on the trafficking of the autophagosome towards the vacuole, the fusion of the autophagosome with the vacuole, the formation and decomposition of autophagic bodies inside the vacuole, and the efflux of metabolites to the cytoplasm. Special attention is given to the formation and degradation of autophagic bodies and metabolite salvage in plant cells.
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Affiliation(s)
- Szymon Stefaniak
- Department of Plant Physiology, Faculty of Biology, Adam Mickiewicz University Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland; (S.S.); (Ł.W.)
| | - Łukasz Wojtyla
- Department of Plant Physiology, Faculty of Biology, Adam Mickiewicz University Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland; (S.S.); (Ł.W.)
| | - Małgorzata Pietrowska-Borek
- Department of Biochemistry and Biotechnology, Faculty of Agronomy and Bioengineering, Poznań University of Life Sciences, Dojazd 11, 60-632 Poznań, Poland;
| | - Sławomir Borek
- Department of Plant Physiology, Faculty of Biology, Adam Mickiewicz University Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland; (S.S.); (Ł.W.)
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13
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Podocyte Lysosome Dysfunction in Chronic Glomerular Diseases. Int J Mol Sci 2020; 21:ijms21051559. [PMID: 32106480 PMCID: PMC7084483 DOI: 10.3390/ijms21051559] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 02/24/2020] [Accepted: 02/24/2020] [Indexed: 02/06/2023] Open
Abstract
Podocytes are visceral epithelial cells covering the outer surface of glomerular capillaries in the kidney. Blood is filtered through the slit diaphragm of podocytes to form urine. The functional and structural integrity of podocytes is essential for the normal function of the kidney. As a membrane-bound organelle, lysosomes are responsible for the degradation of molecules via hydrolytic enzymes. In addition to its degradative properties, recent studies have revealed that lysosomes may serve as a platform mediating cellular signaling in different types of cells. In the last decade, increasing evidence has revealed that the normal function of the lysosome is important for the maintenance of podocyte homeostasis. Podocytes have no ability to proliferate under most pathological conditions; therefore, lysosome-dependent autophagic flux is critical for podocyte survival. In addition, new insights into the pathogenic role of lysosome and associated signaling in podocyte injury and chronic kidney disease have recently emerged. Targeting lysosomal functions or signaling pathways are considered potential therapeutic strategies for some chronic glomerular diseases. This review briefly summarizes current evidence demonstrating the regulation of lysosomal function and signaling mechanisms as well as the canonical and noncanonical roles of podocyte lysosome dysfunction in the development of chronic glomerular diseases and associated therapeutic strategies.
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14
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Wheeler S, Sillence DJ. Niemann-Pick type C disease: cellular pathology and pharmacotherapy. J Neurochem 2019; 153:674-692. [PMID: 31608980 DOI: 10.1111/jnc.14895] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/10/2019] [Accepted: 09/15/2019] [Indexed: 12/22/2022]
Abstract
Niemann-Pick type C disease (NPCD) was first described in 1914 and affects approximately 1 in 150 000 live births. It is characterized clinically by diverse symptoms affecting liver, spleen, motor control, and brain; premature death invariably results. Its molecular origins were traced, as late as 1997, to a protein of late endosomes and lysosomes which was named NPC1. Mutation or absence of this protein leads to accumulation of cholesterol in these organelles. In this review, we focus on the intracellular events that drive the pathology of this disease. We first introduce endocytosis, a much-studied area of dysfunction in NPCD cells, and survey the various ways in which this process malfunctions. We briefly consider autophagy before attempting to map the more complex pathways by which lysosomal cholesterol storage leads to protein misregulation, mitochondrial dysfunction, and cell death. We then briefly introduce the metabolic pathways of sphingolipids (as these emerge as key species for treatment) and critically examine the various treatment approaches that have been attempted to date.
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Affiliation(s)
- Simon Wheeler
- School of Pharmacy, De Montfort University, The Gateway, Leicester, UK
| | - Dan J Sillence
- School of Pharmacy, De Montfort University, The Gateway, Leicester, UK
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15
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Li G, Huang D, Hong J, Bhat OM, Yuan X, Li PL. Control of lysosomal TRPML1 channel activity and exosome release by acid ceramidase in mouse podocytes. Am J Physiol Cell Physiol 2019; 317:C481-C491. [PMID: 31268777 PMCID: PMC6766620 DOI: 10.1152/ajpcell.00150.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 02/07/2023]
Abstract
The transient receptor potential mucolipin 1 (TRPML1) channel has been reported to mediate lysosomal Ca2+ release that is involved in Ca2+-dependent lysosome trafficking and autophagic flux. However, this regulatory mechanism of lysosomal TRPML1 channel activity in podocytes remains poorly understood. In the present study, we tested whether the TRPML1 channel in podocytes mediates lysosome trafficking, which is essential for multivesicular body (MVB) degradation by lysosomes. We first demonstrated the abundant expression of TRPML1 channel in podocytes. By GCaMP3 Ca2+ imaging, we characterized the lysosomal specificity of TRPML1 channel-mediated Ca2+ release in podocytes. Given the important role of acid ceramidase (AC) in lysosome function and podocyte injury, we tested whether AC regulates this TRPML1 channel-mediated Ca2+ release and consequent lysosome-dependent MVB degradation in podocytes. Pharmacologically, it was found that TRPML1 channel activity was remarkably attenuated by the AC inhibitor carmofur. Sphingosine, as an AC product, was demonstrated to induce TRPML1-mediated Ca2+ release, which was inhibited by a TRPML1 blocker, verapamil. Using a Port-a-Patch planar patch-clamp system, we found that AC-associated sphingolipids, sphingomyelin, ceramide, and sphingosine had different effects on TRPML1 channel activity in podocytes. Functionally, the inhibition of AC or blockade of TRPML1 channels was found to suppress the interaction of lysosomes and MVBs, leading to increased exosome release from podocytes. These results suggest that AC is critical for TRPML1 channel-mediated Ca2+ release, which controls lysosome-MVB interaction and exosome release in podocytes.
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Affiliation(s)
- Guangbi Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Dandan Huang
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Jinni Hong
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Owais M Bhat
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Xinxu Yuan
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia
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16
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Röhl J, West ZE, Rudolph M, Zaharia A, Van Lonkhuyzen D, Hickey DK, Semmler ABT, Murray RZ. Invasion by activated macrophages requires delivery of nascent membrane-type-1 matrix metalloproteinase through late endosomes/lysosomes to the cell surface. Traffic 2019; 20:661-673. [PMID: 31297933 DOI: 10.1111/tra.12675] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 12/17/2022]
Abstract
Macrophage migration into injured or infected tissue is a key aspect in the pathophysiology of many diseases where inflammation is a driving factor. Membrane-type-1 matrix metalloproteinase (MT1-MMP) cleaves extracellular matrix components to facilitate invasion. Here we show that, unlike the constitutive MT1-MMP surface recycling seen in cancer cells, unactivated macrophages express low levels of MT1-MMP. Upon lipopolysaccharide (LPS) activation, MT1-MMP synthesis dramatically increases 10-fold at the surface by 15 hours. MT1-MMP is trafficked from the Golgi complex to the surface via late endosomes/lysosomes in a pathway regulated by the late endosome/lysosome R-SNAREs VAMP7 and VAMP8. These form two separate complexes with the surface Q-SNARE complex Stx4/SNAP23 to regulate MT1-MMP delivery to the plasma membrane. Loss of either one of these SNAREs leads to a reduction in surface MT1-MMP, gelatinase activity and reduced invasion. Thus, inhibiting MT1-MMP transport through this pathway could reduce macrophage migration and the resulting inflammation.
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Affiliation(s)
- Joan Röhl
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Zoe E West
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Maren Rudolph
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Andreea Zaharia
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Derek Van Lonkhuyzen
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Danica K Hickey
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Annalese B T Semmler
- Institute of Health and Biomedical Innovation, School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Rachael Z Murray
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia
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17
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Chemogenomic Profiling of Antileishmanial Efficacy and Resistance in the Related Kinetoplastid Parasite Trypanosoma brucei. Antimicrob Agents Chemother 2019; 63:AAC.00795-19. [PMID: 31160283 PMCID: PMC6658743 DOI: 10.1128/aac.00795-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 05/23/2019] [Indexed: 01/01/2023] Open
Abstract
The arsenal of drugs used to treat leishmaniasis, caused by Leishmania spp., is limited and beset by toxicity and emergent resistance. Furthermore, our understanding of drug mode of action and potential routes to resistance is limited. Forward genetic approaches have revolutionized our understanding of drug mode of action in the related kinetoplastid parasite Trypanosoma brucei. The arsenal of drugs used to treat leishmaniasis, caused by Leishmania spp., is limited and beset by toxicity and emergent resistance. Furthermore, our understanding of drug mode of action and potential routes to resistance is limited. Forward genetic approaches have revolutionized our understanding of drug mode of action in the related kinetoplastid parasite Trypanosoma brucei. Therefore, we screened our genome-scale T. brucei RNA interference (RNAi) library against the current antileishmanial drugs sodium stibogluconate (antimonial), paromomycin, miltefosine, and amphotericin B. Identification of T. brucei orthologues of the known Leishmania antimonial and miltefosine plasma membrane transporters effectively validated our approach, while a cohort of 42 novel drug efficacy determinants provides new insights and serves as a resource. Follow-up analyses revealed the antimonial selectivity of the aquaglyceroporin TbAQP3. A lysosomal major facilitator superfamily transporter contributes to paromomycin-aminoglycoside efficacy. The vesicle-associated membrane protein TbVAMP7B and a flippase contribute to amphotericin B and miltefosine action and are potential cross-resistance determinants. Finally, multiple phospholipid-transporting flippases, including the T. brucei orthologue of the Leishmania miltefosine transporter, a putative β-subunit/CDC50 cofactor, and additional membrane-associated hits, affect amphotericin B efficacy, providing new insights into mechanisms of drug uptake and action. The findings from this orthology-based chemogenomic profiling approach substantially advance our understanding of antileishmanial drug action and potential resistance mechanisms and should facilitate the development of improved therapies as well as surveillance for drug-resistant parasites.
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18
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Kriegenburg F, Bas L, Gao J, Ungermann C, Kraft C. The multi-functional SNARE protein Ykt6 in autophagosomal fusion processes. Cell Cycle 2019; 18:639-651. [PMID: 30836834 PMCID: PMC6464585 DOI: 10.1080/15384101.2019.1580488] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/06/2019] [Accepted: 01/29/2019] [Indexed: 01/01/2023] Open
Abstract
Autophagy is a degradative pathway in which cytosolic material is enwrapped within double membrane vesicles, so-called autophagosomes, and delivered to lytic organelles. SNARE (Soluble N-ethylmaleimide sensitive factor attachment protein receptor) proteins are key to drive membrane fusion of the autophagosome and the lytic organelles, called lysosomes in higher eukaryotes or vacuoles in plants and yeast. Therefore, the identification of functional SNARE complexes is central for understanding fusion processes and their regulation. The SNARE proteins Syntaxin 17, SNAP29 and Vamp7/VAMP8 are responsible for the fusion of autophagosomes with lysosomes in higher eukaryotes. Recent studies reported that the R-SNARE Ykt6 is an additional SNARE protein involved in autophagosome-lytic organelle fusion in yeast, Drosophila, and mammals. These current findings point to an evolutionarily conserved role of Ykt6 in autophagosome-related fusion events. Here, we briefly summarize the principal mechanisms of autophagosome-lytic organelle fusion, with a special focus on Ykt6 to highlight some intrinsic features of this unusual SNARE protein.
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Affiliation(s)
- Franziska Kriegenburg
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Levent Bas
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
| | - Jieqiong Gao
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Christian Ungermann
- Biochemistry Section, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Claudine Kraft
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Max F. Perutz Laboratories, Vienna Biocenter, University of Vienna, Vienna, Austria
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg
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19
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Dingjan I, Linders PTA, Verboogen DRJ, Revelo NH, Ter Beest M, van den Bogaart G. Endosomal and Phagosomal SNAREs. Physiol Rev 2018; 98:1465-1492. [PMID: 29790818 DOI: 10.1152/physrev.00037.2017] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein family is of vital importance for organelle communication. The complexing of cognate SNARE members present in both the donor and target organellar membranes drives the membrane fusion required for intracellular transport. In the endocytic route, SNARE proteins mediate trafficking between endosomes and phagosomes with other endosomes, lysosomes, the Golgi apparatus, the plasma membrane, and the endoplasmic reticulum. The goal of this review is to provide an overview of the SNAREs involved in endosomal and phagosomal trafficking. Of the 38 SNAREs present in humans, 30 have been identified at endosomes and/or phagosomes. Many of these SNAREs are targeted by viruses and intracellular pathogens, which thereby reroute intracellular transport for gaining access to nutrients, preventing their degradation, and avoiding their detection by the immune system. A fascinating picture is emerging of a complex transport network with multiple SNAREs being involved in consecutive trafficking routes.
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Affiliation(s)
- Ilse Dingjan
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Peter T A Linders
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Danielle R J Verboogen
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Natalia H Revelo
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Geert van den Bogaart
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
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20
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Balagopalan L, Yi J, Nguyen T, McIntire KM, Harned AS, Narayan K, Samelson LE. Plasma membrane LAT activation precedes vesicular recruitment defining two phases of early T-cell activation. Nat Commun 2018; 9:2013. [PMID: 29789604 PMCID: PMC5964120 DOI: 10.1038/s41467-018-04419-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 04/24/2018] [Indexed: 12/20/2022] Open
Abstract
The relative importance of plasma membrane-localized LAT versus vesicular LAT for microcluster formation and T-cell receptor (TCR) activation is unclear. Here, we show the sequence of events in LAT microcluster formation and vesicle delivery, using lattice light sheet microscopy to image a T cell from the earliest point of activation. A kinetic lag occurs between LAT microcluster formation and vesicular pool recruitment to the synapse. Correlative 3D light and electron microscopy show an absence of vesicles at microclusters at early times, but an abundance of vesicles as activation proceeds. Using TIRF-SIM to look at the activated T-cell surface with high resolution, we capture directed vesicle movement between microclusters on microtubules. We propose a model in which cell surface LAT is recruited rapidly and phosphorylated at sites of T-cell activation, while the vesicular pool is subsequently recruited and dynamically interacts with microclusters.
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Affiliation(s)
- Lakshmi Balagopalan
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bethesda, MD, 20892, USA.
| | - Jason Yi
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bethesda, MD, 20892, USA
| | - Tiffany Nguyen
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bethesda, MD, 20892, USA
| | - Katherine M McIntire
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bethesda, MD, 20892, USA
| | - Adam S Harned
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 8560 Progress Drive, Frederick, MD, 21701, USA
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Kedar Narayan
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 8560 Progress Drive, Frederick, MD, 21701, USA
- Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Lawrence E Samelson
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bethesda, MD, 20892, USA.
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21
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Beckel JM, Gómez NM, Lu W, Campagno KE, Nabet B, Albalawi F, Lim JC, Boesze-Battaglia K, Mitchell CH. Stimulation of TLR3 triggers release of lysosomal ATP in astrocytes and epithelial cells that requires TRPML1 channels. Sci Rep 2018; 8:5726. [PMID: 29636491 PMCID: PMC5893592 DOI: 10.1038/s41598-018-23877-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/16/2018] [Indexed: 01/25/2023] Open
Abstract
Cross-reactions between innate immunity, lysosomal function, and purinergic pathways may link signaling systems in cellular pathologies. We found activation of toll-like receptor 3 (TLR3) triggers lysosomal ATP release from both astrocytes and retinal pigmented epithelial (RPE) cells. ATP efflux was accompanied by lysosomal acid phosphatase and beta hexosaminidase release. Poly(I:C) alkalinized lysosomes, and lysosomal alkalization with bafilomycin or chloroquine triggered ATP release. Lysosomal rupture with glycyl-L-phenylalanine-2-naphthylamide (GPN) eliminated both ATP and acid phosphatase release. Secretory lysosome marker LAMP3 colocalized with VNUT, while MANT-ATP colocalized with LysoTracker. Unmodified membrane-impermeant 21-nt and "non-targeting" scrambled 21-nt siRNA triggered ATP and acid phosphatase release, while smaller 16-nt RNA was ineffective. Poly(I:C)-dependent ATP release was reduced by TBK-1 block and in TRPML1-/- cells, while TRPML activation with ML-SA1 was sufficient to release both ATP and acid phosphatase. The ability of poly(I:C) to raise cytoplasmic Ca2+ was abolished by removing extracellular ATP with apyrase, suggesting ATP release by poly(I:C) increased cellular signaling. Starvation but not rapamycin prevented lysosomal ATP release. In summary, stimulation of TLR3 triggers lysosomal alkalization and release of lysosomal ATP through activation of TRPML1; this links innate immunity to purinergic signaling via lysosomal physiology, and suggests even scrambled siRNA can influence these pathways.
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Affiliation(s)
- Jonathan M Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Néstor Más Gómez
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Wennan Lu
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Keith E Campagno
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Bardia Nabet
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Farraj Albalawi
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Orthodontics, University of Pennsylvania, Philadelphia, PA, USA
| | - Jason C Lim
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Claire H Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA.
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22
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An integrated approach to infer cross-talks between intracellular protein transport and signaling pathways. BMC Bioinformatics 2018. [PMID: 29536825 PMCID: PMC5850946 DOI: 10.1186/s12859-018-2036-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background The endomembrane system, known as secretory pathway, is responsible for the synthesis and transport of protein molecules in cells. Therefore, genes involved in the secretory pathway are essential for the cellular development and function. Recent scientific investigations show that ER and Golgi apparatus may provide a convenient drug target for cancer therapy. On the other hand, it is known that abundantly expressed genes in different cellular organelles share interconnected pathways and co-regulate each other activities. The cross-talks among these genes play an important role in signaling pathways, associated to the regulation of intracellular protein transport. Results In the present study, we device an integrated approach to understand these complex interactions. We analyze gene perturbation expression profiles, reconstruct a directed gene interaction network and decipher the regulatory interactions among genes involved in protein transport signaling. In particular, we focus on expression signatures of genes involved in the secretory pathway of MCF7 breast cancer cell line. Furthermore, network biology analysis delineates these gene-centric cross-talks at the level of specific modules/sub-networks, corresponding to different signaling pathways. Conclusions We elucidate the regulatory connections between genes constituting signaling pathways such as PI3K-Akt, Ras, Rap1, calcium, JAK-STAT, EFGR and FGFR signaling. Interestingly, we determine some key regulatory cross-talks between signaling pathways (PI3K-Akt signaling and Ras signaling pathway) and intracellular protein transport. Electronic supplementary material The online version of this article (10.1186/s12859-018-2036-2) contains supplementary material, which is available to authorized users.
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23
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Currier RB, Cooper A, Burrell-Saward H, MacLeod A, Alsford S. Decoding the network of Trypanosoma brucei proteins that determines sensitivity to apolipoprotein-L1. PLoS Pathog 2018; 14:e1006855. [PMID: 29346416 PMCID: PMC5790291 DOI: 10.1371/journal.ppat.1006855] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 01/30/2018] [Accepted: 01/05/2018] [Indexed: 12/27/2022] Open
Abstract
In contrast to Trypanosoma brucei gambiense and T. b. rhodesiense (the causative agents of human African trypanosomiasis), T. b. brucei is lysed by apolipoprotein-L1 (apoL1)-containing human serum trypanolytic factors (TLF), rendering it non-infectious to humans. While the mechanisms of TLF1 uptake, apoL1 membrane integration, and T. b. gambiense and T. b. rhodesiense apoL1-resistance have been extensively characterised, our understanding of the range of factors that drive apoL1 action in T. b. brucei is limited. Selecting our bloodstream-form T. b. brucei RNAi library with recombinant apoL1 identified an array of factors that supports the trypanocidal action of apoL1, including six putative ubiquitin modifiers and several proteins putatively involved in membrane trafficking; we also identified the known apoL1 sensitivity determinants, TbKIFC1 and the V-ATPase. Most prominent amongst the novel apoL1 sensitivity determinants was a putative ubiquitin ligase. Intriguingly, while loss of this ubiquitin ligase reduces parasite sensitivity to apoL1, its loss enhances parasite sensitivity to TLF1-dominated normal human serum, indicating that free and TLF1-bound apoL1 have contrasting modes-of-action. Indeed, loss of the known human serum sensitivity determinants, p67 (lysosomal associated membrane protein) and the cathepsin-L regulator, 'inhibitor of cysteine peptidase', had no effect on sensitivity to free apoL1. Our findings highlight a complex network of proteins that influences apoL1 action, with implications for our understanding of the anti-trypanosomal action of human serum.
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Affiliation(s)
- Rachel B. Currier
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Anneli Cooper
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | | | - Annette MacLeod
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Sam Alsford
- London School of Hygiene and Tropical Medicine, London, United Kingdom
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24
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Yasui T, Gomi H, Kitahara T, Tsukise A. Ultrastructure and immunohistochemical characterization of proteins concerned with the secretory machinery in goat ceruminous glands. Eur J Histochem 2017; 61:2828. [PMID: 29046053 PMCID: PMC5572411 DOI: 10.4081/ejh.2017.2828] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 07/31/2017] [Accepted: 08/01/2017] [Indexed: 11/26/2022] Open
Abstract
The expression of soluble N-ethylmaleimide sensitive fusion attachment protein receptor (SNARE) proteins in apocrine glands has not been fully elucidated. In addition to performing ultrastructural observation of the ceruminous glands in goats, our study focuses on the demonstration of β-defensins, SNARE proteins and Rab3D in these glands with the use of immunohistochemical methods. The secretory cells were equipped with two types of vesicles, Golgi apparatus and abundant rough endoplasmic reticulum (ER). Additionally, in some of them, the characteristic concentric structures composed of rough ER were observed in their circum- and infranuclear parts. The expression of phosphorylated inositol requiring enzyme 1rrwas also detected. These findings may indicate their ability to produce numerous secretory proteins and the maintenance of homeostasis in the glandular cells. Furthermore, β-defensins were demonstrated as products of the ceruminous glands. The present investigation also revealed the presence of SNARE proteins and Rab3D. It is suggested that these proteins are concerned with the secretory machinery of this gland type.
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Affiliation(s)
- Tadashi Yasui
- Nihon University, Department of Veterinary Anatomy, College of Bioresource Sciences.
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25
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Phosphorylated Presenilin 1 decreases β-amyloid by facilitating autophagosome-lysosome fusion. Proc Natl Acad Sci U S A 2017; 114:7148-7153. [PMID: 28533369 PMCID: PMC5502640 DOI: 10.1073/pnas.1705240114] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Presenilin 1 (PS1), the catalytic subunit of the γ-secretase complex, cleaves βCTF to produce Aβ. We have shown that PS1 regulates Aβ levels by a unique bifunctional mechanism. In addition to its known role as the catalytic subunit of the γ-secretase complex, selective phosphorylation of PS1 on Ser367 decreases Aβ levels by increasing βCTF degradation through autophagy. Here, we report the molecular mechanism by which PS1 modulates βCTF degradation. We show that PS1 phosphorylated at Ser367, but not nonphosphorylated PS1, interacts with Annexin A2, which, in turn, interacts with the lysosomal N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) Vamp8. Annexin A2 facilitates the binding of Vamp8 to the autophagosomal SNARE Syntaxin 17 to modulate the fusion of autophagosomes with lysosomes. Thus, PS1 phosphorylated at Ser367 has an antiamyloidogenic function, promoting autophagosome-lysosome fusion and increasing βCTF degradation. Drugs designed to increase the level of PS1 phosphorylated at Ser367 should be useful in the treatment of Alzheimer's disease.
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26
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Abstract
Lysosomes, the major membrane-bound degradative organelles, have a multitude of functions in eukaryotic cells. Lysosomes are the terminal compartments in the endocytic pathway, though they display highly dynamic behaviors, fusing with each other and with late endosomes in the endocytic pathway, and with the plasma membrane during regulated exocytosis and for wound repair. After fusing with late endosomes, lysosomes are reformed from the resulting hybrid organelles through a process that involves budding of a nascent lysosome, extension of the nascent lysosome from the hybrid organelle, while remaining connected by a membrane bridge, and scission of the membrane bridge to release the newly formed lysosome. The newly formed lysosomes undergo cycles of homotypic fusion and fission reactions to form mature lysosomes. In this study, we used a forward genetic screen in Caenorhabditis elegans to identify six regulators of lysosome biology. We show that these proteins function in different steps of lysosome biology, regulating lysosome formation, lysosome fusion, and lysosome degradation.
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27
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Dingjan I, Linders PTA, van den Bekerom L, Baranov MV, Halder P, Ter Beest M, van den Bogaart G. Oxidized phagosomal NOX2 complex is replenished from lysosomes. J Cell Sci 2017; 130:1285-1298. [PMID: 28202687 PMCID: PMC5399780 DOI: 10.1242/jcs.196931] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/09/2017] [Indexed: 12/11/2022] Open
Abstract
In dendritic cells, the NADPH oxidase 2 complex (NOX2) is recruited to the phagosomal membrane during antigen uptake. NOX2 produces reactive oxygen species (ROS) in the lumen of the phagosome that kill ingested pathogens, delay antigen breakdown and alter the peptide repertoire for presentation to T cells. How the integral membrane component of NOX2, cytochrome b558 (which comprises CYBB and CYBA), traffics to phagosomes is incompletely understood. In this study, we show in dendritic cells derived from human blood-isolated monocytes that cytochrome b558 is initially recruited to the phagosome from the plasma membrane during phagosome formation. Cytochrome b558 also traffics from a lysosomal pool to phagosomes and this is required to replenish oxidatively damaged NOX2. We identified syntaxin-7, SNAP23 and VAMP8 as the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins mediating this process. Our data describe a key mechanism of how dendritic cells sustain ROS production after antigen uptake that is required to initiate T cell responses. Highlighted Article: In human dendritic cells, the membrane component of the NADPH oxidase NOX2 complex is initially recruited to phagosomes from the plasma membrane, and oxidized NOX2 complex subunits are replenished from a lysosomal pool.
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Affiliation(s)
- Ilse Dingjan
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
| | - Peter T A Linders
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
| | - Luuk van den Bekerom
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
| | - Maksim V Baranov
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
| | - Partho Halder
- Department of Neurobiology, Max-Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
| | - Geert van den Bogaart
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
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28
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Obino D, Diaz J, Sáez JJ, Ibañez-Vega J, Sáez PJ, Alamo M, Lankar D, Yuseff MI. Vamp-7-dependent secretion at the immune synapse regulates antigen extraction and presentation in B-lymphocytes. Mol Biol Cell 2017; 28:890-897. [PMID: 28179460 PMCID: PMC5385938 DOI: 10.1091/mbc.e16-10-0722] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 01/31/2017] [Accepted: 02/01/2017] [Indexed: 11/11/2022] Open
Abstract
Recognition of surface-tethered antigens (Ags) by B-cells leads to the formation of an immune synapse that promotes Ag uptake for presentation onto MHC-II molecules. Extraction of immobilized Ags at the immune synapse of B-cells relies on the local secretion of lysosomes, which are recruited to the Ag contact site by polarization of their microtubule network. Although conserved polarity proteins have been implicated in coordinating cytoskeleton remodeling with lysosome trafficking, the cellular machinery associated with lysosomal vesicles that regulates their docking and secretion at the synaptic interface has not been defined. Here we show that the v-SNARE protein Vamp-7 is associated with Lamp-1+ lysosomal vesicles, which are recruited and docked at the center of the immune synapse of B-cells. A decrease in Vamp-7 expression does not alter lysosome transport to the synaptic interface but impairs their local secretion, a defect that compromises the ability of B-cells to extract, process, and present immobilized Ag. Thus our results reveal that B-cells rely on the SNARE protein Vamp-7 to promote the local exocytosis of lysosomes at the immune synapse, which is required for efficient Ag extraction and presentation.
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Affiliation(s)
- Dorian Obino
- INSERM, U932 Immunité et Cancer, Institut Curie, PSL Research University, 75005 Paris, France
| | - Jheimmy Diaz
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Juan José Sáez
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Jorge Ibañez-Vega
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Pablo J Sáez
- INSERM, U932 Immunité et Cancer, Institut Curie, PSL Research University, 75005 Paris, France
| | - Martina Alamo
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Danielle Lankar
- INSERM, U932 Immunité et Cancer, Institut Curie, PSL Research University, 75005 Paris, France
| | - Maria-Isabel Yuseff
- Department of Cellular and Molecular Biology, Faculty of Sciences, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
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29
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Cueto JA, Vanrell MC, Salassa BN, Nola S, Galli T, Colombo MI, Romano PS. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development. Cell Microbiol 2017; 19. [PMID: 27992096 DOI: 10.1111/cmi.12713] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 12/02/2016] [Accepted: 12/15/2016] [Indexed: 01/19/2023]
Abstract
Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development.
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Affiliation(s)
- Juan Agustín Cueto
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina.,Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Cristina Vanrell
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Betiana Nebaí Salassa
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Sébastien Nola
- Membrane Traffic in Health & Disease, INSERM ERL U950, Univ Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, Paris, France
| | - Thierry Galli
- Membrane Traffic in Health & Disease, INSERM ERL U950, Univ Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, Paris, France
| | - María Isabel Colombo
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi y la célula hospedadora - Instituto de Histología y Embriología (IHEM) "Dr. Mario H. Burgos" CCT CONICET Mendoza, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
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30
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Chiaruttini G, Piperno GM, Jouve M, De Nardi F, Larghi P, Peden AA, Baj G, Müller S, Valitutti S, Galli T, Benvenuti F. The SNARE VAMP7 Regulates Exocytic Trafficking of Interleukin-12 in Dendritic Cells. Cell Rep 2016; 14:2624-36. [PMID: 26972013 PMCID: PMC4806224 DOI: 10.1016/j.celrep.2016.02.055] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/21/2015] [Accepted: 02/09/2016] [Indexed: 11/24/2022] Open
Abstract
Interleukin-12 (IL-12), produced by dendritic cells in response to activation, is central to pathogen eradication and tumor rejection. The trafficking pathways controlling spatial distribution and intracellular transport of IL-12 vesicles to the cell surface are still unknown. Here, we show that intracellular IL-12 localizes in late endocytic vesicles marked by the SNARE VAMP7. Dendritic cells (DCs) from VAMP7-deficient mice are partially impaired in the multidirectional release of IL-12. Upon encounter with antigen-specific T cells, IL-12-containing vesicles rapidly redistribute at the immune synapse and release IL-12 in a process entirely dependent on VAMP7 expression. Consistently, acquisition of effector functions is reduced in T cells stimulated by VAMP7-null DCs. These results provide insights into IL-12 intracellular trafficking pathways and show that VAMP7-mediated release of IL-12 at the immune synapse is a mechanism to transmit innate signals to T cells. Intracellular trafficking of IL-12 in dendritic cells is mediated by the SNARE VAMP7 VAMP7 is required for optimal secretion of IL-12 in the extracellular space IL-12/VAMP7+ vesicles gather at the immune synapse VAMP7 controls synaptic release of IL-12 and IFN-γ production in T cells
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Affiliation(s)
- Giulia Chiaruttini
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Giulia M Piperno
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Mabel Jouve
- Génétique et Biologie du Développement, UMR 3215, 26 rue d'Ulm, 75005 Paris, France
| | - Francesca De Nardi
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Paola Larghi
- Department of Pathophysiology and Transplantation, University of Milan, via F. Sforza 35, 20122 Milan, Italy; Istituto Nazionale Genetica Molecolare "Romeo ed Enrica Invernizzi," via F. Sforza 35, 20122 Milan, Italy
| | - Andrew A Peden
- Centre for Membrane Interactions and Dynamics, Department of Biomedical Science, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Gabriele Baj
- Life Sciences Department, University of Trieste, via Giorgieri 5, 34127 Trieste, Italy
| | - Sabina Müller
- Centre de Physiopathologie Toulouse-Purpan, Toulouse, INSERM UMR 1043, Toulouse 31300, France
| | - Salvatore Valitutti
- Centre de Physiopathologie Toulouse-Purpan, Toulouse, INSERM UMR 1043, Toulouse 31300, France
| | - Thierry Galli
- Institut Jacques Monod, UMR 7592, Centre National de la Recherche Scientifique, Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France; Membrane Traffic in Neuronal and Epithelial Morphogenesis, INSERM ERL U950, 75013 Paris, France
| | - Federica Benvenuti
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy.
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31
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He J, Johnson JL, Monfregola J, Ramadass M, Pestonjamasp K, Napolitano G, Zhang J, Catz SD. Munc13-4 interacts with syntaxin 7 and regulates late endosomal maturation, endosomal signaling, and TLR9-initiated cellular responses. Mol Biol Cell 2015; 27:572-87. [PMID: 26680738 PMCID: PMC4751605 DOI: 10.1091/mbc.e15-05-0283] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 12/08/2015] [Indexed: 12/23/2022] Open
Abstract
The molecular mechanisms that regulate late endosomal maturation and function are not completely elucidated, and direct evidence of a calcium sensor is lacking. Here we identify a novel mechanism of late endosomal maturation that involves a new molecular interaction between the tethering factor Munc13-4, syntaxin 7, and VAMP8. Munc13-4 binding to syntaxin 7 was significantly increased by calcium. Colocalization of Munc13-4 and syntaxin 7 at late endosomes was demonstrated by high-resolution and live-cell microscopy. Munc13-4-deficient cells show increased numbers of significantly enlarged late endosomes, a phenotype that was mimicked by the fusion inhibitor chloroquine in wild-type cells and rescued by expression of Munc13-4 but not by a syntaxin 7-binding-deficient mutant. Late endosomes from Munc13-4-KO neutrophils show decreased degradative capacity. Munc13-4-knockout neutrophils show impaired endosomal-initiated, TLR9-dependent signaling and deficient TLR9-specific CD11b up-regulation. Thus we present a novel mechanism of late endosomal maturation and propose that Munc13-4 regulates the late endocytic machinery and late endosomal-associated innate immune cellular functions.
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Affiliation(s)
- Jing He
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037
| | - Jennifer L Johnson
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037
| | - Jlenia Monfregola
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037
| | - Mahalakshmi Ramadass
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037
| | - Kersi Pestonjamasp
- Cancer Center Microscopy Shared Resource, University of California, San Diego, La Jolla, CA 92093
| | - Gennaro Napolitano
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037
| | - Jinzhong Zhang
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037
| | - Sergio D Catz
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, CA 92037
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32
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Napolitano G, Johnson JL, He J, Rocca CJ, Monfregola J, Pestonjamasp K, Cherqui S, Catz SD. Impairment of chaperone-mediated autophagy leads to selective lysosomal degradation defects in the lysosomal storage disease cystinosis. EMBO Mol Med 2015; 7:158-74. [PMID: 25586965 PMCID: PMC4328646 DOI: 10.15252/emmm.201404223] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Metabolite accumulation in lysosomal storage disorders (LSDs) results in impaired cell function and multi-systemic disease. Although substrate reduction and lysosomal overload-decreasing therapies can ameliorate disease progression, the significance of lysosomal overload-independent mechanisms in the development of cellular dysfunction is unknown for most LSDs. Here, we identify a mechanism of impaired chaperone-mediated autophagy (CMA) in cystinosis, a LSD caused by defects in the cystine transporter cystinosin (CTNS) and characterized by cystine lysosomal accumulation. We show that, different from other LSDs, autophagosome number is increased, but macroautophagic flux is not impaired in cystinosis while mTOR activity is not affected. Conversely, the expression and localization of the CMA receptor LAMP2A are abnormal in CTNS-deficient cells and degradation of the CMA substrate GAPDH is defective in Ctns−/− mice. Importantly, cysteamine treatment, despite decreasing lysosomal overload, did not correct defective CMA in Ctns−/− mice or LAMP2A mislocalization in cystinotic cells, which was rescued by CTNS expression instead, suggesting that cystinosin is important for CMA activity. In conclusion, CMA impairment contributes to cell malfunction in cystinosis, highlighting the need for treatments complementary to current therapies that are based on decreasing lysosomal overload.
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Affiliation(s)
- Gennaro Napolitano
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Jennifer L Johnson
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Jing He
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Celine J Rocca
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Jlenia Monfregola
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Kersi Pestonjamasp
- Cancer Center Microscopy Shared Resource, University of California San Diego, La Jolla, CA, USA
| | - Stephanie Cherqui
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Sergio D Catz
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
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33
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Molecular dynamics at the endocytic portal and regulations of endocytic and recycling traffics. Eur J Cell Biol 2015; 94:235-48. [DOI: 10.1016/j.ejcb.2015.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 04/02/2015] [Accepted: 04/08/2015] [Indexed: 02/01/2023] Open
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Abstract
In mammalian cells, lysosomes fuse with late endosomes to form endolysosomes from which lysosomes are reformed. Lysosomal fusion events were initially inferred from light and electron microscopy studies, demonstrated in cell-free content mixing assays and, more recently, shown directly with live cell microscopy. Currently, there is a focus on studying lysosome fusion in cultured cells using various forms of microscopy, especially under conditions in which the use of overexpression of dominant-negative protein constructs or the use of RNA interference to deplete individual proteins allows the investigation of the molecular machinery of fusion. Here, we review a variety of fluorescence, live cell, and electron microscopy techniques with which to study lysosome fusion in cultured mammalian cells. We address the merits and limitations of different techniques when choosing an assay system and provide a series of protocols with which to study endocytic delivery to lysosomes and fusion events between lysosomes and endosomes.
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Affiliation(s)
- Nicholas A Bright
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Cambridge, UK
| | - Lena Wartosch
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Cambridge, UK
| | - J Paul Luzio
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Cambridge, UK
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Levin R, Grinstein S, Schlam D. Phosphoinositides in phagocytosis and macropinocytosis. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:805-23. [PMID: 25238964 DOI: 10.1016/j.bbalip.2014.09.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/23/2014] [Accepted: 09/08/2014] [Indexed: 01/08/2023]
Abstract
Professional phagocytes provide immunoprotection and aid in the maintenance of tissue homeostasis. They perform these tasks by recognizing, engulfing and eliminating pathogens and endogenous cell debris. Here, we examine the paramount role played by phosphoinositides in phagocytosis and macropinocytosis, two major endocytic routes that mediate the uptake of particulate and fluid matter, respectively. We analyze accumulating literature describing the molecular mechanisms whereby phosphoinositides translate environmental cues into the complex, sophisticated responses that underlie the phagocytic and macropinocytic responses. In addition, we exemplify virulence strategies involving modulation of host cell phosphoinositide signaling that are employed by bacteria to undermine immunity. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- Roni Levin
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada
| | - Sergio Grinstein
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada; Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria St., Toronto M5C1N8, Canada.
| | - Daniel Schlam
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada
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Abstract
Lysosomes were once considered the end point of endocytosis, simply used for macromolecule degradation. They are now recognized to be dynamic organelles, able to fuse with a variety of targets and to be re-formed after fusion events. They are also now known to be the site of nutrient sensing and signaling to the cell nucleus. In addition, lysosomes are secretory organelles, with specialized machinery for regulated secretion of proteins in some cell types. The biogenesis of lysosomes and lysosome-related organelles is discussed, taking into account their dynamic nature and multiple roles.
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Falkenstein K, De Lozanne A. Dictyostelium LvsB has a regulatory role in endosomal vesicle fusion. J Cell Sci 2014; 127:4356-67. [PMID: 25086066 DOI: 10.1242/jcs.138123] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Defects in human lysosomal-trafficking regulator (Lyst) are associated with the lysosomal disorder Chediak-Higashi syndrome. The absence of Lyst results in the formation of enlarged lysosome-related compartments, but the mechanism for how these compartments arise is not well established. Two opposing models have been proposed to explain Lyst function. The fission model describes Lyst as a positive regulator of fission from lysosomal compartments, whereas the fusion model identifies Lyst as a negative regulator of fusion between lysosomal vesicles. Here, we used assays that can distinguish between defects in vesicle fusion versus fission. We compared the phenotype of Dictyostelium discoideum cells defective in LvsB, the ortholog of Lyst, with that of two known fission defect mutants (μ3- and WASH-null mutants). We found that the temporal localization characteristics of the post-lysosomal marker vacuolin, as well as vesicular acidity and the fusion dynamics of LvsB-null cells are distinct from those of both μ3- and WASH-null fission defect mutants. These distinctions are predicted by the fusion defect model and implicate LvsB as a negative regulator of vesicle fusion.
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Affiliation(s)
- Kristin Falkenstein
- Section of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Arturo De Lozanne
- Section of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
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38
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Upadhyay RD, Kumar A, Balasinor NH. Localization of proteins involved in endocytosis at tubulobulbar complexes in rat testes. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/arsci.2014.21001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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39
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Li X, Garrity AG, Xu H. Regulation of membrane trafficking by signalling on endosomal and lysosomal membranes. J Physiol 2013; 591:4389-401. [PMID: 23878375 DOI: 10.1113/jphysiol.2013.258301] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Endosomal and lysosomal membrane trafficking requires the coordination of multiple signalling events to control cargo sorting and processing, and endosome maturation. The initiation and termination of signalling events in endosomes and lysosomes is not well understood, but several key regulators have been identified, which include small GTPases, phosphoinositides, and Ca2+. Small GTPases act as master regulators and molecular switches in a GTP-dependent manner, initiating signalling cascades to regulate the direction and specificity of endosomal trafficking. Phosphoinositides are membrane-bound lipids that indicate vesicular identities for recruiting specific cytoplasmic proteins to endosomal membranes, thus allowing specificity of membrane fusion, fission, and cargo sorting to occur within and between specific vesicle compartments. In addition, phosphoinositides regulate the function of membrane proteins such as ion channels and transporters in a compartment-specific manner to mediate transport and signalling. Finally, Ca2+, a locally acting second messenger released from intracellular ion channels, may provide precise spatiotemporal regulation of endosomal signalling and trafficking events. Small GTPase signalling can regulate phosphoinositide conversion during endosome maturation, and electrophysiological studies on isolated endosomes have shown that endosomal and lysosomal Ca2+ channels are directly modulated by endosomal lipids. Thus trafficking and maturation of endosomes and lysosomes can be precisely regulated by dynamic changes in GTPases and membrane lipids, as well as Ca2+ signalling. Importantly, impaired phosphoinositide and Ca2+ signalling can cause endosomal and lysosomal trafficking defects at the cellular level, and a spectrum of lysosome storage diseases.
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Affiliation(s)
- Xinran Li
- H. Xu: University of Michigan, MCDB, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA.
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Wesolowski J, Caldwell V, Paumet F. A novel function for SNAP29 (synaptosomal-associated protein of 29 kDa) in mast cell phagocytosis. PLoS One 2012. [PMID: 23185475 PMCID: PMC3503860 DOI: 10.1371/journal.pone.0049886] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Mast cells play a critical role in the innate immune response to bacterial infection. They internalize and kill a variety of bacteria and process antigen for presentation to T cells via MHC molecules. Although mast cell phagocytosis appears to play a significant role during bacterial infection, little is known about the proteins involved in its regulation. In this study, we demonstrate that the SNARE protein SNAP29 is involved in mast cell phagocytosis. SNAP29 is localized in the endocytic pathway and is transiently recruited to Escherichia coli (E. coli)-containing phagosomes. Interestingly, overexpression of SNAP29 significantly increases the internalization and killing of E. coli, while it does not affect mast cell exocytosis of inflammatory mediators. To our knowledge, these data are the first to demonstrate a novel function of SNAP29 in mast cell phagocytosis and have implications in protection against bacterial infection.
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Affiliation(s)
- Jordan Wesolowski
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Vernon Caldwell
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Fabienne Paumet
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Fader CM, Aguilera MO, Colombo MI. ATP is released from autophagic vesicles to the extracellular space in a VAMP7-dependent manner. Autophagy 2012; 8:1741-56. [PMID: 22951367 DOI: 10.4161/auto.21858] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Autophagy is a normal degradative pathway that involves the sequestration of cytoplasmic components and organelles in a vacuole called autophagosome. SNAREs proteins are key molecules of the vesicle fusion machinery. Our results indicate that in a mammalian tumor cell line a subset of VAMP7 (V-SNARE)-positive vacuoles colocalize with LC3 at the cell periphery (focal adhesions) upon starvation. The re-distribution of VAMP7 positive structures is a microtubule-dependent event, with the participation of the motor protein KIF5 and the RAB7 effector RILP. Interestingly, most of the VAMP7-labeled vesicles were loaded with ATP. Moreover, in cells subjected to starvation, these structures fuse with the plasma membrane to release the nucleotide to the extracellular medium. Summarizing, our results show the molecular components involved in the release of ATP to extracellular space, which is recognized as an important autocrine/paracrine signal molecule that participates in the regulation of several cellular functions such as immunogenicity of cancer cell death or inflammation.
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Affiliation(s)
- Claudio Marcelo Fader
- Laboratorio de Biología Celular y Molecular-Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
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43
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Balse E, Steele DF, Abriel H, Coulombe A, Fedida D, Hatem SN. Dynamic of Ion Channel Expression at the Plasma Membrane of Cardiomyocytes. Physiol Rev 2012; 92:1317-58. [DOI: 10.1152/physrev.00041.2011] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cardiac myocytes are characterized by distinct structural and functional entities involved in the generation and transmission of the action potential and the excitation-contraction coupling process. Key to their function is the specific organization of ion channels and transporters to and within distinct membrane domains, which supports the anisotropic propagation of the depolarization wave. This review addresses the current knowledge on the molecular actors regulating the distinct trafficking and targeting mechanisms of ion channels in the highly polarized cardiac myocyte. In addition to ubiquitous mechanisms shared by other excitable cells, cardiac myocytes show unique specialization, illustrated by the molecular organization of myocyte-myocyte contacts, e.g., the intercalated disc and the gap junction. Many factors contribute to the specialization of the cardiac sarcolemma and the functional expression of cardiac ion channels, including various anchoring proteins, motors, small GTPases, membrane lipids, and cholesterol. The discovery of genetic defects in some of these actors, leading to complex cardiac disorders, emphasizes the importance of trafficking and targeting of ion channels to cardiac function. A major challenge in the field is to understand how these and other actors work together in intact myocytes to fine-tune ion channel expression and control cardiac excitability.
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Affiliation(s)
- Elise Balse
- Institute of Cardiometabolism and Nutrition, Paris, France; Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Heart and Metabolism Division, Paris, France; Institut National de la Santé et de la Recherche Médicale UMR_S956, Paris, France; Université Pierre et Marie Curie, Paris, France; Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, Canada; and Department of Clinical Research University of Bern, Bern, Switzerland
| | - David F. Steele
- Institute of Cardiometabolism and Nutrition, Paris, France; Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Heart and Metabolism Division, Paris, France; Institut National de la Santé et de la Recherche Médicale UMR_S956, Paris, France; Université Pierre et Marie Curie, Paris, France; Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, Canada; and Department of Clinical Research University of Bern, Bern, Switzerland
| | - Hugues Abriel
- Institute of Cardiometabolism and Nutrition, Paris, France; Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Heart and Metabolism Division, Paris, France; Institut National de la Santé et de la Recherche Médicale UMR_S956, Paris, France; Université Pierre et Marie Curie, Paris, France; Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, Canada; and Department of Clinical Research University of Bern, Bern, Switzerland
| | - Alain Coulombe
- Institute of Cardiometabolism and Nutrition, Paris, France; Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Heart and Metabolism Division, Paris, France; Institut National de la Santé et de la Recherche Médicale UMR_S956, Paris, France; Université Pierre et Marie Curie, Paris, France; Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, Canada; and Department of Clinical Research University of Bern, Bern, Switzerland
| | - David Fedida
- Institute of Cardiometabolism and Nutrition, Paris, France; Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Heart and Metabolism Division, Paris, France; Institut National de la Santé et de la Recherche Médicale UMR_S956, Paris, France; Université Pierre et Marie Curie, Paris, France; Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, Canada; and Department of Clinical Research University of Bern, Bern, Switzerland
| | - Stéphane N. Hatem
- Institute of Cardiometabolism and Nutrition, Paris, France; Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Heart and Metabolism Division, Paris, France; Institut National de la Santé et de la Recherche Médicale UMR_S956, Paris, France; Université Pierre et Marie Curie, Paris, France; Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, Canada; and Department of Clinical Research University of Bern, Bern, Switzerland
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Proux-Gillardeaux V, Raposo G, Irinopoulou T, Galli T. Expression of the Longin domain of TI-VAMP impairs lysosomal secretion and epithelial cell migration. Biol Cell 2012; 99:261-71. [PMID: 17288539 DOI: 10.1042/bc20060097] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION TI-VAMP (tetanus neurotoxin-insensitive vesicle-associated membrane protein; also called VAMP7) belongs to the Longin subfamily of v-SNAREs (vesicular soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptors). The regulatory N-terminal extension, called the Longin domain, of TI-VAMP has been shown previously to have a dual biochemical function: it inhibits the capacity of TI-VAMP to form SNARE complexes and it binds to the delta subunit of the AP-3 (adaptor protein 3) complex in early endosomes, thereby targeting TI-VAMP to late endosomes. RESULTS We have generated MDCK (Madin-Darby canine kidney) cell lines expressing the Longin domain of TI-VAMP coupled to GFP (green fluorescent protein) in a doxycycline-dependent manner. As expected, AP-3delta (AP-3 delta subunit) is not properly localized in Longin-expressing cells. We have shown that the expression of the Longin domain impairs lysosomal secretion, as determined by the release of a pre-internalized fluorescent fluid-phase marker and by electron microscopy of the membrane-associated released particles. Membrane repair following mechanical wounding, a process requiring lysosomal secretion, is also impaired in cells expressing the Longin domain. Furthermore, cell migration, assessed by wound healing of MDCK monolayers, is also inhibited. CONCLUSIONS The results of the present study suggest that the expression of the Longin domain of TI-VAMP regulates lysosomal secretion of epithelial cells and provide molecular evidence for a role of the late endocytic system in cell migration.
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45
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Durchfort N, Verhoef S, Vaughn MB, Shrestha R, Adam D, Kaplan J, Ward DM. The enlarged lysosomes in beige j cells result from decreased lysosome fission and not increased lysosome fusion. Traffic 2011; 13:108-19. [PMID: 21985295 DOI: 10.1111/j.1600-0854.2011.01300.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Chediak-Higashi syndrome is an autosomal recessive disorder that affects vesicle morphology. The Chs1/Lyst protein is a member of the BEige And CHediak family of proteins. The absence of Chs1/Lyst gives rise to enlarged lysosomes. Lysosome size is regulated by a balance between vesicle fusion and fission and can be reversibly altered by acidifying the cytoplasm using Acetate Ringer's or by incubating with the drug vacuolin-1. We took advantage of these procedures to determine rates of lysosome fusion and fission in the presence or absence of Chs1/Lyst. Here, we show by microscopy, flow cytometry and in vitro fusion that the absence of the Chs1/Lyst protein does not increase the rate of lysosome fusion. Rather, our data indicate that loss of this protein decreases the rate of lysosome fission. We further show that overexpression of the Chs1/Lyst protein gives rise to a faster rate of lysosome fission. These results indicate that Chs1/Lyst regulates lysosome size by affecting fission.
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Affiliation(s)
- Nina Durchfort
- Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT 84132, USA
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46
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Nakae I, Fujino T, Kobayashi T, Sasaki A, Kikko Y, Fukuyama M, Gengyo-Ando K, Mitani S, Kontani K, Katada T. The arf-like GTPase Arl8 mediates delivery of endocytosed macromolecules to lysosomes in Caenorhabditis elegans. Mol Biol Cell 2010; 21:2434-42. [PMID: 20484575 PMCID: PMC2903672 DOI: 10.1091/mbc.e09-12-1010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 04/19/2010] [Accepted: 05/12/2010] [Indexed: 02/07/2023] Open
Abstract
Late endocytic organelles including lysosomes are highly dynamic acidic organelles. Late endosomes and lysosomes directly fuse for content mixing to form hybrid organelles, from which lysosomes are reformed. It is not fully understood how these processes are regulated and maintained. Here we show that the Caenorhabditis elegans ARL-8 GTPase is localized primarily to lysosomes and involved in late endosome-lysosome fusion in the macrophage-like coelomocytes. Loss of arl-8 results in an increase in the number of late endosomal/lysosomal compartments, which are smaller than wild type. In arl-8 mutants, late endosomal compartments containing endocytosed macromolecules fail to fuse with lysosomal compartments enriched in the aspartic protease ASP-1. Furthermore, loss of arl-8 strongly suppresses formation of enlarged late endosome-lysosome hybrid organelles caused by mutations of cup-5, which is the orthologue of human mucolipin-1. These findings suggest that ARL-8 mediates delivery of endocytosed macromolecules to lysosomes by facilitating late endosome-lysosome fusion.
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Affiliation(s)
- Isei Nakae
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomoko Fujino
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tetsuo Kobayashi
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ayaka Sasaki
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yorifumi Kikko
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masamitsu Fukuyama
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Keiko Gengyo-Ando
- Department of Physiology, Tokyo Women's Medical University, School of Medicine, Shinjuku-ku, Tokyo 162-8666, Japan; and
- CREST, JST, Kawaguchi, Saitama, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University, School of Medicine, Shinjuku-ku, Tokyo 162-8666, Japan; and
- CREST, JST, Kawaguchi, Saitama, Japan
| | - Kenji Kontani
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiaki Katada
- *Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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Xie LX, Calafat J, Janssen H, de la Iglesia-Vicente J, Mollinedo F. Intracellular location of syntaxin 7 in human neutrophils. Immunol Lett 2010; 129:72-7. [PMID: 20170677 DOI: 10.1016/j.imlet.2010.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2009] [Revised: 02/07/2010] [Accepted: 02/09/2010] [Indexed: 11/17/2022]
Abstract
Neutrophils are the first line of defense in the innate immune system. Neutrophils neutralize invading microorganisms mainly by phagocytosis, but the mechanism and molecules involved in this process are not well characterized. Because the endosomal soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein syntaxin 7 regulates vesicle trafficking events in phagocytosis, we investigated the expression and subcellular localization of syntaxin 7 in human neutrophils. Here we have found that human peripheral blood neutrophils and neutrophil-differentiated HL-60 cells express syntaxin 7 at both mRNA and protein levels. Using biochemical and ultrastructural approaches, we found that syntaxin 7 was broadly located in the membranes of the three major cytoplasmic granules of human neutrophils, with a major location in azurophilic granules, which are mainly involved in phagocytosis. A secondary, but extensive, location of syntaxin 7 was in specific and tertiary granules, which resulted translocated to the plasma membrane upon cell activation that promoted mobilization of these organelles. These data reveal the presence of syntaxin 7 in the membranes of exocytosis-prone granules (specific and tertiary granules) and phagocytosis-related granules (azurophilic granules) in human neutrophils, and therefore it might play a role in both exocytosis and phagocytosis in human neutrophils.
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Affiliation(s)
- Li-xin Xie
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
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48
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Chaineau M, Danglot L, Galli T. Multiple roles of the vesicular-SNARE TI-VAMP in post-Golgi and endosomal trafficking. FEBS Lett 2009; 583:3817-26. [PMID: 19837067 DOI: 10.1016/j.febslet.2009.10.026] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 10/09/2009] [Accepted: 10/13/2009] [Indexed: 01/13/2023]
Abstract
SNARE (Soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins are the core machinery of membrane fusion. Vesicular SNAREs (v-SNAREs) interact with their target SNAREs (t-SNAREs) to form SNARE complexes which mediate membrane fusion. Here we review the basic properties and functions of the v-SNARE TI-VAMP/VAMP7 (Tetanus neurotoxin insensitive-vesicle associated membrane protein). TI-VAMP interacts with its t-SNARE partners, particularly plasmalemmal syntaxins, to mediate membrane fusion and with several regulatory proteins especially via its amino-terminal regulatory Longin domain. Partners include AP-3, Hrb/(Human immunodeficiency virus Rev binding) protein, and Varp (Vps9 domain and ankyrin repeats containing protein) and regulate TI-VAMP's function and targeting. TI-VAMP is involved both in secretory and endocytic pathways which mediate neurite outgrowth and synaptic transmission, plasma membrane remodeling and lysosomal secretion.
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Affiliation(s)
- Mathilde Chaineau
- Membrane Traffic in Neuronal and Epithelial Morphogenesis', INSERM U950, Paris F-75013, France
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49
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Fader CM, Sánchez DG, Mestre MB, Colombo MI. TI-VAMP/VAMP7 and VAMP3/cellubrevin: two v-SNARE proteins involved in specific steps of the autophagy/multivesicular body pathways. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1901-16. [PMID: 19781582 DOI: 10.1016/j.bbamcr.2009.09.011] [Citation(s) in RCA: 358] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 09/14/2009] [Indexed: 12/19/2022]
Abstract
During reticulocyte maturation, some membrane proteins and organelles that are not required in the mature red cell are lost. Several of these proteins are released into the extracellular medium associated with the internal vesicles present in multivesicular bodies (MVBs). Likewise, organelles such as mitochondria and endoplasmic reticulum are wrapped into double membrane vacuoles (i.e., autophagosomes) and degraded via autophagy. Morphological, molecular, and biochemical studies have shown that autophagosomes fuse with MVBs forming the so-called amphisomes, a prelysosomal hybrid organelle. SNAREs are key molecules of the vesicle fusion machinery. TI-VAMP/VAMP7 and VAMP3/cellubrevin are two v-SNARE proteins involved in the endocytic and exocytic pathways. We have previously shown that in the human leukemic K562 cells, Rab11 decorates MVBs and it is necessary for fusion between autophagosomes with MVBs. In the present report, we present evidence indicating that VAMP3 is required for the fusion between MVBs with autophagosomes to generate the amphisome, allowing the maturation of the autophagosome, but it does not seem to be involved in the next step, i. e., fusion with the lysosome. On the other hand, we demonstrate that VAMP7 is necessary for this latter event, allowing the completion of the autophagic pathway. Furthermore, VAMP7 and ATPase NSF, a protein required for SNAREs disassembly, participate in the fusion between MVBs with the plasma membrane to release the internal vesicles (i.e., exosomes) into the extracellular medium.
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Affiliation(s)
- Claudio Marcelo Fader
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, (5500) Mendoza, Argentina
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50
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de Chastellier C, Forquet F, Gordon A, Thilo L. Mycobacterium requires an all-around closely apposing phagosome membrane to maintain the maturation block and this apposition is re-established when it rescues itself from phagolysosomes. Cell Microbiol 2009; 11:1190-207. [DOI: 10.1111/j.1462-5822.2009.01324.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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