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Palmulli R, Couty M, Piontek MC, Ponnaiah M, Dingli F, Verweij FJ, Charrin S, Tantucci M, Sasidharan S, Rubinstein E, Kontush A, Loew D, Lhomme M, Roos WH, Raposo G, van Niel G. CD63 sorts cholesterol into endosomes for storage and distribution via exosomes. Nat Cell Biol 2024; 26:1093-1109. [PMID: 38886558 DOI: 10.1038/s41556-024-01432-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 05/01/2024] [Indexed: 06/20/2024]
Abstract
Extracellular vesicles such as exosomes are now recognized as key players in intercellular communication. Their role is influenced by the specific repertoires of proteins and lipids, which are enriched when they are generated as intraluminal vesicles (ILVs) in multivesicular endosomes. Here we report that a key component of small extracellular vesicles, the tetraspanin CD63, sorts cholesterol to ILVs, generating a pool that can be mobilized by the NPC1/2 complex, and exported via exosomes to recipient cells. In the absence of CD63, cholesterol is retrieved from the endosomes by actin-dependent vesicular transport, placing CD63 and cholesterol at the centre of a balance between inward and outward budding of endomembranes. These results establish CD63 as a lipid-sorting mechanism within endosomes, and show that ILVs and exosomes are alternative providers of cholesterol.
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Affiliation(s)
- Roberta Palmulli
- Institut Curie, PSL Research University, CNRS, UMR144, 26 rue d'Ulm, 75248, Paris Cedex 05, France
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université de Paris, Paris, France
| | - Mickaël Couty
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université de Paris, Paris, France
- CRCI2NA, Nantes Université, Inserm UMR1307, CNRS UMR6075, Université d'Angers, Nantes, France
| | - Melissa C Piontek
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Maharajah Ponnaiah
- Foundation for Innovation in Cardiometabolism and Nutrition (IHU ICAN, ICAN OMICS and ICAN I/O), F-75013, Paris, France
| | - Florent Dingli
- CurieCoreTech Spectrométrie de Masse Protéomique, Institut Curie, PSL Research University, Paris, France
| | - Frederik J Verweij
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université de Paris, Paris, France
| | - Stéphanie Charrin
- Centre d'Immunologie et des Maladies Infectieuses (CIMI), Sorbonne Université, Inserm, Paris, France
| | - Matteo Tantucci
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université de Paris, Paris, France
| | - Sajitha Sasidharan
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Eric Rubinstein
- Centre d'Immunologie et des Maladies Infectieuses (CIMI), Sorbonne Université, Inserm, Paris, France
| | - Anatol Kontush
- ICAN, National Institute for Health and Medical Research, Paris, France
| | - Damarys Loew
- CurieCoreTech Spectrométrie de Masse Protéomique, Institut Curie, PSL Research University, Paris, France
| | - Marie Lhomme
- Foundation for Innovation in Cardiometabolism and Nutrition (IHU ICAN, ICAN OMICS and ICAN I/O), F-75013, Paris, France
| | - Wouter H Roos
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Graça Raposo
- Institut Curie, PSL Research University, CNRS, UMR144, 26 rue d'Ulm, 75248, Paris Cedex 05, France
- Institut Curie, PSL Research University, CNRS, UMR144, Cell and Tissue Imaging Facility (PICT-IBiSA), 26, rue d'Ulm, 75248, Paris Cedex 05, France
| | - Guillaume van Niel
- Institut Curie, PSL Research University, CNRS, UMR144, 26 rue d'Ulm, 75248, Paris Cedex 05, France.
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université de Paris, Paris, France.
- CRCI2NA, Nantes Université, Inserm UMR1307, CNRS UMR6075, Université d'Angers, Nantes, France.
- GHU-Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Paris, France.
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2
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Yoshida T, Goto K, Kodama A, Bolidong D, Seto T, Hanayama R. Extracellular vesicles promote silica nanoparticle aggregation that inhibits silica-induced cytotoxicity. Arch Biochem Biophys 2024; 755:109964. [PMID: 38527699 DOI: 10.1016/j.abb.2024.109964] [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: 09/01/2023] [Revised: 03/19/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
Amorphous silica has been approved as a food and pharmaceutical additive. However, its potential to enhance the carcinogenicity of epithelial cells is incontrovertible. With their expanded surface area per unit mass and distinctive cellular incorporation, nano-sized silica particles (nSPs) exhibit heightened cytotoxicity compared to micrometer-sized counterparts. The precise effect of nSPs on the generation of small extracellular vesicles (sEVs) within endosomes after cellular uptake remains unclear. In the present study, we explored the secretion of sEVs from cells and their functional implications following exposure to nSPs. Our findings demonstrate that nSP50 exposure not only induced epithelial-mesenchymal transition (EMT) but also promoted the maturation of multivesicular endosomes (MVEs) along with the secretion of sEVs in A549 cells. Inhibition of sEV secretion using GW4869 and apoptosis activator 2 exacerbated nSP50-induced EMT, indicating that sEV secretion may suppress EMT. Analysis of the function of sEV in a cell-free system revealed that co-incubation of sEVs with nSP50 led to the formation of micrometer-sized aggregates, which exhibited limited uptake efficiency within A549 cells. These results strongly suggest that the secretion of sEVs plays a protective role against the cytotoxicity attributed to nSP50 exposure.
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Affiliation(s)
- Takeshi Yoshida
- WPI Nano Life Science Institute (NanoLSI), Kanazawa University, Japan; Department of Immunology, Graduate School of Medical Sciences, Kanazawa University, Japan.
| | - Kenji Goto
- WPI Nano Life Science Institute (NanoLSI), Kanazawa University, Japan; Faculty of Frontier Engineering, Institute of Science and Engineering, Kanazawa University, Japan
| | - Akihito Kodama
- WPI Nano Life Science Institute (NanoLSI), Kanazawa University, Japan; Faculty of Frontier Engineering, Institute of Science and Engineering, Kanazawa University, Japan
| | - Dilireba Bolidong
- WPI Nano Life Science Institute (NanoLSI), Kanazawa University, Japan
| | - Takafumi Seto
- Faculty of Frontier Engineering, Institute of Science and Engineering, Kanazawa University, Japan.
| | - Rikinari Hanayama
- WPI Nano Life Science Institute (NanoLSI), Kanazawa University, Japan; Department of Immunology, Graduate School of Medical Sciences, Kanazawa University, Japan.
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3
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Dogrammatzis C, Saud R, Waisner H, Lasnier S, Suma SM, Grieshaber B, Kalamvoki M. Tracing the STING exocytosis pathway during herpes viruses infection. mBio 2024; 15:e0037324. [PMID: 38470056 PMCID: PMC11005388 DOI: 10.1128/mbio.00373-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 02/20/2024] [Indexed: 03/13/2024] Open
Abstract
The STimulator of INterferon Genes (STING) constitutes a major DNA-sensing pathway that restricts HSV-1 infection in different models by activating type I interferon and pro-inflammatory responses. To counteract STING, HSV-1 has evolved numerous strategies including mechanisms to interfere with its oligomerization, post-translational modifications, and downstream signaling. Previously, we demonstrated that STING is packaged in extracellular vesicles (EVs) produced from HSV-1-infected cells. These EVs activated antiviral responses in uninfected recipient cells and suppressed a subsequent HSV-1 infection in a STING-dependent manner. Here, we provide information on the packaging of STING in EVs and its exocytosis. We found that STING exocytosis did not occur in CD63 knockdown cells supporting that STING follows the CD63 exocytosis pathway. Consistently, we found that STING co-localized with CD63 in cytoplasmic globular structures and exosomal STING and CD63 co-fractionated. Both golgicide A and brefeldin A prevented STING exocytosis during HSV-1 infection suggesting that STING trafficking through the Golgi is required. A STING ligand was insufficient for STING exocytosis, and downstream signaling through TBK1 was not required. However, STING palmitoylation and tethering to the ER by STIM1 were required for STING exocytosis. Finally, we found that HSV-1 replication/late gene expression triggered CD63 exocytosis that was required for STING exocytosis. Surprisingly, HSV-2 strain G did not trigger CD63 or STING exocytosis as opposed to VZV and HCMV. Also, EVs from HSV-1(F)- and HSV-2(G)-infected cells displayed differences in their ability to restrict these viruses. Overall, STING exocytosis is induced by certain viruses and shapes the microenvironment of infection.IMPORTANCEExtracellular vesicles (EVs) are released by all types of cells as they constitute a major mechanism of intercellular communication. The packaging of specific cargo in EVs and the pathway of exocytosis are not fully understood. STING is a sensor of a broad spectrum of pathogens and a key component of innate immunity. STING exocytosis during HSV-1 infection has been an intriguing observation, raising questions of whether this is a virus-induced process, the purpose it serves, and whether it is observed after infection with other viruses. Here, we have provided insights into the pathway of STING exocytosis and determined factors involved. STING exocytosis is a virus-induced process and not a response of the host to the infection. Besides HSV-1, other herpes viruses triggered STING exocytosis, but HSV-2(G) did not. HSV-1 EVs displayed different restriction capabilities compared with HSV-2(G) EVs. Overall, STING exocytosis is triggered by viruses to shape the microenvironment of infection.
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Affiliation(s)
- Christos Dogrammatzis
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Rabina Saud
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Hope Waisner
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Sarah Lasnier
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Sreenath Muraleedharan Suma
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Brandon Grieshaber
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Maria Kalamvoki
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
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Eriksson I, Öllinger K. Lysosomes in Cancer-At the Crossroad of Good and Evil. Cells 2024; 13:459. [PMID: 38474423 DOI: 10.3390/cells13050459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
Although it has been known for decades that lysosomes are central for degradation and recycling in the cell, their pivotal role as nutrient sensing signaling hubs has recently become of central interest. Since lysosomes are highly dynamic and in constant change regarding content and intracellular position, fusion/fission events allow communication between organelles in the cell, as well as cell-to-cell communication via exocytosis of lysosomal content and release of extracellular vesicles. Lysosomes also mediate different forms of regulated cell death by permeabilization of the lysosomal membrane and release of their content to the cytosol. In cancer cells, lysosomal biogenesis and autophagy are increased to support the increased metabolism and allow growth even under nutrient- and oxygen-poor conditions. Tumor cells also induce exocytosis of lysosomal content to the extracellular space to promote invasion and metastasis. However, due to the enhanced lysosomal function, cancer cells are often more susceptible to lysosomal membrane permeabilization, providing an alternative strategy to induce cell death. This review summarizes the current knowledge of cancer-associated alterations in lysosomal structure and function and illustrates how lysosomal exocytosis and release of extracellular vesicles affect disease progression. We focus on functional differences depending on lysosomal localization and the regulation of intracellular transport, and lastly provide insight how new therapeutic strategies can exploit the power of the lysosome and improve cancer treatment.
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Affiliation(s)
- Ida Eriksson
- Division of Cell Biology, Department of Biomedical and Clinical Sciences, Linköping University, 58185 Linköping, Sweden
| | - Karin Öllinger
- Division of Cell Biology, Department of Biomedical and Clinical Sciences, Linköping University, 58185 Linköping, Sweden
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Liu J, Liu YY, Li CS, Cao A, Wang H. Exocytosis of Nanoparticles: A Comprehensive Review. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2215. [PMID: 37570533 PMCID: PMC10421347 DOI: 10.3390/nano13152215] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 07/24/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023]
Abstract
Both biomedical applications and safety assessments of manufactured nanomaterials require a thorough understanding of the interaction between nanomaterials and cells, including how nanomaterials enter cells, transport within cells, and leave cells. However, compared to the extensively studied uptake and trafficking of nanoparticles (NPs) in cells, less attention has been paid to the exocytosis of NPs. Yet exocytosis is an indispensable process of regulating the content of NPs in cells, which in turn influences, even decides, the toxicity of NPs to cells. A comprehensive understanding of the mechanisms and influencing factors of the exocytosis of NPs is not only essential for the safety assessment of NPs but also helpful for guiding the design of safe and highly effective NP-based materials for various purposes. Herein, we review the current status and progress of studies on the exocytosis of NPs. Firstly, we introduce experimental procedures and considerations. Then, exocytosis mechanisms/pathways are summarized with a detailed introduction of the main pathways (lysosomal and endoplasmic reticulum/Golgi pathway) and the role of microtubules; the patterns of exocytosis kinetics are presented and discussed. Subsequently, the influencing factors (initial content and location of intracellular NPs, physiochemical properties of NPs, cell type, and extracellular conditions) are fully discussed. Although there are inconsistent results, some rules are obtained, like smaller and charged NPs are more easily excreted. Finally, the challenges and future directions in the field have been discussed.
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Affiliation(s)
| | | | | | | | - Haifang Wang
- Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444, China
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6
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Minami Y, Hoshino A, Higuchi Y, Hamaguchi M, Kaneko Y, Kirita Y, Taminishi S, Nishiji T, Taruno A, Fukui M, Arany Z, Matoba S. Liver lipophagy ameliorates nonalcoholic steatohepatitis through extracellular lipid secretion. Nat Commun 2023; 14:4084. [PMID: 37443159 PMCID: PMC10344867 DOI: 10.1038/s41467-023-39404-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 06/12/2023] [Indexed: 07/15/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is a progressive disorder with aberrant lipid accumulation and subsequent inflammatory and profibrotic response. Therapeutic efforts at lipid reduction via increasing cytoplasmic lipolysis unfortunately worsens hepatitis due to toxicity of liberated fatty acid. An alternative approach could be lipid reduction through autophagic disposal, i.e., lipophagy. We engineered a synthetic adaptor protein to induce lipophagy, combining a lipid droplet-targeting signal with optimized LC3-interacting domain. Activating hepatocyte lipophagy in vivo strongly mitigated both steatosis and hepatitis in a diet-induced mouse NASH model. Mechanistically, activated lipophagy promoted the excretion of lipid from hepatocytes, thereby suppressing harmful intracellular accumulation of nonesterified fatty acid. A high-content compound screen identified alpelisib and digoxin, clinically-approved compounds, as effective activators of lipophagy. Administration of alpelisib or digoxin in vivo strongly inhibited the transition to steatohepatitis. These data thus identify lipophagy as a promising therapeutic approach to prevent NASH progression.
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Affiliation(s)
- Yoshito Minami
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Atsushi Hoshino
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.
| | - Yusuke Higuchi
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Masahide Hamaguchi
- Department of Endocrinology and Metabolism, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Yusaku Kaneko
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Yuhei Kirita
- Department of Nephrology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Shunta Taminishi
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Toshiyuki Nishiji
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Akiyuki Taruno
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
- Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama, 332-0012, Japan
- Japan Science and Technology Agency, CREST, Kawaguchi, Saitama, 332-0012, Japan
| | - Michiaki Fukui
- Department of Endocrinology and Metabolism, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Zoltan Arany
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Satoaki Matoba
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
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Domingues N, Marques ARA, Calado RDA, Ferreira IS, Ramos C, Ramalho J, Soares MIL, Pereira T, Oliveira L, Vicente JR, Wong LH, Simões ICM, Pinho E Melo TMVD, Peden A, Almeida CG, Futter CE, Puertollano R, Vaz WLC, Vieira OV. Oxidized cholesteryl ester induces exocytosis of dysfunctional lysosomes in lipidotic macrophages. Traffic 2023; 24:284-307. [PMID: 37129279 DOI: 10.1111/tra.12888] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/29/2023] [Accepted: 04/20/2023] [Indexed: 05/03/2023]
Abstract
A key event in atherogenesis is the formation of lipid-loaded macrophages, lipidotic cells, which exhibit irreversible accumulation of undigested modified low-density lipoproteins (LDL) in lysosomes. This event culminates in the loss of cell homeostasis, inflammation, and cell death. Nevertheless, the exact chemical etiology of atherogenesis and the molecular and cellular mechanisms responsible for the impairment of lysosome function in plaque macrophages are still unknown. Here, we demonstrate that macrophages exposed to cholesteryl hemiazelate (ChA), one of the most prevalent products of LDL-derived cholesteryl ester oxidation, exhibit enlarged peripheral dysfunctional lysosomes full of undigested ChA and neutral lipids. Both lysosome area and accumulation of neutral lipids are partially irreversible. Interestingly, the dysfunctional peripheral lysosomes are more prone to fuse with the plasma membrane, secreting their undigested luminal content into the extracellular milieu with potential consequences for the pathology. We further demonstrate that this phenotype is mechanistically linked to the nuclear translocation of the MiT/TFE family of transcription factors. The induction of lysosome biogenesis by ChA appears to partially protect macrophages from lipid-induced cytotoxicity. In sum, our data show that ChA is involved in the etiology of lysosome dysfunction and promotes the exocytosis of these organelles. This latter event is a new mechanism that may be important in the pathogenesis of atherosclerosis.
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Affiliation(s)
- Neuza Domingues
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - André R A Marques
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Rita Diogo Almeida Calado
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Inês S Ferreira
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Cristiano Ramos
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - José Ramalho
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Maria I L Soares
- CQC and Department of Chemistry, University of Coimbra, Coimbra, Portugal
| | - Telmo Pereira
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Luís Oliveira
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - José R Vicente
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Louise H Wong
- Department of Cell Biology, UCL Institute of Ophthalmology, London, UK
| | - Inês C M Simões
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | | | - Andrew Peden
- Department of Biomedical Science & Center for Membrane Interactions and Dynamics, University of Sheffield, UK
| | - Cláudia Guimas Almeida
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Clare E Futter
- Department of Cell Biology, UCL Institute of Ophthalmology, London, UK
| | - Rosa Puertollano
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Winchil L C Vaz
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Otília V Vieira
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, NMS|FCM, Universidade Nova de Lisboa, Lisbon, Portugal
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8
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Ho GPH, Wilkie EC, White AJ, Selkoe DJ. Palmitoylation of the Parkinson's disease-associated protein synaptotagmin-11 links its turnover to α-synuclein homeostasis. Sci Signal 2023; 16:eadd7220. [PMID: 36787382 PMCID: PMC10150695 DOI: 10.1126/scisignal.add7220] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 01/11/2023] [Indexed: 02/16/2023]
Abstract
Synaptotagmin-11 (Syt11) is a vesicle-trafficking protein that is linked genetically to Parkinson's disease (PD). Likewise, the protein α-synuclein regulates vesicle trafficking, and its abnormal aggregation in neurons is the defining cytopathology of PD. Because of their functional similarities in the same disease context, we investigated whether the two proteins were connected. We found that Syt11 was palmitoylated in mouse and human brain tissue and in cultured cortical neurons and that this modification to Syt11 disrupted α-synuclein homeostasis in neurons. Palmitoylation of two cysteines adjacent to the transmembrane domain, Cys39 and Cys40, localized Syt11 to digitonin-insoluble portions of intracellular membranes and protected it from degradation by the endolysosomal system. In neurons, palmitoylation of Syt11 increased its abundance and enhanced the binding of α-synuclein to intracellular membranes. As a result, the abundance of the physiologic tetrameric form of α-synuclein was decreased, and that of its aggregation-prone monomeric form was increased. These effects were replicated by overexpression of wild-type Syt11 but not a palmitoylation-deficient mutant. These findings suggest that palmitoylation-mediated increases in Syt11 amounts may promote pathological α-synuclein aggregation in PD.
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Affiliation(s)
- Gary P. H. Ho
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Erin C. Wilkie
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Andrew J. White
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Dennis J. Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115 USA
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Ravindran R, Velikkakath AKG, Narendradev ND, Chandrasekharan A, Santhoshkumar TR, Srinivasula SM. Endosomal-associated RFFL facilitates mitochondrial clearance by enhancing PRKN/parkin recruitment to mitochondria. Autophagy 2022; 18:2851-2864. [PMID: 35373701 PMCID: PMC9673925 DOI: 10.1080/15548627.2022.2052460] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Mutations in the ubiquitin ligase PRKN (parkin RBR E3 ubiquitin protein ligase) are associated with Parkinson disease and defective mitophagy. Conceptually, PRKN-dependent mitophagy is classified into two phases: 1. PRKN recruits to and ubiquitinates mitochondrial proteins; 2. formation of phagophore membrane, sequestering mitochondria for degradation. Recently, endosomal machineries are reported to contribute to the later stage for membrane assembly. We reported a role for endosomes in the events upstream of phase 1. We demonstrate that the endosomal ubiquitin ligase RFFL (ring finger and FYVE like domain containing E3 ubiquitin protein ligase) associated with damaged mitochondria, and this association preceded that of PRKN. RFFL interacted with PRKN, and stable recruitment of PRKN to damaged mitochondria was substantially reduced in RFFL KO cells. Our study unraveled a novel role of endosomes in modulating upstream pathways of PRKN-dependent mitophagy initiation.Abbreviations CCCP: carbonyl cyanide 3-chlorophenylhydrazone; DMSO: dimethyl sulfoxide; EGFP: enhanced green fluorescence protein; KO: knockout; PRKN: parkin RBR E3 ubiquitin protein ligase; RFFL: ring finger and FYVE like domain containing E3 ubiquitin protein ligase; UQCRC1: ubiquinol-cytochrome c reductase core protein 1; WT: wild-type.
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Affiliation(s)
- Rishith Ravindran
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala, India
| | - Anoop Kumar G. Velikkakath
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala, India,Central Research Laboratory, K.S. Hegde Medical Academy, Nitte (Deemed to Be University), Karnataka, India
| | - Nikhil Dev Narendradev
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala, India
| | | | - T. R. Santhoshkumar
- Cancer Research Program-1, Rajiv Gandhi Centre for Biotechnology, Kerala, India
| | - Srinivasa M. Srinivasula
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala, India,CONTACT Srinivasa M. Srinivasula School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala695551, India
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10
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Hendricks EL, Smith IR, Prates B, Barmaleki F, Liebl FLW. The CD63 homologs, Tsp42Ee and Tsp42Eg, restrict endocytosis and promote neurotransmission through differential regulation of synaptic vesicle pools. Front Cell Neurosci 2022; 16:957232. [PMID: 36072568 PMCID: PMC9441712 DOI: 10.3389/fncel.2022.957232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/04/2022] [Indexed: 11/30/2022] Open
Abstract
The Tetraspanin (Tsp), CD63, is a transmembrane component of late endosomes and facilitates vesicular trafficking through endosomal pathways. Despite being widely expressed in the human brain and localized to late endosomes, CD63's role in regulating endo- and exocytic cycling at the synapse has not been investigated. Synaptic vesicle pools are highly dynamic and disruptions in the mobilization and replenishment of these vesicle pools have adverse neuronal effects. We find that the CD63 homologs, Tsp42Ee and Tsp42Eg, are expressed at the Drosophila neuromuscular junction to regulate synaptic vesicle pools through both shared and unique mechanisms. Tsp42Ee and Tsp42Eg negatively regulate endocytosis and positively regulate neurotransmitter release. Both tsp mutants show impaired locomotion, reduced miniature endplate junctional current frequencies, and increased endocytosis. Expression of human CD63 in Drosophila neurons leads to impaired endocytosis suggesting the role of Tsps in endocytosis is conserved. We further show that Tsps influence the synaptic cytoskeleton and membrane composition by regulating Futsch loop formation and synaptic levels of SCAR and PI(4,5)P2. Finally, Tsp42Ee and Tsp42Eg influence the synaptic localization of several vesicle-associated proteins including Synapsin, Synaptotagmin, and Cysteine String Protein. Together, our results present a novel function for Tsps in the regulation of vesicle pools and provide insight into the molecular mechanisms of Tsp-related synaptic dysfunction.
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Affiliation(s)
| | | | | | | | - Faith L. W. Liebl
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, United States
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11
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Rudnik S, Heybrock S, Saftig P, Damme M. S-palmitoylation determines TMEM55B-dependent positioning of lysosomes. J Cell Sci 2022; 135:jcs258566. [PMID: 34350967 DOI: 10.1242/jcs.258566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 07/23/2021] [Indexed: 11/20/2022] Open
Abstract
The spatiotemporal cellular distribution of lysosomes depends on active transport mainly driven by microtubule motors such as kinesins and dynein. Different protein complexes attach these molecular motors to their vesicular cargo. TMEM55B (also known as PIP4P1), as an integral lysosomal membrane protein, is a component of such a complex that mediates the retrograde transport of lysosomes by establishing interactions with the cytosolic scaffold protein JIP4 (also known as SPAG9) and dynein-dynactin. Here, we show that TMEM55B and its paralog TMEM55A (PIP4P2) are S-palmitoylated proteins that are lipidated at multiple cysteine residues. Mutation of all cysteines in TMEM55B prevents S-palmitoylation and causes retention of the mutated protein in the Golgi. Consequently, non-palmitoylated TMEM55B is no longer able to modulate lysosomal positioning and the perinuclear clustering of lysosomes. Additional mutagenesis of the dileucine-based lysosomal sorting motif in non-palmitoylated TMEM55B leads to partial missorting to the plasma membrane instead of retention in the Golgi, implicating a direct effect of S-palmitoylation on the adaptor protein-dependent sorting of TMEM55B. Our data suggest a critical role for S-palmitoylation in the trafficking of TMEM55B and TMEM55B-dependent lysosomal positioning.
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Affiliation(s)
- Sönke Rudnik
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Saskia Heybrock
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Paul Saftig
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Markus Damme
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
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12
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Titu S, Grapa CM, Mocan T, Balacescu O, Irimie A. Tetraspanins: Physiology, Colorectal Cancer Development, and Nanomediated Applications. Cancers (Basel) 2021; 13:cancers13225662. [PMID: 34830819 PMCID: PMC8616055 DOI: 10.3390/cancers13225662] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/01/2021] [Accepted: 11/09/2021] [Indexed: 01/10/2023] Open
Abstract
Simple Summary Considering the high incidence of colorectal cancer in adults, as well as the need for identifying novel therapies, we hereby explore the role of tetraspanins in the development of colorectal cancer. We have focused on variate aspects starting from the structure and general physiology and ending with the precise mechanisms involved in the dual reported role of tetraspanins (pro–tumoral and tumor suppressor key player element). Moreover, the present review focuses on the potential of tetraspanins as a target for nanotechnology-mediated therapies, also gathering the limited attempts towards this aim and their reported data. Abstract Tetraspanins are transmembrane proteins expressed in a multitude of cells throughout the organism. They contribute to many processes that surround cell–cell interactions and are associated with the progress of some diseases, including cancer. Their crucial role in cell physiology is often understated. Furthermore, recent studies have shown their great potential in being used as targeting molecules. Data have suggested the potential of tetraspanins as a targeting vector for nanomediated distribution and delivery for colorectal cancer applications. Our aim is to provide a review on the important part that tetraspanins play in the human organism and highlight their potential use for drug delivery systems using nanotechnology.
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Affiliation(s)
- Stefan Titu
- “Iuliu Hatieganu” University of Medicine and Pharmacy, Faculty of Medicine, 400126 Cluj-Napoca, Romania; (S.T.); (C.M.G.); (A.I.)
- Department of Surgical Oncology, The Oncology Institute “Prof. Dr. Ion Chiricuta” Cluj-Napoca, 400015 Cluj-Napoca, Romania
| | - Cristiana Maria Grapa
- “Iuliu Hatieganu” University of Medicine and Pharmacy, Faculty of Medicine, 400126 Cluj-Napoca, Romania; (S.T.); (C.M.G.); (A.I.)
- Nanomedicine Department, Regional Institute of Gastroenterology and Hepatology, 400126 Cluj-Napoca, Romania
| | - Teodora Mocan
- “Iuliu Hatieganu” University of Medicine and Pharmacy, Faculty of Medicine, 400126 Cluj-Napoca, Romania; (S.T.); (C.M.G.); (A.I.)
- Nanomedicine Department, Regional Institute of Gastroenterology and Hepatology, 400126 Cluj-Napoca, Romania
- Correspondence:
| | - Ovidiu Balacescu
- Department of Genetics, Genomics and Experimental Pathology, The Oncology Institute “Prof. Dr. Ion Chiricuta” Cluj-Napoca, 400015 Cluj-Napoca, Romania;
| | - Alexandru Irimie
- “Iuliu Hatieganu” University of Medicine and Pharmacy, Faculty of Medicine, 400126 Cluj-Napoca, Romania; (S.T.); (C.M.G.); (A.I.)
- Department of Surgical Oncology, The Oncology Institute “Prof. Dr. Ion Chiricuta” Cluj-Napoca, 400015 Cluj-Napoca, Romania
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13
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Vevea JD, Kusick GF, Courtney KC, Chen E, Watanabe S, Chapman ER. Synaptotagmin 7 is targeted to the axonal plasma membrane through γ-secretase processing to promote synaptic vesicle docking in mouse hippocampal neurons. eLife 2021; 10:e67261. [PMID: 34543184 PMCID: PMC8452306 DOI: 10.7554/elife.67261] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 08/27/2021] [Indexed: 12/28/2022] Open
Abstract
Synaptotagmin 7 (SYT7) has emerged as a key regulator of presynaptic function, but its localization and precise role in the synaptic vesicle cycle remain the subject of debate. Here, we used iGluSnFR to optically interrogate glutamate release, at the single-bouton level, in SYT7KO-dissociated mouse hippocampal neurons. We analyzed asynchronous release, paired-pulse facilitation, and synaptic vesicle replenishment and found that SYT7 contributes to each of these processes to different degrees. 'Zap-and-freeze' electron microscopy revealed that a loss of SYT7 diminishes docking of synaptic vesicles after a stimulus and inhibits the recovery of depleted synaptic vesicles after a stimulus train. SYT7 supports these functions from the axonal plasma membrane, where its localization and stability require both γ-secretase-mediated cleavage and palmitoylation. In summary, SYT7 is a peripheral membrane protein that controls multiple modes of synaptic vesicle (SV) exocytosis and plasticity, in part, through enhancing activity-dependent docking of SVs.
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Affiliation(s)
- Jason D Vevea
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Grant F Kusick
- Department of Cell Biology, Johns Hopkins University, School of MedicineBaltimoreUnited States
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University, School of MedicineBaltimoreUnited States
| | - Kevin C Courtney
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Erin Chen
- Department of Cell Biology, Johns Hopkins University, School of MedicineBaltimoreUnited States
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University, School of MedicineBaltimoreUnited States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of MedicineBaltimoreUnited States
| | - Edwin R Chapman
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
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14
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Bourgeois-Jaarsma Q, Miaja Hernandez P, Groffen AJ. Ca 2+ sensor proteins in spontaneous release and synaptic plasticity: Limited contribution of Doc2c, rabphilin-3a and synaptotagmin 7 in hippocampal glutamatergic neurons. Mol Cell Neurosci 2021; 112:103613. [PMID: 33753311 DOI: 10.1016/j.mcn.2021.103613] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 03/09/2021] [Accepted: 03/13/2021] [Indexed: 11/28/2022] Open
Abstract
Presynaptic neurotransmitter release is strictly regulated by SNARE proteins, Ca2+ and a number of Ca2+ sensors including synaptotagmins (Syts) and Double C2 domain proteins (Doc2s). More than seventy years after the original description of spontaneous release, the mechanism that regulates this process is still poorly understood. Syt-1, Syt7 and Doc2 proteins contribute predominantly, but not exclusively, to synchronous, asynchronous and spontaneous phases of release. The proteins share a conserved tandem C2 domain architecture, but are functionally diverse in their subcellular location, Ca2+-binding properties and protein interactions. In absence of Syt-1, Doc2a and -b, neurons still exhibit spontaneous vesicle fusion which remains Ca2+-sensitive, suggesting the existence of additional sensors. Here, we selected Doc2c, rabphilin-3a and Syt-7 as three potential Ca2+ sensors for their sequence homology with Syt-1 and Doc2b. We genetically ablated each candidate gene in absence of Doc2a and -b and investigated spontaneous and evoked release in glutamatergic hippocampal neurons, cultured either in networks or on microglial islands (autapses). The removal of Doc2c had no effect on spontaneous or evoked release. Syt-7 removal also did not affect spontaneous release, although it altered short-term plasticity by accentuating short-term depression. The removal of rabphilin caused an increased spontaneous release frequency in network cultures, an effect that was not observed in autapses. Taken together, we conclude that Doc2c and Syt-7 do not affect spontaneous release of glutamate in hippocampal neurons, while our results suggest a possible regulatory role of rabphilin-3a in neuronal networks. These findings importantly narrow down the repertoire of synaptic Ca2+ sensors that may be implicated in the spontaneous release of glutamate.
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Affiliation(s)
- Quentin Bourgeois-Jaarsma
- Department of Functional Genomics, Faculty of Science, Center for Neurogenomics and Cognitive Research, VU University, De Boelelaan 1085, 1081HV Amsterdam, the Netherlands
| | - Pablo Miaja Hernandez
- Department of Functional Genomics, Faculty of Science, Center for Neurogenomics and Cognitive Research, VU University, De Boelelaan 1085, 1081HV Amsterdam, the Netherlands
| | - Alexander J Groffen
- Department of Functional Genomics, Faculty of Science, Center for Neurogenomics and Cognitive Research, VU University, De Boelelaan 1085, 1081HV Amsterdam, the Netherlands; Department of Clinical Genetics, VU Medical Center, De Boelelaan 1085, 1081HV Amsterdam, the Netherlands.
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15
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Chamberlain LH, Shipston MJ, Gould GW. Regulatory effects of protein S-acylation on insulin secretion and insulin action. Open Biol 2021; 11:210017. [PMID: 33784857 PMCID: PMC8061761 DOI: 10.1098/rsob.210017] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Post-translational modifications (PTMs) such as phosphorylation and ubiquitination are well-studied events with a recognized importance in all aspects of cellular function. By contrast, protein S-acylation, although a widespread PTM with important functions in most physiological systems, has received far less attention. Perturbations in S-acylation are linked to various disorders, including intellectual disability, cancer and diabetes, suggesting that this less-studied modification is likely to be of considerable biological importance. As an exemplar, in this review, we focus on the newly emerging links between S-acylation and the hormone insulin. Specifically, we examine how S-acylation regulates key components of the insulin secretion and insulin response pathways. The proteins discussed highlight the diverse array of proteins that are modified by S-acylation, including channels, transporters, receptors and trafficking proteins and also illustrate the diverse effects that S-acylation has on these proteins, from membrane binding and micro-localization to regulation of protein sorting and protein interactions.
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Affiliation(s)
- Luke H Chamberlain
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Michael J Shipston
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - Gwyn W Gould
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
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16
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Function of Drosophila Synaptotagmins in membrane trafficking at synapses. Cell Mol Life Sci 2021; 78:4335-4364. [PMID: 33619613 PMCID: PMC8164606 DOI: 10.1007/s00018-021-03788-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/29/2021] [Accepted: 02/09/2021] [Indexed: 12/13/2022]
Abstract
The Synaptotagmin (SYT) family of proteins play key roles in regulating membrane trafficking at neuronal synapses. Using both Ca2+-dependent and Ca2+-independent interactions, several SYT isoforms participate in synchronous and asynchronous fusion of synaptic vesicles (SVs) while preventing spontaneous release that occurs in the absence of stimulation. Changes in the function or abundance of the SYT1 and SYT7 isoforms alter the number and route by which SVs fuse at nerve terminals. Several SYT family members also regulate trafficking of other subcellular organelles at synapses, including dense core vesicles (DCV), exosomes, and postsynaptic vesicles. Although SYTs are linked to trafficking of multiple classes of synaptic membrane compartments, how and when they interact with lipids, the SNARE machinery and other release effectors are still being elucidated. Given mutations in the SYT family cause disorders in both the central and peripheral nervous system in humans, ongoing efforts are defining how these proteins regulate vesicle trafficking within distinct neuronal compartments. Here, we review the Drosophila SYT family and examine their role in synaptic communication. Studies in this invertebrate model have revealed key similarities and several differences with the predicted activity of their mammalian counterparts. In addition, we highlight the remaining areas of uncertainty in the field and describe outstanding questions on how the SYT family regulates membrane trafficking at nerve terminals.
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17
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Yu S, Chen J, Quan M, Li L, Li Y, Gao Y. CD63 negatively regulates hepatocellular carcinoma development through suppression of inflammatory cytokine-induced STAT3 activation. J Cell Mol Med 2021; 25:1024-1034. [PMID: 33277798 PMCID: PMC7812266 DOI: 10.1111/jcmm.16167] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 11/12/2020] [Accepted: 11/17/2020] [Indexed: 12/15/2022] Open
Abstract
Tetraspanin CD63 has been widely implicated in tumour progression of human malignancies. However, its role in the tumorigenesis and metastasis of hepatocellular carcinoma (HCC) remains unclear yet. In the present study, we aimed to investigate the specific function and underlying mechanisms of CD63 in HCC progression. CD63 expression in HCC tissues was detected using immunohistochemistry and quantitative real-time PCR analyses; effects of CD63 on HCC cell proliferation and migration were investigated by CCK-8 assay, colony formation assay, transwell assay and a xenograft model of nude mice. RNA-sequencing, bioinformatics analysis, dual-luciferase reporter assay and Western blot analysis were performed to explore the underlying molecular mechanisms. Results of our experiments showed that CD63 expression was frequently reduced in HCC tissues compared with adjacent normal tissues, and decreased CD63 expression was significantly associated with larger tumour size, distant site metastasis and higher tumour stages of HCC. Overexpression of CD63 inhibited HCC cell proliferation and migration, whereas knockdown of CD63 promoted these phenotypes. IL-6, IL-27 and STAT3 activity was regulated by CD63, and blockade of STAT3 activation impaired the promotive effects of CD63 knockdown on HCC cell growth and migration. Our findings identified a novel CD63-IL-6/IL-27-STAT3 axis in the development of HCC and provided a potential target for the diagnosis and treatment of this disease.
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Affiliation(s)
- Shijun Yu
- Department of OncologyShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Jingde Chen
- Department of OncologyShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Ming Quan
- Department of OncologyShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Li Li
- Department of OncologyShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Yandong Li
- Department of OncologyShanghai East HospitalTongji University School of MedicineShanghaiChina
| | - Yong Gao
- Department of OncologyShanghai East HospitalTongji University School of MedicineShanghaiChina
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18
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Levic DS, Ryan S, Marjoram L, Honeycutt J, Bagwell J, Bagnat M. Distinct roles for luminal acidification in apical protein sorting and trafficking in zebrafish. J Cell Biol 2020; 219:133852. [PMID: 32328632 PMCID: PMC7147097 DOI: 10.1083/jcb.201908225] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/20/2019] [Accepted: 01/27/2020] [Indexed: 02/06/2023] Open
Abstract
Epithelial cell physiology critically depends on the asymmetric distribution of channels and transporters. However, the mechanisms targeting membrane proteins to the apical surface are still poorly understood. Here, we performed a visual forward genetic screen in the zebrafish intestine and identified mutants with defective apical targeting of membrane proteins. One of these mutants, affecting the vacuolar H+-ATPase gene atp6ap1b, revealed specific requirements for luminal acidification in apical, but not basolateral, membrane protein sorting and transport. Using a low temperature block assay combined with genetic and pharmacologic perturbation of luminal pH, we monitored transport of newly synthesized membrane proteins from the TGN to apical membrane in live zebrafish. We show that vacuolar H+-ATPase activity regulates sorting of O-glycosylated proteins at the TGN, as well as Rab8-dependent post-Golgi trafficking of different classes of apical membrane proteins. Thus, luminal acidification plays distinct and specific roles in apical membrane biogenesis.
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Affiliation(s)
| | - Sean Ryan
- Department of Cell Biology, Duke University, Durham, NC
| | | | | | | | - Michel Bagnat
- Department of Cell Biology, Duke University, Durham, NC
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19
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Kreutzberger AJB, Kiessling V, Doyle CA, Schenk N, Upchurch CM, Elmer-Dixon M, Ward AE, Preobraschenski J, Hussein SS, Tomaka W, Seelheim P, Kattan I, Harris M, Liang B, Kenworthy AK, Desai BN, Leitinger N, Anantharam A, Castle JD, Tamm LK. Distinct insulin granule subpopulations implicated in the secretory pathology of diabetes types 1 and 2. eLife 2020; 9:e62506. [PMID: 33164744 PMCID: PMC7738183 DOI: 10.7554/elife.62506] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/06/2020] [Indexed: 12/12/2022] Open
Abstract
Insulin secretion from β-cells is reduced at the onset of type-1 and during type-2 diabetes. Although inflammation and metabolic dysfunction of β-cells elicit secretory defects associated with type-1 or type-2 diabetes, accompanying changes to insulin granules have not been established. To address this, we performed detailed functional analyses of insulin granules purified from cells subjected to model treatments that mimic type-1 and type-2 diabetic conditions and discovered striking shifts in calcium affinities and fusion characteristics. We show that this behavior is correlated with two subpopulations of insulin granules whose relative abundance is differentially shifted depending on diabetic model condition. The two types of granules have different release characteristics, distinct lipid and protein compositions, and package different secretory contents alongside insulin. This complexity of β-cell secretory physiology establishes a direct link between granule subpopulation and type of diabetes and leads to a revised model of secretory changes in the diabetogenic process.
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Affiliation(s)
- Alex J B Kreutzberger
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Volker Kiessling
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Catherine A Doyle
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Noah Schenk
- Department of Pharmacology, University of MichiganAnn ArborUnited States
| | - Clint M Upchurch
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Margaret Elmer-Dixon
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Amanda E Ward
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Julia Preobraschenski
- Department of Neurobiology, Max Planck Institute for Biophysical ChemistryGöttingenGermany
- Cluster of Excellence in Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells and Institute for Auditory Neuroscience, University of GöttingenGöttingenGermany
| | - Syed S Hussein
- Department of Microbiology, University of VirginiaCharlottesvilleUnited States
| | - Weronika Tomaka
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Patrick Seelheim
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Iman Kattan
- Department of Neurobiology, Max Planck Institute for Biophysical ChemistryGöttingenGermany
| | - Megan Harris
- Department of Cell Biology, University of VirginiaCharlottesvilleUnited States
| | - Binyong Liang
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Anne K Kenworthy
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Bimal N Desai
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Norbert Leitinger
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Arun Anantharam
- Department of Pharmacology, University of MichiganAnn ArborUnited States
| | - J David Castle
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department of Cell Biology, University of VirginiaCharlottesvilleUnited States
| | - Lukas K Tamm
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
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20
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Guan Z, Quiñones-Frías MC, Akbergenova Y, Littleton JT. Drosophila Synaptotagmin 7 negatively regulates synaptic vesicle release and replenishment in a dosage-dependent manner. eLife 2020; 9:e55443. [PMID: 32343229 PMCID: PMC7224696 DOI: 10.7554/elife.55443] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 04/28/2020] [Indexed: 01/03/2023] Open
Abstract
Synchronous neurotransmitter release is triggered by Ca2+ binding to the synaptic vesicle protein Synaptotagmin 1, while asynchronous fusion and short-term facilitation is hypothesized to be mediated by plasma membrane-localized Synaptotagmin 7 (SYT7). We generated mutations in Drosophila Syt7 to determine if it plays a conserved role as the Ca2+ sensor for these processes. Electrophysiology and quantal imaging revealed evoked release was elevated 2-fold. Syt7 mutants also had a larger pool of readily-releasable vesicles, faster recovery following stimulation, and intact facilitation. Syt1/Syt7 double mutants displayed more release than Syt1 mutants alone, indicating SYT7 does not mediate the residual asynchronous release remaining in the absence of SYT1. SYT7 localizes to an internal membrane tubular network within the peri-active zone, but does not enrich at active zones. These findings indicate the two Ca2+ sensor model of SYT1 and SYT7 mediating all phases of neurotransmitter release and facilitation is not applicable at Drosophila synapses.
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Affiliation(s)
- Zhuo Guan
- The Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Monica C Quiñones-Frías
- The Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Yulia Akbergenova
- The Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
| | - J Troy Littleton
- The Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of TechnologyCambridgeUnited States
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21
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Bajaj L, Lotfi P, Pal R, di Ronza A, Sharma J, Sardiello M. Lysosome biogenesis in health and disease. J Neurochem 2019; 148:573-589. [PMID: 30092616 PMCID: PMC6368902 DOI: 10.1111/jnc.14564] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/01/2018] [Accepted: 08/03/2018] [Indexed: 01/01/2023]
Abstract
This review focuses on the pathways that regulate lysosome biogenesis and that are implicated in numerous degenerative storage diseases, including lysosomal storage disorders and late-onset neurodegenerative diseases. Lysosomal proteins are synthesized in the endoplasmic reticulum and trafficked to the endolysosomal system through the secretory route. Several receptors have been characterized that execute post-Golgi trafficking of lysosomal proteins. Some of them recognize their cargo proteins based on specific amino acid signatures, others based on a particular glycan modification that is exclusively found on lysosomal proteins. Nearly all receptors serving lysosome biogenesis are under the transcriptional control of transcription factor EB (TFEB), a master regulator of the lysosomal system. TFEB coordinates the expression of lysosomal hydrolases, lysosomal membrane proteins, and autophagy proteins in response to pathways sensing lysosomal stress and the nutritional conditions of the cell among other stimuli. TFEB is primed for activation in lysosomal storage disorders but surprisingly its function is impaired in some late-onset neurodegenerative storage diseases like Alzheimer's and Parkinson's, because of specific detrimental interactions that limit TFEB expression or activation. Thus, disrupted TFEB function presumably plays a role in the pathogenesis of these diseases. Multiple studies in animal models of degenerative storage diseases have shown that exogenous expression of TFEB and pharmacological activation of endogenous TFEB attenuate disease phenotypes. These results highlight TFEB-mediated enhancement of lysosomal biogenesis and function as a candidate strategy to counteract the progression of these diseases. This article is part of the Special Issue "Lysosomal Storage Disorders".
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Affiliation(s)
- Lakshya Bajaj
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030 USA
| | - Parisa Lotfi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030 USA
| | - Rituraj Pal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030 USA
| | - Alberto di Ronza
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030 USA
| | - Jaiprakash Sharma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030 USA
| | - Marco Sardiello
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030 USA
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22
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MacDougall DD, Lin Z, Chon NL, Jackman SL, Lin H, Knight JD, Anantharam A. The high-affinity calcium sensor synaptotagmin-7 serves multiple roles in regulated exocytosis. J Gen Physiol 2018; 150:783-807. [PMID: 29794152 PMCID: PMC5987875 DOI: 10.1085/jgp.201711944] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 05/07/2018] [Indexed: 12/19/2022] Open
Abstract
MacDougall et al. review the structure and function of the calcium sensor synaptotagmin-7 in exocytosis. Synaptotagmin (Syt) proteins comprise a 17-member family, many of which trigger exocytosis in response to calcium. Historically, most studies have focused on the isoform Syt-1, which serves as the primary calcium sensor in synchronous neurotransmitter release. Recently, Syt-7 has become a topic of broad interest because of its extreme calcium sensitivity and diversity of roles in a wide range of cell types. Here, we review the known and emerging roles of Syt-7 in various contexts and stress the importance of its actions. Unique functions of Syt-7 are discussed in light of recent imaging, electrophysiological, and computational studies. Particular emphasis is placed on Syt-7–dependent regulation of synaptic transmission and neuroendocrine cell secretion. Finally, based on biochemical and structural data, we propose a mechanism to link Syt-7’s role in membrane fusion with its role in subsequent fusion pore expansion via strong calcium-dependent phospholipid binding.
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Affiliation(s)
| | - Zesen Lin
- Department of Pharmacology, University of Michigan, Ann Arbor, MI
| | - Nara L Chon
- Department of Chemistry, University of Colorado, Denver, CO
| | - Skyler L Jackman
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Hai Lin
- Department of Chemistry, University of Colorado, Denver, CO
| | | | - Arun Anantharam
- Department of Pharmacology, University of Michigan, Ann Arbor, MI
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23
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Jiang H, Zhang X, Chen X, Aramsangtienchai P, Tong Z, Lin H. Protein Lipidation: Occurrence, Mechanisms, Biological Functions, and Enabling Technologies. Chem Rev 2018; 118:919-988. [PMID: 29292991 DOI: 10.1021/acs.chemrev.6b00750] [Citation(s) in RCA: 286] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein lipidation, including cysteine prenylation, N-terminal glycine myristoylation, cysteine palmitoylation, and serine and lysine fatty acylation, occurs in many proteins in eukaryotic cells and regulates numerous biological pathways, such as membrane trafficking, protein secretion, signal transduction, and apoptosis. We provide a comprehensive review of protein lipidation, including descriptions of proteins known to be modified and the functions of the modifications, the enzymes that control them, and the tools and technologies developed to study them. We also highlight key questions about protein lipidation that remain to be answered, the challenges associated with answering such questions, and possible solutions to overcome these challenges.
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Affiliation(s)
- Hong Jiang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiaoyu Zhang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiao Chen
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Pornpun Aramsangtienchai
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Zhen Tong
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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24
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Rodenburg RNP, Snijder J, van de Waterbeemd M, Schouten A, Granneman J, Heck AJR, Gros P. Stochastic palmitoylation of accessible cysteines in membrane proteins revealed by native mass spectrometry. Nat Commun 2017; 8:1280. [PMID: 29097667 PMCID: PMC5668376 DOI: 10.1038/s41467-017-01461-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 09/19/2017] [Indexed: 01/09/2023] Open
Abstract
Palmitoylation affects membrane partitioning, trafficking and activities of membrane proteins. However, how specificity of palmitoylation and multiple palmitoylations in membrane proteins are determined is not well understood. Here, we profile palmitoylation states of three human claudins, human CD20 and cysteine-engineered prokaryotic KcsA and bacteriorhodopsin by native mass spectrometry. Cysteine scanning of claudin-3, KcsA, and bacteriorhodopsin shows that palmitoylation is independent of a sequence motif. Palmitoylations are observed for cysteines exposed on the protein surface and situated up to 8 Å into the inner leaflet of the membrane. Palmitoylation on multiple sites in claudin-3 and CD20 occurs stochastically, giving rise to a distribution of palmitoylated membrane-protein isoforms. Non-native sites in claudin-3 indicate that membrane-protein function imposed evolutionary restraints on native palmitoylation sites. These results suggest a generic, stochastic membrane-protein palmitoylation process that is determined by the accessibility of palmitoyl-acyl transferases to cysteines on membrane-embedded proteins, and not by a preferred substrate-sequence motif.
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Affiliation(s)
- Remco N P Rodenburg
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Dept. of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584CH, Utrecht, The Netherlands
| | - Joost Snijder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Padualaan 8, 3584CH, Utrecht, The Netherlands
| | - Michiel van de Waterbeemd
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Padualaan 8, 3584CH, Utrecht, The Netherlands
| | - Arie Schouten
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Dept. of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584CH, Utrecht, The Netherlands
| | - Joke Granneman
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Dept. of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584CH, Utrecht, The Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, Padualaan 8, 3584CH, Utrecht, The Netherlands.
| | - Piet Gros
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Dept. of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584CH, Utrecht, The Netherlands.
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25
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N-terminal S-acylation facilitates tonoplast targeting of the calcium sensor CBL6. FEBS Lett 2017; 591:3745-3756. [DOI: 10.1002/1873-3468.12880] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 09/22/2017] [Accepted: 09/22/2017] [Indexed: 12/21/2022]
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26
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Daniotti JL, Pedro MP, Valdez Taubas J. The role of S-acylation in protein trafficking. Traffic 2017; 18:699-710. [DOI: 10.1111/tra.12510] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 08/16/2017] [Accepted: 08/20/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Jose L. Daniotti
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET; Universidad Nacional de Córdoba; Córdoba Argentina
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas; Universidad Nacional de Córdoba; Córdoba Argentina
| | - Maria P. Pedro
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET; Universidad Nacional de Córdoba; Córdoba Argentina
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas; Universidad Nacional de Córdoba; Córdoba Argentina
| | - Javier Valdez Taubas
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET; Universidad Nacional de Córdoba; Córdoba Argentina
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas; Universidad Nacional de Córdoba; Córdoba Argentina
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27
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Bulfone-Paus S, Nilsson G, Draber P, Blank U, Levi-Schaffer F. Positive and Negative Signals in Mast Cell Activation. Trends Immunol 2017; 38:657-667. [DOI: 10.1016/j.it.2017.01.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/17/2017] [Accepted: 01/27/2017] [Indexed: 01/05/2023]
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28
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Li Y, Qi B. Progress toward Understanding Protein S-acylation: Prospective in Plants. FRONTIERS IN PLANT SCIENCE 2017; 8:346. [PMID: 28392791 PMCID: PMC5364179 DOI: 10.3389/fpls.2017.00346] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 02/28/2017] [Indexed: 05/02/2023]
Abstract
S-acylation, also known as S-palmitoylation or palmitoylation, is a reversible post-translational lipid modification in which long chain fatty acid, usually the 16-carbon palmitate, covalently attaches to a cysteine residue(s) throughout the protein via a thioester bond. It is involved in an array of important biological processes during growth and development, reproduction and stress responses in plant. S-acylation is a ubiquitous mechanism in eukaryotes catalyzed by a family of enzymes called Protein S-Acyl Transferases (PATs). Since the discovery of the first PAT in yeast in 2002 research in S-acylation has accelerated in the mammalian system and followed by in plant. However, it is still a difficult field to study due to the large number of PATs and even larger number of putative S-acylated substrate proteins they modify in each genome. This is coupled with drawbacks in the techniques used to study S-acylation, leading to the slower progress in this field compared to protein phosphorylation, for example. In this review we will summarize the discoveries made so far based on knowledge learnt from the characterization of protein S-acyltransferases and the S-acylated proteins, the interaction mechanisms between PAT and its specific substrate protein(s) in yeast and mammals. Research in protein S-acylation and PATs in plants will also be covered although this area is currently less well studied in yeast and mammalian systems.
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29
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Subcellular Trafficking of Mammalian Lysosomal Proteins: An Extended View. Int J Mol Sci 2016; 18:ijms18010047. [PMID: 28036022 PMCID: PMC5297682 DOI: 10.3390/ijms18010047] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 12/15/2016] [Accepted: 12/18/2016] [Indexed: 01/02/2023] Open
Abstract
Lysosomes clear macromolecules, maintain nutrient and cholesterol homeostasis, participate in tissue repair, and in many other cellular functions. To assume these tasks, lysosomes rely on their large arsenal of acid hydrolases, transmembrane proteins and membrane-associated proteins. It is therefore imperative that, post-synthesis, these proteins are specifically recognized as lysosomal components and are correctly sorted to this organelle through the endosomes. Lysosomal transmembrane proteins contain consensus motifs in their cytosolic regions (tyrosine- or dileucine-based) that serve as sorting signals to the endosomes, whereas most lysosomal acid hydrolases acquire mannose 6-phosphate (Man-6-P) moieties that mediate binding to two membrane receptors with endosomal sorting motifs in their cytosolic tails. These tyrosine- and dileucine-based motifs are tickets for boarding in clathrin-coated carriers that transport their cargo from the trans-Golgi network and plasma membrane to the endosomes. However, increasing evidence points to additional mechanisms participating in the biogenesis of lysosomes. In some cell types, for example, there are alternatives to the Man-6-P receptors for the transport of some acid hydrolases. In addition, several “non-consensus” sorting motifs have been identified, and atypical transport routes to endolysosomes have been brought to light. These “unconventional” or “less known” transport mechanisms are the focus of this review.
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30
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Wolfes AC, Ahmed S, Awasthi A, Stahlberg MA, Rajput A, Magruder DS, Bonn S, Dean C. A novel method for culturing stellate astrocytes reveals spatially distinct Ca2+ signaling and vesicle recycling in astrocytic processes. J Gen Physiol 2016; 149:149-170. [PMID: 27908976 PMCID: PMC5217085 DOI: 10.1085/jgp.201611607] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 11/09/2016] [Accepted: 11/11/2016] [Indexed: 12/20/2022] Open
Abstract
Communication between astrocytes and neurons has been difficult to study because cultured astrocytes do not resemble those in vivo. Wolfes et al. develop a stellate astrocyte monoculture with physiological characteristics and find that VAMP2 and SYT7 mark distinct vesicle populations in astrocytes. Interactions between astrocytes and neurons rely on the release and uptake of glial and neuronal molecules. But whether astrocytic vesicles exist and exocytose in a regulated or constitutive fashion is under debate. The majority of studies have relied on indirect methods or on astrocyte cultures that do not resemble stellate astrocytes found in vivo. Here, to investigate vesicle-associated proteins and exocytosis in stellate astrocytes specifically, we developed a simple, fast, and economical method for growing stellate astrocyte monocultures. This method is superior to other monocultures in terms of astrocyte morphology, mRNA expression profile, protein expression of cell maturity markers, and Ca2+ fluctuations: In astrocytes transduced with GFAP promoter–driven Lck-GCaMP3, spontaneous Ca2+ events in distinct domains (somata, branchlets, and microdomains) are similar to those in astrocytes co-cultured with other glia and neurons but unlike Ca2+ events in astrocytes prepared using the McCarthy and de Vellis (MD) method and immunopanned (IP) astrocytes. We identify two distinct populations of constitutively recycling vesicles (harboring either VAMP2 or SYT7) specifically in branchlets of cultured stellate astrocytes. SYT7 is developmentally regulated in these astrocytes, and we observe significantly fewer synapses in wild-type mouse neurons grown on Syt7−/− astrocytes. SYT7 may thus be involved in trafficking or releasing synaptogenic factors. In summary, our novel method yields stellate astrocyte monocultures that can be used to study Ca2+ signaling and vesicle recycling and dynamics in astrocytic processes.
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Affiliation(s)
- Anne C Wolfes
- Trans-Synaptic Signaling Group, European Neuroscience Institute Göttingen, 37077 Göttingen, Germany
| | - Saheeb Ahmed
- Trans-Synaptic Signaling Group, European Neuroscience Institute Göttingen, 37077 Göttingen, Germany
| | - Ankit Awasthi
- Trans-Synaptic Signaling Group, European Neuroscience Institute Göttingen, 37077 Göttingen, Germany
| | - Markus A Stahlberg
- Trans-Synaptic Signaling Group, European Neuroscience Institute Göttingen, 37077 Göttingen, Germany
| | - Ashish Rajput
- Research Group for Computational Systems Biology, German Center for Neurodegenerative Disease (DZNE), 37075 Göttingen, Germany
| | - Daniel S Magruder
- Research Group for Computational Systems Biology, German Center for Neurodegenerative Disease (DZNE), 37075 Göttingen, Germany
| | - Stefan Bonn
- Research Group for Computational Systems Biology, German Center for Neurodegenerative Disease (DZNE), 37075 Göttingen, Germany
| | - Camin Dean
- Trans-Synaptic Signaling Group, European Neuroscience Institute Göttingen, 37077 Göttingen, Germany
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31
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Yong T, Hu J, Zhang X, Li F, Yang H, Gan L, Yang X. Domino-Like Intercellular Delivery of Undecylenic Acid-Conjugated Porous Silicon Nanoparticles for Deep Tumor Penetration. ACS APPLIED MATERIALS & INTERFACES 2016; 8:27611-27621. [PMID: 27653799 DOI: 10.1021/acsami.6b11127] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Improving the intratumoral distribution of anticancer agents remains the critical challenge for developing efficient cancer chemotherapy. Luminescent porous silicon nanoparticles (PSiNPs) have attracted considerable attention in the biomedical field especially in drug delivery. Here, we described the lysosomal exocytosis-mediated domino-like intercellular delivery of undecylenic acid-conjugated PSiNPs (UA-PSiNPs) for deep tumor penetration. UA-PSiNPs with significantly improved stability in physiological conditions were internalized into tumor cells by macropinocytosis-, caveolae-, and clathrin-mediated endocytosis and mainly colocalized with Golgi apparatus and lysosomes. Substantial evidence showed that UA-PSiNPs was excreted from cells via lysosomal exocytosis after cellular uptake. The exocytosed UA-PSiNPs induced a domino-like infection of adjacent cancer cells and allowed encapsulated doxorubicin (DOX) to deeply penetrate into both three-dimensional tumor spheroids and in vivo tumors. In addition, DOX-loaded UA-PSiNPs exhibited strong antitumor activity and few side effects in vivo. This study demonstrated that UA-PSiNPs as a drug carrier might be applied for deep tumor penetration, offering a new insight into the design of more efficient delivery systems of anticancer drugs.
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Affiliation(s)
- Tuying Yong
- National Engineering Research Center for Nanomedicine, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, Hubei 430074, China
| | - Jun Hu
- National Engineering Research Center for Nanomedicine, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, Hubei 430074, China
| | - Xiaoqiong Zhang
- National Engineering Research Center for Nanomedicine, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, Hubei 430074, China
| | - Fuying Li
- National Engineering Research Center for Nanomedicine, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, Hubei 430074, China
| | - Hao Yang
- National Engineering Research Center for Nanomedicine, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, Hubei 430074, China
| | - Lu Gan
- National Engineering Research Center for Nanomedicine, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, Hubei 430074, China
| | - Xiangliang Yang
- National Engineering Research Center for Nanomedicine, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology , Wuhan, Hubei 430074, China
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32
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The CD63-Syntenin-1 Complex Controls Post-Endocytic Trafficking of Oncogenic Human Papillomaviruses. Sci Rep 2016; 6:32337. [PMID: 27578500 PMCID: PMC5006017 DOI: 10.1038/srep32337] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 08/02/2016] [Indexed: 12/31/2022] Open
Abstract
Human papillomaviruses enter host cells via a clathrin-independent endocytic pathway involving tetraspanin proteins. However, post-endocytic trafficking required for virus capsid disassembly remains unclear. Here we demonstrate that the early trafficking pathway of internalised HPV particles involves tetraspanin CD63, syntenin-1 and ESCRT-associated adaptor protein ALIX. Following internalisation, viral particles are found in CD63-positive endosomes recruiting syntenin-1, a CD63-interacting adaptor protein. Electron microscopy and immunofluorescence experiments indicate that the CD63-syntenin-1 complex controls delivery of internalised viral particles to multivesicular endosomes. Accordingly, infectivity of high-risk HPV types 16, 18 and 31 as well as disassembly and post-uncoating processing of viral particles was markedly suppressed in CD63 or syntenin-1 depleted cells. Our analyses also present the syntenin-1 interacting protein ALIX as critical for HPV infection and CD63-syntenin-1-ALIX complex formation as a prerequisite for intracellular transport enabling viral capsid disassembly. Thus, our results identify the CD63-syntenin-1-ALIX complex as a key regulatory component in post-endocytic HPV trafficking.
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33
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Cooper C, Clode PL, Peacock C, Thompson RCA. Host-Parasite Relationships and Life Histories of Trypanosomes in Australia. ADVANCES IN PARASITOLOGY 2016; 97:47-109. [PMID: 28325373 DOI: 10.1016/bs.apar.2016.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Trypanosomes constitute a group of flagellate protozoan parasites responsible for a number of important, yet neglected, diseases in both humans and livestock. The most significantly studied include the causative agents of African sleeping sickness (Trypanosoma brucei) and Chagas disease (Trypanosoma cruzi) in humans. Much of our knowledge about trypanosome host-parasite relationships and life histories has come from these two human pathogens. Recent investigations into the diversity and life histories of wildlife trypanosomes in Australia highlight that there exists a great degree of biological and behavioural variation within and between trypanosomes. In addition, the genetic relationships between some Australian trypanosomes show that they are unexpectedly more closely related to species outside Australia than within it. These findings have led to a growing focus on the importance of understanding parasites occurring naturally in wildlife to (1) better document parasite biodiversity, (2) determine evolutionary relationships and degree of host specificity, (3) understand host-parasite interactions and the role of parasites in the natural ecosystem and (4) identify biosecurity issues of emerging disease in both wildlife and human populations. Here we review what is known about the diversity, life histories, host-parasite interactions and evolutionary relationships of trypanosomes in Australian wildlife. In this context, we focus upon the genetic proximity of key Australian species to the pathogenic T. cruzi and discuss similarities in their biology and behaviour that present a potential risk of human disease transmission by Australian vectors and wildlife.
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Affiliation(s)
- C Cooper
- The University of Western Australia, Crawley, WA, Australia
| | - P L Clode
- The University of Western Australia, Crawley, WA, Australia
| | - C Peacock
- The University of Western Australia, Crawley, WA, Australia; Telethon Kids Institute, Subiaco, WA, Australia
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34
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Resh MD. Fatty acylation of proteins: The long and the short of it. Prog Lipid Res 2016; 63:120-31. [PMID: 27233110 DOI: 10.1016/j.plipres.2016.05.002] [Citation(s) in RCA: 193] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/19/2016] [Accepted: 05/21/2016] [Indexed: 12/22/2022]
Abstract
Long, short and medium chain fatty acids are covalently attached to hundreds of proteins. Each fatty acid confers distinct biochemical properties, enabling fatty acylation to regulate intracellular trafficking, subcellular localization, protein-protein and protein-lipid interactions. Myristate and palmitate represent the most common fatty acid modifying groups. New insights into how fatty acylation reactions are catalyzed, and how fatty acylation regulates protein structure and function continue to emerge. Myristate is typically linked to an N-terminal glycine, but recent studies reveal that lysines can also be myristoylated. Enzymes that remove N-terminal myristoyl-glycine or myristate from lysines have now been identified. DHHC proteins catalyze S-palmitoylation, but the mechanisms that regulate substrate recognition by individual DHHC family members remain to be determined. New studies continue to reveal thioesterases that remove palmitate from S-acylated proteins. Another area of rapid expansion is fatty acylation of the secreted proteins hedgehog, Wnt and Ghrelin, by Hhat, Porcupine and GOAT, respectively. Understanding how these membrane bound O-acyl transferases recognize their protein and fatty acyl CoA substrates is an active area of investigation, and is punctuated by the finding that these enzymes are potential drug targets in human diseases.
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Affiliation(s)
- Marilyn D Resh
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 143, New York, NY 10075, United States.
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35
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Abstract
Protein S-acylation, the only fully reversible posttranslational lipid modification of proteins, is emerging as a ubiquitous mechanism to control the properties and function of a diverse array of proteins and consequently physiological processes. S-acylation results from the enzymatic addition of long-chain lipids, most typically palmitate, onto intracellular cysteine residues of soluble and transmembrane proteins via a labile thioester linkage. Addition of lipid results in increases in protein hydrophobicity that can impact on protein structure, assembly, maturation, trafficking, and function. The recent explosion in global S-acylation (palmitoyl) proteomic profiling as a result of improved biochemical tools to assay S-acylation, in conjunction with the recent identification of enzymes that control protein S-acylation and de-acylation, has opened a new vista into the physiological function of S-acylation. This review introduces key features of S-acylation and tools to interrogate this process, and highlights the eclectic array of proteins regulated including membrane receptors, ion channels and transporters, enzymes and kinases, signaling adapters and chaperones, cell adhesion, and structural proteins. We highlight recent findings correlating disruption of S-acylation to pathophysiology and disease and discuss some of the major challenges and opportunities in this rapidly expanding field.
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Affiliation(s)
- Luke H Chamberlain
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Strathclyde University, Glasgow, United Kingdom; and Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael J Shipston
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Strathclyde University, Glasgow, United Kingdom; and Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
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36
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Oeste CL, Pinar M, Schink KO, Martínez-Turrión J, Stenmark H, Peñalva MA, Pérez-Sala D. An isoprenylation and palmitoylation motif promotes intraluminal vesicle delivery of proteins in cells from distant species. PLoS One 2014; 9:e107190. [PMID: 25207810 PMCID: PMC4160200 DOI: 10.1371/journal.pone.0107190] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 08/07/2014] [Indexed: 12/22/2022] Open
Abstract
The C-terminal ends of small GTPases contain hypervariable sequences which may be posttranslationally modified by defined lipid moieties. The diverse structural motifs generated direct proteins towards specific cellular membranes or organelles. However, knowledge on the factors that determine these selective associations is limited. Here we show, using advanced microscopy, that the isoprenylation and palmitoylation motif of human RhoB (–CINCCKVL) targets chimeric proteins to intraluminal vesicles of endolysosomes in human cells, displaying preferential co-localization with components of the late endocytic pathway. Moreover, this distribution is conserved in distant species, including cells from amphibians, insects and fungi. Blocking lipidic modifications results in accumulation of CINCCKVL chimeras in the cytosol, from where they can reach endolysosomes upon release of this block. Remarkably, CINCCKVL constructs are sorted to intraluminal vesicles in a cholesterol-dependent process. In the lower species, neither the C-terminal sequence of RhoB, nor the endosomal distribution of its homologs are conserved; in spite of this, CINCCKVL constructs also reach endolysosomes in Xenopus laevis and insect cells. Strikingly, this behavior is prominent in the filamentous ascomycete fungus Aspergillus nidulans, in which GFP-CINCCKVL is sorted into endosomes and vacuoles in a lipidation-dependent manner and allows monitoring endosomal movement in live fungi. In summary, the isoprenylated and palmitoylated CINCCKVL sequence constitutes a specific structure which delineates an endolysosomal sorting strategy operative in phylogenetically diverse organisms.
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Affiliation(s)
- Clara L. Oeste
- Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Mario Pinar
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Kay O. Schink
- Centre for Cancer Biomedicine, Faculty of Medicine, Oslo University Hospital, Oslo, Norway
| | - Javier Martínez-Turrión
- Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Harald Stenmark
- Centre for Cancer Biomedicine, Faculty of Medicine, Oslo University Hospital, Oslo, Norway
| | - Miguel A. Peñalva
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Dolores Pérez-Sala
- Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- * E-mail:
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Abstract
Tetraspanins are a family of proteins with four transmembrane domains that play a role in many aspects of cell biology and physiology; they are also used by several pathogens for infection and regulate cancer progression. Many tetraspanins associate specifically and directly with a limited number of proteins, and also with other tetraspanins, thereby generating a hierarchical network of interactions. Through these interactions, tetraspanins are believed to have a role in cell and membrane compartmentalization. In this Cell Science at a Glance article and the accompanying poster, we describe the basic principles underlying tetraspanin-based assemblies and highlight examples of how tetraspanins regulate the trafficking and function of their partner proteins that are required for the normal development and function of several organs, including, in humans, the eye, the kidney and the immune system.
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Affiliation(s)
- Stéphanie Charrin
- Inserm, U1004, F-94807, Villejuif, France Université Paris-Sud, Institut André Lwoff, F-94807 Villejuif, France
| | - Stéphanie Jouannet
- Inserm, U1004, F-94807, Villejuif, France Université Paris-Sud, Institut André Lwoff, F-94807 Villejuif, France
| | - Claude Boucheix
- Inserm, U1004, F-94807, Villejuif, France Université Paris-Sud, Institut André Lwoff, F-94807 Villejuif, France
| | - Eric Rubinstein
- Inserm, U1004, F-94807, Villejuif, France Université Paris-Sud, Institut André Lwoff, F-94807 Villejuif, France
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Kukic I, Kelleher SL, Kiselyov K. Zn2+ efflux through lysosomal exocytosis prevents Zn2+-induced toxicity. J Cell Sci 2014; 127:3094-103. [PMID: 24829149 DOI: 10.1242/jcs.145318] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Zn(2+) is an essential micronutrient and an important ionic signal whose excess, as well as scarcity, is detrimental to cells. Free cytoplasmic Zn(2+) is controlled by a network of Zn(2+) transporters and chelating proteins. Recently, lysosomes became the focus of studies in Zn(2+) transport, as they were shown to play a role in Zn(2+)-induced toxicity by serving as Zn(2+) sinks that absorb Zn(2+) from the cytoplasm. Here, we investigated the impact of the lysosomal Zn(2+) sink on the net cellular Zn(2+) distribution and its role in cell death. We found that lysosomes played a cytoprotective role during exposure to extracellular Zn(2+). Such a role required lysosomal acidification and exocytosis. Specifically, we found that the inhibition of lysosomal acidification using Bafilomycin A1 (Baf) led to a redistribution of Zn(2+) pools and increased apoptosis. Additionally, the inhibition of lysosomal exocytosis through knockdown (KD) of the lysosomal SNARE proteins VAMP7 and synaptotagmin VII (SYT7) suppressed Zn(2+) secretion and VAMP7 KD cells had increased apoptosis. These data show that lysosomes play a central role in Zn(2+) handling, suggesting that there is a new Zn(2+) detoxification pathway.
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Affiliation(s)
- Ira Kukic
- The Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Shannon L Kelleher
- The Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, University Park, PA 16802, USA Department of Surgery, Penn State Hershey Medical Center, Hershey, PA 17033, USA Department of Cellular and Molecular Physiology, Penn State Hershey Medical Center, Hershey, PA 17033, USA
| | - Kirill Kiselyov
- The Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Fröhlich M, Dejanovic B, Kashkar H, Schwarz G, Nussberger S. S-palmitoylation represents a novel mechanism regulating the mitochondrial targeting of BAX and initiation of apoptosis. Cell Death Dis 2014; 5:e1057. [PMID: 24525733 PMCID: PMC3944235 DOI: 10.1038/cddis.2014.17] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 12/23/2013] [Accepted: 01/02/2014] [Indexed: 12/19/2022]
Abstract
The intrinsic pathway of apoptotic cell death is mainly mediated by the BCL-2-associated X (BAX) protein through permeabilization of the mitochondrial outer membrane (MOM) and the concomitant release of cytochrome c into the cytosol. In healthy, non-apoptotic cells, BAX is predominantly localized in the cytosol and exhibits a dynamic shuttle cycle between the cytosol and the mitochondria. Thus, the initial association with mitochondria represents a critical regulatory step enabling BAX to insert into MOMs, promoting the release of cytochrome c and ultimately resulting in apoptosis. However, the molecular mode of how BAX associates with MOMs and whether a cellular regulatory mechanism governs this process is poorly understood. Here we show that in both primary tissues and cultured cells, the association with MOMs and the proapoptotic action of BAX is controlled by its S-palmitoylation at Cys-126. A lack of BAX palmitoylation reduced BAX mitochondrial translocation, BAX oligomerization, caspase activity and apoptosis. Furthermore, ectopic expression of specific palmitoyl transferases in cultured healthy cells increases BAX S-palmitoylation and accelerates apoptosis, whereas malignant tumor cells show reduced BAX S-palmitoylation consistent with their reduced BAX-mediated proapoptotic activity. Our findings suggest that S-palmitoylation of BAX at Cys126 is a key regulatory process of BAX-mediated apoptosis.
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Affiliation(s)
- M Fröhlich
- Institute of Biochemistry, Department of Chemistry and Center for Molecular Medicine, Cologne University, Zülpicher Strasse 47, Cologne 50674, Germany
| | - B Dejanovic
- Institute of Biochemistry, Department of Chemistry and Center for Molecular Medicine, Cologne University, Zülpicher Strasse 47, Cologne 50674, Germany
| | - H Kashkar
- Institute for Medical Microbiology, Immunology and Hygiene and Center for Molecular Medicine, Cologne University, Goldenfels Strasse 19-21, Cologne 50935, Germany
| | - G Schwarz
- Institute of Biochemistry, Department of Chemistry and Center for Molecular Medicine, Cologne University, Zülpicher Strasse 47, Cologne 50674, Germany
| | - S Nussberger
- 1] Institute of Biochemistry, Department of Chemistry and Center for Molecular Medicine, Cologne University, Zülpicher Strasse 47, Cologne 50674, Germany [2] Biophysics Department, Institute of Biology, University of Stuttgart, Pfaffenwaldring 57, Stuttgart 70550, Germany
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40
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Exocytosis of nanoparticles from cells: role in cellular retention and toxicity. Adv Colloid Interface Sci 2013; 201-202:18-29. [PMID: 24200091 DOI: 10.1016/j.cis.2013.10.013] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 10/11/2013] [Accepted: 10/13/2013] [Indexed: 01/06/2023]
Abstract
Over the past decade, nanoparticles (NPs) have been increasingly developed in various biomedical applications such as cell tracking, biosensing, contrast imaging, targeted drug delivery, and tissue engineering. Their versatility in design and function has made them an attractive, alternative choice in many biological and biomedical applications. Cellular responses to NPs, their uptake, and adverse biological effects caused by NPs are rapidly-growing research niches. However, NP excretion and its underlying mechanisms and cell signaling pathways are yet elusive. In this review, we present an overview of how NPs are handled intracellularly and how they are excreted from cells following the uptake. We also discuss how exocytosis of nanomaterials impacts both the therapeutic delivery of nanoscale objects and their nanotoxicology.
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Patnaik BB, Kang SM, Seo GW, Lee HJ, Patnaik HH, Jo YH, Tindwa H, Lee YS, Lee BL, Kim NJ, Bang IS, Han YS. Molecular cloning, sequence characterization and expression analysis of a CD63 homologue from the coleopteran beetle, Tenebrio molitor. Int J Mol Sci 2013; 14:20744-67. [PMID: 24132157 PMCID: PMC3821641 DOI: 10.3390/ijms141020744] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 09/27/2013] [Accepted: 10/03/2013] [Indexed: 01/13/2023] Open
Abstract
CD63, a member of the tetraspanin membrane protein family, plays a pivotal role in cell growth, motility, signal transduction, host-pathogen interactions and cancer. In this work, the cDNA encoding CD63 homologue (TmCD63) was cloned from larvae of a coleopteran beetle, Tenebrio molitor. The cDNA is comprised of an open reading frame of 705 bp, encoding putative protein of 235 amino acid residues. In silico analysis shows that the protein has four putative transmembrane domains and one large extracellular loop. The characteristic “Cys-Cys-Gly” motif and “Cys188” residues are highly conserved in the large extracellular loop. Phylogenetic analysis of TmCD63 revealed that they belong to the insect cluster with 50%–56% identity. Analysis of spatial expression patterns demonstrated that TmCD63 mRNA is mainly expressed in gut and Malphigian tubules of larvae and the testis of the adult. Developmental expression patterns of CD63 mRNA showed that TmCD63 transcripts are detected in late larval, pupal and adult stages. Interestingly, TmCD63 transcripts are upregulated to the maximum level of 4.5 fold, in response to DAP-type peptidoglycan during the first 6 h, although other immune elicitors also caused significant increase to the transcript level at later time-points. These results suggest that CD63 might contribute to T. molitor immune response against various microbial pathogens.
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Affiliation(s)
- Bharat Bhusan Patnaik
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea; E-Mails: (B.B.P.); (G.W.S.); (H.J.L.); (H.H.P.); (Y.H.J.); (H.T.)
| | - Seong Min Kang
- National Research Laboratory of Defense Proteins, College of Pharmacy, Pusan National University, Jangjeon Dong, Kumjeong Ku, Busan 609-735, Korea; E-Mails: (S.M.K.); (B.L.L.)
| | - Gi Won Seo
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea; E-Mails: (B.B.P.); (G.W.S.); (H.J.L.); (H.H.P.); (Y.H.J.); (H.T.)
| | - Hyo Jeong Lee
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea; E-Mails: (B.B.P.); (G.W.S.); (H.J.L.); (H.H.P.); (Y.H.J.); (H.T.)
| | - Hongray Howrelia Patnaik
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea; E-Mails: (B.B.P.); (G.W.S.); (H.J.L.); (H.H.P.); (Y.H.J.); (H.T.)
| | - Yong Hun Jo
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea; E-Mails: (B.B.P.); (G.W.S.); (H.J.L.); (H.H.P.); (Y.H.J.); (H.T.)
| | - Hamisi Tindwa
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea; E-Mails: (B.B.P.); (G.W.S.); (H.J.L.); (H.H.P.); (Y.H.J.); (H.T.)
| | - Yong Seok Lee
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan city 336-745, Korea; E-Mail:
| | - Bok Luel Lee
- National Research Laboratory of Defense Proteins, College of Pharmacy, Pusan National University, Jangjeon Dong, Kumjeong Ku, Busan 609-735, Korea; E-Mails: (S.M.K.); (B.L.L.)
| | - Nam Jung Kim
- Division of Applied Entomology, National Academy of Agricultural Science, Rural Development, 61th, Seodun-dong, Gwonseon-gu, Suwon, Gyeonggi-do 441-853, Korea; E-Mail:
| | - In Seok Bang
- Department of Biological Science and the Research Institute for Basic Sciences, Hoseo University, Asan 336-795, Korea; E-Mail:
| | - Yeon Soo Han
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea; E-Mails: (B.B.P.); (G.W.S.); (H.J.L.); (H.H.P.); (Y.H.J.); (H.T.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +82-62-530-2072; Fax: +82-62-530-2069
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Kraft S, Jouvin MH, Kulkarni N, Kissing S, Morgan ES, Dvorak AM, Schröder B, Saftig P, Kinet JP. The tetraspanin CD63 is required for efficient IgE-mediated mast cell degranulation and anaphylaxis. THE JOURNAL OF IMMUNOLOGY 2013; 191:2871-8. [PMID: 23945142 DOI: 10.4049/jimmunol.1202323] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mast cell (MC) activation through the high-affinity IgE receptor FcεRI leads to the release of mediators involved in immediate-type allergic reactions. Although Abs against the tetraspanins CD63 and CD81 inhibit FcεRI-induced MC degranulation, the intrinsic role of these molecules in FcεRI-induced MC activation is unknown. In MCs, CD63 is expressed at the cell surface and in lysosomes (particularly secretory lysosomes that contain allergic mediators). In this study, we investigated the role of CD63 in MC using a CD63 knockout mouse model. CD63-deficiency did not affect in vivo MC numbers and tissue distribution. Bone marrow-derived MC developed normally in the absence of CD63 protein. However, CD63-deficient bone marrow-derived MC showed a significant decrease in FcεRI-mediated degranulation, but not PMA/ionomycin-induced degranulation, as shown by β-hexosaminidase release assays. The secretion of TNF-α, which is both released from granules and synthesized de novo upon MC activation, was also decreased. IL-6 secretion and production of the lipid mediator leukotriene C₄ were unaffected. There were no ultrastructural differences in granule content and morphology, late endosomal/lysosomal marker expression, FcεRI-induced global tyrosine phosphorylation, and Akt phosphorylation. Finally, local reconstitution in genetically MC-deficient Kit(w/w-v) mice was unaffected by the absence of CD63. However, the sites reconstituted with CD63-deficient MC developed significantly attenuated cutaneous anaphylactic reactions. These findings demonstrate that the absence of CD63 results in a significant decrease of MC degranulation, which translates into a reduction of acute allergic reactions in vivo, thus identifying CD63 as an important component of allergic inflammation.
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Affiliation(s)
- Stefan Kraft
- Laboratory of Allergy and Immunology, Department of Pathology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
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Schwake M, Schröder B, Saftig P. Lysosomal membrane proteins and their central role in physiology. Traffic 2013; 14:739-48. [PMID: 23387372 DOI: 10.1111/tra.12056] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 02/01/2013] [Accepted: 02/06/2013] [Indexed: 12/19/2022]
Abstract
The lysosomal membrane was thought for a long time to primarily act as a physical barrier separating the luminal acidic milieu from the cytoplasmic environment. Meanwhile, it has been realized that unique lysosomal membranes play essential roles in a number of cellular events ranging from phagocytosis, autophagy, cell death, virus infection to membrane repair. This review provides an overview about the most interesting emerging functions of lysosomal membrane proteins and how they contribute to health and disease. Their importance is exemplified by their role in acidification, transport of metabolites and ions across the membrane, intracellular transport of hydrolases and the regulation of membrane fusion events. Studies in patient cells, non-mammalian model organisms and knockout mice contributed to our understanding of how the different lysosomal membrane proteins affect cellular homeostasis, developmental processes as well as tissue functions. Because these proteins are central for the biogenesis of this compartment they are also considered as attractive targets to modulate the lysosomal machinery in cases where impaired lysosomal degradation leads to cellular pathologies. We are only beginning to understand the complex composition and function of these proteins which are tightly linked to processes occurring throughout the endocytic and biosynthetic pathways.
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Affiliation(s)
- Michael Schwake
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, Olshausenstrasse 40, D-24098, Kiel, Germany
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44
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Blaskovic S, Blanc M, van der Goot FG. What does S-palmitoylation do to membrane proteins? FEBS J 2013; 280:2766-74. [PMID: 23551889 DOI: 10.1111/febs.12263] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/20/2013] [Accepted: 03/25/2013] [Indexed: 12/19/2022]
Abstract
S-palmitoylation is post-translational modification, which consists in the addition of a C16 acyl chain to cytosolic cysteines and which is unique amongst lipid modifications in that it is reversible. It can thus, like phosphorylation or ubiquitination, act as a switch. While palmitoylation of soluble proteins allows them to interact with membranes, the consequences of palmitoylation for transmembrane proteins are more enigmatic. We briefly review the current knowledge regarding the enzymes responsible for palmitate addition and removal. We then describe various observed consequences of membrane protein palmitoylation. We propose that the direct effects of palmitoylation on transmembrane proteins, however, might be limited to four non-mutually exclusive mechanistic consequences: alterations in the conformation of transmembrane domains, association with specific membrane domains, controlled interactions with other proteins and controlled interplay with other post-translational modifications.
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Affiliation(s)
- Sanja Blaskovic
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Switzerland
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45
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Schröder HM, Hoffmann SC, Hecker M, Korff T, Ludwig T. The tetraspanin network modulates MT1-MMP cell surface trafficking. Int J Biochem Cell Biol 2013; 45:1133-44. [PMID: 23500527 DOI: 10.1016/j.biocel.2013.02.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 02/11/2013] [Accepted: 02/21/2013] [Indexed: 10/27/2022]
Abstract
The membrane-type 1 matrix metalloproteinase (MT1-MMP) drives fundamental physiological and pathophysiological processes. Among other substrates, MT1-MMP cleaves components of the extracellular matrix and activates other matrix-cleaving proteases such as MMP-2. Trafficking is a highly effective means to modulate MT1-MMP cell surface expression, and hence regulate its function. Here, we describe the complex interaction of MT1-MMP with tetraspanins, their effects on MT1-MMP intracellular trafficking and proteolytic function. Tetraspanins are credited as membrane organizers that form a network within the membrane to regulate the trafficking of associated proteins. In short, we found MT1-MMP to interact with the tetraspanin-associated EWI-2 protein by a yeast two-hybrid screen. Immunoprecipitation analysis confirmed this interaction and further revealed that MT1-MMP also stably interacts with distinct tetraspanins (CD9, CD37, CD53, CD63, CD81, and CD82) and the tetraspanin-like MAL protein. By using different MT1-MMP truncation constructs and mutants, we observed that all tetraspanins and MAL associated with the hemopexin domain of MT1-MMP. Moreover, this interaction was independent of O-glycosylation of MT1-MMP and exclusively occurred in the endoplasmic reticulum. Here, the respective subcellular compartment was identified by fitting the MT1-MMP interaction pattern to a model for post-translational processing of MT1-MMP. In addition, tetraspanins differentially affected the cell surface localization of MT1-MMP, its capacity to activate pro-MMP-2, and the collagen invasion capacity. Interestingly, the degree of tetraspanin-MT1-MMP association did not correlate with its impact on MT1-MMP function. Tetraspanins thus distinctly affect MT1-MMP subcellular localization and function, and may constitute an effective mechanism to control MT1-MMP-dependent proteolysis at the cell surface.
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Affiliation(s)
- H M Schröder
- Institute of Physiology and Pathophysiology, Division of Cardiovascular Physiology, Heidelberg University, 69120 Heidelberg, Germany.
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46
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Yanes RE, Tarn D, Hwang AA, Ferris DP, Sherman SP, Thomas CR, Lu J, Pyle AD, Zink JI, Tamanoi F. Involvement of lysosomal exocytosis in the excretion of mesoporous silica nanoparticles and enhancement of the drug delivery effect by exocytosis inhibition. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:697-704. [PMID: 23152124 PMCID: PMC3767416 DOI: 10.1002/smll.201201811] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Indexed: 05/22/2023]
Abstract
The exocytosis of phosphonate modified mesoporous silica nanoparticles (P-MSNs) is demonstrated and lysosomal exocytosis is identified as the mechanism responsible for this event. Regulation of P-MSN exocytosis can be achieved by inhibiting or accelerating lysosomal exocytosis. Slowing down P-MSN exocytosis enhances the drug delivery effect of CPT-loaded P-MSNs by improving cell killing.
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Affiliation(s)
- Rolando E Yanes
- Department of Microbiology, California NanoSystems Institute, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
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47
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Fernandes MC, Flannery AR, Andrews N, Mortara RA. Extracellular amastigotes of Trypanosoma cruzi are potent inducers of phagocytosis in mammalian cells. Cell Microbiol 2013; 15:977-91. [PMID: 23241026 PMCID: PMC3638054 DOI: 10.1111/cmi.12090] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 11/26/2012] [Accepted: 12/11/2012] [Indexed: 12/15/2022]
Abstract
The protozoan parasite Trypanosoma cruzi, the aetiological agent of Chagas' disease, has two infective life cycle stages, trypomastigotes and amastigotes. While trypomastigotes actively enter mammalian cells, highly infective extracellular amastigotes (type I T. cruzi) rely on actin-mediated uptake, which is generally inefficient in non-professional phagocytes. We found that extracellular amastigotes (EAs) of T. cruzi G strain (type I), but not Y strain (type II), were taken up 100-fold more efficiently than inert particles. Mammalian cell lines showed levels of parasite uptake comparable to macrophages, and extensive actin recruitment and polymerization was observed at the site of entry. EA uptake was not dependent on parasite-secreted molecules and required the same molecular machinery utilized by professional phagocytes during large particle phagocytosis. Transcriptional silencing of synaptotagmin VII and CD63 significantly inhibited EA internalization, demonstrating that delivery of supplemental lysosomal membrane to form the phagosome is involved in parasite uptake. Importantly, time-lapse live imaging using fluorescent reporters revealed phagosome-associated modulation of phosphoinositide metabolism during EA uptake that closely resembles what occurs during phagocytosis by macrophages. Collectively, our results demonstrate that T. cruzi EAs are potent inducers of phagocytosis in non-professional phagocytes, a process that may facilitate parasite persistence in infected hosts.
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Affiliation(s)
- Maria Cecilia Fernandes
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
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48
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Batistic O. Genomics and localization of the Arabidopsis DHHC-cysteine-rich domain S-acyltransferase protein family. PLANT PHYSIOLOGY 2012; 160:1597-612. [PMID: 22968831 PMCID: PMC3490592 DOI: 10.1104/pp.112.203968] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 09/07/2012] [Indexed: 05/18/2023]
Abstract
Protein lipid modification of cysteine residues, referred to as S-palmitoylation or S-acylation, is an important secondary and reversible modification that regulates membrane association, trafficking, and function of target proteins. This enzymatic reaction is mediated by protein S-acyl transferases (PATs). Here, the phylogeny, genomic organization, protein topology, expression, and localization pattern of the 24 PAT family members from Arabidopsis (Arabidopsis thaliana) is described. Most PATs are expressed at ubiquitous levels and tissues throughout the development, while few genes are expressed especially during flower development preferentially in pollen and stamen. The proteins display large sequence and structural variations but exhibit a common protein topology that is preserved in PATs from various organisms. Arabidopsis PAT proteins display a complex targeting pattern and were detected at the endoplasmic reticulum, Golgi, endosomal compartments, and the vacuolar membrane. However, most proteins were targeted to the plasma membrane. This large concentration of plant PAT activity to the plasma membrane suggests that the plant cellular S-acylation machinery is functionally different compared with that of yeast (Saccharomyces cerevisiae) and mammalians.
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Affiliation(s)
- Oliver Batistic
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, 48149 Muenster, Germany.
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S-acylation-dependent association of the calcium sensor CBL2 with the vacuolar membrane is essential for proper abscisic acid responses. Cell Res 2012; 22:1155-68. [PMID: 22547024 DOI: 10.1038/cr.2012.71] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Calcineurin B-like (CBL) proteins contribute to decoding calcium signals by interacting with CBL-interacting protein kinases (CIPKs). Currently, there is still very little information about the function and specific targeting mechanisms of CBL proteins that are localized at the vacuolar membrane. In this study, we focus on CBL2, an abundant vacuolar membrane-localized calcium sensor of unknown function from Arabidopsis thaliana. We show that vacuolar targeting of CBL2 is specifically brought about by S-acylation of three cysteine residues in its N-terminus and that CBL2 S-acylation and targeting occur by a Brefeldin A-insensitive pathway. Loss of CBL2 function renders plants hypersensitive to the phytohormone abscisic acid (ABA) during seed germination and only fully S-acylated and properly vacuolar-targeted CBL2 proteins can complement this mutant phenotype. These findings define an S-acylation-dependent vacuolar membrane targeting pathway for proteins and uncover a crucial role of vacuolar calcium sensors in ABA responses.
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Schaefer T, Zajonz A, Lorentz P, Bohnacker T, Wymann MP, Schweighoffer T. Luminal decoration of blood vessels by activated perivasal mast cells in allergic rhinitis. Allergy 2012; 67:510-20. [PMID: 22313335 DOI: 10.1111/j.1398-9995.2012.02790.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2011] [Indexed: 12/14/2022]
Abstract
BACKGROUND In allergic diseases, like in rhinitis, antigen challenge induces rapid degranulation of tissue resident mast cells and subsequent recruitment of leukocytes in response to soluble immunmodulators. The fate of mast cell-derived, membrane associated factors in inflamed tissue remained however unresolved. METHODS Components of the mast cell granular membrane, including the unique marker CD63var, were examined by FACS and by confocal laser scanning microscopy in cell culture and in diseased human tissue. RESULTS We discovered that selected mast cell membrane components appeared on the surface of distinct bystander cells. Acceptor cells did not acquire these molecules simply by uptake of soluble material or in the form of exosomes. Instead, physically stable cell-to-cell contact was required for transfer, in which a Notch2-Jagged1 interaction played a decisive role. This process is activation-dependent, unidirectional, and involves a unique membrane topology. Endothelial cells were particularly efficient acceptors. In organotypic 3D in vitro cultures we found that transferred mast cell molecules traversed an endothelial monolayer, and reappeared focally compacted on its distal surface, away from the actual contact zone. Moreover, we observed that such mast cell-derived membrane patches decorate microcapillaries in the nasal mucosa of allergic rhinitis patients. CONCLUSION Direct membrane transfer from perivasal mast cells into nearby blood vessels constitutes a novel mechanism to modulate endothelial surface features with apparent significance in allergic diseases.
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Affiliation(s)
- T. Schaefer
- Novartis Institutes for Biomedical Research (NIBR); Basel; Switzerland
| | - A. Zajonz
- Novartis Institutes for Biomedical Research (NIBR); Basel; Switzerland
| | - P. Lorentz
- Institute of Biochemistry and Genetics; Department of Biomedicine; University of Basel; Basel; Switzerland
| | - T. Bohnacker
- Institute of Biochemistry and Genetics; Department of Biomedicine; University of Basel; Basel; Switzerland
| | - M. P. Wymann
- Institute of Biochemistry and Genetics; Department of Biomedicine; University of Basel; Basel; Switzerland
| | - T. Schweighoffer
- Novartis Institutes for Biomedical Research (NIBR); Basel; Switzerland
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