301
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Ashraf S, Tay YD, Kelly DA, Sawin KE. Microtubule-independent movement of the fission yeast nucleus. J Cell Sci 2021; 134:jcs.253021. [PMID: 33602740 PMCID: PMC8015250 DOI: 10.1242/jcs.253021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 02/09/2021] [Indexed: 12/14/2022] Open
Abstract
Movement of the cell nucleus typically involves the cytoskeleton and either polymerization-based pushing forces or motor-based pulling forces. In the fission yeast Schizosaccharomyces pombe, nuclear movement and positioning are thought to depend on microtubule polymerization-based pushing forces. Here, we describe a novel, microtubule-independent, form of nuclear movement in fission yeast. Microtubule-independent nuclear movement is directed towards growing cell tips, and it is strongest when the nucleus is close to a growing cell tip, and weakest when the nucleus is far from that tip. Microtubule-independent nuclear movement requires actin cables but does not depend on actin polymerization-based pushing or myosin V-based pulling forces. The vesicle-associated membrane protein (VAMP)-associated proteins (VAPs) Scs2 and Scs22, which are critical for endoplasmic reticulum-plasma membrane contact sites in fission yeast, are also required for microtubule-independent nuclear movement. We also find that in cells in which microtubule-based pushing forces are present, disruption of actin cables leads to increased fluctuations in interphase nuclear positioning and subsequent altered septation. Our results suggest two non-exclusive mechanisms for microtubule-independent nuclear movement, which may help illuminate aspects of nuclear positioning in other cells.
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302
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Acoba MG, Senoo N, Claypool SM. Phospholipid ebb and flow makes mitochondria go. J Cell Biol 2021; 219:151918. [PMID: 32614384 PMCID: PMC7401802 DOI: 10.1083/jcb.202003131] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 01/19/2023] Open
Abstract
Mitochondria, so much more than just being energy factories, also have the capacity to synthesize macromolecules including phospholipids, particularly cardiolipin (CL) and phosphatidylethanolamine (PE). Phospholipids are vital constituents of mitochondrial membranes, impacting the plethora of functions performed by this organelle. Hence, the orchestrated movement of phospholipids to and from the mitochondrion is essential for cellular integrity. In this review, we capture recent advances in the field of mitochondrial phospholipid biosynthesis and trafficking, highlighting the significance of interorganellar communication, intramitochondrial contact sites, and lipid transfer proteins in maintaining membrane homeostasis. We then discuss the physiological functions of CL and PE, specifically how they associate with protein complexes in mitochondrial membranes to support bioenergetics and maintain mitochondrial architecture.
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Affiliation(s)
- Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nanami Senoo
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
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303
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Wong LH, Edgar JR, Martello A, Ferguson BJ, Eden ER. Exploiting Connections for Viral Replication. Front Cell Dev Biol 2021; 9:640456. [PMID: 33816489 PMCID: PMC8012536 DOI: 10.3389/fcell.2021.640456] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/01/2021] [Indexed: 12/16/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of the COVID-19 (coronavirus disease 2019) pandemic, is a positive strand RNA (+RNA) virus. Like other +RNA viruses, SARS-CoV-2 is dependent on host cell metabolic machinery to survive and replicate, remodeling cellular membranes to generate sites of viral replication. Viral RNA-containing double-membrane vesicles (DMVs) are a striking feature of +RNA viral replication and are abundant in SARS-CoV-2-infected cells. Their generation involves rewiring of host lipid metabolism, including lipid biosynthetic pathways. Viruses can also redirect lipids from host cell organelles; lipid exchange at membrane contact sites, where the membranes of adjacent organelles are in close apposition, has been implicated in the replication of several +RNA viruses. Here we review current understanding of DMV biogenesis. With a focus on the exploitation of contact site machinery by +RNA viruses to generate replication organelles, we discuss evidence that similar mechanisms support SARS-CoV-2 replication, protecting its RNA from the host cell immune response.
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Affiliation(s)
| | - James R. Edgar
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | | | - Brian J. Ferguson
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Emily R. Eden
- UCL Institute of Ophthalmology, London, United Kingdom
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304
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Anastasia I, Ilacqua N, Raimondi A, Lemieux P, Ghandehari-Alavijeh R, Faure G, Mekhedov SL, Williams KJ, Caicci F, Valle G, Giacomello M, Quiroga AD, Lehner R, Miksis MJ, Toth K, de Aguiar Vallim TQ, Koonin EV, Scorrano L, Pellegrini L. Mitochondria-rough-ER contacts in the liver regulate systemic lipid homeostasis. Cell Rep 2021; 34:108873. [PMID: 33730569 DOI: 10.1016/j.celrep.2021.108873] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/18/2020] [Accepted: 02/23/2021] [Indexed: 12/12/2022] Open
Abstract
Contacts between organelles create microdomains that play major roles in regulating key intracellular activities and signaling pathways, but whether they also regulate systemic functions remains unknown. Here, we report the ultrastructural organization and dynamics of the inter-organellar contact established by sheets of curved rough endoplasmic reticulum closely wrapped around the mitochondria (wrappER). To elucidate the in vivo function of this contact, mouse liver fractions enriched in wrappER-associated mitochondria are analyzed by transcriptomics, proteomics, and lipidomics. The biochemical signature of the wrappER points to a role in the biogenesis of very-low-density lipoproteins (VLDL). Altering wrappER-mitochondria contacts curtails VLDL secretion and increases hepatic fatty acids, lipid droplets, and neutral lipid content. Conversely, acute liver-specific ablation of Mttp, the most upstream regulator of VLDL biogenesis, recapitulates this hepatic dyslipidemia phenotype and promotes remodeling of the wrappER-mitochondria contact. The discovery that liver wrappER-mitochondria contacts participate in VLDL biology suggests an involvement of inter-organelle contacts in systemic lipid homeostasis.
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Affiliation(s)
- Irene Anastasia
- Graduate Program in Neuroscience, Faculty of Medicine, Laval University, Quebec, QC, Canada; Mitochondria Biology Laboratory, Brain Research Center, Quebec, QC, Canada
| | - Nicolò Ilacqua
- Graduate Program in Neuroscience, Faculty of Medicine, Laval University, Quebec, QC, Canada; Mitochondria Biology Laboratory, Brain Research Center, Quebec, QC, Canada
| | - Andrea Raimondi
- Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
| | - Philippe Lemieux
- Mitochondria Biology Laboratory, Brain Research Center, Quebec, QC, Canada
| | | | - Guilhem Faure
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; National Center for Biotechnology Information, NLM, NIH, Bethesda, MD, USA
| | - Sergei L Mekhedov
- National Center for Biotechnology Information, NLM, NIH, Bethesda, MD, USA
| | - Kevin J Williams
- Department of Biological Chemistry, Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | | | - Giorgio Valle
- Department of Biology, University of Padua, Padua, Italy
| | | | - Ariel D Quiroga
- Instituto de Fisiología Experimental, CONICET, UNR, Rosario, Argentina; Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Richard Lehner
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Michael J Miksis
- Department of Engineering Science and Applied Mathematics, Northwestern University, Evanston, IL, USA
| | - Katalin Toth
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Thomas Q de Aguiar Vallim
- Department of Biological Chemistry, Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Department of Medicine, Division of Cardiology, UCLA, Los Angeles, CA, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, NLM, NIH, Bethesda, MD, USA
| | - Luca Scorrano
- Department of Biology, University of Padua, Padua, Italy
| | - Luca Pellegrini
- Mitochondria Biology Laboratory, Brain Research Center, Quebec, QC, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec, QC, Canada.
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305
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Lujan P, Angulo-Capel J, Chabanon M, Campelo F. Interorganelle communication and membrane shaping in the early secretory pathway. Curr Opin Cell Biol 2021; 71:95-102. [PMID: 33711785 DOI: 10.1016/j.ceb.2021.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/25/2021] [Accepted: 01/30/2021] [Indexed: 01/02/2023]
Abstract
Biomolecules in the secretory pathway use membrane trafficking for reaching their final intracellular destination or for secretion outside the cell. This highly dynamic and multipartite process involves different organelles that communicate to one another while maintaining their identity, shape, and function. Recent studies unraveled new mechanisms of interorganelle communication that help organize the early secretory pathway. We highlight how the spatial proximity between endoplasmic reticulum (ER) exit sites and early Golgi elements provides novel means of ER-Golgi communication for ER export. We also review recent findings on how membrane contact sites between the ER and the trans-Golgi membranes can sustain anterograde traffic out of the Golgi complex.
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Affiliation(s)
- Pablo Lujan
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Barcelona, Spain
| | - Jessica Angulo-Capel
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Barcelona, Spain
| | - Morgan Chabanon
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Barcelona, Spain; Universitat Politècnica de Catalunya-BarcelonaTech, E-08034, Barcelona, Spain
| | - Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Barcelona, Spain.
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306
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From observing to controlling: Inducible control of organelle dynamics and interactions. Curr Opin Cell Biol 2021; 71:69-76. [PMID: 33706236 DOI: 10.1016/j.ceb.2021.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/27/2021] [Accepted: 02/04/2021] [Indexed: 12/17/2022]
Abstract
The dynamics and interactions of cellular organelles underlie many aspects of cellular functioning. Until recently, assessment of organelle dynamics has been primarily observational or required whole-cell perturbations to assess the implications of altered organelle motility and positioning. However, thanks to recently developed and optimized intervention strategies, we now have the ability to control organelles in their unperturbed state, altering organelle positioning, membrane trafficking pathways, as well as organelle interactions. This can be performed both globally and locally, giving fine control over the range, reversibility, and extent of organelle dynamics. Here, we describe how these tools are currently used for controlling organelles and give insight into the exciting future of this emerging field.
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307
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Ahumada-Castro U, Bustos G, Silva-Pavez E, Puebla-Huerta A, Lovy A, Cárdenas C. In the Right Place at the Right Time: Regulation of Cell Metabolism by IP3R-Mediated Inter-Organelle Ca 2+ Fluxes. Front Cell Dev Biol 2021; 9:629522. [PMID: 33738285 PMCID: PMC7960657 DOI: 10.3389/fcell.2021.629522] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 01/19/2021] [Indexed: 12/18/2022] Open
Abstract
In the last few years, metabolism has been shown to be controlled by cross-organelle communication. The relationship between the endoplasmic reticulum and mitochondria/lysosomes is the most studied; here, inositol 1,4,5-triphosphate (IP3) receptor (IP3R)-mediated calcium (Ca2+) release plays a central role. Recent evidence suggests that IP3R isoforms participate in synthesis and degradation pathways. This minireview will summarize the current findings in this area, emphasizing the critical role of Ca2+ communication on organelle function as well as catabolism and anabolism, particularly in cancer.
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Affiliation(s)
- Ulises Ahumada-Castro
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Galdo Bustos
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Eduardo Silva-Pavez
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Andrea Puebla-Huerta
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Alenka Lovy
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Department of Neuroscience, Center for Neuroscience Research, Tufts University School of Medicine, Boston, MA, United States
| | - César Cárdenas
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Buck Institute for Research on Aging, Novato, CA, United States.,Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
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308
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Pipitone R, Eicke S, Pfister B, Glauser G, Falconet D, Uwizeye C, Pralon T, Zeeman SC, Kessler F, Demarsy E. A multifaceted analysis reveals two distinct phases of chloroplast biogenesis during de-etiolation in Arabidopsis. eLife 2021; 10:e62709. [PMID: 33629953 PMCID: PMC7906606 DOI: 10.7554/elife.62709] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 02/04/2021] [Indexed: 11/18/2022] Open
Abstract
Light triggers chloroplast differentiation whereby the etioplast transforms into a photosynthesizing chloroplast and the thylakoid rapidly emerges. However, the sequence of events during chloroplast differentiation remains poorly understood. Using Serial Block Face Scanning Electron Microscopy (SBF-SEM), we generated a series of chloroplast 3D reconstructions during differentiation, revealing chloroplast number and volume and the extent of envelope and thylakoid membrane surfaces. Furthermore, we used quantitative lipid and whole proteome data to complement the (ultra)structural data, providing a time-resolved, multi-dimensional description of chloroplast differentiation. This showed two distinct phases of chloroplast biogenesis: an initial photosynthesis-enabling 'Structure Establishment Phase' followed by a 'Chloroplast Proliferation Phase' during cell expansion. Moreover, these data detail thylakoid membrane expansion during de-etiolation at the seedling level and the relative contribution and differential regulation of proteins and lipids at each developmental stage. Altogether, we establish a roadmap for chloroplast differentiation, a critical process for plant photoautotrophic growth and survival.
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Affiliation(s)
- Rosa Pipitone
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Simona Eicke
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Barbara Pfister
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Gaetan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of NeuchâtelNeuchâtelSwitzerland
| | - Denis Falconet
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Clarisse Uwizeye
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Thibaut Pralon
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Felix Kessler
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Emilie Demarsy
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
- Department of Botany and Plant Biology, University of GenevaGenevaSwitzerland
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309
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Díaz P, Sandoval-Bórquez A, Bravo-Sagua R, Quest AFG, Lavandero S. Perspectives on Organelle Interaction, Protein Dysregulation, and Cancer Disease. Front Cell Dev Biol 2021; 9:613336. [PMID: 33718356 PMCID: PMC7946981 DOI: 10.3389/fcell.2021.613336] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 02/01/2021] [Indexed: 11/13/2022] Open
Abstract
In recent decades, compelling evidence has emerged showing that organelles are not static structures but rather form a highly dynamic cellular network and exchange information through membrane contact sites. Although high-throughput techniques facilitate identification of novel contact sites (e.g., organelle-organelle and organelle-vesicle interactions), little is known about their impact on cellular physiology. Moreover, even less is known about how the dysregulation of these structures impacts on cellular function and therefore, disease. Particularly, cancer cells display altered signaling pathways involving several cell organelles; however, the relevance of interorganelle communication in oncogenesis and/or cancer progression remains largely unknown. This review will focus on organelle contacts relevant to cancer pathogenesis. We will highlight specific proteins and protein families residing in these organelle-interfaces that are known to be involved in cancer-related processes. First, we will review the relevance of endoplasmic reticulum (ER)-mitochondria interactions. This section will focus on mitochondria-associated membranes (MAMs) and particularly the tethering proteins at the ER-mitochondria interphase, as well as their role in cancer disease progression. Subsequently, the role of Ca2+ at the ER-mitochondria interphase in cancer disease progression will be discussed. Members of the Bcl-2 protein family, key regulators of cell death, also modulate Ca2+ transport pathways at the ER-mitochondria interphase. Furthermore, we will review the role of ER-mitochondria communication in the regulation of proteostasis, focusing on the ER stress sensor PERK (PRKR-like ER kinase), which exerts dual roles in cancer. Second, we will review the relevance of ER and mitochondria interactions with other organelles. This section will focus on peroxisome and lysosome organelle interactions and their impact on cancer disease progression. In this context, the peroxisome biogenesis factor (PEX) gene family has been linked to cancer. Moreover, the autophagy-lysosome system is emerging as a driving force in the progression of numerous human cancers. Thus, we will summarize our current understanding of the role of each of these organelles and their communication, highlighting how alterations in organelle interfaces participate in cancer development and progression. A better understanding of specific organelle communication sites and their relevant proteins may help to identify potential pharmacological targets for novel therapies in cancer control.
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Affiliation(s)
- Paula Díaz
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences and Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Center for Studies on Exercise, Metabolism and Cancer (CEMC), Program of Cell and Molecular Biology, Faculty of Medicine, Institute of Biomedical Sciences (ICBM), Universidad de Chile, Santiago, Chile
| | - Alejandra Sandoval-Bórquez
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences and Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Center for Studies on Exercise, Metabolism and Cancer (CEMC), Program of Cell and Molecular Biology, Faculty of Medicine, Institute of Biomedical Sciences (ICBM), Universidad de Chile, Santiago, Chile
| | - Roberto Bravo-Sagua
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences and Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile
| | - Andrew F G Quest
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences and Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Center for Studies on Exercise, Metabolism and Cancer (CEMC), Program of Cell and Molecular Biology, Faculty of Medicine, Institute of Biomedical Sciences (ICBM), Universidad de Chile, Santiago, Chile.,Corporación Centro de Estudios Científicos de las Enfermedades Crónicas (CECEC), Santiago, Chile
| | - Sergio Lavandero
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences and Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Center for Studies on Exercise, Metabolism and Cancer (CEMC), Program of Cell and Molecular Biology, Faculty of Medicine, Institute of Biomedical Sciences (ICBM), Universidad de Chile, Santiago, Chile.,Corporación Centro de Estudios Científicos de las Enfermedades Crónicas (CECEC), Santiago, Chile.,Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
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310
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Wang J, Fang N, Xiong J, Du Y, Cao Y, Ji WK. An ESCRT-dependent step in fatty acid transfer from lipid droplets to mitochondria through VPS13D-TSG101 interactions. Nat Commun 2021; 12:1252. [PMID: 33623047 PMCID: PMC7902631 DOI: 10.1038/s41467-021-21525-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 02/01/2021] [Indexed: 12/13/2022] Open
Abstract
Upon starvation, cells rewire their metabolism, switching from glucose-based metabolism to mitochondrial oxidation of fatty acids, which require the transfer of FAs from lipid droplets (LDs) to mitochondria at mitochondria−LD membrane contact sites (MCSs). However, factors responsible for FA transfer at these MCSs remain uncharacterized. Here, we demonstrate that vacuolar protein sorting-associated protein 13D (VPS13D), loss-of-function mutations of which cause spastic ataxia, coordinates FA trafficking in conjunction with the endosomal sorting complex required for transport (ESCRT) protein tumor susceptibility 101 (TSG101). The VPS13 adaptor-binding domain of VPS13D and TSG101 directly remodels LD membranes in a cooperative manner. The lipid transfer domain of human VPS13D binds glycerophospholipids and FAs in vitro. Depletion of VPS13D, TSG101, or ESCRT-III proteins inhibits FA trafficking from LDs to mitochondria. Our findings suggest that VPS13D mediates the ESCRT-dependent remodeling of LD membranes to facilitate FA transfer at mitochondria-LD contacts. Metabolic rewiring requires the mobilization of fatty acids (FA) from lipid droplets (LDs) at membrane contact sites (MCSs), although the details of FA transfer remain unclear. Here, the authors show that VPS13D and the ESCRT complex remodel LD membranes to promote FA trafficking to mitochondria.
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Affiliation(s)
- Jingru Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Na Fang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Juan Xiong
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yuanjiao Du
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yue Cao
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Wei-Ke Ji
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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311
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Leal NS, Martins LM. Mind the Gap: Mitochondria and the Endoplasmic Reticulum in Neurodegenerative Diseases. Biomedicines 2021; 9:biomedicines9020227. [PMID: 33672391 PMCID: PMC7926795 DOI: 10.3390/biomedicines9020227] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/16/2022] Open
Abstract
The way organelles are viewed by cell biologists is quickly changing. For many years, these cellular entities were thought to be unique and singular structures that performed specific roles. However, in recent decades, researchers have discovered that organelles are dynamic and form physical contacts. In addition, organelle interactions modulate several vital biological functions, and the dysregulation of these contacts is involved in cell dysfunction and different pathologies, including neurodegenerative diseases. Mitochondria–ER contact sites (MERCS) are among the most extensively studied and understood juxtapositioned interorganelle structures. In this review, we summarise the major biological and ultrastructural dysfunctions of MERCS in neurodegeneration, with a particular focus on Alzheimer’s disease as well as Parkinson’s disease, amyotrophic lateral sclerosis and frontotemporal dementia. We also propose an updated version of the MERCS hypothesis in Alzheimer’s disease based on new findings. Finally, we discuss the possibility of MERCS being used as possible drug targets to halt cell death and neurodegeneration.
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312
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Morphological bases of phytoplankton energy management and physiological responses unveiled by 3D subcellular imaging. Nat Commun 2021; 12:1049. [PMID: 33594064 PMCID: PMC7886885 DOI: 10.1038/s41467-021-21314-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 01/12/2021] [Indexed: 01/31/2023] Open
Abstract
Eukaryotic phytoplankton have a small global biomass but play major roles in primary production and climate. Despite improved understanding of phytoplankton diversity and evolution, we largely ignore the cellular bases of their environmental plasticity. By comparative 3D morphometric analysis across seven distant phytoplankton taxa, we observe constant volume occupancy by the main organelles and preserved volumetric ratios between plastids and mitochondria. We hypothesise that phytoplankton subcellular topology is modulated by energy-management constraints. Consistent with this, shifting the diatom Phaeodactylum from low to high light enhances photosynthesis and respiration, increases cell-volume occupancy by mitochondria and the plastid CO2-fixing pyrenoid, and boosts plastid-mitochondria contacts. Changes in organelle architectures and interactions also accompany Nannochloropsis acclimation to different trophic lifestyles, along with respiratory and photosynthetic responses. By revealing evolutionarily-conserved topologies of energy-managing organelles, and their role in phytoplankton acclimation, this work deciphers phytoplankton responses at subcellular scales.
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313
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Wang Y, Yuan P, Grabon A, Tripathi A, Lee D, Rodriguez M, Lönnfors M, Eisenberg-Bord M, Wang Z, Man Lam S, Schuldiner M, Bankaitis VA. Noncanonical regulation of phosphatidylserine metabolism by a Sec14-like protein and a lipid kinase. J Cell Biol 2021; 219:151686. [PMID: 32303746 PMCID: PMC7199851 DOI: 10.1083/jcb.201907128] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/20/2019] [Accepted: 02/10/2020] [Indexed: 01/20/2023] Open
Abstract
The yeast phosphatidylserine (PtdSer) decarboxylase Psd2 is proposed to engage in a membrane contact site (MCS) for PtdSer decarboxylation to phosphatidylethanolamine (PtdEtn). This proposed MCS harbors Psd2, the Sec14-like phosphatidylinositol transfer protein (PITP) Sfh4, the Stt4 phosphatidylinositol (PtdIns) 4-OH kinase, the Scs2 tether, and an uncharacterized protein. We report that, of these components, only Sfh4 and Stt4 regulate Psd2 activity in vivo. They do so via distinct mechanisms. Sfh4 operates via a mechanism for which its PtdIns-transfer activity is dispensable but requires an Sfh4-Psd2 physical interaction. The other requires Stt4-mediated production of PtdIns-4-phosphate (PtdIns4P), where Stt4 (along with the Sac1 PtdIns4P phosphatase and endoplasmic reticulum–plasma membrane tethers) indirectly modulate Psd2 activity via a PtdIns4P homeostatic mechanism that influences PtdSer accessibility to Psd2. These results identify an example in which the biological function of a Sec14-like PITP is cleanly uncoupled from its canonical in vitro PtdIns-transfer activity and challenge popular functional assumptions regarding lipid-transfer protein involvements in MCS function.
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Affiliation(s)
- Yaxi Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX.,Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Peihua Yuan
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Aby Grabon
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Ashutosh Tripathi
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Dongju Lee
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | - Martin Rodriguez
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX
| | - Max Lönnfors
- Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX
| | | | - Zehua Wang
- University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Sin Man Lam
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Vytas A Bankaitis
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX.,Department of Molecular & Cellular Medicine, Texas A&M Health Science Center, College Station, TX.,Department of Chemistry, Texas A&M University, College Station, TX
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314
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Hewlett B, Singh NP, Vannier C, Galli T. ER-PM Contact Sites - SNARING Actors in Emerging Functions. Front Cell Dev Biol 2021; 9:635518. [PMID: 33681218 PMCID: PMC7928305 DOI: 10.3389/fcell.2021.635518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/21/2021] [Indexed: 11/13/2022] Open
Abstract
The compartmentalisation achieved by confining cytoplasm into membrane-enclosed organelles in eukaryotic cells is essential for maintaining vital functions including ATP production, synthetic and degradative pathways. While intracellular organelles are highly specialised in these functions, the restricting membranes also impede exchange of molecules responsible for the synchronised and responsive cellular activities. The initial identification of contact sites between the ER and plasma membrane (PM) provided a potential candidate structure for communication between organelles without mixing by fusion. Over the past decades, research has revealed a far broader picture of the events. Membrane contact sites (MCSs) have been recognized as increasingly important actors in cell differentiation, plasticity and maintenance, and, upon dysfunction, responsible for pathological conditions such as cancer and neurodegenerative diseases. Present in multiple organelles and cell types, MCSs promote transport of lipids and Ca2+ homoeostasis, with a range of associated protein families. Interestingly, each MCS displays a unique molecular signature, adapted to organelle functions. This review will explore the literature describing the molecular components and interactions taking place at ER-PM contact sites, their functions, and implications in eukaryotic cells, particularly neurons, with emphasis on lipid transfer proteins and emerging function of SNAREs.
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Affiliation(s)
- Bailey Hewlett
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Neha Pratap Singh
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Christian Vannier
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Thierry Galli
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France.,GHU PARIS Psychiatrie and Neurosciences, Paris, France
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315
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Herker E, Vieyres G, Beller M, Krahmer N, Bohnert M. Lipid Droplet Contact Sites in Health and Disease. Trends Cell Biol 2021; 31:345-358. [PMID: 33546922 DOI: 10.1016/j.tcb.2021.01.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 01/04/2023]
Abstract
After having been disregarded for a long time as inert fat drops, lipid droplets (LDs) are now recognized as ubiquitous cellular organelles with key functions in lipid biology and beyond. The identification of abundant LD contact sites, places at which LDs are physically attached to other organelles, has uncovered an unexpected level of communication between LDs and the rest of the cell. In recent years, many disease factors mutated in hereditary disorders have been recognized as LD contact site proteins. Furthermore, LD contact sites are dramatically rearranged in response to infections with intracellular pathogens, as well as under pathological metabolic conditions such as hepatic steatosis. Collectively, it is emerging that LD-organelle contacts are important players in development and progression of disease.
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Affiliation(s)
- Eva Herker
- Institute of Virology, Philipps-University Marburg, 35043 Marburg, Germany.
| | - Gabrielle Vieyres
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany; Leibniz ScienceCampus InterACt, Hamburg, Germany.
| | - Mathias Beller
- Institute for Mathematical Modeling of Biological Systems, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; Systems Biology of Lipid Metabolism, Heinrich Heine University Düsseldorf, Germany.
| | - Natalie Krahmer
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
| | - Maria Bohnert
- Institute of Cell Dynamics and Imaging, University of Münster, 48149 Münster, Germany; Cells in Motion Interfaculty Centre (CiM), University of Münster, Münster, Germany.
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316
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Mitochondrial control of cellular protein homeostasis. Biochem J 2021; 477:3033-3054. [PMID: 32845275 DOI: 10.1042/bcj20190654] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/20/2020] [Accepted: 08/03/2020] [Indexed: 02/08/2023]
Abstract
Mitochondria are involved in several vital functions of the eukaryotic cell. The majority of mitochondrial proteins are coded by nuclear DNA. Constant import of proteins from the cytosol is a prerequisite for the efficient functioning of the organelle. The protein import into mitochondria is mediated by diverse import pathways and is continuously under watch by quality control systems. However, it is often challenged by both internal and external factors, such as oxidative stress or energy shortage. The impaired protein import and biogenesis leads to the accumulation of mitochondrial precursor proteins in the cytosol and activates several stress response pathways. These defense mechanisms engage a network of processes involving transcription, translation, and protein clearance to restore cellular protein homeostasis. In this review, we provide a comprehensive analysis of various factors and processes contributing to mitochondrial stress caused by protein biogenesis failure and summarize the recovery mechanisms employed by the cell.
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317
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Rasul F, Zheng F, Dong F, He J, Liu L, Liu W, Cheema JY, Wei W, Fu C. Emr1 regulates the number of foci of the endoplasmic reticulum-mitochondria encounter structure complex. Nat Commun 2021; 12:521. [PMID: 33483504 PMCID: PMC7822926 DOI: 10.1038/s41467-020-20866-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 12/16/2020] [Indexed: 11/21/2022] Open
Abstract
The endoplasmic reticulum-mitochondria encounter structure (ERMES) complex creates contact sites between the endoplasmic reticulum and mitochondria, playing crucial roles in interorganelle communication, mitochondrial fission, mtDNA inheritance, lipid transfer, and autophagy. The mechanism regulating the number of ERMES foci within the cell remains unclear. Here, we demonstrate that the mitochondrial membrane protein Emr1 contributes to regulating the number of ERMES foci. We show that the absence of Emr1 significantly decreases the number of ERMES foci. Moreover, we find that Emr1 interacts with the ERMES core component Mdm12 and colocalizes with Mdm12 on mitochondria. Similar to ERMES mutant cells, cells lacking Emr1 display defective mitochondrial morphology and impaired mitochondrial segregation, which can be rescued by an artificial tether capable of linking the endoplasmic reticulum and mitochondria. We further demonstrate that the cytoplasmic region of Emr1 is required for regulating the number of ERMES foci. This work thus reveals a crucial regulatory protein necessary for ERMES functions and provides mechanistic insights into understanding the dynamic regulation of endoplasmic reticulum-mitochondria communication. Interorganelle membrane contact sites between the endoplasmic reticulum and mitochondria can be mediated with the ER-mitochondria encounter structure (ERMES) complex, though precise regulation is unclear. Here, the authors report that the number of ERMES foci is regulated by the previously uncharacterized mitochondrial membrane protein Emr1.
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Affiliation(s)
- Faiz Rasul
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Fan Zheng
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Fenfen Dong
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Jiajia He
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Ling Liu
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Wenyue Liu
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Javairia Yousuf Cheema
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China
| | - Wenfan Wei
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China.
| | - Chuanhai Fu
- Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027, Hefei, People's Republic of China.
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318
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Cantarero L, Juárez-Escoto E, Civera-Tregón A, Rodríguez-Sanz M, Roldán M, Benítez R, Hoenicka J, Palau F. Mitochondria-lysosome membrane contacts are defective in GDAP1-related Charcot-Marie-Tooth disease. Hum Mol Genet 2021; 29:3589-3605. [PMID: 33372681 PMCID: PMC7823109 DOI: 10.1093/hmg/ddaa243] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/13/2020] [Accepted: 10/28/2020] [Indexed: 12/17/2022] Open
Abstract
Mutations in the GDAP1 gene cause Charcot-Marie-Tooth (CMT) neuropathy. GDAP1 is an atypical glutathione S-transferase (GST) of the outer mitochondrial membrane and the mitochondrial membrane contacts with the endoplasmic reticulum (MAMs). Here, we investigate the role of this GST in the autophagic flux and the membrane contact sites (MCSs) between mitochondria and lysosomes in the cellular pathophysiology of GDAP1 deficiency. We demonstrate that GDAP1 participates in basal autophagy and that its depletion affects LC3 and PI3P biology in autophagosome biogenesis and membrane trafficking from MAMs. GDAP1 also contributes to the maturation of lysosome by interacting with PYKfyve kinase, a pH-dependent master lysosomal regulator. GDAP1 deficiency causes giant lysosomes with hydrolytic activity, a delay in the autophagic lysosome reformation, and TFEB activation. Notably, we found that GDAP1 interacts with LAMP-1, which supports that GDAP1-LAMP-1 is a new tethering pair of mitochondria and lysosome membrane contacts. We observed mitochondria-lysosome MCSs in soma and axons of cultured mouse embryonic motor neurons and human neuroblastoma cells. GDAP1 deficiency reduces the MCSs between these organelles, causes mitochondrial network abnormalities, and decreases levels of cellular glutathione (GSH). The supply of GSH-MEE suffices to rescue the lysosome membranes and the defects of the mitochondrial network, but not the interorganelle MCSs nor early autophagic events. Overall, we show that GDAP1 enables the proper function of mitochondrial MCSs in both degradative and nondegradative pathways, which could explain primary insults in GDAP1-related CMT pathophysiology, and highlights new redox-sensitive targets in axonopathies where mitochondria and lysosomes are involved.
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Affiliation(s)
- Lara Cantarero
- Department of Neurogenetics and Molecular Medicine—IPER, Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona 08950, Spain
- Department of Neurogenetics and Molecular Medicine, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona 08950, Spain
| | - Elena Juárez-Escoto
- Department of Neurogenetics and Molecular Medicine—IPER, Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona 08950, Spain
- Department of Neurogenetics and Molecular Medicine, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona 08950, Spain
| | - Azahara Civera-Tregón
- Department of Neurogenetics and Molecular Medicine—IPER, Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona 08950, Spain
- Department of Neurogenetics and Molecular Medicine, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona 08950, Spain
| | - María Rodríguez-Sanz
- Department of Neurogenetics and Molecular Medicine—IPER, Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona 08950, Spain
| | - Mónica Roldán
- Confocal Microscopy Unit, IPER, Department of Genetic and Molecular Medicine, and Department of Pathology, Hospital Sant Joan de Déu, Barcelona 08950, Spain
| | - Raúl Benítez
- Biomedical Engineering Research Center (CREB), Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona 08950, Spain
- Automatic Control Department and Biomedical Engineering Research Center, Universitat Politècnica de Catalunya, Barcelona 08028, Spain
| | - Janet Hoenicka
- Department of Neurogenetics and Molecular Medicine—IPER, Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona 08950, Spain
- Department of Neurogenetics and Molecular Medicine, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona 08950, Spain
| | - Francesc Palau
- Department of Neurogenetics and Molecular Medicine—IPER, Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona 08950, Spain
- Department of Neurogenetics and Molecular Medicine, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona 08950, Spain
- Department of Genetic and Molecular Medicine—IPER, Hospital Sant Joan de Déu, Barcelona 08950, Spain
- Department of General Internal Medicine, Clinic Institute of Medicine and Dermatology (ICMiD), Hospital Clínic, Barcelona 08036, Spain
- Division of Pediatrics, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona 08036, Spain
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319
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Tosal-Castano S, Peselj C, Kohler V, Habernig L, Berglund LL, Ebrahimi M, Vögtle FN, Höög J, Andréasson C, Büttner S. Snd3 controls nucleus-vacuole junctions in response to glucose signaling. Cell Rep 2021; 34:108637. [PMID: 33472077 DOI: 10.1016/j.celrep.2020.108637] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 12/08/2020] [Accepted: 12/21/2020] [Indexed: 12/29/2022] Open
Abstract
Membrane contact sites facilitate the exchange of metabolites between organelles to support interorganellar communication. The nucleus-vacuole junctions (NVJs) establish physical contact between the perinuclear endoplasmic reticulum (ER) and the vacuole. Although the NVJ tethers are known, how NVJ abundance and composition are controlled in response to metabolic cues remains elusive. Here, we identify the ER protein Snd3 as central factor for NVJ formation. Snd3 interacts with NVJ tethers, supports their targeting to the contacts, and is essential for NVJ formation. Upon glucose exhaustion, Snd3 relocalizes from the ER to NVJs and promotes contact expansion regulated by central glucose signaling pathways. Glucose replenishment induces the rapid dissociation of Snd3 from the NVJs, preceding the slow disassembly of the junctions. In sum, this study identifies a key factor required for formation and regulation of NVJs and provides a paradigm for metabolic control of membrane contact sites.
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Affiliation(s)
- Sergi Tosal-Castano
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden
| | - Carlotta Peselj
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden
| | - Verena Kohler
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden
| | - Lukas Habernig
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden
| | - Lisa Larsson Berglund
- Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, 41390 Gothenburg, Sweden
| | - Mahsa Ebrahimi
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden
| | - F-Nora Vögtle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Stefan-Meier-Straße 17, 79104 Freiburg, Germany; Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Johanna Höög
- Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, 41390 Gothenburg, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 10691 Stockholm, Sweden; Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010 Graz, Austria.
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320
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Gil-Hernández A, Arroyo-Campuzano M, Simoni-Nieves A, Zazueta C, Gomez-Quiroz LE, Silva-Palacios A. Relevance of Membrane Contact Sites in Cancer Progression. Front Cell Dev Biol 2021; 8:622215. [PMID: 33511135 PMCID: PMC7835521 DOI: 10.3389/fcell.2020.622215] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/10/2020] [Indexed: 01/01/2023] Open
Abstract
Membrane contact sites (MCS) are typically defined as areas of proximity between heterologous or homologous membranes characterized by specific proteins. The study of MCS is considered as an emergent field that shows how crucial organelle interactions are in cell physiology. MCS regulate a myriad of physiological processes such as apoptosis, calcium, and lipid signaling, just to name a few. The membranal interactions between the endoplasmic reticulum (ER)–mitochondria, the ER–plasma membrane, and the vesicular traffic have received special attention in recent years, particularly in cancer research, in which it has been proposed that MCS regulate tumor metabolism and fate, contributing to their progression. However, as the therapeutic or diagnostic potential of MCS has not been fully revisited, in this review, we provide recent information on MCS relevance on calcium and lipid signaling in cancer cells and on its role in tumor progression. We also describe some proteins associated with MCS, like CERT, STIM1, VDAC, and Orai, that impact on cancer progression and that could be a possible diagnostic marker. Overall, these information might contribute to the understanding of the complex biology of cancer cells.
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Affiliation(s)
- Aurora Gil-Hernández
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Miguel Arroyo-Campuzano
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Arturo Simoni-Nieves
- Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico
| | - Cecilia Zazueta
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Luis Enrique Gomez-Quiroz
- Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico
| | - Alejandro Silva-Palacios
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
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321
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Kohler V, Büttner S. Remodelling of Nucleus-Vacuole Junctions During Metabolic and Proteostatic Stress. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211016608. [PMID: 34124572 PMCID: PMC7610967 DOI: 10.1177/25152564211016608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 12/18/2022]
Abstract
Cellular adaptation to stress and metabolic cues requires a coordinated response of different intracellular compartments, separated by semipermeable membranes. One way to facilitate interorganellar communication is via membrane contact sites, physical bridges between opposing organellar membranes formed by an array of tethering machineries. These contact sites are highly dynamic and establish an interconnected organellar network able to quickly respond to external and internal stress by changing size, abundance and molecular architecture. Here, we discuss recent work on nucleus-vacuole junctions, connecting yeast vacuoles with the nucleus. Appearing as small, single foci in mitotic cells, these contacts expand into one enlarged patch upon nutrient exhaustion and entry into quiescence or can be shaped into multiple large foci essential to sustain viability upon proteostatic stress at the nuclear envelope. We highlight the remarkable plasticity and rapid remodelling of these contact sites upon metabolic or proteostatic stress and their emerging importance for cellular fitness.
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Affiliation(s)
- Verena Kohler
- Department of Molecular Biosciences, The Wenner‐Gren Institute, Stockholm University, Stockholm, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner‐Gren Institute, Stockholm University, Stockholm, Sweden
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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322
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Chambers IG, Willoughby MM, Hamza I, Reddi AR. One ring to bring them all and in the darkness bind them: The trafficking of heme without deliverers. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2021; 1868:118881. [PMID: 33022276 PMCID: PMC7756907 DOI: 10.1016/j.bbamcr.2020.118881] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/22/2020] [Accepted: 09/25/2020] [Indexed: 02/07/2023]
Abstract
Heme, as a hydrophobic iron-containing organic ring, is lipid soluble and can interact with biological membranes. The very same properties of heme that nature exploits to support life also renders heme potentially cytotoxic. In order to utilize heme, while also mitigating its toxicity, cells are challenged to tightly control the concentration and bioavailability of heme. On the bright side, it is reasonable to envision that, analogous to other transition metals, a combination of membrane-bound transporters, soluble carriers, and chaperones coordinate heme trafficking to subcellular compartments. However, given the dual properties exhibited by heme as a transition metal and lipid, it is compelling to consider the dark side: the potential role of non-proteinaceous biomolecules including lipids and nucleic acids that bind, sequester, and control heme trafficking and bioavailability. The emergence of inter-organellar membrane contact sites, as well as intracellular vesicles derived from various organelles, have raised the prospect that heme can be trafficked through hydrophobic channels. In this review, we aim to focus on heme delivery without deliverers - an alternate paradigm for the regulation of heme homeostasis through chaperone-less pathways for heme trafficking.
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Affiliation(s)
- Ian G Chambers
- Department of Animal and Avian Sciences, Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20740, United States of America
| | - Mathilda M Willoughby
- School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, United States of America
| | - Iqbal Hamza
- Department of Animal and Avian Sciences, Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20740, United States of America.
| | - Amit R Reddi
- School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, United States of America.
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323
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Cheema JY, He J, Wei W, Fu C. The Endoplasmic Reticulum-Mitochondria Encounter Structure and its Regulatory Proteins. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211064491. [PMID: 37366373 PMCID: PMC10243566 DOI: 10.1177/25152564211064491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
In fungi, the endoplasmic reticulum-mitochondria encounter structure (ERMES) is present between the endoplasmic reticulon (ER) and mitochondria to promote the formation of the ER-mitochondria contact sites. Four constitutive components (Mmm1, Mdm12, Mdm34, and Mdm10) assemble to form the ERMES complex while regulator proteins are required for regulating the organization and function of the ERMES complex. Multiple regulator proteins, including Gem1, Lam6, Tom7, and Emr1, of the ERMES complex, have been identified recently. In this review, we discuss the organization of the ERMES complex and the roles of the regulator proteins of the ERMES complex.
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Affiliation(s)
- Javairia Y. Cheema
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
| | - Jiajia He
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
| | - Wenfan Wei
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
| | - Chuanhai Fu
- Ministry of Education Key Laboratory for Cellular
Dynamics, CAS Center for Excellence in Molecular Cell Sciences, Hefei National
Laboratory for Physical Sciences at the Microscale, School of Life Sciences,
Division of Life Sciences and Medicine, University of Science and Technology
of China, Hefei, P.R. China
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324
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David Y, Castro IG, Schuldiner M. The Fast and the Furious: Golgi Contact Sites. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:1-15. [PMID: 35071979 PMCID: PMC7612241 DOI: 10.1177/25152564211034424] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Contact sites are areas of close apposition between two membranes that coordinate nonvesicular communication between organelles. Such interactions serve a wide range of cellular functions from regulating metabolic pathways to executing stress responses and coordinating organelle inheritance. The past decade has seen a dramatic increase in information on certain contact sites, mostly those involving the endoplasmic reticulum. However, despite its central role in the secretory pathway, the Golgi apparatus and its contact sites remain largely unexplored. In this review, we discuss the current knowledge of Golgi contact sites and share our thoughts as to why Golgi contact sites are understudied. We also highlight what exciting future directions may exist in this emerging field.
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Affiliation(s)
- Yotam David
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Inês G Castro
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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325
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Zhemkov V, Liou J, Bezprozvanny I. Sigma 1 Receptor, Cholesterol and Endoplasmic Reticulum Contact Sites. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211026505. [PMID: 37366370 PMCID: PMC10243589 DOI: 10.1177/25152564211026505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 06/28/2023]
Abstract
Recent studies indicated potential importance of membrane contact sites (MCS) between the endoplasmic reticulum (ER) and other cellular organelles. These MCS have unique protein and lipid composition and serve as hubs for inter-organelle communication and signaling. Despite extensive investigation of MCS protein composition and functional roles, little is known about the process of MCS formation. In this perspective, we propose a hypothesis that MCS are formed not as a result of random interactions between membranes of ER and other organelles but on the basis of pre-existing cholesterol-enriched ER microdomains.
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Affiliation(s)
- Vladimir Zhemkov
- Department of Physiology,
UT Southwestern Medical Center at Dallas, Texas, United States
| | - Jen Liou
- Department of Physiology,
UT Southwestern Medical Center at Dallas, Texas, United States
| | - Ilya Bezprozvanny
- Department of Physiology,
UT Southwestern Medical Center at Dallas, Texas, United States
- Laboratory of Molecular
Neurodegeneration, Peter the Great St Petersburg State Polytechnic
University, Russia
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326
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Benhammouda S, Vishwakarma A, Gatti P, Germain M. Mitochondria Endoplasmic Reticulum Contact Sites (MERCs): Proximity Ligation Assay as a Tool to Study Organelle Interaction. Front Cell Dev Biol 2021. [PMID: 34926468 DOI: 10.3389/fcell.2021.789959.ecollection2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023] Open
Abstract
Organelles cooperate with each other to regulate vital cellular homoeostatic functions. This occurs through the formation of close connections through membrane contact sites. Mitochondria-Endoplasmic-Reticulum (ER) contact sites (MERCS) are one of such contact sites that regulate numerous biological processes by controlling calcium and metabolic homeostasis. However, the extent to which contact sites shape cellular biology and the underlying mechanisms remain to be fully elucidated. A number of biochemical and imaging approaches have been established to address these questions, resulting in the identification of a number of molecular tethers between mitochondria and the ER. Among these techniques, fluorescence-based imaging is widely used, including analysing signal overlap between two organelles and more selective techniques such as in-situ proximity ligation assay (PLA). While these two techniques allow the detection of endogenous proteins, preventing some problems associated with techniques relying on overexpression (FRET, split fluorescence probes), they come with their own issues. In addition, proper image analysis is required to minimise potential artefacts associated with these methods. In this review, we discuss the protocols and outline the limitations of fluorescence-based approaches used to assess MERCs using endogenous proteins.
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Affiliation(s)
- Sara Benhammouda
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université Du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre D'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Montréal, Montréal, QC, Canada
| | - Anjali Vishwakarma
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université Du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre D'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Montréal, Montréal, QC, Canada
| | - Priya Gatti
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université Du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre D'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Montréal, Montréal, QC, Canada
| | - Marc Germain
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université Du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
- Centre D'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois, Université du Québec à Montréal, Montréal, QC, Canada
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327
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Xu J, Huang X. Lipid Metabolism at Membrane Contacts: Dynamics and Functions Beyond Lipid Homeostasis. Front Cell Dev Biol 2020; 8:615856. [PMID: 33425923 PMCID: PMC7786193 DOI: 10.3389/fcell.2020.615856] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 11/30/2020] [Indexed: 01/12/2023] Open
Abstract
Membrane contact sites (MCSs), regions where the membranes of two organelles are closely apposed, play critical roles in inter-organelle communication, such as lipid trafficking, intracellular signaling, and organelle biogenesis and division. First identified as “fraction X” in the early 90s, MCSs are now widely recognized to facilitate local lipid synthesis and inter-organelle lipid transfer, which are important for maintaining cellular lipid homeostasis. In this review, we discuss lipid metabolism and related cellular and physiological functions in MCSs. We start with the characteristics of lipid synthesis and breakdown at MCSs. Then we focus on proteins involved in lipid synthesis and turnover at these sites. Lastly, we summarize the cellular function of lipid metabolism at MCSs beyond mere lipid homeostasis, including the physiological meaning and relevance of MCSs regarding systemic lipid metabolism. This article is part of an article collection entitled: Coupling and Uncoupling: Dynamic Control of Membrane Contacts.
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Affiliation(s)
- Jiesi Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China.,College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
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328
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Schulze RJ, Krueger EW, Weller SG, Johnson KM, Casey CA, Schott MB, McNiven MA. Direct lysosome-based autophagy of lipid droplets in hepatocytes. Proc Natl Acad Sci U S A 2020; 117:32443-32452. [PMID: 33288726 PMCID: PMC7768785 DOI: 10.1073/pnas.2011442117] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hepatocytes metabolize energy-rich cytoplasmic lipid droplets (LDs) in the lysosome-directed process of autophagy. An organelle-selective form of this process (macrolipophagy) results in the engulfment of LDs within double-membrane delimited structures (autophagosomes) before lysosomal fusion. Whether this is an exclusive autophagic mechanism used by hepatocytes to catabolize LDs is unclear. It is also unknown whether lysosomes alone might be sufficient to mediate LD turnover in the absence of an autophagosomal intermediate. We performed live-cell microscopy of hepatocytes to monitor the dynamic interactions between lysosomes and LDs in real-time. We additionally used a fluorescent variant of the LD-specific protein (PLIN2) that exhibits altered fluorescence in response to LD interactions with the lysosome. We find that mammalian lysosomes and LDs undergo interactions during which proteins and lipids can be transferred from LDs directly into lysosomes. Electron microscopy (EM) of primary hepatocytes or hepatocyte-derived cell lines supports the existence of these interactions. It reveals a dramatic process whereby the lipid contents of the LD can be "extruded" directly into the lysosomal lumen under nutrient-limited conditions. Significantly, these interactions are not affected by perturbations to crucial components of the canonical macroautophagy machinery and can occur in the absence of double-membrane lipoautophagosomes. These findings implicate the existence of an autophagic mechanism used by mammalian cells for the direct transfer of LD components into the lysosome for breakdown. This process further emphasizes the critical role of lysosomes in hepatic LD catabolism and provides insights into the mechanisms underlying lipid homeostasis in the liver.
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Affiliation(s)
- Ryan J Schulze
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - Eugene W Krueger
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - Shaun G Weller
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - Katherine M Johnson
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - Carol A Casey
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198
| | - Micah B Schott
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - Mark A McNiven
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905;
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
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329
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Koppers M, Özkan N, Farías GG. Complex Interactions Between Membrane-Bound Organelles, Biomolecular Condensates and the Cytoskeleton. Front Cell Dev Biol 2020; 8:618733. [PMID: 33409284 PMCID: PMC7779554 DOI: 10.3389/fcell.2020.618733] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 12/03/2020] [Indexed: 12/13/2022] Open
Abstract
Membrane-bound and membraneless organelles/biomolecular condensates ensure compartmentalization into functionally distinct units enabling proper organization of cellular processes. Membrane-bound organelles form dynamic contacts with each other to enable the exchange of molecules and to regulate organelle division and positioning in coordination with the cytoskeleton. Crosstalk between the cytoskeleton and dynamic membrane-bound organelles has more recently also been found to regulate cytoskeletal organization. Interestingly, recent work has revealed that, in addition, the cytoskeleton and membrane-bound organelles interact with cytoplasmic biomolecular condensates. The extent and relevance of these complex interactions are just beginning to emerge but may be important for cytoskeletal organization and organelle transport and remodeling. In this review, we highlight these emerging functions and emphasize the complex interplay of the cytoskeleton with these organelles. The crosstalk between membrane-bound organelles, biomolecular condensates and the cytoskeleton in highly polarized cells such as neurons could play essential roles in neuronal development, function and maintenance.
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Affiliation(s)
| | | | - Ginny G. Farías
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
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330
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Tashiro S, Kakimoto Y, Shinmyo M, Fujimoto S, Tamura Y. Improved Split-GFP Systems for Visualizing Organelle Contact Sites in Yeast and Human Cells. Front Cell Dev Biol 2020; 8:571388. [PMID: 33330450 PMCID: PMC7714769 DOI: 10.3389/fcell.2020.571388] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/26/2020] [Indexed: 12/27/2022] Open
Abstract
Inter-organelle contact sites have attracted a lot of attention as functionally specialized regions that mediate the exchange of metabolites, including lipids and ions, between distinct organelles. However, studies on inter-organelle contact sites are at an early stage and it remains enigmatic what directly mediates the organelle-organelle interactions and how the number and degree of the contacts are regulated. As a first step to answer these questions, we previously developed split-GFP probes that could visualize and quantify multiple inter-organelle contact sites in the yeast and human cultured cells. However, the split-GFP probes possessed a disadvantage of inducing artificial connections between two different organelle membranes, especially when overexpressed. In the present study, we developed a way to express the split-GFP probes whose expressions remained at low levels, with minimal variations between different yeast cells. Besides, we constructed a HeLa cell line in which the expression of the split-GFP probes could be induced by the addition of doxycycline to minimize the artificial effects. The improved split-GFP systems may be faithful tools to quantify organelle contact sites and screen new factors involved in organelle-organelle tethering in yeast and mammalian cells.
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Affiliation(s)
- Shinya Tashiro
- Faculty of Science, Yamagata University, Yamagata, Japan
| | - Yuriko Kakimoto
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
| | | | | | - Yasushi Tamura
- Faculty of Science, Yamagata University, Yamagata, Japan
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331
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Human VAPome Analysis Reveals MOSPD1 and MOSPD3 as Membrane Contact Site Proteins Interacting with FFAT-Related FFNT Motifs. Cell Rep 2020; 33:108475. [DOI: 10.1016/j.celrep.2020.108475] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 10/05/2020] [Accepted: 11/12/2020] [Indexed: 12/21/2022] Open
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332
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Desai R, East DA, Hardy L, Faccenda D, Rigon M, Crosby J, Alvarez MS, Singh A, Mainenti M, Hussey LK, Bentham R, Szabadkai G, Zappulli V, Dhoot GK, Romano LE, Xia D, Coppens I, Hamacher-Brady A, Chapple JP, Abeti R, Fleck RA, Vizcay-Barrena G, Smith K, Campanella M. Mitochondria form contact sites with the nucleus to couple prosurvival retrograde response. SCIENCE ADVANCES 2020; 6:eabc9955. [PMID: 33355129 PMCID: PMC11206220 DOI: 10.1126/sciadv.abc9955] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 11/13/2020] [Indexed: 05/25/2023]
Abstract
Mitochondria drive cellular adaptation to stress by retro-communicating with the nucleus. This process is known as mitochondrial retrograde response (MRR) and is induced by mitochondrial dysfunction. MRR results in the nuclear stabilization of prosurvival transcription factors such as the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Here, we demonstrate that MRR is facilitated by contact sites between mitochondria and the nucleus. The translocator protein (TSPO) by preventing the mitophagy-mediated segregation o mitochonria is required for this interaction. The complex formed by TSPO with the protein kinase A (PKA), via the A-kinase anchoring protein acyl-CoA binding domain containing 3 (ACBD3), established the tethering. The latter allows for cholesterol redistribution of cholesterol in the nucleus to sustain the prosurvival response by blocking NF-κB deacetylation. This work proposes a previously unidentified paradigm in MRR: the formation of contact sites between mitochondria and nucleus to aid communication.
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Affiliation(s)
- Radha Desai
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Daniel A East
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Liana Hardy
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Danilo Faccenda
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Manuel Rigon
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - James Crosby
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - María Soledad Alvarez
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Aarti Singh
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Marta Mainenti
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Laura Kuhlman Hussey
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Robert Bentham
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, London WC1E 6BT, UK
| | - Gyorgy Szabadkai
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, London WC1E 6BT, UK
- Department of Biomedical Science, University of Padua, Via Ugo Bassi, 35131 Padua, Italy
- Francis Crick Institute, Midland Road, London NW1 AT, UK
| | - Valentina Zappulli
- Department of Comparative Biomedicine and Food Sciences, University of Padua, Viale dell'Universita' 16, 35020 Legnaro (PD), Italy
| | - Gurtej K Dhoot
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Lisa E Romano
- William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
| | - Dong Xia
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK
| | - Isabelle Coppens
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Baltimore, Baltimore, MD 21205, USA
| | - Anne Hamacher-Brady
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Baltimore, Baltimore, MD 21205, USA
| | - J Paul Chapple
- William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
| | - Rosella Abeti
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Roland A Fleck
- Centre for Ultrastructural Imaging, King's College London, London SE1 1UL, UK
| | - Gema Vizcay-Barrena
- Centre for Ultrastructural Imaging, King's College London, London SE1 1UL, UK
| | - Kenneth Smith
- Pathobiology and Population Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
| | - Michelangelo Campanella
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK.
- Department of Cell and Developmental Biology, Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, London WC1E 6BT, UK
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333
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Bosch M, Parton RG, Pol A. Lipid droplets, bioenergetic fluxes, and metabolic flexibility. Semin Cell Dev Biol 2020; 108:33-46. [DOI: 10.1016/j.semcdb.2020.02.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/13/2020] [Accepted: 02/27/2020] [Indexed: 12/18/2022]
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334
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Gil-Hernández A, Silva-Palacios A. Relevance of endoplasmic reticulum and mitochondria interactions in age-associated diseases. Ageing Res Rev 2020; 64:101193. [PMID: 33069818 DOI: 10.1016/j.arr.2020.101193] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 02/06/2023]
Abstract
Although the elixir of youth remains in the darkness, medical and scientific advances have succeeded in increasing human longevity; however, the predisposition to disease and its high economic cost are raising. Different strategies (e.g., antioxidants) and signaling pathways (e.g., Nrf2) have been identified to help regulate disease progression, nevertheless, there are still missing links that we need to understand. Contact sites called mitochondria-associated membranes (MAM) allow bi-directional communication between organelles as part of the essential functions in the cell to maintain its homeostasis. Different groups have deeply studied the role of MAM in aging; however, it's necessary to analyze their involvement in the progression of age-related diseases. In this review, we highlight the role of contact sites in these conditions, as well as the morphological and functional changes of mitochondria and ER in aging. We emphasize the intimate relationship between both organelles as a reflection of the biological processes that take place in the cell to try to regulate the deterioration characteristic of the aging process; proposing MAM as a potential target to help limit the disease progression with age.
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335
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Almeida C, Amaral MD. A central role of the endoplasmic reticulum in the cell emerges from its functional contact sites with multiple organelles. Cell Mol Life Sci 2020; 77:4729-4745. [PMID: 32313974 PMCID: PMC11104799 DOI: 10.1007/s00018-020-03523-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/30/2020] [Accepted: 04/06/2020] [Indexed: 02/08/2023]
Abstract
Early eukaryotic cells emerged from the compartmentalization of metabolic processes into specific organelles through the development of an endomembrane system (ES), a precursor of the endoplasmic reticulum (ER), which was essential for their survival. Recently, substantial evidence emerged on how organelles communicate among themselves and with the plasma membrane (PM) through contact sites (CSs). From these studies, the ER-the largest single structure in eukaryotic cells-emerges as a central player communicating with all organelles to coordinate cell functions and respond to external stimuli to maintain cellular homeostasis. Herein we review the functional insights into the ER-CSs with other organelles in a physiological perspective. We hypothesize that, in addition to the primitive role by the ES in the appearance of proto-eukaryotes, its successor-the ER-emerges as the key coordinator of inter-organelle/PM communication. The ER thus appears to be the 'maestro' driving eukaryotic cell evolution by incorporating new functions/organelles, while remaining the real coordinator overarching cellular functions and orchestrating them with the external milieu.
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Affiliation(s)
- Celso Almeida
- Faculty of Sciences, BioISI, Biosystems and Integrative Sciences Institute, University of Lisboa, Campo Grande, C8 bdg, 1749-016, Lisbon, Portugal.
| | - Margarida D Amaral
- Faculty of Sciences, BioISI, Biosystems and Integrative Sciences Institute, University of Lisboa, Campo Grande, C8 bdg, 1749-016, Lisbon, Portugal.
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336
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Vallese F, Catoni C, Cieri D, Barazzuol L, Ramirez O, Calore V, Bonora M, Giamogante F, Pinton P, Brini M, Calì T. An expanded palette of improved SPLICS reporters detects multiple organelle contacts in vitro and in vivo. Nat Commun 2020; 11:6069. [PMID: 33247103 PMCID: PMC7699637 DOI: 10.1038/s41467-020-19892-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 11/04/2020] [Indexed: 12/21/2022] Open
Abstract
Membrane contact sites between virtually any known organelle have been documented and, in the last decades, their study received momentum due to their importance for fundamental activities of the cell and for the subtle comprehension of many human diseases. The lack of tools to finely image inter-organelle proximity hindered our understanding on how these subcellular communication hubs mediate and regulate cell homeostasis. We develop an improved and expanded palette of split-GFP-based contact site sensors (SPLICS) for the detection of single and multiple organelle contact sites within a scalable distance range. We demonstrate their flexibility under physiological conditions and in living organisms.
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Affiliation(s)
- Francesca Vallese
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Domenico Cieri
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lucia Barazzuol
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Omar Ramirez
- Department of Neurobiology, Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
| | - Valentina Calore
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Massimo Bonora
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Flavia Giamogante
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Paolo Pinton
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, University of Ferrara, Ferrara, Italy.,Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Marisa Brini
- Department of Biology, University of Padova, Padova, Italy.
| | - Tito Calì
- Department of Biomedical Sciences, University of Padova, Padova, Italy. .,Padova Neuroscience Center (PNC), University of Padova, Padova, Italy.
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337
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Licchesi JDF, Laman H, Ikeda F, Bolanos-Garcia VM. Editorial: E3 Ubiquitin Ligases: From Structure to Physiology. Front Physiol 2020; 11:621053. [PMID: 33329070 PMCID: PMC7731889 DOI: 10.3389/fphys.2020.621053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 11/02/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Julien D F Licchesi
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Heike Laman
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Fumiyo Ikeda
- Division of Inflammation and Proteostasis, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Victor M Bolanos-Garcia
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
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338
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Cerebellar and hepatic alterations in ACBD5-deficient mice are associated with unexpected, distinct alterations in cellular lipid homeostasis. Commun Biol 2020; 3:713. [PMID: 33244184 PMCID: PMC7691522 DOI: 10.1038/s42003-020-01442-x] [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: 03/04/2020] [Accepted: 10/31/2020] [Indexed: 11/27/2022] Open
Abstract
ACBD5 deficiency is a novel peroxisome disorder with a largely uncharacterized pathology. ACBD5 was recently identified in a tethering complex mediating membrane contacts between peroxisomes and the endoplasmic reticulum (ER). An ACBD5-deficient mouse was analyzed to correlate ACBD5 tethering functions with the disease phenotype. ACBD5-deficient mice exhibit elevated very long-chain fatty acid levels and a progressive cerebellar pathology. Liver did not exhibit pathologic changes but increased peroxisome abundance and drastically reduced peroxisome-ER contacts. Lipidomics of liver and cerebellum revealed tissue-specific alterations in distinct lipid classes and subspecies. In line with the neurological pathology, unusual ultra-long chain fatty acids (C > 32) were elevated in phosphocholines from cerebelli but not liver indicating an organ-specific imbalance in fatty acid degradation and elongation pathways. By contrast, ether lipid formation was perturbed in liver towards an accumulation of alkyldiacylglycerols. The alterations in several lipid classes suggest that ACBD5, in addition to its acyl-CoA binding function, might maintain peroxisome-ER contacts in order to contribute to the regulation of anabolic and catabolic cellular lipid pathways. Darwisch, von Spangenberg et al. show that ACBD5‐deficient mice exhibit elevated levels of very long‐chain fatty acids and a progressive cerebellar pathology. A complex metabolic phenotype suggests that ACBD5 with its acyl‐CoA binding and peroxisome‐ER tethering functions might contribute to the regulation of anabolic and catabolic cellular lipid pathways.
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Topolska M, Roelants FM, Si EP, Thorner J. TORC2-Dependent Ypk1-Mediated Phosphorylation of Lam2/Ltc4 Disrupts Its Association with the β-Propeller Protein Laf1 at Endoplasmic Reticulum-Plasma Membrane Contact Sites in the Yeast Saccharomyces cerevisiae. Biomolecules 2020; 10:biom10121598. [PMID: 33255682 PMCID: PMC7760575 DOI: 10.3390/biom10121598] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 12/11/2022] Open
Abstract
Membrane-tethered sterol-binding Lam/Ltc proteins localize at junctions between the endoplasmic reticulum (ER) membrane and other organelles. Two of the six family members-Lam2/Ltc4 (initially Ysp2) and paralog Lam4/Ltc3-localize to ER-plasma membrane (PM) contact sites (CSs) and mediate retrograde ergosterol transport from the PM to the ER. Our prior work demonstrated that Lam2 and Lam4 are substrates of TORC2-regulated protein kinase Ypk1, that Ypk1-mediated phosphorylation inhibits their function in retrograde sterol transport, and that PM sterol retention bolsters cell survival under stressful conditions. At ER-PM CSs, Lam2 and Lam4 associate with Laf1/Ymr102c and Dgr2/Ykl121w (paralogous WD40 repeat-containing proteins) that reportedly bind sterol. Using fluorescent tags, we found that Lam2 and Lam4 remain at ER-PM CSs when Laf1 and Dgr2 are absent, whereas neither Laf1 nor Dgr2 remain at ER-PM CSs when Lam2 and Lam4 are absent. Loss of Laf1 (but not Dgr2) impedes retrograde ergosterol transport, and a laf1∆ mutation does not exacerbate the transport defect of lam2∆ lam4∆ cells, indicating a shared function. Lam2 and Lam4 bind Laf1 and Dgr2 in vitro in a pull-down assay, and the PH domain in Lam2 hinders its interaction with Laf1. Lam2 phosphorylated by Ypk1, and Lam2 with phosphomimetic (Glu) replacements at its Ypk1 sites, exhibited a marked reduction in Laf1 binding. Thus, phosphorylation prevents Lam2 interaction with Laf1 at ER-PM CSs, providing a mechanism by which Ypk1 action inhibits retrograde sterol transport.
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Affiliation(s)
- Magdalena Topolska
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA; (M.T.); (F.M.R.); (E.P.S.)
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5000 Odense, Denmark
| | - Françoise M. Roelants
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA; (M.T.); (F.M.R.); (E.P.S.)
| | - Edward P. Si
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA; (M.T.); (F.M.R.); (E.P.S.)
- Eastern Virginia Medical School, P.O. Box 1980, Norfolk, VA 23501-1980, USA
| | - Jeremy Thorner
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA; (M.T.); (F.M.R.); (E.P.S.)
- Correspondence: ; Tel.: +1-510-642-2558; Fax: +1-510-642-6420
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340
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Raeisossadati R, Ferrari MFR. Mitochondria-ER Tethering in Neurodegenerative Diseases. Cell Mol Neurobiol 2020; 42:917-930. [PMID: 33196974 DOI: 10.1007/s10571-020-01008-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 11/11/2020] [Indexed: 12/12/2022]
Abstract
Organelles juxtaposition has been detected for decades, although only recently gained importance due to a pivotal role in the regulation of cellular processes dependent on membrane contact sites. Endoplasmic reticulum (ER) and mitochondria interaction is a prime example of organelles contact sites. Mitochondria-associated membranes (MAM) are proposed to harbor ER-mitochondria tether complexes, mainly when these organelles are less than 30 nm apart. Dysfunctions of proteins located at the MAM are associated with neurodegenerative diseases such as Parkinson's, Alzheimer's and amyotrophic lateral sclerosis, as well as neurodevelopmental disorders; hence any malfunction in MAM can potentially trigger cell death. This review will focus on the role of ER-mitochondria contact sites, regarding calcium homeostasis, lipid metabolism, autophagy, morphology and dynamics of mitochondria, mainly in the context of neurodegenerative diseases. Approaches that have been employed so far to study organelles contact sites, as well as methods that were not used in neurosciences yet, but are promising and accurate ways to unveil the functions of MAM during neurodegeneration, is also discussed in the present review.
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Affiliation(s)
- Reza Raeisossadati
- Departamento de Genetica e Biologia Evolutiva, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
| | - Merari F R Ferrari
- Departamento de Genetica e Biologia Evolutiva, Instituto de Biociencias, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
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341
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Inter-organelle membrane contact sites: implications for lipid metabolism. Biol Direct 2020; 15:24. [PMID: 33176847 PMCID: PMC7661199 DOI: 10.1186/s13062-020-00279-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 10/30/2020] [Indexed: 11/10/2022] Open
Abstract
This article supplements a recent Perspective by Scorrano et al. in Nature Communications [10 [ (1)]:1287] in which the properties and functions of inter-organelle membrane contact sites were summarized. It is now clear that inter-organelle membrane contact sites are widespread in eukaryotic cells and that diverse pairs of organelles can be linked via unique protein tethers. An appropriate definition of what constitutes an inter-organelle membrane contact site was proposed in the Perspective. In addition, the various experimental approaches that are frequently used to study these organelle associations, as well as the advantages and disadvantages of each of these methods, were considered. The nature of the tethers that link the pairs of organelles at the contact sites was discussed in detail and some biological functions that have been ascribed to specific membrane contact sites were highlighted. Nevertheless, the functions of most types of organelle contact sites remain unclear. In the current article I have considered some of the points raised in the Perspective but have omitted detailed information on the roles of membrane contact sites in biological functions such as apoptosis, autophagy, calcium homeostasis and mitochondrial fusion. Instead, I have provided some background on the initial discovery of mitochondria-endoplasmic reticulum membrane contact sites, and have focussed on the known roles of membrane contact sites in inter-organelle lipid transport. In addition, potential roles for membrane contact sites in human diseases are briefly discussed.
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342
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Adachi Y, Kato T, Yamada T, Murata D, Arai K, Stahelin RV, Chan DC, Iijima M, Sesaki H. Drp1 Tubulates the ER in a GTPase-Independent Manner. Mol Cell 2020; 80:621-632.e6. [PMID: 33152269 DOI: 10.1016/j.molcel.2020.10.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 09/10/2020] [Accepted: 10/09/2020] [Indexed: 01/08/2023]
Abstract
Mitochondria are highly dynamic organelles that continuously grow, divide, and fuse. The division of mitochondria is crucial for human health. During mitochondrial division, the mechano-guanosine triphosphatase (GTPase) dynamin-related protein (Drp1) severs mitochondria at endoplasmic reticulum (ER)-mitochondria contact sites, where peripheral ER tubules interact with mitochondria. Here, we report that Drp1 directly shapes peripheral ER tubules in human and mouse cells. This ER-shaping activity is independent of GTP hydrolysis and located in a highly conserved peptide of 18 amino acids (termed D-octadecapeptide), which is predicted to form an amphipathic α helix. Synthetic D-octadecapeptide tubulates liposomes in vitro and the ER in cells. ER tubules formed by Drp1 promote mitochondrial division by facilitating ER-mitochondria interactions. Thus, Drp1 functions as a two-in-one protein during mitochondrial division, with ER tubulation and mechano-GTPase activities.
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Affiliation(s)
- Yoshihiro Adachi
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Takashi Kato
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tatsuya Yamada
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Daisuke Murata
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kenta Arai
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Robert V Stahelin
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA
| | - David C Chan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Miho Iijima
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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343
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Friend or Foe: Lipid Droplets as Organelles for Protein and Lipid Storage in Cellular Stress Response, Aging and Disease. Molecules 2020; 25:molecules25215053. [PMID: 33143278 PMCID: PMC7663626 DOI: 10.3390/molecules25215053] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 02/06/2023] Open
Abstract
Lipid droplets (LDs) were considered as a mere lipid storage organelle for a long time. Recent evidence suggests that LDs are in fact distinct and dynamic organelles with a specialized proteome and functions in many cellular roles. As such, LDs contribute to cellular signaling, protein and lipid homeostasis, metabolic diseases and inflammation. In line with the multitude of functions, LDs interact with many cellular organelles including mitochondria, peroxisomes, lysosomes, the endoplasmic reticulum and the nucleus. LDs are highly mobile and dynamic organelles and impaired motility disrupts the interaction with other organelles. The reduction of interorganelle contacts results in a multitude of pathophysiologies and frequently in neurodegenerative diseases. Contacts not only supply lipids for β-oxidation in mitochondria and peroxisomes, but also may include the transfer of toxic lipids as well as misfolded and harmful proteins to LDs. Furthermore, LDs assist in the removal of protein aggregates when severe proteotoxic stress overwhelms the proteasomal system. During imbalance of cellular lipid homeostasis, LDs also support cellular detoxification. Fine-tuning of LD function is of crucial importance and many diseases are associated with dysfunctional LDs. We summarize the current understanding of LDs and their interactions with organelles, providing a storage site for harmful proteins and lipids during cellular stress, aging inflammation and various disease states.
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344
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Zhou Y, Zhao R, Schwarz EC, Akbar R, Kaba M, Pattu V, Helms V, Rieger H, Nunes-Hasler P, Qu B. Interorganelle Tethering to Endocytic Organelles Determines Directional Cytokine Transport in CD4 + T Cells. THE JOURNAL OF IMMUNOLOGY 2020; 205:2988-3000. [PMID: 33106338 DOI: 10.4049/jimmunol.2000195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/20/2020] [Indexed: 12/24/2022]
Abstract
Delivery of vesicles to their desired destinations plays a central role in maintaining proper cell functionality. In certain scenarios, depending on loaded cargos, the vesicles have spatially distinct destinations. For example, in T cells, some cytokines (e.g., IL-2) are polarized to the T cell-target cell interface, whereas the other cytokines are delivered multidirectionally (e.g., TNF-α). In this study, we show that in primary human CD4+ T cells, both TNF-α+ and IL-2+ vesicles can tether with endocytic organelles (lysosomes/late endosomes) by forming membrane contact sites. Tethered cytokine-containing vesicle (CytV)-endocytic organelle pairs are released sequentially. Only endocytic organelle-tethered CytVs are preferentially transported to their desired destination. Mathematical models suggest that endocytic organelle tethering could regulate the direction of cytokine transport by selectively attaching different microtubule motor proteins (such as kinesin and dynein) to the corresponding CytVs. These findings establish the previously unknown interorganelle tethering to endocytic organelles as a universal solution for directional cytokine transport in CD4+ T cells. Modulating tethering to endocytic organelles can, therefore, coordinately control directionally distinct cytokine transport.
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Affiliation(s)
- Yan Zhou
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany
| | - Renping Zhao
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany
| | - Eva C Schwarz
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany
| | - Rahmad Akbar
- Center for Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
| | - Mayis Kaba
- Department of Cell Physiology and Metabolism, University Medical Center, University of Geneva, 1211 Geneva, Switzerland
| | - Varsha Pattu
- Department of Physiology, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
| | - Heiko Rieger
- Department of Theoretical Physics, Saarland University, 66123 Saarbrücken, Germany
| | - Paula Nunes-Hasler
- Department of Cell Physiology and Metabolism, University Medical Center, University of Geneva, 1211 Geneva, Switzerland.,Department of Pathology and Immunology, University Medical Center, University of Geneva, 1211 Geneva, Switzerland; and
| | - Bin Qu
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany; .,Leibniz Institute for New Materials, 66123 Saarbrücken, Germany
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345
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Knatko EV, Tatham MH, Zhang Y, Castro C, Higgins M, Dayalan Naidu S, Leonardi C, de la Vega L, Honda T, Griffin JL, Hay RT, Dinkova-Kostova AT. Downregulation of Keap1 Confers Features of a Fasted Metabolic State. iScience 2020; 23:101638. [PMID: 33103077 PMCID: PMC7575887 DOI: 10.1016/j.isci.2020.101638] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/02/2020] [Accepted: 09/29/2020] [Indexed: 12/12/2022] Open
Abstract
Transcription factor nuclear factor erythroid 2 p45-related factor 2 (Nrf2) and its main negative regulator, Kelch-like ECH-associated protein 1 (Keap1), are at the interface between redox and intermediary metabolism, allowing adaptation and survival under conditions of oxidative, inflammatory, and metabolic stress. Nrf2 is the principal determinant of redox homeostasis, and contributes to mitochondrial function and integrity and cellular bioenergetics. Using proteomics and lipidomics, we show that genetic downregulation of Keap1 in mice, and the consequent Nrf2 activation to pharmacologically relevant levels, leads to upregulation of carboxylesterase 1 (Ces1) and acyl-CoA oxidase 2 (Acox2), decreases triglyceride levels, and alters the lipidome. This is accompanied by downregulation of hepatic ATP-citrate lyase (Acly) and decreased levels of acetyl-CoA, a trigger for autophagy. These findings suggest that downregulation of Keap1 confers features of a fasted metabolic state, which is an important consideration in the drug development of Keap1-targeting pharmacologic Nrf2 activators.
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Affiliation(s)
- Elena V. Knatko
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, Scotland DD1 9SY, UK
| | - Michael H. Tatham
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK
| | - Ying Zhang
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, Scotland DD1 9SY, UK
| | - Cecilia Castro
- Department of Biochemistry and the Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Maureen Higgins
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, Scotland DD1 9SY, UK
| | - Sharadha Dayalan Naidu
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, Scotland DD1 9SY, UK
| | - Chiara Leonardi
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, Scotland DD1 9SY, UK
| | - Laureano de la Vega
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, Scotland DD1 9SY, UK
| | - Tadashi Honda
- Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Julian L. Griffin
- Department of Biochemistry and the Cambridge Systems Biology Centre, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1QW, UK
- Section of Biomolecular Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Ronald T. Hay
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK
| | - Albena T. Dinkova-Kostova
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, Scotland DD1 9SY, UK
- Department of Pharmacology and Molecular Sciences and Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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346
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Loncke J, Kerkhofs M, Kaasik A, Bezprozvanny I, Bultynck G. Recent advances in understanding IP3R function with focus on ER-mitochondrial Ca2+ transfers. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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347
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Escobar-Henriques M, Anton V. Mitochondrial Surveillance by Cdc48/p97: MAD vs. Membrane Fusion. Int J Mol Sci 2020; 21:E6841. [PMID: 32961852 PMCID: PMC7555132 DOI: 10.3390/ijms21186841] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 11/16/2022] Open
Abstract
Cdc48/p97 is a ring-shaped, ATP-driven hexameric motor, essential for cellular viability. It specifically unfolds and extracts ubiquitylated proteins from membranes or protein complexes, mostly targeting them for proteolytic degradation by the proteasome. Cdc48/p97 is involved in a multitude of cellular processes, reaching from cell cycle regulation to signal transduction, also participating in growth or death decisions. The role of Cdc48/p97 in endoplasmic reticulum-associated degradation (ERAD), where it extracts proteins targeted for degradation from the ER membrane, has been extensively described. Here, we present the roles of Cdc48/p97 in mitochondrial regulation. We discuss mitochondrial quality control surveillance by Cdc48/p97 in mitochondrial-associated degradation (MAD), highlighting the potential pathologic significance thereof. Furthermore, we present the current knowledge of how Cdc48/p97 regulates mitofusin activity in outer membrane fusion and how this may impact on neurodegeneration.
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Affiliation(s)
- Mafalda Escobar-Henriques
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Straße 26, 50931 Cologne, Germany;
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348
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Protrudin and PDZD8 contribute to neuronal integrity by promoting lipid extraction required for endosome maturation. Nat Commun 2020; 11:4576. [PMID: 32917905 PMCID: PMC7486383 DOI: 10.1038/s41467-020-18413-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/21/2020] [Indexed: 01/08/2023] Open
Abstract
Endosome maturation depends on membrane contact sites (MCSs) formed between endoplasmic reticulum (ER) and endolysosomes (LyLEs). The mechanism underlying lipid supply for this process and its pathophysiological relevance remains unclear, however. Here, we identify PDZD8-the mammalian ortholog of a yeast ERMES subunit-as a protein that interacts with protrudin, which is located at ER-LyLE MCSs. Protrudin and PDZD8 promote the formation of ER-LyLE MCSs, and PDZD8 shows the ability to extract various lipids from the ER. Overexpression of both protrudin and PDZD8 in HeLa cells, as well as their depletion in mouse primary neurons, impairs endosomal homeostasis by inducing the formation of abnormal large vacuoles reminiscent of those apparent in spastin- or REEP1-deficient neurons. The protrudin-PDZD8 system is also essential for the establishment of neuronal polarity. Our results suggest that protrudin and PDZD8 cooperatively promote endosome maturation by mediating ER-LyLE tethering and lipid extraction at MCSs, thereby maintaining neuronal polarity and integrity.
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349
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Li W, Zhang S, Yang G. Dynamic organization of intracellular organelle networks. WIREs Mech Dis 2020; 13:e1505. [PMID: 32865347 DOI: 10.1002/wsbm.1505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/06/2020] [Accepted: 07/09/2020] [Indexed: 01/07/2023]
Abstract
Intracellular organelles are membrane-bound and biochemically distinct compartments constructed to serve specialized functions in eukaryotic cells. Through extensive interactions, they form networks to coordinate and integrate their specialized functions for cell physiology. A fundamental property of these organelle networks is that they constantly undergo dynamic organization via membrane fusion and fission to remodel their internal connections and to mediate direct material exchange between compartments. The dynamic organization not only enables them to serve critical physiological functions adaptively but also differentiates them from many other biological networks such as gene regulatory networks and cell signaling networks. This review examines this fundamental property of the organelle networks from a systems point of view. The focus is exclusively on homotypic networks formed by mitochondria, lysosomes, endosomes, and the endoplasmic reticulum, respectively. First, key mechanisms that drive the dynamic organization of these networks are summarized. Then, several distinct organizational properties of these networks are highlighted. Next, spatial properties of the dynamic organization of these networks are emphasized, and their functional implications are examined. Finally, some representative molecular machineries that mediate the dynamic organization of these networks are surveyed. Overall, the dynamic organization of intracellular organelle networks is emerging as a fundamental and unifying paradigm in the internal organization of eukaryotic cells. This article is categorized under: Metabolic Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Wenjing Li
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Shuhao Zhang
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, Nankai University, Tianjin, China
| | - Ge Yang
- Laboratory of Computational Biology and Machine Intelligence, School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing, China.,Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.,Department of Computational Biology, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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350
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Agrawal RR, Montesinos J, Larrea D, Area-Gomez E, Pera M. The silence of the fats: A MAM's story about Alzheimer. Neurobiol Dis 2020; 145:105062. [PMID: 32866617 DOI: 10.1016/j.nbd.2020.105062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 08/07/2020] [Accepted: 08/22/2020] [Indexed: 02/07/2023] Open
Abstract
The discovery of contact sites was a breakthrough in cell biology. We have learned that an organelle cannot function in isolation, and that many cellular functions depend on communication between two or more organelles. One such contact site results from the close apposition of the endoplasmic reticulum (ER) and mitochondria, known as mitochondria-associated ER membranes (MAMs). These intracellular lipid rafts serve as hubs for the regulation of cellular lipid and calcium homeostasis, and a growing body of evidence indicates that MAM domains modulate cellular function in both health and disease. Indeed, MAM dysfunction has been described as a key event in Alzheimer disease (AD) pathogenesis. Our most recent work shows that, by means of its affinity for cholesterol, APP-C99 accumulates in MAM domains of the ER and induces the uptake of extracellular cholesterol as well as its trafficking from the plasma membrane to the ER. As a result, MAM functionality becomes chronically upregulated while undergoing continual turnover. The goal of this review is to discuss the consequences of C99 elevation in AD, specifically the upregulation of cholesterol trafficking and MAM activity, which abrogate cellular lipid homeostasis and disrupt the lipid composition of cellular membranes. Overall, we present a novel framework for AD pathogenesis that can be linked to the many complex alterations that occur during disease progression, and that may open a door to new therapeutic strategies.
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Affiliation(s)
- Rishi R Agrawal
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Jorge Montesinos
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Delfina Larrea
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Estela Area-Gomez
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, NY, 10032, USA; Department of Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Marta Pera
- Departament of Basic Sciences, Facultat de Medicina I Ciències de la Salut, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallés, 08195, Spain.
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