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Bif-1 promotes tumor cell migration and metastasis via Cdc42 expression and activity. Clin Exp Metastasis 2016; 34:11-23. [PMID: 27730394 DOI: 10.1007/s10585-016-9825-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 09/30/2016] [Indexed: 12/13/2022]
Abstract
Tumor metastasis is the process by which tumor cells disseminate from tumors and enter nearby and distant microenvironments for new colonization. Bif-1 (BAX-interacting factor 1), which has a BAR domain and an SH3 domain, has been reported to be involved in cell growth, apoptosis and autophagy. However, the influence of Bif-1 on metastasis has been less studied. To understand the role of Bif-1 in metastasis, we studied the expression levels of Bif-1 in human HCC specimens using immunohistochemistry, a tissue microarray and quantitative PCR. The function of Bif-1 was assessed in migration and translocation assays and the pulmonary metastatic animal model. The relationship between Bif-1 and the Rho family was determined using immunoblot analyses and chromatin immunoprecipitation. The results showed that the expression of Bif-1 was higher in hepatocellular carcinoma (HCC) than matched adjacent non-tumor liver tissues. Increased Bif-1 expression was associated with tumor size and the intercellular spread and metastasis of HCC. Analysis of the relationship between Bif-1 expression and patients' clinical characteristics revealed that patients with higher levels of Bif-1 had shorter disease-free and overall survival rates. Knockdown of Bif-1 with RNAi suppressed the migration of HCC cells and pulmonary metastasis and decreased the expression of Cdc42, a member of the Rho family. Bif-1 localized to the cytosol and nucleus and interacted with the promoter transcription region of Cdc42, which may regulate Cdc42 expression. Our results demonstrate a novel role of Bif-1 in HCC, in which Bif-1 promotes cell metastasis by regulating Cdc42 expression and activity.
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Mesquita A, Cardenal-Muñoz E, Dominguez E, Muñoz-Braceras S, Nuñez-Corcuera B, Phillips BA, Tábara LC, Xiong Q, Coria R, Eichinger L, Golstein P, King JS, Soldati T, Vincent O, Escalante R. Autophagy in Dictyostelium: Mechanisms, regulation and disease in a simple biomedical model. Autophagy 2016; 13:24-40. [PMID: 27715405 DOI: 10.1080/15548627.2016.1226737] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Autophagy is a fast-moving field with an enormous impact on human health and disease. Understanding the complexity of the mechanism and regulation of this process often benefits from the use of simple experimental models such as the social amoeba Dictyostelium discoideum. Since the publication of the first review describing the potential of D. discoideum in autophagy, significant advances have been made that demonstrate both the experimental advantages and interest in using this model. Since our previous review, research in D. discoideum has shed light on the mechanisms that regulate autophagosome formation and contributed significantly to the study of autophagy-related pathologies. Here, we review these advances, as well as the current techniques to monitor autophagy in D. discoideum. The comprehensive bioinformatics search of autophagic proteins that was a substantial part of the previous review has not been revisited here except for those aspects that challenged previous predictions such as the composition of the Atg1 complex. In recent years our understanding of, and ability to investigate, autophagy in D. discoideum has evolved significantly and will surely enable and accelerate future research using this model.
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Affiliation(s)
- Ana Mesquita
- a Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid , Spain.,b University of Cincinnati College of Medicine , Cincinnati , OH , USA
| | - Elena Cardenal-Muñoz
- c Départment de Biochimie , Faculté des Sciences, Université de Genève , Switzerland
| | - Eunice Dominguez
- a Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid , Spain.,d Departamento de Genética Molecular , Instituto de Fisiología Celular, Universidad Nacional Autónoma de México , Mexico City , México
| | - Sandra Muñoz-Braceras
- a Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid , Spain
| | | | - Ben A Phillips
- e Department of Biomedical Sciences , University of Sheffield , UK
| | - Luis C Tábara
- a Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid , Spain
| | - Qiuhong Xiong
- f Center for Biochemistry, Medical Faculty, University of Cologne , Cologne , Germany
| | - Roberto Coria
- d Departamento de Genética Molecular , Instituto de Fisiología Celular, Universidad Nacional Autónoma de México , Mexico City , México
| | - Ludwig Eichinger
- f Center for Biochemistry, Medical Faculty, University of Cologne , Cologne , Germany
| | - Pierre Golstein
- g Centre d'Immunologie de Marseille-Luminy, Aix Marseille Université UM2 , Inserm, U1104, CNRS UMR7280, Marseille , France
| | - Jason S King
- e Department of Biomedical Sciences , University of Sheffield , UK
| | - Thierry Soldati
- c Départment de Biochimie , Faculté des Sciences, Université de Genève , Switzerland
| | - Olivier Vincent
- a Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid , Spain
| | - Ricardo Escalante
- a Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid , Spain
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53
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Dong Z, Liang S, Hu J, Jin W, Zhan Q, Zhao K. Autophagy as a target for hematological malignancy therapy. Blood Rev 2016; 30:369-80. [DOI: 10.1016/j.blre.2016.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/27/2016] [Accepted: 04/14/2016] [Indexed: 01/08/2023]
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54
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Schröter S, Beckmann S, Schmitt HD. ER arrival sites for COPI vesicles localize to hotspots of membrane trafficking. EMBO J 2016; 35:1935-55. [PMID: 27440402 DOI: 10.15252/embj.201592873] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 06/21/2016] [Indexed: 11/09/2022] Open
Abstract
COPI-coated vesicles mediate retrograde membrane traffic from the cis-Golgi to the endoplasmic reticulum (ER) in all eukaryotic cells. However, it is still unknown whether COPI vesicles fuse everywhere or at specific sites with the ER membrane. Taking advantage of the circumstance that the vesicles still carry their coat when they arrive at the ER, we have visualized active ER arrival sites (ERAS) by monitoring contact between COPI coat components and the ER-resident Dsl tethering complex using bimolecular fluorescence complementation (BiFC). ERAS form punctate structures near Golgi compartments, clearly distinct from ER exit sites. Furthermore, ERAS are highly polarized in an actin and myosin V-dependent manner and are localized near hotspots of plasma membrane expansion. Genetic experiments suggest that the COPI•Dsl BiFC complexes recapitulate the physiological interaction between COPI and the Dsl complex and that COPI vesicles are mistargeted in dsl1 mutants. We conclude that the Dsl complex functions in confining COPI vesicle fusion sites.
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Affiliation(s)
- Saskia Schröter
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Sabrina Beckmann
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Hans Dieter Schmitt
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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55
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Wu TT, Li WM, Yao YM. Interactions between Autophagy and Inhibitory Cytokines. Int J Biol Sci 2016; 12:884-97. [PMID: 27313501 PMCID: PMC4910606 DOI: 10.7150/ijbs.15194] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/12/2016] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a degradative pathway that plays an essential role in maintaining cellular homeostasis. Most early studies of autophagy focused on its involvement in age-associated degeneration and nutrient deprivation. However, the immunological functions of autophagy have become more widely studied in recent years. Autophagy has been shown to be an intrinsic cellular defense mechanism in the innate and adaptive immune responses. Cytokines belong to a broad and loose category of proteins and are crucial for innate and adaptive immunity. Inhibitory cytokines have evolved to permit tolerance to self while also contributing to the eradication of invading pathogens. Interactions between inhibitory cytokines and autophagy have recently been reported, revealing a novel mechanism by which autophagy controls the immune response. In this review, we discuss interactions between autophagy and the regulatory cytokines IL-10, transforming growth factor-β, and IL-27. We also mention possible interactions between two newly discovered cytokines, IL-35 and IL-37, and autophagy.
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Affiliation(s)
- Tian-Tian Wu
- 1. Department of Hepatobiliary Surgery, the 309th Hospital of Chinese PLA, Beijing 100091, People's Republic of China
| | - Wei-Min Li
- 1. Department of Hepatobiliary Surgery, the 309th Hospital of Chinese PLA, Beijing 100091, People's Republic of China
| | - Yong-Ming Yao
- 2. Trauma Research Center, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing 100048, People's Republic of China; 3. State Key Laboratory of Kidney Disease, the Chinese PLA General Hospital, Beijing 100853, People's Republic of China
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56
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Schroeter S, Beckmann S, Schmitt HD. Coat/Tether Interactions-Exception or Rule? Front Cell Dev Biol 2016; 4:44. [PMID: 27243008 PMCID: PMC4868844 DOI: 10.3389/fcell.2016.00044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/25/2016] [Indexed: 12/02/2022] Open
Abstract
Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers.
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Affiliation(s)
- Saskia Schroeter
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
| | - Sabrina Beckmann
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
| | - Hans Dieter Schmitt
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
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57
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Paul P, Münz C. Autophagy and Mammalian Viruses: Roles in Immune Response, Viral Replication, and Beyond. Adv Virus Res 2016; 95:149-95. [PMID: 27112282 DOI: 10.1016/bs.aivir.2016.02.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autophagy is an important cellular catabolic process conserved from yeast to man. Double-membrane vesicles deliver their cargo to the lysosome for degradation. Hence, autophagy is one of the key mechanisms mammalian cells deploy to rid themselves of intracellular pathogens including viruses. However, autophagy serves many more functions during viral infection. First, it regulates the immune response through selective degradation of immune components, thus preventing possibly harmful overactivation and inflammation. Additionally, it delivers virus-derived antigens to antigen-loading compartments for presentation to T lymphocytes. Second, it might take an active part in the viral life cycle by, eg, facilitating its release from cells. Lastly, in the constant arms race between host and virus, autophagy is often hijacked by viruses and manipulated to their own advantage. In this review, we will highlight key steps during viral infection in which autophagy plays a role. We have selected some exemplary viruses and will describe the molecular mechanisms behind their intricate relationship with the autophagic machinery, a result of host-pathogen coevolution.
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Affiliation(s)
- P Paul
- Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - C Münz
- Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland.
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Abstract
Bilayered phospholipid membranes are vital to the organization of the living cell. Based on fundamental principles of polarity, membranes create borders allowing defined spaces to be encapsulated. This compartmentalization is a prerequisite for the complex functional design of the eukaryotic cell, yielding localities that can differ in composition and operation. During macroautophagy, cytoplasmic components become enclosed by a growing double bilayered membrane, which upon closure creates a separate compartment, the autophagosome. The autophagosome is then primed for fusion with endosomal and lysosomal compartments, leading to degradation of the captured material. A large number of proteins have been found to be essential for autophagy, but little is known about the specific lipids that constitute the autophagic membranes and the membrane modeling events that are responsible for regulation of autophagosome shape and size. In this Commentary, we review the recent progress in our understanding of the membrane shaping and remodeling events that are required at different steps of the autophagy pathway. This article is part of a Focus on Autophagosome biogenesis. For further reading, please see related articles: 'ERES: sites for autophagosome biogenesis and maturation?' by Jana Sanchez-Wandelmer et al. (J. Cell Sci. 128, 185-192) and 'WIPI proteins: essential PtdIns3P effectors at the nascent autophagosome' by Tassula Proikas-Cezanne et al. (J. Cell Sci. 128, 207-217).
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Affiliation(s)
- Sven R Carlsson
- Department of Medical Biochemistry and Biophysics, University of Umeå, SE-901 87 Umeå, Sweden
| | - Anne Simonsen
- Institute of Basic Medical Sciences, University of Oslo, NO-0317 Oslo, Norway
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59
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Liu Y, Takahashi Y, Desai N, Zhang J, Serfass JM, Shi YG, Lynch CJ, Wang HG. Bif-1 deficiency impairs lipid homeostasis and causes obesity accompanied by insulin resistance. Sci Rep 2016; 6:20453. [PMID: 26857140 PMCID: PMC4746598 DOI: 10.1038/srep20453] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 01/04/2016] [Indexed: 12/27/2022] Open
Abstract
Bif-1 is a membrane-curvature inducing protein that is implicated in the regulation of autophagy and tumorigenesis. Here, we report that Bif-1 plays a critical role in regulating lipid catabolism to control the size of lipid droplets and prevent the development of obesity and insulin resistance upon aging or dietary challenge. Our data show that Bif-1 deficiency promotes the expansion of adipose tissue mass without altering food intake or physical activities. While Bif-1 is dispensable for adipose tissue development, its deficiency reduces the basal rate of adipose tissue lipolysis and results in adipocyte hypertrophy upon aging. The importance of Bif-1 in lipid turnover is not limited to adipose tissue since fasting and refeeding-induced lipid droplet clearance is also attenuated by Bif-1 loss in the liver. Interestingly, obesity induced by a high fat-diet or Bif-1 deficiency downregulates the expression of proteins involved in the autophagy-lysosomal pathway, including Atg9a and Lamp1 in the adipose tissue. These findings thus identify Bif-1 as a novel regulator of lipid homeostasis to prevent the pathogenesis of obesity and its associated metabolic complications.
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Affiliation(s)
- Ying Liu
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Yoshinori Takahashi
- Department of Pediatrics, Penn State University College of Medicine, Hershey, PA 17033, USA
- Penn State Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Neelam Desai
- Department of Pediatrics, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Jun Zhang
- Department of Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Jacob M. Serfass
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Yu-Guang Shi
- Department of Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Christopher J. Lynch
- Department of Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Hong-Gang Wang
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA 17033, USA
- Department of Pediatrics, Penn State University College of Medicine, Hershey, PA 17033, USA
- Penn State Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033, USA
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60
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Son JH, Hwang EC, Kim J. Systematic analyses of the ultraviolet radiation resistance-associated gene product (UVRAG) protein interactome by tandem affinity purification. Arch Pharm Res 2015; 39:370-9. [DOI: 10.1007/s12272-015-0689-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 11/18/2015] [Indexed: 11/30/2022]
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61
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Tan X, Thapa N, Choi S, Anderson RA. Emerging roles of PtdIns(4,5)P2--beyond the plasma membrane. J Cell Sci 2015; 128:4047-56. [PMID: 26574506 PMCID: PMC4712784 DOI: 10.1242/jcs.175208] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Phosphoinositides are a collection of lipid messengers that regulate most subcellular processes. Amongst the seven phosphoinositide species, the roles for phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at the plasma membrane, such as in endocytosis, exocytosis, actin polymerization and focal adhesion assembly, have been extensively studied. Recent studies have argued for the existence of PtdIns(4,5)P2 at multiple intracellular compartments, including the nucleus, endosomes, lysosomes, autolysosomes, autophagic precursor membranes, ER, mitochondria and the Golgi complex. Although the generation, regulation and functions of PtdIns(4,5)P2 are less well-defined in most other intracellular compartments, accumulating evidence demonstrates crucial roles for PtdIns(4,5)P2 in endolysosomal trafficking, endosomal recycling, as well as autophagosomal pathways, which are the focus of this Commentary. We summarize and discuss how phosphatidylinositol phosphate kinases, PtdIns(4,5)P2 and PtdIns(4,5)P2-effectors regulate these intracellular protein and membrane trafficking events.
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Affiliation(s)
- Xiaojun Tan
- Program in Molecular and Cellular Pharmacology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
| | - Narendra Thapa
- Program in Molecular and Cellular Pharmacology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
| | - Suyong Choi
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
| | - Richard A Anderson
- Program in Molecular and Cellular Pharmacology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA Program in Cellular and Molecular Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA
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62
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Rey-Jurado E, Riedel CA, González PA, Bueno SM, Kalergis AM. Contribution of autophagy to antiviral immunity. FEBS Lett 2015; 589:3461-70. [PMID: 26297829 PMCID: PMC7094639 DOI: 10.1016/j.febslet.2015.07.047] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 07/20/2015] [Accepted: 07/29/2015] [Indexed: 12/22/2022]
Abstract
Although identified in the 1960's, interest in autophagy has significantly increased in the past decade with notable research efforts oriented at understanding as to how this multi-protein complex operates and is regulated. Autophagy is commonly defined as a "self-eating" process evolved by eukaryotic cells to recycle senescent organelles and expired proteins, which is significantly increased during cellular stress responses. In addition, autophagy can also play important roles during human diseases, such as cancer, neurodegenerative and autoimmune disorders. Furthermore, novel findings suggest that autophagy contributes to the host defense against microbial infections. In this article, we review the role of macroautophagy in antiviral immune responses and discuss molecular mechanisms evolved by viral pathogens to evade this process. A role for autophagy as an effector mechanism used both, by innate and adaptive immunity is also discussed.
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Affiliation(s)
- Emma Rey-Jurado
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia A Riedel
- Millennium Institute on Immunology and Immunotherapy, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas y Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile
| | - Pablo A González
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Susan M Bueno
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Alexis M Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile; Departamento de Inmunología Clínica y Reumatología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile; INSERM U1064, Nantes, France.
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63
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Rint1 inactivation triggers genomic instability, ER stress and autophagy inhibition in the brain. Cell Death Differ 2015; 23:454-68. [PMID: 26383973 DOI: 10.1038/cdd.2015.113] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 06/30/2015] [Accepted: 07/08/2015] [Indexed: 11/08/2022] Open
Abstract
Endoplasmic reticulum (ER) stress, defective autophagy and genomic instability in the central nervous system are often associated with severe developmental defects and neurodegeneration. Here, we reveal the role played by Rint1 in these different biological pathways to ensure normal development of the central nervous system and to prevent neurodegeneration. We found that inactivation of Rint1 in neuroprogenitors led to death at birth. Depletion of Rint1 caused genomic instability due to chromosome fusion in dividing cells. Furthermore, Rint1 deletion in developing brain promotes the disruption of ER and Cis/Trans Golgi homeostasis in neurons, followed by ER-stress increase. Interestingly, Rint1 deficiency was also associated with the inhibition of the autophagosome clearance. Altogether, our findings highlight the crucial roles of Rint1 in vivo in genomic stability maintenance, as well as in prevention of ER stress and autophagy.
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64
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ALS-associated mutant FUS inhibits macroautophagy which is restored by overexpression of Rab1. Cell Death Discov 2015; 1:15030. [PMID: 27551461 PMCID: PMC4979432 DOI: 10.1038/cddiscovery.2015.30] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 07/30/2015] [Indexed: 12/14/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is characterised by the formation of intracellular misfolded protein inclusions that form in motor neurons. Autophagy is the major degradation pathway for aggregate-prone proteins within lysosomes. Autophagy begins by the production of the omegasome, forming the autophagosome membrane, which then fuses with the lysosome. Mutations in fused in sarcoma (FUS) cause 5% of familial ALS cases and FUS-positive inclusions are also formed in sporadic ALS tissues. In this study, we demonstrate that the expression of ALS-associated mutant FUS impairs autophagy in neuronal cells. In mutant FUS-expressing neuronal cells, accumulation of ubiquitinated proteins and autophagy substrates p62 and NBR1 was detected, and formation of both the omegasome and autophagosome was inhibited in these cells. However, overexpression of Rab1 rescued these defects, suggesting that Rab1 is protective in ALS. The number of LC3-positive vesicles was also increased in motor neurons from the spinal cord of an ALS patient carrying a FUS (R521C) mutation compared with a control patient, providing additional evidence that autophagy is dysregulated in mutant FUS-associated ALS. This study provides further understanding of the intricate autophagy system and neurodegeneration in ALS.
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65
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Munson MJ, Allen GF, Toth R, Campbell DG, Lucocq JM, Ganley IG. mTOR activates the VPS34-UVRAG complex to regulate autolysosomal tubulation and cell survival. EMBO J 2015; 34:2272-90. [PMID: 26139536 PMCID: PMC4585463 DOI: 10.15252/embj.201590992] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 05/16/2015] [Accepted: 06/04/2015] [Indexed: 02/01/2023] Open
Abstract
Lysosomes are essential organelles that function to degrade and recycle unwanted, damaged and toxic biological components. Lysosomes also act as signalling platforms in activating the nutrient-sensing kinase mTOR. mTOR regulates cellular growth, but it also helps to maintain lysosome identity by initiating lysosomal tubulation through a process termed autophagosome-lysosome reformation (ALR). Here we identify a lysosomal pool of phosphatidylinositol 3-phosphate that, when depleted by specific inhibition of the class III phosphoinositide 3-kinase VPS34, results in prolonged lysosomal tubulation. This tubulation requires mTOR activity, and we identified two direct mTOR phosphorylation sites on UVRAG (S550 and S571) that activate VPS34. Loss of these phosphorylation sites reduced VPS34 lipid kinase activity and resulted in an increase in number and length of lysosomal tubules. In cells in which phosphorylation at these UVRAG sites is disrupted, the result of impaired lysosomal tubulation alongside ALR activation is massive cell death. Our data imply that ALR is critical for cell survival under nutrient stress and that VPS34 is an essential regulatory element in this process.
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Affiliation(s)
- Michael J Munson
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - George Fg Allen
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Rachel Toth
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - David G Campbell
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - John M Lucocq
- School of Medicine University of St Andrews, St Andrews, UK
| | - Ian G Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
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66
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Wang S, Xia P, Rehm M, Fan Z. Autophagy and cell reprogramming. Cell Mol Life Sci 2015; 72:1699-713. [PMID: 25572296 PMCID: PMC11113636 DOI: 10.1007/s00018-014-1829-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 12/23/2014] [Accepted: 12/30/2014] [Indexed: 12/17/2022]
Abstract
Autophagy is an evolutionarily conserved process that degrades cytoplasmic components, thus contributing to cell survival and tissue homeostasis. Recent studies have demonstrated that autophagy maintains stem cells in relatively undifferentiated states (stemness) and also contributes to differentiation processes. Autophagy likewise plays a crucial role in somatic cell reprogramming, a finely regulated process that resets differentiated cells to a pluripotent state and that requires comprehensive alterations in transcriptional activities and epigenetic signatures. Autophagy assists in manifesting the functional consequences that arise from these alterations by modifying cellular protein expression profiles. The role of autophagy appears to be particularly relevant for early phases of cell reprogramming during the generation of induced pluripotent stems cells (iPSCs). In this review, we provide an overview of the core molecular machinery that constitutes the autophagic degradation system, describe the roles of autophagy in maintenance, self-renewal, and differentiation of stem cells, and discuss the autophagic process and its regulation during cell reprogramming.
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Affiliation(s)
- Shuo Wang
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Pengyan Xia
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Markus Rehm
- Department of Physiology and Medical Physics, Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Zusen Fan
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
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67
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Kim YM, Park JM, Grunwald D, Kim DH. An expanded role for mTORC1 in autophagy. Mol Cell Oncol 2015; 3:e1010958. [PMID: 27308528 PMCID: PMC4845164 DOI: 10.1080/23723556.2015.1010958] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 01/18/2015] [Accepted: 01/19/2015] [Indexed: 01/08/2023]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) negatively regulates autophagy at early stages by phosphorylating Unc51-like kinase 1 (ULK1). Our recent study expanded the roles of mTORC1 in autophagy by identifying ultraviolet radiation resistance-associated gene product (UVRAG) as a substrate of mTORC1. This finding has provided new insight into the roles of mTORC1 in cellular membrane processes and cancer.
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Affiliation(s)
- Young-Mi Kim
- Department of Biochemistry; Molecular Biology, and Biophysics; University of Minnesota ; Minneapolis, MN USA
| | - Ji-Man Park
- Department of Biochemistry; Molecular Biology, and Biophysics; University of Minnesota ; Minneapolis, MN USA
| | - Douglas Grunwald
- Department of Biochemistry; Molecular Biology, and Biophysics; University of Minnesota ; Minneapolis, MN USA
| | - Do-Hyung Kim
- Department of Biochemistry; Molecular Biology, and Biophysics; University of Minnesota; Minneapolis, MN USA; Masonic Cancer Center; University of Minnesota; Minneapolis, MN USA
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68
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Yu X, Long YC, Shen HM. Differential regulatory functions of three classes of phosphatidylinositol and phosphoinositide 3-kinases in autophagy. Autophagy 2015; 11:1711-28. [PMID: 26018563 PMCID: PMC4824607 DOI: 10.1080/15548627.2015.1043076] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/11/2015] [Accepted: 04/14/2015] [Indexed: 02/06/2023] Open
Abstract
Autophagy is an evolutionarily conserved and exquisitely regulated self-eating cellular process with important biological functions. Phosphatidylinositol 3-kinases (PtdIns3Ks) and phosphoinositide 3-kinases (PI3Ks) are involved in the autophagic process. Here we aim to recapitulate how 3 classes of these lipid kinases differentially regulate autophagy. Generally, activation of the class I PI3K suppresses autophagy, via the well-established PI3K-AKT-MTOR (mechanistic target of rapamycin) complex 1 (MTORC1) pathway. In contrast, the class III PtdIns3K catalytic subunit PIK3C3/Vps34 forms a protein complex with BECN1 and PIK3R4 and produces phosphatidylinositol 3-phosphate (PtdIns3P), which is required for the initiation and progression of autophagy. The class II enzyme emerged only recently as an alternative source of PtdIns3P and autophagic initiator. However, the orthodox paradigm is challenged by findings that the PIK3CB catalytic subunit of class I PI3K acts as a positive regulator of autophagy, and PIK3C3 was thought to be an amino acid sensor for MTOR, which curbs autophagy. At present, a number of PtdIns3K and PI3K inhibitors, including specific PIK3C3 inhibitors, have been developed for suppression of autophagy and for clinical applications in autophagy-related human diseases.
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Affiliation(s)
- Xinlei Yu
- a Department of Biochemistry; Yong Loo Lin School of Medicine, National University of Singapore ; Singapore
| | - Yun Chau Long
- a Department of Biochemistry; Yong Loo Lin School of Medicine, National University of Singapore ; Singapore
| | - Han-Ming Shen
- b Department of Physiology; Yong Loo Lin School of Medicine, National University of Singapore ; Singapore
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69
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Abstract
Dynamins and BAR proteins are crucial in a wide variety of cellular processes for their ability to mediate membrane remodeling, such as membrane curvature and membrane fission and fusion. In this review, we highlight dynamins and BAR proteins and the cellular mechanisms that are involved in the initiation and progression of cancer. We specifically discuss the roles of the seproteinsin endocytosis, endo-lysosomal trafficking, autophagy, and apoptosis as these processes are all tightly linked to membrane remodeling and cancer.
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Affiliation(s)
- Anna C. Sundborger
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Jenny E. Hinshaw
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
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70
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Reidick C, El Magraoui F, Meyer HE, Stenmark H, Platta HW. Regulation of the Tumor-Suppressor Function of the Class III Phosphatidylinositol 3-Kinase Complex by Ubiquitin and SUMO. Cancers (Basel) 2014; 7:1-29. [PMID: 25545884 PMCID: PMC4381249 DOI: 10.3390/cancers7010001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/08/2014] [Indexed: 12/19/2022] Open
Abstract
The occurrence of cancer is often associated with a dysfunction in one of the three central membrane-involution processes—autophagy, endocytosis or cytokinesis. Interestingly, all three pathways are controlled by the same central signaling module: the class III phosphatidylinositol 3-kinase (PI3K-III) complex and its catalytic product, the phosphorylated lipid phosphatidylinositol 3-phosphate (PtdIns3P). The activity of the catalytic subunit of the PI3K-III complex, the lipid-kinase VPS34, requires the presence of the membrane-targeting factor VPS15 as well as the adaptor protein Beclin 1. Furthermore, a growing list of regulatory proteins associates with VPS34 via Beclin 1. These accessory factors define distinct subunit compositions and thereby guide the PI3K-III complex to its different cellular and physiological roles. Here we discuss the regulation of the PI3K-III complex components by ubiquitination and SUMOylation. Especially Beclin 1 has emerged as a highly regulated protein, which can be modified with Lys11-, Lys48- or Lys63-linked polyubiquitin chains catalyzed by distinct E3 ligases from the RING-, HECT-, RBR- or Cullin-type. We also point out other cross-links of these ligases with autophagy in order to discuss how these data might be merged into a general concept.
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Affiliation(s)
- Christina Reidick
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Bochum 44801, Germany.
| | - Fouzi El Magraoui
- Biomedical Research, Human Brain Proteomics II, Leibniz-Institut für Analytische Wissenschaften-ISAS, Dortmund 44139, Germany.
| | - Helmut E Meyer
- Biomedical Research, Human Brain Proteomics II, Leibniz-Institut für Analytische Wissenschaften-ISAS, Dortmund 44139, Germany.
| | - Harald Stenmark
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo 0310, Norway.
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Bochum 44801, Germany.
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71
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Kim YM, Jung CH, Seo M, Kim EK, Park JM, Bae SS, Kim DH. mTORC1 phosphorylates UVRAG to negatively regulate autophagosome and endosome maturation. Mol Cell 2014; 57:207-18. [PMID: 25533187 DOI: 10.1016/j.molcel.2014.11.013] [Citation(s) in RCA: 205] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 09/22/2014] [Accepted: 11/14/2014] [Indexed: 02/07/2023]
Abstract
mTORC1 plays a key role in autophagy as a negative regulator. The currently known targets of mTORC1 in the autophagy pathway mainly function at early stages of autophagosome formation. Here, we identify that mTORC1 inhibits later stages of autophagy by phosphorylating UVRAG. Under nutrient-enriched conditions, mTORC1 binds and phosphorylates UVRAG. The phosphorylation positively regulates the association of UVRAG with RUBICON, thereby enhancing the antagonizing effect of RUBICON on UVRAG-mediated autophagosome maturation. Upon dephosphorylation, UVRAG is released from RUBICON to interact with the HOPS complex, a component for the late endosome and lysosome fusion machinery, and enhances autophagosome and endosome maturation. Consequently, the dephosphorylation of UVRAG facilitates the lysosomal degradation of epidermal growth factor receptor (EGFR), reduces EGFR signaling, and suppresses cancer cell proliferation and tumor growth. These results demonstrate that mTORC1 engages in late stages of autophagy and endosome maturation, defining a broader range of mTORC1 functions in the membrane-associated processes.
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Affiliation(s)
- Young-Mi Kim
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Chang Hwa Jung
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Division of Metabolism and Functionality Research, Korea Food Research Institute, 463-746, Republic of Korea
| | - Minchul Seo
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Eun Kyoung Kim
- Department of Pharmacology, Pusan National University, Pusan, 626-870, Republic of Korea
| | - Ji-Man Park
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sun Sik Bae
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Pharmacology, Pusan National University, Pusan, 626-870, Republic of Korea
| | - Do-Hyung Kim
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA.
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72
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McKnight NC, Zhong Y, Wold MS, Gong S, Phillips GR, Dou Z, Zhao Y, Heintz N, Zong WX, Yue Z. Beclin 1 is required for neuron viability and regulates endosome pathways via the UVRAG-VPS34 complex. PLoS Genet 2014; 10:e1004626. [PMID: 25275521 PMCID: PMC4183436 DOI: 10.1371/journal.pgen.1004626] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 07/25/2014] [Indexed: 01/24/2023] Open
Abstract
Deficiency of autophagy protein beclin 1 is implicated in tumorigenesis and neurodegenerative diseases, but the molecular mechanism remains elusive. Previous studies showed that Beclin 1 coordinates the assembly of multiple VPS34 complexes whose distinct phosphatidylinositol 3-kinase III (PI3K-III) lipid kinase activities regulate autophagy at different steps. Recent evidence suggests a function of beclin 1 in regulating multiple VPS34-mediated trafficking pathways beyond autophagy; however, the precise role of beclin 1 in autophagy-independent cellular functions remains poorly understood. Herein we report that beclin 1 regulates endocytosis, in addition to autophagy, and is required for neuron viability in vivo. We find that neuronal beclin 1 associates with endosomes and regulates EEA1/early endosome localization and late endosome formation. Beclin 1 maintains proper cellular phosphatidylinositol 3-phosphate (PI(3)P) distribution and total levels, and loss of beclin 1 causes a disruption of active Rab5 GTPase-associated endosome formation and impairment of endosome maturation, likely due to a failure of Rab5 to recruit VPS34. Furthermore, we find that Beclin 1 deficiency causes complete loss of the UVRAG-VPS34 complex and associated lipid kinase activity. Interestingly, beclin 1 deficiency impairs p40phox-linked endosome formation, which is rescued by overexpressed UVRAG or beclin 1, but not by a coiled-coil domain-truncated beclin 1 (a UVRAG-binding mutant), Atg14L or RUBICON. Thus, our study reveals the essential role for beclin 1 in neuron survival involving multiple membrane trafficking pathways including endocytosis and autophagy, and suggests that the UVRAG-beclin 1 interaction underlies beclin 1's function in endocytosis.
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Affiliation(s)
- Nicole C. McKnight
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Yun Zhong
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Mitchell S. Wold
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Shiaoching Gong
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, Rockefeller University, New York, New York, United States of America
| | - Greg R. Phillips
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Zhixun Dou
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Yanxiang Zhao
- Department of Applied Biology and Chemical Technology, State Key Laboratory of Chirosciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, Rockefeller University, New York, New York, United States of America
| | - Wei-Xing Zong
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Zhenyu Yue
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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73
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Maycotte P, Thorburn A. Targeting autophagy in breast cancer. World J Clin Oncol 2014; 5:224-240. [PMID: 25114840 PMCID: PMC4127596 DOI: 10.5306/wjco.v5.i3.224] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 04/02/2014] [Accepted: 05/29/2014] [Indexed: 02/06/2023] Open
Abstract
Macroautophagy (referred to as autophagy here) is an intracellular degradation pathway enhanced in response to a variety of stresses and in response to nutrient deprivation. This process provides the cell with nutrients and energy by degrading aggregated and damaged proteins as well as compromised organelles. Since autophagy has been linked to diverse diseases including cancer, it has recently become a very interesting target in breast cancer treatment. Indeed, current clinical trials are trying to use chloroquine or hydroxychloroquine, alone or in combination with other drugs to inhibit autophagy during breast cancer therapy since chemotherapy and radiation, regimens that are used to treat breast cancer, are known to induce autophagy in cancer cells. Importantly, in breast cancer, autophagy has been involved in the development of resistance to chemotherapy and to anti-estrogens. Moreover, a close relationship has recently been described between autophagy and the HER2 receptor. Here, we discuss some of the recent findings relating autophagy and cancer with a particular focus on breast cancer therapy.
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74
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Ma B, Cao W, Li W, Gao C, Qi Z, Zhao Y, Du J, Xue H, Peng J, Wen J, Chen H, Ning Y, Huang L, Zhang H, Gao X, Yu L, Chen YG. Dapper1 promotes autophagy by enhancing the Beclin1-Vps34-Atg14L complex formation. Cell Res 2014; 24:912-24. [PMID: 24980960 PMCID: PMC4123296 DOI: 10.1038/cr.2014.84] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 05/16/2014] [Accepted: 06/02/2014] [Indexed: 02/06/2023] Open
Abstract
Autophagy is an intracellular degradation process to clear up aggregated proteins or aged and damaged organelles. The Beclin1-Vps34-Atg14L complex is essential for autophagosome formation. However, how the complex formation is regulated is unclear. Here, we show that Dapper1 (Dpr1) acts as a critical regulator of the Beclin1-Vps34-Atg14L complex to promote autophagy. Dpr1 ablation in the central nervous system results in motor coordination defect and accumulation of p62 and ubiquitinated proteins. Dpr1 increases autophagosome formation as indicated by elevated puncta formation of LC3, Atg14L and DFCP1 (Double FYVE-containing protein 1). Conversely, loss of Dpr1 impairs LC3 lipidation and causes p62/SQSTM1 accumulation. Dpr1 directly interacts with Beclin1 and Atg14L and enhances the Beclin1-Vps34 interaction and Vps34 activity. Together, our findings suggest that Dpr1 enhances the Atg14L-Beclin1-Vps34 complex formation to drive autophagy.
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Affiliation(s)
- Benyu Ma
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Weipeng Cao
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Current address: CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Wenxia Li
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Chan Gao
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhen Qi
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yan Zhao
- State Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jun Du
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hua Xue
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Junya Peng
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jun Wen
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hua Chen
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yuanheng Ning
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lei Huang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hong Zhang
- State Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiang Gao
- Key Laboratory of Model Animal for Disease Study of Ministry of Education, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu 210061, China
| | - Li Yu
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ye-Guang Chen
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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75
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Tagaya M, Arasaki K, Inoue H, Kimura H. Moonlighting functions of the NRZ (mammalian Dsl1) complex. Front Cell Dev Biol 2014; 2:25. [PMID: 25364732 PMCID: PMC4206994 DOI: 10.3389/fcell.2014.00025] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/20/2014] [Indexed: 12/31/2022] Open
Abstract
The yeast Dsl1 complex, which comprises Dsl1, Tip20, and Sec39/Dsl3, has been shown to participate, as a vesicle-tethering complex, in retrograde trafficking from the Golgi apparatus to the endoplasmic reticulum. Its metazoan counterpart NRZ complex, which comprises NAG, RINT1, and ZW10, is also involved in Golgi-to-ER retrograde transport, but each component of the complex has diverse cellular functions including endosome-to-Golgi transport, cytokinesis, cell cycle checkpoint, autophagy, and mRNA decay. In this review, we summarize the current knowledge of the metazoan NRZ complex and discuss the "moonlighting" functions and intercorrelation of their subunits.
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Affiliation(s)
- Mitsuo Tagaya
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Kohei Arasaki
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Hiroki Inoue
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Hana Kimura
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
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76
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UVRAG is required for virus entry through combinatorial interaction with the class C-Vps complex and SNAREs. Proc Natl Acad Sci U S A 2014; 111:2716-21. [PMID: 24550300 DOI: 10.1073/pnas.1320629111] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Enveloped viruses exploit the endomembrane system to enter host cells. Through a cascade of membrane-trafficking events, virus-bearing vesicles fuse with acidic endosomes and/or lysosomes mediated by SNAREs triggering viral fusion. However, the molecular mechanisms underlying this process remain elusive. Here, we found that UV-radiation resistance-associated gene (UVRAG), an autophagic tumor suppressor, is required for the entry of the prototypic negative-strand RNA virus, including influenza A virus and vesicular stomatitis virus, by a mechanism independent of IFN and autophagy. UVRAG mediates viral endocytic transport and membrane penetration through interactions with the class C vacuolar protein sorting (C-Vps) tethering complex and endosomal glutamine-containing SNAREs [syntaxin 7 (STX7), STX8, and vesicle transport through t-SNARE homolog 1B (Vti1b)], leading to the assembly of a fusogenic trans-SNARE complex involving vesicle-associated membrane protein (VAMP8), but not VAMP7. Indeed, UVRAG stimulates VAMP8 translocation to virus-bearing endosomes. Inhibition of VAMP8, but not VAMP7, significantly reduces viral entry. Our data indicate that UVRAG, in concert with C-Vps, regulates viral entry by assembling a specific fusogenic SNARE complex. Thus, UVRAG governs downstream viral entry, highlighting an important pathway capable of potential antiviral therapeutics.
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