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DAmico KA, Stanton AE, Shirkey JD, Travis SM, Jeffrey PD, Hughson FM. Structure of a membrane tethering complex incorporating multiple SNAREs. Nat Struct Mol Biol 2024; 31:246-254. [PMID: 38196032 PMCID: PMC10923073 DOI: 10.1038/s41594-023-01164-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 10/26/2023] [Indexed: 01/11/2024]
Abstract
Most membrane fusion reactions in eukaryotic cells are mediated by multisubunit tethering complexes (MTCs) and SNARE proteins. MTCs are much larger than SNAREs and are thought to mediate the initial attachment of two membranes. Complementary SNAREs then form membrane-bridging complexes whose assembly draws the membranes together for fusion. Here we present a cryo-electron microscopy structure of the simplest known MTC, the 255-kDa Dsl1 complex of Saccharomyces cerevisiae, bound to the two SNAREs that anchor it to the endoplasmic reticulum. N-terminal domains of the SNAREs form an integral part of the structure, stabilizing a Dsl1 complex configuration with unexpected similarities to the 850-kDa exocyst MTC. The structure of the SNARE-anchored Dsl1 complex and its comparison with exocyst reveal what are likely to be common principles underlying MTC function. Our structure also implies that tethers and SNAREs can work together as a single integrated machine.
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Affiliation(s)
- Kevin A DAmico
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Abigail E Stanton
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Jaden D Shirkey
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Sophie M Travis
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Philip D Jeffrey
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
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2
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Jahn R, Cafiso DC, Tamm LK. Mechanisms of SNARE proteins in membrane fusion. Nat Rev Mol Cell Biol 2024; 25:101-118. [PMID: 37848589 DOI: 10.1038/s41580-023-00668-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2023] [Indexed: 10/19/2023]
Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a family of small conserved eukaryotic proteins that mediate membrane fusion between organelles and with the plasma membrane. SNAREs are directly or indirectly anchored to membranes. Prior to fusion, complementary SNAREs assemble between membranes with the aid of accessory proteins that provide a scaffold to initiate SNARE zippering, pulling the membranes together and mediating fusion. Recent advances have enabled the construction of detailed models describing bilayer transitions and energy barriers along the fusion pathway and have elucidated the structures of SNAREs complexed in various states with regulatory proteins. In this Review, we discuss how these advances are yielding an increasingly detailed picture of the SNARE-mediated fusion pathway, leading from first contact between the membranes via metastable non-bilayer intermediates towards the opening and expansion of a fusion pore. We describe how SNARE proteins assemble into complexes, how this assembly is regulated by accessory proteins and how SNARE complexes overcome the free energy barriers that prevent spontaneous membrane fusion.
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Affiliation(s)
- Reinhard Jahn
- Laboratory of Neurobiology, Max-Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| | - David C Cafiso
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Lukas K Tamm
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
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3
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Launay N, Ruiz M, Planas-Serra L, Verdura E, Rodríguez-Palmero A, Schlüter A, Goicoechea L, Guilera C, Casas J, Campelo F, Jouanguy E, Casanova JL, Boespflug-Tanguy O, Vazquez Cancela M, Gutiérrez-Solana LG, Casasnovas C, Area-Gomez E, Pujol A. RINT1 deficiency disrupts lipid metabolism and underlies a complex hereditary spastic paraplegia. J Clin Invest 2023; 133:e162836. [PMID: 37463447 DOI: 10.1172/jci162836] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 05/26/2023] [Indexed: 07/20/2023] Open
Abstract
The Rad50 interacting protein 1 (Rint1) is a key player in vesicular trafficking between the ER and Golgi apparatus. Biallelic variants in RINT1 cause infantile-onset episodic acute liver failure (ALF). Here, we describe 3 individuals from 2 unrelated families with novel biallelic RINT1 loss-of-function variants who presented with early onset spastic paraplegia, ataxia, optic nerve hypoplasia, and dysmorphic features, broadening the previously described phenotype. Our functional and lipidomic analyses provided evidence that pathogenic RINT1 variants induce defective lipid-droplet biogenesis and profound lipid abnormalities in fibroblasts and plasma that impact both neutral lipid and phospholipid metabolism, including decreased triglycerides and diglycerides, phosphatidylcholine/phosphatidylserine ratios, and inhibited Lands cycle. Further, RINT1 mutations induced intracellular ROS production and reduced ATP synthesis, affecting mitochondria with membrane depolarization, aberrant cristae ultrastructure, and increased fission. Altogether, our results highlighted the pivotal role of RINT1 in lipid metabolism and mitochondria function, with a profound effect in central nervous system development.
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Affiliation(s)
- Nathalie Launay
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Laura Planas-Serra
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Edgard Verdura
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Agustí Rodríguez-Palmero
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- Pediatric Neurology unit, Department of Pediatrics, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, Spain
| | - Agatha Schlüter
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Leire Goicoechea
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Cristina Guilera
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Josefina Casas
- Research Unit on BioActive Molecules (RUBAM), Departament de Química Biomèdica, Institut de Química Avançada de Catalunya (IQAC-CSIC), Barcelona, Spain
- CIBEREHD, Centro de Investigación Biomédica en Red de Enfermedades heoaticas y digestivas, ISCIII, Madrid, Spain
| | - Felix Campelo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Spain
| | - Emmanuelle Jouanguy
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale, UMR 1163, Necker Hospital for Sick Children, Paris, France
- University of Paris, Imagine Institute, Paris, France
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, New York, USA
| | - Jean-Laurent Casanova
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale, UMR 1163, Necker Hospital for Sick Children, Paris, France
- University of Paris, Imagine Institute, Paris, France
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, New York, USA
- Pediatric Hematology-Immunology Unit, Necker Hospital for Sick Children, Paris, France
- Howard Hughes Medical Institute, New York, New York, USA
| | - Odile Boespflug-Tanguy
- CRMR Leukofrance Service de Neuropédiatrie, Hôpital Robert Debré AP-HP, Paris, France
- UMR1141 Neurodiderot Université de Paris Cité, Paris, France
| | | | - Luis González Gutiérrez-Solana
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
- Consulta de Neurodegenerativas, Sección de Neurología Pediátrica, Hospital, Infantil Universitario Niño Jesús, Madrid, Spain
| | - Carlos Casasnovas
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
- Neuromuscular Unit, Neurology Department, Hospital Universitari de Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Estela Area-Gomez
- Department of Neurology, Columbia University, New York, New York, USA
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospital Duran i Reynals, L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
- Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Spain
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4
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Taylor RJ, Tagiltsev G, Briggs JAG. The structure of COPI vesicles and regulation of vesicle turnover. FEBS Lett 2023; 597:819-835. [PMID: 36513395 DOI: 10.1002/1873-3468.14560] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/15/2022]
Abstract
COPI-coated vesicles mediate transport between Golgi stacks and retrograde transport from the Golgi to the endoplasmic reticulum. The COPI coat exists as a stable heptameric complex in the cytosol termed coatomer and is recruited en bloc to the membrane for vesicle formation. Recruitment of COPI onto membranes is mediated by the Arf family of small GTPases, which, in their GTP-bound state, bind both membrane and coatomer. Arf GTPases also influence cargo selection, vesicle scission and vesicle uncoating. Guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) regulate nucleotide binding by Arf GTPases. To understand the mechanism of COPI-coated vesicle trafficking, it is necessary to characterize the interplay between coatomer and Arf GTPases and their effectors. It is also necessary to understand interactions between coatomer and cargo, cargo adaptors/receptors and tethers facilitating binding to the target membrane. Here, we summarize current knowledge of COPI coat protein structure; we describe how structural and biochemical studies contributed to this knowledge; we review mechanistic insights into COPI vesicle biogenesis and disassembly; and we discuss the potential to answer open questions in the field.
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Affiliation(s)
- Rebecca J Taylor
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Grigory Tagiltsev
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - John A G Briggs
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Martinsried, Germany
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5
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DAmico KA, Stanton AE, Shirkey JD, Travis SM, Jeffrey PD, Hughson FM. Structure of a Membrane Tethering Complex Incorporating Multiple SNAREs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526244. [PMID: 36778436 PMCID: PMC9915479 DOI: 10.1101/2023.01.30.526244] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Most membrane fusion reactions in eukaryotic cells are mediated by membrane tethering complexes (MTCs) and SNARE proteins. MTCs are much larger than SNAREs and are thought to mediate the initial attachment of two membranes. Complementary SNAREs then form membrane-bridging complexes whose assembly draws the membranes together for fusion. Here, we present a cryo-EM structure of the simplest known MTC, the 255-kDa Dsl1 complex, bound to the two SNAREs that anchor it to the endoplasmic reticulum. N-terminal domains of the SNAREs form an integral part of the structure, stabilizing a Dsl1 complex configuration with remarkable and unexpected similarities to the 850-kDa exocyst MTC. The structure of the SNARE-anchored Dsl1 complex and its comparison with exocyst reveal what are likely to be common principles underlying MTC function. Our structure also implies that tethers and SNAREs can work together as a single integrated machine.
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Affiliation(s)
- Kevin A DAmico
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Abigail E Stanton
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Jaden D Shirkey
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Sophie M Travis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Philip D Jeffrey
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
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6
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Raisch T, Ciossani G, d’Amico E, Cmentowski V, Carmignani S, Maffini S, Merino F, Wohlgemuth S, Vetter IR, Raunser S, Musacchio A. Structure of the RZZ complex and molecular basis of Spindly-driven corona assembly at human kinetochores. EMBO J 2022; 41:e110411. [PMID: 35373361 PMCID: PMC9058546 DOI: 10.15252/embj.2021110411] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 11/09/2022] Open
Abstract
In metazoans, a ≈1 megadalton (MDa) multiprotein complex comprising the dynein-dynactin adaptor Spindly and the ROD-Zwilch-ZW10 (RZZ) complex is the building block of a fibrous biopolymer, the kinetochore fibrous corona. The corona assembles on mitotic kinetochores to promote microtubule capture and spindle assembly checkpoint (SAC) signaling. We report here a high-resolution cryo-EM structure that captures the essential features of the RZZ complex, including a farnesyl-binding site required for Spindly binding. Using a highly predictive in vitro assay, we demonstrate that the SAC kinase MPS1 is necessary and sufficient for corona assembly at supercritical concentrations of the RZZ-Spindly (RZZS) complex, and describe the molecular mechanism of phosphorylation-dependent filament nucleation. We identify several structural requirements for RZZS polymerization in rings and sheets. Finally, we identify determinants of kinetochore localization and corona assembly of Spindly. Our results describe a framework for the long-sought-for molecular basis of corona assembly on metazoan kinetochores.
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Affiliation(s)
- Tobias Raisch
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Giuseppe Ciossani
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
- Present address:
European Institute of OncologyMilanItaly
| | - Ennio d’Amico
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Verena Cmentowski
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Sara Carmignani
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Stefano Maffini
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Felipe Merino
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
- Present address:
Department of Protein EvolutionMax Planck Institute for Developmental BiologyTübingenGermany
| | - Sabine Wohlgemuth
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Ingrid R Vetter
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Stefan Raunser
- Department of Structural BiochemistryMax Planck Institute of Molecular PhysiologyDortmundGermany
| | - Andrea Musacchio
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyDortmundGermany
- Centre for Medical BiotechnologyFaculty of BiologyUniversity Duisburg‐EssenEssenGermany
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7
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Holling T, Bhavani GS, von Elsner L, Shah H, Kausthubham N, Bhattacharyya SS, Shukla A, Mortier GR, Schinke T, Danyukova T, Pohl S, Kutsche K, Girisha KM. A homozygous hypomorphic BNIP1 variant causes an increase in autophagosomes and reduced autophagic flux and results in a spondylo-epiphyseal dysplasia. Hum Mutat 2022; 43:625-642. [PMID: 35266227 DOI: 10.1002/humu.24368] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 02/24/2022] [Accepted: 03/04/2022] [Indexed: 01/18/2023]
Abstract
BNIP1 (BCL2 interacting protein 1) is a soluble N-ethylmaleimide-sensitive factor-attachment protein receptor involved in ER membrane fusion. We identified the homozygous BNIP1 intronic variant c.84+3A>T in the apparently unrelated patients 1 and 2 with disproportionate short stature. Radiographs showed abnormalities affecting both the axial and appendicular skeleton and spondylo-epiphyseal dysplasia. We detected ~80% aberrantly spliced BNIP1 pre-mRNAs, reduced BNIP1 mRNA level to ~80%, and BNIP1 protein level reduction by ~50% in patient 1 compared to control fibroblasts. The BNIP1 ortholog in drosophila, Sec. 20, regulates autophagy and lysosomal degradation. We assessed lysosome positioning and identified a decrease in lysosomes in the perinuclear region and an increase in the cell periphery in patient 1 cells. Immunofluorescence microscopy and immunoblotting demonstrated an increase in LC3B-positive structures and LC3B-II levels, respectively, in patient 1 fibroblasts under steady-state condition. Treatment of serum-starved fibroblasts with or without bafilomycin A1 identified significantly decreased autophagic flux in patient 1 cells. Our data suggest a block at the terminal stage of autolysosome formation and/or clearance in patient fibroblasts. BNIP1 together with RAB33B and VPS16, disease genes for Smith-McCort dysplasia 2 and a multisystem disorder with short stature, respectively, highlight the importance of autophagy in skeletal development. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Tess Holling
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gandham SriLakshmi Bhavani
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Leonie von Elsner
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hitesh Shah
- Department of Orthopedics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Neethukrishna Kausthubham
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | | | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Geert R Mortier
- Center for Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tatyana Danyukova
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sandra Pohl
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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8
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Santana-Molina C, Gutierrez F, Devos DP. Homology and Modular Evolution of CATCHR at the Origin of the Eukaryotic Endomembrane System. Genome Biol Evol 2021; 13:6290715. [PMID: 34061181 PMCID: PMC8290106 DOI: 10.1093/gbe/evab125] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2021] [Indexed: 01/02/2023] Open
Abstract
The membrane trafficking is an essential process of eukaryotic cells, as it manages vesicular trafficking toward different parts of the cell. In this process, membrane fusions between vesicles and target membranes are mediated by several factors, including the multisubunit tethering complexes. One type of multisubunit tethering complex, the complexes associated with tethering containing helical rods (CATCHR), encompasses the exocyst, COG, GARP, and DSL1 complexes. The CATCHR share similarities at sequence, structural, and protein-complex organization level although their actual relationship is still poorly understood. In this study, we have re-evaluated CATCHR at different levels, demonstrating that gene duplications followed by neofunctionalization, were key for their origin. Our results, reveals that there are specific homology relationships and parallelism within and between the CATCHR suggesting that most of these complexes are composed by modular tetramers of four different kinds of proteins, three of them having a clear common origin. The extension of CATCHR family occurred concomitantly with the protein family expansions of their molecular partners, such as small GTPases and SNAREs, among others, and likely providing functional specificity. Our results provide novel insights into the structural organization and mechanism of action of CATCHR, with implications for the evolution of the endomembrane system of eukaryotes and promoting CATCHR as ideal candidates to study the evolution of multiprotein complexes.
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Affiliation(s)
- Carlos Santana-Molina
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas/Universidad Pablo de Olavide/Junta de Andalucía, Seville, Spain
| | - Fernando Gutierrez
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas/Universidad Pablo de Olavide/Junta de Andalucía, Seville, Spain.,Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Damien P Devos
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas/Universidad Pablo de Olavide/Junta de Andalucía, Seville, Spain
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9
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Morelli E, Speranza EA, Pellegrino E, Beznoussenko GV, Carminati F, Garré M, Mironov AA, Onorati M, Vaccari T. Activity of the SNARE Protein SNAP29 at the Endoplasmic Reticulum and Golgi Apparatus. Front Cell Dev Biol 2021; 9:637565. [PMID: 33718375 PMCID: PMC7945952 DOI: 10.3389/fcell.2021.637565] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 01/14/2021] [Indexed: 01/21/2023] Open
Abstract
Snap29 is a conserved regulator of membrane fusion essential to complete autophagy and to support other cellular processes, including cell division. In humans, inactivating SNAP29 mutations causes CEDNIK syndrome, a rare multi-systemic disorder characterized by congenital neuro-cutaneous alterations. The fibroblasts of CEDNIK patients show alterations of the Golgi apparatus (GA). However, whether and how Snap29 acts at the GA is unclear. Here we investigate SNAP29 function at the GA and endoplasmic reticulum (ER). As part of the elongated structures in proximity to these membrane compartments, a pool of SNAP29 forms a complex with Syntaxin18, or with Syntaxin5, which we find is required to engage SEC22B-loaded vesicles. Consistent with this, in HeLa cells, in neuroepithelial stem cells, and in vivo, decreased SNAP29 activity alters GA architecture and reduces ER to GA trafficking. Our data reveal a new regulatory function of Snap29 in promoting secretory trafficking.
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Affiliation(s)
- Elena Morelli
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Elisa A Speranza
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Enrica Pellegrino
- Dipartimento di Biologia, Unità di Biologia Cellulare e dello Sviluppo, Università di Pisa, Pisa, Italy
| | | | | | | | | | - Marco Onorati
- Dipartimento di Biologia, Unità di Biologia Cellulare e dello Sviluppo, Università di Pisa, Pisa, Italy
| | - Thomas Vaccari
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
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10
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Gaurav S, Ranjan R, Kuldeep J, Dhiman K, Mahapatra PP, Ashish, Siddiqi MI, Ahmed S. The N-terminus region of Drp1, a Rint1 family protein is essential for cell survival and its interaction with Rad50 protein in fission yeast S.pombe. Biochim Biophys Acta Gen Subj 2020; 1865:129739. [PMID: 32956753 DOI: 10.1016/j.bbagen.2020.129739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Defects in DNA repair pathway can lead to double-strand breaks leading to genomic instability. Earlier we have shown that S.pombe Drp1, a Rint1/Tip1 family protein is required for the recovery from DNA damage. METHODS Various truncations of Drp1 protein were constructed and their role in DNA damage response and interaction with Rad50 protein has been studied by co-immunoprecipitation and pull-down assays. RESULTS The structural and functional analysis of Drp1 protein revealed that the N-terminus region of Drp1 is indispensable for the survival. The C-terminus truncation mutants, drp1C1Δ and drp1C2Δ exhibit temperature sensitive phenotype and are hypersensitive against DNA damaging agents with elevated level of Rad52-YFP foci at non-permissive temperature indicating the impairment for DNA damage repair pathway. The essential N-terminus region of Drp1 interacts with the C-terminus region of Rad50 and might be involved in influencing the MRN/X function. Small-angle X-ray (SAXS) analysis revealed three-domain like shapes in Drp1 protein while the C-terminus region of Rad50 exhibit unusual bulges. Computational docking studies revealed the amino acid residues at the C-terminus region of Rad50 that are involved in the interaction with the residues present at the N-terminal region of Drp1 indicating the importance of the N-terminal region of Drp1 protein. CONCLUSIONS We have identified the region of Drp1 and Rad50 proteins that are involved in the interaction and their role in the DNA damage response pathway has been analyzed. GENERAL SIGNIFICANCE The functional and structural aspects of fission yeast Drp1 protein and its interaction with Rad50 have been elucidated.
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Affiliation(s)
- Sachin Gaurav
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Rajeev Ranjan
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Jitendra Kuldeep
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Kanika Dhiman
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Pinaki Prasad Mahapatra
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Ashish
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Mohammad Imran Siddiqi
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Shakil Ahmed
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India.
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11
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Travis SM, DAmico K, Yu IM, McMahon C, Hamid S, Ramirez-Arellano G, Jeffrey PD, Hughson FM. Structural basis for the binding of SNAREs to the multisubunit tethering complex Dsl1. J Biol Chem 2020; 295:10125-10135. [PMID: 32409579 DOI: 10.1074/jbc.ra120.013654] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/01/2020] [Indexed: 01/02/2023] Open
Abstract
Multisubunit-tethering complexes (MTCs) are large (250 to >750 kDa), conserved macromolecular machines that are essential for soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion in all eukaryotes. MTCs are thought to organize membrane trafficking by mediating the initial long-range interaction between a vesicle and its target membrane and promoting the formation of membrane-bridging SNARE complexes. Previously, we reported the structure of the yeast Dsl1 complex, the simplest known MTC, which is essential for coat protein I (COPI) mediated transport from the Golgi to the endoplasmic reticulum (ER). This structure suggests how the Dsl1 complex might tether a vesicle to its target membrane by binding at one end to the COPI coat and at the other to ER-associated SNAREs. Here, we used X-ray crystallography to investigate these Dsl1-SNARE interactions in greater detail. The Dsl1 complex comprises three subunits that together form a two-legged structure with a central hinge. We found that distal regions of each leg bind N-terminal Habc domains of the ER SNAREs Sec20 (a Qb-SNARE) and Use1 (a Qc-SNARE). The observed binding modes appear to anchor the Dsl1 complex to the ER target membrane while simultaneously ensuring that both SNAREs are in open conformations, with their SNARE motifs available for assembly. The proximity of the two SNARE motifs, and therefore their ability to enter the same SNARE complex, will depend on the relative orientation of the two Dsl1 legs. These results underscore the critical roles of SNARE N-terminal domains in mediating interactions with other elements of the vesicle docking and fusion machinery.
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Affiliation(s)
- Sophie M Travis
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Kevin DAmico
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - I-Mei Yu
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Conor McMahon
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Safraz Hamid
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | | | - Philip D Jeffrey
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Frederick M Hughson
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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12
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Roy Chowdhury S, Bhattacharjee C, Casler JC, Jain BK, Glick BS, Bhattacharyya D. ER arrival sites associate with ER exit sites to create bidirectional transport portals. J Cell Biol 2020; 219:e201902114. [PMID: 32328626 PMCID: PMC7147096 DOI: 10.1083/jcb.201902114] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/11/2019] [Accepted: 01/17/2020] [Indexed: 01/30/2023] Open
Abstract
COPI vesicles mediate Golgi-to-ER recycling, but COPI vesicle arrival sites at the ER have been poorly defined. We explored this issue using the yeast Pichia pastoris. ER arrival sites (ERAS) can be visualized by labeling COPI vesicle tethers such as Tip20. Our results place ERAS at the periphery of COPII-labeled ER export sites (ERES). The dynamics of ERES and ERAS are indistinguishable, indicating that these structures are tightly coupled. Displacement or degradation of Tip20 does not alter ERES organization, whereas displacement or degradation of either COPII or COPI components disrupts ERAS organization. We infer that Golgi compartments form at ERES and then produce COPI vesicles to generate ERAS. As a result, ERES and ERAS are functionally linked to create bidirectional transport portals at the ER-Golgi interface. COPI vesicles likely become tethered while they bud, thereby promoting efficient retrograde transport. In mammalian cells, the Tip20 homologue RINT1 associates with ERES, indicating possible conservation of the link between ERES and ERAS.
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Affiliation(s)
- Sudeshna Roy Chowdhury
- Department of Cell and Tumor Biology, Advanced Centre for Treatment Research & Education in Cancer, Tata Memorial Centre, Navi Mumbai, India
- Homi Bhabha National Institute, Training School Complex, Mumbai, India
| | - Chumki Bhattacharjee
- Department of Cell and Tumor Biology, Advanced Centre for Treatment Research & Education in Cancer, Tata Memorial Centre, Navi Mumbai, India
- Homi Bhabha National Institute, Training School Complex, Mumbai, India
| | - Jason C. Casler
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL
| | - Bhawik Kumar Jain
- Department of Cell and Tumor Biology, Advanced Centre for Treatment Research & Education in Cancer, Tata Memorial Centre, Navi Mumbai, India
- Homi Bhabha National Institute, Training School Complex, Mumbai, India
| | - Benjamin S. Glick
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL
| | - Dibyendu Bhattacharyya
- Department of Cell and Tumor Biology, Advanced Centre for Treatment Research & Education in Cancer, Tata Memorial Centre, Navi Mumbai, India
- Homi Bhabha National Institute, Training School Complex, Mumbai, India
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13
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Travis SM, Kokona B, Fairman R, Hughson FM. Roles of singleton tryptophan motifs in COPI coat stability and vesicle tethering. Proc Natl Acad Sci U S A 2019; 116:24031-24040. [PMID: 31712447 PMCID: PMC6883825 DOI: 10.1073/pnas.1909697116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Coat protein I (COPI)-coated vesicles mediate retrograde transport from the Golgi to the endoplasmic reticulum (ER), as well as transport within the Golgi. Major progress has been made in defining the structure of COPI coats, in vitro and in vivo, at resolutions as high as 9 Å. Nevertheless, important questions remain unanswered, including what specific interactions stabilize COPI coats, how COPI vesicles recognize their target membranes, and how coat disassembly is coordinated with vesicle fusion and cargo delivery. Here, we use X-ray crystallography to identify a conserved site on the COPI subunit α-COP that binds to flexible, acidic sequences containing a single tryptophan residue. One such sequence, found within α-COP itself, mediates α-COP homo-oligomerization. Another such sequence is contained within the lasso of the ER-resident Dsl1 complex, where it helps mediate the tethering of Golgi-derived COPI vesicles at the ER membrane. Together, our findings suggest that α-COP homo-oligomerization plays a key role in COPI coat stability, with potential implications for the coordination of vesicle tethering, uncoating, and fusion.
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Affiliation(s)
- Sophie M Travis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Bashkim Kokona
- Department of Biology, Haverford College, Haverford, PA 19041
- Department of Chemistry, Haverford College, Haverford, PA 19041
| | - Robert Fairman
- Department of Biology, Haverford College, Haverford, PA 19041
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14
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Blackburn JB, D'Souza Z, Lupashin VV. Maintaining order: COG complex controls Golgi trafficking, processing, and sorting. FEBS Lett 2019; 593:2466-2487. [PMID: 31381138 PMCID: PMC6771879 DOI: 10.1002/1873-3468.13570] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/31/2022]
Abstract
The conserved oligomeric Golgi (COG) complex, a multisubunit tethering complex of the CATCHR (complexes associated with tethering containing helical rods) family, controls membrane trafficking and ensures Golgi homeostasis by orchestrating retrograde vesicle targeting within the Golgi. In humans, COG defects lead to severe multisystemic diseases known as COG-congenital disorders of glycosylation (COG-CDG). The COG complex both physically and functionally interacts with all classes of molecules maintaining intra-Golgi trafficking, namely SNAREs, SNARE-interacting proteins, Rabs, coiled-coil tethers, and vesicular coats. Here, we review our current knowledge of COG-related trafficking and glycosylation defects in humans and model organisms, and analyze possible scenarios for the molecular mechanism of the COG orchestrated vesicle targeting.
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Affiliation(s)
- Jessica B. Blackburn
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
- Present address:
Division of Allergy, Pulmonary and Critical Care MedicineDepartment of MedicineVanderbilt University Medical CenterNashvilleTNUSA
| | - Zinia D'Souza
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
| | - Vladimir V. Lupashin
- Department of Physiology and BiophysicsUniversity of Arkansas for Medical SciencesLittle RockARUSA
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15
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Lakatos Z, Lőrincz P, Szabó Z, Benkő P, Kenéz LA, Csizmadia T, Juhász G. Sec20 is Required for Autophagic and Endocytic Degradation Independent of Golgi-ER Retrograde Transport. Cells 2019; 8:cells8080768. [PMID: 31344970 PMCID: PMC6721519 DOI: 10.3390/cells8080768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 01/07/2023] Open
Abstract
Endocytosis and autophagy are evolutionarily conserved degradative processes in all eukaryotes. Both pathways converge to the lysosome where cargo is degraded. Improper lysosomal degradation is observed in many human pathologies, so its regulatory mechanisms are important to understand. Sec20/BNIP1 (BCL2/adenovirus E1B 19 kDa protein-interacting protein 1) is a BH3 (Bcl-2 homology 3) domain-containing SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptors) protein that has been suggested to promote Golgi-ER retrograde transport, mitochondrial fission, apoptosis and mitophagy in yeast and vertebrates. Here, we show that loss of Sec20 in Drosophila fat cells causes the accumulation of autophagic vesicles and prevents proper lysosomal acidification and degradation during bulk, starvation-induced autophagy. Furthermore, Sec20 knockdown leads to the enlargement of late endosomes and accumulation of defective endolysosomes in larval Drosophila nephrocytes. Importantly, the loss of Syx18 (Syntaxin 18), one of the known partners of Sec20, led to similar changes in nephrocytes and fat cells. Interestingly. Sec20 appears to function independent of its role in Golgi-ER retrograde transport in regulating lysosomal degradation, as the loss of its other partner SNAREs Use1 (Unconventional SNARE In The ER 1) and Sec22 or tethering factor Zw10 (Zeste white 10), which function together in the Golgi-ER pathway, does not cause defects in autophagy or endocytosis. Thus, our data identify a potential new transport route specific to lysosome biogenesis and function.
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Affiliation(s)
- Zsolt Lakatos
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
- Premium Postdoctoral Research Program, Hungarian Academy of Sciences, H-1117 Budapest, Hungary
| | - Zoltán Szabó
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Péter Benkő
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Lili Anna Kenéz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary.
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary.
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16
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Gillingham AK, Munro S. Transport carrier tethering - how vesicles are captured by organelles. Curr Opin Cell Biol 2019; 59:140-146. [PMID: 31154044 DOI: 10.1016/j.ceb.2019.04.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/16/2019] [Accepted: 04/24/2019] [Indexed: 12/20/2022]
Abstract
All cells contain numerous membrane-bound organelles that carry out specific functions. These compartments do not, however, act in isolation. Some are in direct contact via membrane contact sites, while others exchange material via specific vesicles or tubular carriers laden with cargo. The term tethering in the context of this review is used to describe the primary recognition and docking of transport carriers with acceptor organelles that occurs before SNARE engagement and membrane fusion. However, it is important to note that other tethering events occur, for example, between organelles in direct contact, which do not lead to fusion.
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Affiliation(s)
- Alison K Gillingham
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
| | - Sean Munro
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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17
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Ungermann C, Kümmel D. Structure of membrane tethers and their role in fusion. Traffic 2019; 20:479-490. [DOI: 10.1111/tra.12655] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/26/2019] [Accepted: 05/03/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Christian Ungermann
- Biochemistry Section, Department of Biology/ChemistryUniversity of Osnabrück Osnabrück Germany
- Center for Cellular Nanoanalytics (CellNanOs)University of Osnabrück Osnabrück Germany
| | - Daniel Kümmel
- Biochemistry & Structural Biology Section, Institute of BiochemistryUniversity of Münster Münster Germany
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18
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Zhao X, Guo X, Tang X, Zhang H, Wang M, Kong Y, Zhang X, Zhao Z, Lv M, Li L. Misregulation of ER-Golgi Vesicle Transport Induces ER Stress and Affects Seed Vigor and Stress Response. FRONTIERS IN PLANT SCIENCE 2018; 9:658. [PMID: 29868102 PMCID: PMC5968616 DOI: 10.3389/fpls.2018.00658] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 04/30/2018] [Indexed: 05/20/2023]
Abstract
Seeds of higher plants accumulate numerous storage proteins to use as nitrogen resources for early plant development. Seed storage proteins (SSPs) are synthesized as large precursors on the rough endoplasmic reticulum (rER), and are delivered to protein storage vacuoles (PSVs) via vesicle transport, where they are processed to mature forms. We previously identified an Arabidopsis ER-localized tethering complex, MAG2 complex, which might be involved in Golgi to ER retrograde transport. The MAG2 complex is composed of 4 subunits, MAG2, MIP1, MIP2, and MIP3. Mutants with defective alleles for these subunits accumulated SSP precursors inside the ER lumen. Here, we report that the mag2-1 mip3-1 and mip2-1 mip3-1 double mutant have more serious vesicle transport defects than the mag2-1, mip2-1, and mip3-1 single mutants, since they accumulate more SSP precursors than the corresponding single mutants, and ER stress is more severe than the single mutants. The mag2-1 mip3-1 and mip2-1 mip3-1 double mutants show growth and developmental defects rather than the single mutants. Both single and double mutant seeds are found to have lower protein content and decreased germinating vigor than wild type seeds. All the mutants are sensitive to abscisic acid (ABA) and salt stress, and exhibit alteration in ABA signaling pathway. Our study clarified that ER-Golgi vesicle transport affects seed vigor through controlling seed protein quality and content, as well as plant response to environmental stress via influencing ABA signaling pathway.
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Affiliation(s)
- Xiaonan Zhao
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Xiufen Guo
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Xiaofei Tang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
- Institute of Soybean Research, Heilongjiang Provincial Academy of Agricultural Sciences, Harbin, China
| | - Hailong Zhang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Mingjing Wang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Yun Kong
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Xiaomeng Zhang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Zhenjie Zhao
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Min Lv
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Lixin Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
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19
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Xu D, Li Y, Wu L, Li Y, Zhao D, Yu J, Huang T, Ferguson C, Parton RG, Yang H, Li P. Rab18 promotes lipid droplet (LD) growth by tethering the ER to LDs through SNARE and NRZ interactions. J Cell Biol 2018; 217:975-995. [PMID: 29367353 PMCID: PMC5839781 DOI: 10.1083/jcb.201704184] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 10/12/2017] [Accepted: 12/22/2017] [Indexed: 12/16/2022] Open
Abstract
Lipid incorporation from endoplasmic reticulum (ER) to lipid droplet (LD) is important in controlling LD growth and intracellular lipid homeostasis. However, the molecular link mediating ER and LD cross talk remains elusive. Here, we identified Rab18 as an important Rab guanosine triphosphatase in controlling LD growth and maturation. Rab18 deficiency resulted in a drastically reduced number of mature LDs and decreased lipid storage, and was accompanied by increased ER stress. Rab3GAP1/2, the GEF of Rab18, promoted LD growth by activating and targeting Rab18 to LDs. LD-associated Rab18 bound specifically to the ER-associated NAG-RINT1-ZW10 (NRZ) tethering complex and their associated SNAREs (Syntaxin18, Use1, BNIP1), resulting in the recruitment of ER to LD and the formation of direct ER-LD contact. Cells with defects in the NRZ/SNARE complex function showed reduced LD growth and lipid storage. Overall, our data reveal that the Rab18-NRZ-SNARE complex is critical protein machinery for tethering ER-LD and establishing ER-LD contact to promote LD growth.
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Affiliation(s)
- Dijin Xu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuqi Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Lizhen Wu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ying Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Dongyu Zhao
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jinhai Yu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Tuozhi Huang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Charles Ferguson
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia.,Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Australia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Peng Li
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
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20
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Liu D, Li X, Shen D, Novick P. Two subunits of the exocyst, Sec3p and Exo70p, can function exclusively on the plasma membrane. Mol Biol Cell 2018; 29:736-750. [PMID: 29343551 PMCID: PMC6003224 DOI: 10.1091/mbc.e17-08-0518] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 11/18/2022] Open
Abstract
The exocyst is an octameric complex that tethers secretory vesicles to the plasma membrane in preparation for fusion. We anchored each subunit with a transmembrane (TM) domain at its N- or C-terminus. Only N-terminally anchored TM-Sec3p and C-terminally anchored Exo70p-TM proved functional. These findings orient the complex with respect to the membrane and establish that Sec3p and Exo70p can function exclusively on the membrane. The functions of TM-Sec3p and Exo70p-TM were largely unaffected by blocks in endocytic recycling, suggesting that they act on the plasma membrane rather than on secretory vesicles. Cytosolic pools of the other exocyst subunits were unaffected in TM-sec3 cells, while they were partially depleted in exo70-TM cells. Blocking actin-dependent delivery of secretory vesicles in act1-3 cells results in loss of Sec3p from the purified complex. Our results are consistent with a model in which Sec3p and Exo70p can function exclusively on the plasma membrane while the other subunits are brought to them on secretory vesicles.
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Affiliation(s)
- Dongmei Liu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92130
| | - Xia Li
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92130
| | - David Shen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92130
| | - Peter Novick
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92130
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21
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Mosalaganti S, Keller J, Altenfeld A, Winzker M, Rombaut P, Saur M, Petrovic A, Wehenkel A, Wohlgemuth S, Müller F, Maffini S, Bange T, Herzog F, Waldmann H, Raunser S, Musacchio A. Structure of the RZZ complex and molecular basis of its interaction with Spindly. J Cell Biol 2017; 216:961-981. [PMID: 28320825 PMCID: PMC5379955 DOI: 10.1083/jcb.201611060] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/20/2016] [Accepted: 01/23/2017] [Indexed: 12/14/2022] Open
Abstract
The Rod–Zw10–Zwilch (RZZ) complex assembles as a fibrous corona on kinetochores before microtubule attachment during mitotic spindle formation. Mosalaganti et al. provide new structural insight into the Spindly–RZZ complex that suggests that it resembles a dynein adaptor–cargo pair in the kinetochore corona. Kinetochores are macromolecular assemblies that connect chromosomes to spindle microtubules (MTs) during mitosis. The metazoan-specific ≈800-kD ROD–Zwilch–ZW10 (RZZ) complex builds a fibrous corona that assembles on mitotic kinetochores before MT attachment to promote chromosome alignment and robust spindle assembly checkpoint signaling. In this study, we combine biochemical reconstitutions, single-particle electron cryomicroscopy, cross-linking mass spectrometry, and structural modeling to build a complete model of human RZZ. We find that RZZ is structurally related to self-assembling cytosolic coat scaffolds that mediate membrane cargo trafficking, including Clathrin, Sec13–Sec31, and αβ’ε-COP. We show that Spindly, a dynein adaptor, is related to BicD2 and binds RZZ directly in a farnesylation-dependent but membrane-independent manner. Through a targeted chemical biology approach, we identify ROD as the Spindly farnesyl receptor. Our results suggest that RZZ is dynein’s cargo at human kinetochores.
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Affiliation(s)
- Shyamal Mosalaganti
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Jenny Keller
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Anika Altenfeld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Michael Winzker
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Pascaline Rombaut
- Gene Center, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Michael Saur
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Arsen Petrovic
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Annemarie Wehenkel
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Sabine Wohlgemuth
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Franziska Müller
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Stefano Maffini
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Tanja Bange
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Franz Herzog
- Gene Center, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Herbert Waldmann
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany.,Department of Chemistry and Chemical Biology, Technical University Dortmund, 44227 Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany .,Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45141 Essen, Germany
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22
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Association of Human Papillomavirus 16 E2 with Rad50-Interacting Protein 1 Enhances Viral DNA Replication. J Virol 2017; 91:JVI.02305-16. [PMID: 28031358 PMCID: PMC5309968 DOI: 10.1128/jvi.02305-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 12/15/2016] [Indexed: 12/19/2022] Open
Abstract
Rad50-interacting protein 1 (Rint1) associates with the DNA damage response protein Rad50 during the transition from the S phase to the G2/M phase and functions in radiation-induced G2 checkpoint control. It has also been demonstrated that Rint1 is essential in vesicle trafficking from the Golgi apparatus to the endoplasmic reticulum (ER) through an interaction with Zeste-White 10 (ZW10). We have isolated a novel interaction between Rint1 and the human papillomavirus 16 (HPV16) transcription and replication factor E2. E2 binds to Rint1 within its ZW10 interaction domain, and we show that in the absence of E2, Rint1 is localized to the ER and associates with ZW10. E2 expression results in a disruption of the Rint1-ZW10 interaction and an accumulation of nuclear Rint1, coincident with a significant reduction in vesicle movement from the ER to the Golgi apparatus. Interestingly, nuclear Rint1 and members of the Mre11/Rad50/Nbs1 (MRN) complex were found in distinct E2 nuclear foci, which peaked during mid-S phase, indicating that the recruitment of Rint1 to E2 foci within the nucleus may also result in the recruitment of this DNA damage-sensing protein complex. We show that exogenous Rint1 expression enhances E2-dependent virus replication. Conversely, the overexpression of a truncated Rint1 protein that retains the E2 binding domain but not the Rad50 binding domain acts as a dominant negative inhibitor of E2-dependent HPV replication. Put together, these experiments demonstrate that the interaction between Rint1 and E2 has an important function in HPV replication. IMPORTANCE HPV infections are an important driver of many epithelial cancers, including those within the anogenital and oropharyngeal tracts. The HPV life cycle is tightly regulated and intimately linked to the differentiation of the epithelial cells that it infects. HPV replication factories formed in the nucleus are locations where viral DNA is copied to support virus persistence and amplification of infection. The recruitment of specific cellular protein complexes to these factories aids efficient and controlled viral replication. We have identified a novel HPV-host interaction that functions in the cellular response to DNA damage and cell cycle control. We show that the HPV E2 protein targets Rad50-interacting protein 1 (Rint1) to facilitate virus genome replication. These findings add to our understanding of how HPV replicates and the host cell pathways that are targeted by HPV to support virus replication. Understanding these pathways will allow further research into novel inhibitors of HPV genome replication.
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23
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Yue P, Zhang Y, Mei K, Wang S, Lesigang J, Zhu Y, Dong G, Guo W. Sec3 promotes the initial binary t-SNARE complex assembly and membrane fusion. Nat Commun 2017; 8:14236. [PMID: 28112172 PMCID: PMC5267525 DOI: 10.1038/ncomms14236] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 12/12/2016] [Indexed: 01/04/2023] Open
Abstract
The soluble N-ethylmaleimide-sensitive factor-attachment protein receptors (SNAREs) constitute the core machinery for membrane fusion during eukaryotic cell vesicular trafficking. However, how the assembly of the SNARE complex is initiated is unknown. Here we report that Sec3, a component of the exocyst complex that mediates vesicle tethering during exocytosis, directly interacts with the t-SNARE protein Sso2. This interaction promotes the formation of an Sso2-Sec9 'binary' t-SNARE complex, the early rate-limiting step in SNARE complex assembly, and stimulates membrane fusion. The crystal structure of the Sec3-Sso2 complex suggests that Sec3 binding induces conformational changes of Sso2 that are crucial for the relief of its auto-inhibition. Interestingly, specific disruption of the Sec3-Sso2 interaction in cells blocks exocytosis without affecting the function of Sec3 in vesicle tethering. Our study reveals an activation mechanism for SNARE complex assembly, and uncovers a role of the exocyst in promoting membrane fusion in addition to vesicle tethering.
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Affiliation(s)
- Peng Yue
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yubo Zhang
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
| | - Kunrong Mei
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Shaoxiao Wang
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Johannes Lesigang
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
| | - Yueyao Zhu
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Gang Dong
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
| | - Wei Guo
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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24
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Crystal structure of Sec10, a subunit of the exocyst complex. Sci Rep 2017; 7:40909. [PMID: 28098232 PMCID: PMC5241887 DOI: 10.1038/srep40909] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/13/2016] [Indexed: 12/22/2022] Open
Abstract
The exocyst complex is a heterooctameric protein complex composed of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84. This complex plays an essential role in trafficking secretory vesicles to the plasma membrane through its interaction with phosphatidylinositol 4,5-bisphosphate and small GTPases. To date, the near-full-length structural information of each subunit has been limited to Exo70, although the C-terminal half structures of Sec6, Sec15 and Exo84 and the structures of the small GTPase-binding domains of Sec3, Sec5 and Exo84 have been reported. Here, we report the crystal structure of the near-full-length zebrafish Sec10 (zSec10) at 2.73 Å resolution. The structure of zSec10 consists of tandem antiparallel helix bundles that form a straight rod, like helical core regions of other exocyst subunits. This structure provides the first atomic details of Sec10, which may be useful for future functional and structural studies of this subunit and the exocyst complex.
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25
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Climer LK, Hendrix RD, Lupashin VV. Conserved Oligomeric Golgi and Neuronal Vesicular Trafficking. Handb Exp Pharmacol 2017; 245:227-247. [PMID: 29063274 DOI: 10.1007/164_2017_65] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The conserved oligomeric Golgi (COG) complex is an evolutionary conserved multi-subunit vesicle tethering complex essential for the majority of Golgi apparatus functions: protein and lipid glycosylation and protein sorting. COG is present in neuronal cells, but the repertoire of COG function in different Golgi-like compartments is an enigma. Defects in COG subunits cause alteration of Golgi morphology, protein trafficking, and glycosylation resulting in human congenital disorders of glycosylation (CDG) type II. In this review we summarize and critically analyze recent advances in the function of Golgi and Golgi-like compartments in neuronal cells and functions and dysfunctions of the COG complex and its partner proteins.
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Affiliation(s)
- Leslie K Climer
- College of Medicine, Physiology and Biophysics, UAMS, Little Rock, AR, USA
| | - Rachel D Hendrix
- College of Medicine, Neurobiology and Developmental Sciences, UAMS, Little Rock, AR, USA
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26
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Distinct Roles for the N- and C-terminal Regions of M-Sec in Plasma Membrane Deformation during Tunneling Nanotube Formation. Sci Rep 2016; 6:33548. [PMID: 27629377 PMCID: PMC5024327 DOI: 10.1038/srep33548] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 08/30/2016] [Indexed: 01/07/2023] Open
Abstract
The tunneling nanotube (TNT) is a structure used for intercellular communication, and is a thin membrane protrusion mediating transport of various signaling molecules and cellular components. M-Sec has potent membrane deformation ability and induces TNT formation in cooperation with the Ral/exocyst complex. Here, we show that the N-terminal polybasic region of M-Sec directly binds phosphatidylinositol (4,5)-bisphosphate for its localization to the plasma membrane during the initial stage of TNT formation. We further report a crystal structure of M-Sec, which consists of helix bundles arranged in a straight rod-like shape, similar to the membrane tethering complex subunits. A positively charged surface in the C-terminal domains is required for M-Sec interaction with active RalA to extend the plasma membrane protrusions. Our results suggest that the membrane-associated M-Sec recruits active RalA, which directs the exocyst complex to form TNTs.
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27
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Schröter S, Beckmann S, Schmitt HD. ER arrival sites for COPI vesicles localize to hotspots of membrane trafficking. EMBO J 2016; 35:1935-55. [PMID: 27440402 DOI: 10.15252/embj.201592873] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 06/21/2016] [Indexed: 11/09/2022] Open
Abstract
COPI-coated vesicles mediate retrograde membrane traffic from the cis-Golgi to the endoplasmic reticulum (ER) in all eukaryotic cells. However, it is still unknown whether COPI vesicles fuse everywhere or at specific sites with the ER membrane. Taking advantage of the circumstance that the vesicles still carry their coat when they arrive at the ER, we have visualized active ER arrival sites (ERAS) by monitoring contact between COPI coat components and the ER-resident Dsl tethering complex using bimolecular fluorescence complementation (BiFC). ERAS form punctate structures near Golgi compartments, clearly distinct from ER exit sites. Furthermore, ERAS are highly polarized in an actin and myosin V-dependent manner and are localized near hotspots of plasma membrane expansion. Genetic experiments suggest that the COPI•Dsl BiFC complexes recapitulate the physiological interaction between COPI and the Dsl complex and that COPI vesicles are mistargeted in dsl1 mutants. We conclude that the Dsl complex functions in confining COPI vesicle fusion sites.
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Affiliation(s)
- Saskia Schröter
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Sabrina Beckmann
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Hans Dieter Schmitt
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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28
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Ha JY, Chou HT, Ungar D, Yip CK, Walz T, Hughson FM. Molecular architecture of the complete COG tethering complex. Nat Struct Mol Biol 2016; 23:758-60. [PMID: 27428773 PMCID: PMC4972656 DOI: 10.1038/nsmb.3263] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/16/2016] [Indexed: 12/14/2022]
Abstract
The conserved oligomeric Golgi (COG) complex orchestrates vesicular trafficking to and within the Golgi apparatus. Here, we use negative-stain electron microscopy to elucidate the architecture of the hetero-octameric COG complex from Saccharomyces cerevisiae. Intact COG has an intricate shape, with four (or possibly five) flexible legs, that differs strikingly from the exocyst complex and appears well-suited for vesicle capture and fusion.
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Affiliation(s)
- Jun Yong Ha
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Hui-Ting Chou
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel Ungar
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Calvin K Yip
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Thomas Walz
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Frederick M Hughson
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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29
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Abstract
Intracellular membrane fusion is mediated in most cases by membrane-bridging complexes of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). However, the assembly of such complexes in vitro is inefficient, and their uncatalysed disassembly is undetectably slow. Here, we focus on the cellular machinery that orchestrates assembly and disassembly of SNARE complexes, thereby regulating processes ranging from vesicle trafficking to organelle fusion to neurotransmitter release. Rapid progress is being made on many fronts, including the development of more realistic cell-free reconstitutions, the application of single-molecule biophysics, and the elucidation of X-ray and high-resolution electron microscopy structures of the SNARE assembly and disassembly machineries 'in action'.
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Affiliation(s)
- Richard W Baker
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.,Present address: Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - Frederick M Hughson
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
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30
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Schroeter S, Beckmann S, Schmitt HD. Coat/Tether Interactions-Exception or Rule? Front Cell Dev Biol 2016; 4:44. [PMID: 27243008 PMCID: PMC4868844 DOI: 10.3389/fcell.2016.00044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/25/2016] [Indexed: 12/02/2022] Open
Abstract
Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers.
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Affiliation(s)
- Saskia Schroeter
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
| | - Sabrina Beckmann
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
| | - Hans Dieter Schmitt
- Neurobiology, Max Planck Institute for Biophysical Chemistry Göttingen, Germany
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31
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Kuhlee A, Raunser S, Ungermann C. Functional homologies in vesicle tethering. FEBS Lett 2015; 589:2487-97. [PMID: 26072291 DOI: 10.1016/j.febslet.2015.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 05/30/2015] [Accepted: 06/01/2015] [Indexed: 11/24/2022]
Abstract
The HOPS multisubunit tethering factor (MTC) is a macromolecular protein complex composed of six different subunits. It is one of the key components in the perception and subsequent fusion of multivesicular bodies and vacuoles. Electron microscopy studies indicate structural flexibility of the purified HOPS complex. Inducing higher rigidity into HOPS by biochemically modifying the complex declines the potential to mediate SNARE-driven membrane fusion. Thus, we propose that integral flexibility seems to be not only a feature, but of essential need for the function of HOPS. This review focuses on the general features of membrane tethering and fusion. For this purpose, we compare the structure and mode of action of different tethering factors to highlight their common central features and mechanisms.
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Affiliation(s)
- Anne Kuhlee
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
| | - Stefan Raunser
- Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Christian Ungermann
- Department of Biology, University of Osnabrück, Barbarastrasse 13, 49076 Osnabrück, Germany
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32
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Yang X, Wang S, Sheng Y, Zhang M, Zou W, Wu L, Kang L, Rizo J, Zhang R, Xu T, Ma C. Syntaxin opening by the MUN domain underlies the function of Munc13 in synaptic-vesicle priming. Nat Struct Mol Biol 2015; 22:547-54. [PMID: 26030875 DOI: 10.1038/nsmb.3038] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 05/01/2015] [Indexed: 11/09/2022]
Abstract
UNC-13-Munc13s have a central function in synaptic-vesicle priming through their MUN domains. However, it is unclear whether this function arises from the ability of the MUN domain to mediate the transition from the Munc18-1-closed syntaxin-1 complex to the SNARE complex in vitro. The crystal structure of the rat Munc13-1 MUN domain now reveals an elongated, arch-shaped architecture formed by α-helical bundles, with a highly conserved hydrophobic pocket in the middle. Mutation of two residues (NF) in this pocket abolishes the stimulation caused by the Munc13-1 MUN domain on SNARE-complex assembly and on SNARE-dependent proteoliposome fusion in vitro. Moreover, the same mutation in UNC-13 abrogates synaptic-vesicle priming in Caenorhabditis elegans neuromuscular junctions. These results support the notion that orchestration of syntaxin-1 opening and SNARE-complex assembly underlies the central role of UNC-13-Munc13s in synaptic-vesicle priming.
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Affiliation(s)
- Xiaoyu Yang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Shen Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yi Sheng
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Mingshu Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wenjuan Zou
- Institute of Neuroscience, Zhejiang University, Hangzhou, China
| | - Lijie Wu
- Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Lijun Kang
- Institute of Neuroscience, Zhejiang University, Hangzhou, China
| | - Josep Rizo
- Department of Biophysics, Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Rongguang Zhang
- 1] National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China. [2] Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Tao Xu
- 1] Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China. [2] National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China. [3] College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Cong Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
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33
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Cog5-Cog7 crystal structure reveals interactions essential for the function of a multisubunit tethering complex. Proc Natl Acad Sci U S A 2014; 111:15762-7. [PMID: 25331899 DOI: 10.1073/pnas.1414829111] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The conserved oligomeric Golgi (COG) complex is required, along with SNARE and Sec1/Munc18 (SM) proteins, for vesicle docking and fusion at the Golgi. COG, like other multisubunit tethering complexes (MTCs), is thought to function as a scaffold and/or chaperone to direct the assembly of productive SNARE complexes at the sites of membrane fusion. Reflecting this essential role, mutations in the COG complex can cause congenital disorders of glycosylation. A deeper understanding of COG function and dysfunction will likely depend on elucidating its molecular structure. Despite some progress toward this goal, including EM studies of COG lobe A (subunits 1-4) and higher-resolution structures of portions of Cog2 and Cog4, the structures of COG's eight subunits and the principles governing their assembly are mostly unknown. Here, we report the crystal structure of a complex between two lobe B subunits, Cog5 and Cog7. The structure reveals that Cog5 is a member of the complexes associated with tethering containing helical rods (CATCHR) fold family, with homology to subunits of other MTCs including the Dsl1, exocyst, and Golgi-associated retrograde protein (GARP) complexes. The Cog5-Cog7 interaction is analyzed in relation to the Dsl1 complex, the only other CATCHR-family MTC for which subunit interactions have been characterized in detail. Biochemical and functional studies validate the physiological relevance of the observed Cog5-Cog7 interface, indicate that it is conserved from yeast to humans, and demonstrate that its disruption in human cells causes defects in trafficking and glycosylation.
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34
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Abstract
Membrane trafficking depends on transport vesicles and carriers docking and fusing with the target organelle for the delivery of cargo. Membrane tethers and small guanosine triphosphatases (GTPases) mediate the docking of transport vesicles/carriers to enhance the efficiency of the subsequent SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-mediated fusion event with the target membrane bilayer. Different classes of membrane tethers and their specific intracellular location throughout the endomembrane system are now well defined. Recent biochemical and structural studies have led to a deeper understanding of the mechanism by which membrane tethers mediate docking of membrane carriers as well as an appreciation of the role of tethers in coordinating the correct SNARE complex and in regulating the organization of membrane compartments. This review will summarize the properties and roles of membrane tethers of both secretory and endocytic systems.
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Affiliation(s)
- Pei Zhi Cheryl Chia
- National Institute of Dental and Craniofacial Research, National Institutes of Health30 Convent Drive, Bethesda, MD 20892-4340USA
| | - Paul A. Gleeson
- The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute30 Flemington Road, The University of Melbourne, Victoria 3010Australia
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35
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Rogers JV, McMahon C, Baryshnikova A, Hughson FM, Rose MD. ER-associated retrograde SNAREs and the Dsl1 complex mediate an alternative, Sey1p-independent homotypic ER fusion pathway. Mol Biol Cell 2014; 25:3401-12. [PMID: 25187651 PMCID: PMC4214786 DOI: 10.1091/mbc.e14-07-1220] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
SNAREs and the Dsl1 complex mediate an alternative, Sey1p-independent homotypic endoplasmic reticulum (ER) fusion pathway in yeast. When both pathways and the reticulons are simultaneously disrupted, cells are inviable. This demonstrates that homotypic ER fusion is an essential process in yeast and that the Dsl1 complex has vesicle trafficking-independent functions. The peripheral endoplasmic reticulum (ER) network is dynamically maintained by homotypic (ER–ER) fusion. In Saccharomyces cerevisiae, the dynamin-like GTPase Sey1p can mediate ER–ER fusion, but sey1Δ cells have no growth defect and only slightly perturbed ER structure. Recent work suggested that ER-localized soluble N-ethylmaleimide–sensitive factor attachment protein receptors (SNAREs) mediate a Sey1p-independent ER–ER fusion pathway. However, an alternative explanation—that the observed phenotypes arose from perturbed vesicle trafficking—could not be ruled out. In this study, we used candidate and synthetic genetic array (SGA) approaches to more fully characterize SNARE-mediated ER–ER fusion. We found that Dsl1 complex mutations in sey1Δ cells cause strong synthetic growth and ER structure defects and delayed ER–ER fusion in vivo, additionally implicating the Dsl1 complex in SNARE-mediated ER–ER fusion. In contrast, cytosolic coat protein I (COPI) vesicle coat mutations in sey1Δ cells caused no synthetic defects, excluding perturbed retrograde trafficking as a cause for the previously observed synthetic defects. Finally, deleting the reticulons that help maintain ER architecture in cells disrupted for both ER–ER fusion pathways caused almost complete inviability. We conclude that the ER SNAREs and the Dsl1 complex directly mediate Sey1p-independent ER–ER fusion and that, in the absence of both pathways, cell viability depends upon membrane curvature–promoting reticulons.
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Affiliation(s)
- Jason V Rogers
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014
| | - Conor McMahon
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014
| | - Anastasia Baryshnikova
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544-1014
| | - Frederick M Hughson
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014
| | - Mark D Rose
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014
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36
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Tagaya M, Arasaki K, Inoue H, Kimura H. Moonlighting functions of the NRZ (mammalian Dsl1) complex. Front Cell Dev Biol 2014; 2:25. [PMID: 25364732 PMCID: PMC4206994 DOI: 10.3389/fcell.2014.00025] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/20/2014] [Indexed: 12/31/2022] Open
Abstract
The yeast Dsl1 complex, which comprises Dsl1, Tip20, and Sec39/Dsl3, has been shown to participate, as a vesicle-tethering complex, in retrograde trafficking from the Golgi apparatus to the endoplasmic reticulum. Its metazoan counterpart NRZ complex, which comprises NAG, RINT1, and ZW10, is also involved in Golgi-to-ER retrograde transport, but each component of the complex has diverse cellular functions including endosome-to-Golgi transport, cytokinesis, cell cycle checkpoint, autophagy, and mRNA decay. In this review, we summarize the current knowledge of the metazoan NRZ complex and discuss the "moonlighting" functions and intercorrelation of their subunits.
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Affiliation(s)
- Mitsuo Tagaya
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Kohei Arasaki
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Hiroki Inoue
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Hana Kimura
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
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37
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Crystal structure of the herpesvirus inner tegument protein UL37 supports its essential role in control of viral trafficking. J Virol 2014; 88:5462-73. [PMID: 24599989 DOI: 10.1128/jvi.00163-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED In cells infected with herpesviruses, two capsid-associated, or inner tegument, proteins, UL37 and UL36, control cytosolic trafficking of capsids by as yet poorly understood mechanisms. Here, we report the crystal structure of the N-terminal half of UL37 from pseudorabies virus, an alphaherpesvirus closely related to herpes simplex viruses and varicella-zoster virus. The structure--the first for any alphaherpesvirus inner tegument protein--reveals an elongated molecule of a complex architecture rich in helical bundles. To explore the function of the UL37 N terminus, we used the three-dimensional framework provided by the structure in combination with evolutionary trace analysis to pinpoint several surface-exposed regions of potential functional importance and test their importance using mutagenesis. This approach identified a novel functional region important for cell-cell spread. These results suggest a novel role for UL37 in intracellular virus trafficking that promotes spread of viral infection, a finding that expands the repertoire of UL37 functions. Supporting this, the N terminus of UL37 shares structural similarity with cellular multisubunit tethering complexes (MTCs), which control vesicular trafficking in eukaryotic cells by tethering transport vesicles to their destination membranes. Our results suggest that UL37 could be the first viral MTC mimic and provide a structural rationale for the importance of UL37 for viral trafficking. We propose that herpesviruses may have co-opted the MTC functionality of UL37 to bring capsids to cytoplasmic budding destinations and further on to cell junctions for spread to nearby cells. IMPORTANCE To move within an infected cell, viruses encode genes for proteins that interact with host trafficking machinery. In cells infected with herpesviruses, two capsid-associated proteins control the cytosolic movement of capsids by as yet poorly understood mechanisms. Here, we report the crystal structure for the N-terminal half of one of these proteins, UL37. Structure-based mutagenesis revealed a novel function for UL37 in virus trafficking to cell junctions for cell-cell spread. The unexpected structural similarity to components of cellular multisubunit tethering complexes, which control vesicular traffic, suggests that UL37 could be the first viral MTC mimic and provides a structural basis for the importance of UL37 for virus trafficking.
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Hong W, Lev S. Tethering the assembly of SNARE complexes. Trends Cell Biol 2014; 24:35-43. [DOI: 10.1016/j.tcb.2013.09.006] [Citation(s) in RCA: 219] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 09/09/2013] [Accepted: 09/10/2013] [Indexed: 12/11/2022]
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Mgbeahuruike AC, Kovalchuk A, Chen H, Ubhayasekera W, Asiegbu FO. Evolutionary analysis of hydrophobin gene family in two wood-degrading basidiomycetes, Phlebia brevispora and Heterobasidion annosum s.l. BMC Evol Biol 2013; 13:240. [PMID: 24188142 PMCID: PMC3879219 DOI: 10.1186/1471-2148-13-240] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 10/11/2013] [Indexed: 12/25/2022] Open
Abstract
Background Hydrophobins are small secreted cysteine-rich proteins that play diverse roles during different phases of fungal life cycle. In basidiomycetes, hydrophobin-encoding genes often form large multigene families with up to 40 members. The evolutionary forces driving hydrophobin gene expansion and diversification in basidiomycetes are poorly understood. The functional roles of individual genes within such gene families also remain unclear. The relationship between the hydrophobin gene number, the genome size and the lifestyle of respective fungal species has not yet been thoroughly investigated. Here, we present results of our survey of hydrophobin gene families in two species of wood-degrading basidiomycetes, Phlebia brevispora and Heterobasidion annosum s.l. We have also investigated the regulatory pattern of hydrophobin-encoding genes from H. annosum s.s. during saprotrophic growth on pine wood as well as on culture filtrate from Phlebiopsis gigantea using micro-arrays. These data are supplemented by results of the protein structure modeling for a representative set of hydrophobins. Results We have identified hydrophobin genes from the genomes of two wood-degrading species of basidiomycetes, Heterobasidion irregulare, representing one of the microspecies within the aggregate H. annosum s.l., and Phlebia brevispora. Although a high number of hydrophobin-encoding genes were observed in H. irregulare (16 copies), a remarkable expansion of these genes was recorded in P. brevispora (26 copies). A significant expansion of hydrophobin-encoding genes in other analyzed basidiomycetes was also documented (1–40 copies), whereas contraction through gene loss was observed among the analyzed ascomycetes (1–11 copies). Our phylogenetic analysis confirmed the important role of gene duplication events in the evolution of hydrophobins in basidiomycetes. Increased number of hydrophobin-encoding genes appears to have been linked to the species’ ecological strategy, with the non-pathogenic fungi having increased numbers of hydrophobins compared with their pathogenic counterparts. However, there was no significant relationship between the number of hydrophobin-encoding genes and genome size. Furthermore, our results revealed significant differences in the expression levels of the 16 H. annosum s.s. hydrophobin-encoding genes which suggest possible differences in their regulatory patterns. Conclusions A considerable expansion of the hydrophobin-encoding genes in basidiomycetes has been observed. The distribution and number of hydrophobin-encoding genes in the analyzed species may be connected to their ecological preferences. Results of our analysis also have shown that H. annosum s.l. hydrophobin-encoding genes may be under positive selection. Our gene expression analysis revealed differential expression of H. annosum s.s. hydrophobin genes under different growth conditions, indicating their possible functional diversification.
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He S, Ni D, Ma B, Lee JH, Zhang T, Ghozalli I, Pirooz SD, Zhao Z, Bharatham N, Li B, Oh S, Lee WH, Takahashi Y, Wang HG, Minassian A, Feng P, Deretic V, Pepperkok R, Tagaya M, Yoon HS, Liang C. PtdIns(3)P-bound UVRAG coordinates Golgi-ER retrograde and Atg9 transport by differential interactions with the ER tether and the beclin 1 complex. Nat Cell Biol 2013; 15:1206-1219. [PMID: 24056303 PMCID: PMC3805255 DOI: 10.1038/ncb2848] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 08/21/2013] [Indexed: 12/14/2022]
Abstract
Endoplasmic reticulum (ER)-Golgi membrane transport and autophagy are intersecting trafficking pathways that are tightly regulated and crucial for homeostasis, development and disease. Here, we identify UVRAG, a beclin-1-binding autophagic factor, as a phosphatidylinositol-3-phosphate (PtdIns(3)P)-binding protein that depends on PtdIns(3)P for its ER localization. We further show that UVRAG interacts with RINT-1, and acts as an integral component of the RINT-1-containing ER tethering complex, which couples phosphoinositide metabolism to COPI-vesicle tethering. Displacement or knockdown of UVRAG profoundly disrupted COPI cargo transfer to the ER and Golgi integrity. Intriguingly, autophagy caused the dissociation of UVRAG from the ER tether, which in turn worked in concert with the Bif-1-beclin-1-PI(3)KC3 complex to mobilize Atg9 translocation for autophagosome formation. These findings identify a regulatory mechanism that coordinates Golgi-ER retrograde and autophagy-related vesicular trafficking events through physical and functional interactions between UVRAG, phosphoinositide and their regulatory factors, thereby ensuring spatiotemporal fidelity of membrane trafficking and maintenance of organelle homeostasis.
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Affiliation(s)
- Shanshan He
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Duojiao Ni
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Binyun Ma
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Joo-Hyung Lee
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Tian Zhang
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Irene Ghozalli
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Sara Dolatshahi Pirooz
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Zhen Zhao
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Nagakumar Bharatham
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Baihong Li
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Soohwan Oh
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Wen-Hwa Lee
- Department of Biological Chemistry, University of California, Irvine, Irvine, California 92697
| | - Yoshinori Takahashi
- Department of Pharmacology and Penn State Hershey Cancer Institute; The Pennsylvania State University College of Medicine; Hershey, PA USA
| | - Hong-Gang Wang
- Department of Pharmacology and Penn State Hershey Cancer Institute; The Pennsylvania State University College of Medicine; Hershey, PA USA
| | - Arlet Minassian
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Pinghui Feng
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
| | - Vojo Deretic
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| | - Rainer Pepperkok
- European Molecular Biology Laboratory, Heidelberg, Cell Biology/Cell Biophysics Unit, Meyerhofstr. 1, D-69117 Heidelberg Germany
| | - Mitsuo Tagaya
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0393, Japan
| | - Ho Sup Yoon
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore 637551
- Department of Genetic Engineering, College of Life Sciences, Kyung Hee University, Yongin-si, Gyeonggi-do, 446-701, Republic of Korea
| | - Chengyu Liang
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA 90033, USA
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Comparative genomic analysis of multi-subunit tethering complexes demonstrates an ancient pan-eukaryotic complement and sculpting in Apicomplexa. PLoS One 2013; 8:e76278. [PMID: 24086721 PMCID: PMC3785458 DOI: 10.1371/journal.pone.0076278] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/22/2013] [Indexed: 11/19/2022] Open
Abstract
Apicomplexa are obligate intracellular parasites that cause tremendous disease burden world-wide. They utilize a set of specialized secretory organelles in their invasive process that require delivery of components for their biogenesis and function, yet the precise mechanisms underpinning such processes remain unclear. One set of potentially important components is the multi-subunit tethering complexes (MTCs), factors increasingly implicated in all aspects of vesicle-target interactions. Prompted by the results of previous studies indicating a loss of membrane trafficking factors in Apicomplexa, we undertook a bioinformatic analysis of MTC conservation. Building on knowledge of the ancient presence of most MTC proteins, we demonstrate the near complete retention of MTCs in the newly available genomes for Guillardiatheta and Bigelowiellanatans. The latter is a key taxonomic sampling point as a basal sister taxa to the group including Apicomplexa. We also demonstrate an ancient origin of the CORVET complex subunits Vps8 and Vps3, as well as the TRAPPII subunit Tca17. Having established that the lineage leading to Apicomplexa did at one point possess the complete eukaryotic complement of MTC components, we undertook a deeper taxonomic investigation in twelve apicomplexan genomes. We observed excellent conservation of the VpsC core of the HOPS and CORVET complexes, as well as the core TRAPP subunits, but sparse conservation of TRAPPII, COG, Dsl1, and HOPS/CORVET-specific subunits. However, those subunits that we did identify appear to be expressed with similar patterns to the fully conserved MTC proteins, suggesting that they may function as minimal complexes or with analogous partners. Strikingly, we failed to identify any subunits of the exocyst complex in all twelve apicomplexan genomes, as well as the dinoflagellate Perkinsus marinus. Overall, we demonstrate reduction of MTCs in Apicomplexa and their ancestors, consistent with modification during, and possibly pre-dating, the move from free-living marine algae to deadly human parasites.
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Arasaki K, Takagi D, Furuno A, Sohda M, Misumi Y, Wakana Y, Inoue H, Tagaya M. A new role for RINT-1 in SNARE complex assembly at the trans-Golgi network in coordination with the COG complex. Mol Biol Cell 2013; 24:2907-17. [PMID: 23885118 PMCID: PMC3771952 DOI: 10.1091/mbc.e13-01-0014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Yeast Tip20, a subunit of the Dsl1 complex, is implicated in Golgi-to–endoplasmic reticulum retrograde transport. Differing from Tip20, its mammalian counterpart, RINT-1, is required for endosome-to–trans-Golgi network transport. RINT-1 in coordination with the COG complex regulates SNARE complex assembly at the trans-Golgi network. Docking and fusion of transport vesicles/carriers with the target membrane involve a tethering factor–mediated initial contact followed by soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE)–catalyzed membrane fusion. The multisubunit tethering CATCHR family complexes (Dsl1, COG, exocyst, and GARP complexes) share very low sequence homology among subunits despite likely evolving from a common ancestor and participate in fundamentally different membrane trafficking pathways. Yeast Tip20, as a subunit of the Dsl1 complex, has been implicated in retrograde transport from the Golgi apparatus to the endoplasmic reticulum. Our previous study showed that RINT-1, the mammalian counterpart of yeast Tip20, mediates the association of ZW10 (mammalian Dsl1) with endoplasmic reticulum–localized SNARE proteins. In the present study, we show that RINT-1 is also required for endosome-to–trans-Golgi network trafficking. RINT-1 uncomplexed with ZW10 interacts with the COG complex, another member of the CATCHR family complex, and regulates SNARE complex assembly at the trans-Golgi network. This additional role for RINT-1 may in part reflect adaptation to the demand for more diverse transport routes from endosomes to the trans-Golgi network in mammals compared with those in a unicellular organism, yeast. The present findings highlight a new role of RINT-1 in coordination with the COG complex.
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Affiliation(s)
- Kohei Arasaki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan Division of Oral Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan Department of Cell Biology, Fukuoka University School of Medicine, Jonan-ku, Fukuoka 814-0180, Japan
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Abstract
The secretory pathway is responsible for the synthesis, folding, and delivery of a diverse array of cellular proteins. Secretory protein synthesis begins in the endoplasmic reticulum (ER), which is charged with the tasks of correctly integrating nascent proteins and ensuring correct post-translational modification and folding. Once ready for forward traffic, proteins are captured into ER-derived transport vesicles that form through the action of the COPII coat. COPII-coated vesicles are delivered to the early Golgi via distinct tethering and fusion machineries. Escaped ER residents and other cycling transport machinery components are returned to the ER via COPI-coated vesicles, which undergo similar tethering and fusion reactions. Ultimately, organelle structure, function, and cell homeostasis are maintained by modulating protein and lipid flux through the early secretory pathway. In the last decade, structural and mechanistic studies have added greatly to the strong foundation of yeast genetics on which this field was built. Here we discuss the key players that mediate secretory protein biogenesis and trafficking, highlighting recent advances that have deepened our understanding of the complexity of this conserved and essential process.
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Zhao P, Liu F, Zhang B, Liu X, Wang B, Gong J, Yu G, Ma M, Lu Y, Sun J, Wang Z, Jia P, Liu H. MAIGO2 is involved in abscisic acid-mediated response to abiotic stresses and Golgi-to-ER retrograde transport. PHYSIOLOGIA PLANTARUM 2013; 148:246-60. [PMID: 23025793 DOI: 10.1111/j.1399-3054.2012.01704.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/29/2012] [Accepted: 09/09/2012] [Indexed: 05/24/2023]
Abstract
The central role of multisubunit tethering complexes in intracellular trafficking has been established in yeast and mammalian systems. However, little is known about their roles in the stress responses and the early secretory pathway in Arabidopsis. In this study, Maigo2 (MAG2), which is equivalent to the yeast Tip20p and mammalian Rad50-interacting protein, is found to be required for the responses to salt stress, osmotic stress and abscisic acid in seed germination and vegetative growth, and MAG2-like (MAG2L) is partially redundant with MAG2 in response to environmental stresses. MAG2 strongly interacts with the central region of ZW10, and both proteins are important as plant endoplasmic reticulum (ER)-stress regulators. ER morphology and vacuolar protein trafficking are unaffected in the mag2, mag2l and zw10 mutants, and the secretory marker to the apoplast is correctly transported in mag2 plants, which indicate that MAG2 functions as a complex with ZW10, and is potentially involved in Golgi-to-ER retrograde trafficking. Therefore, a new role for ER-Golgi membrane trafficking in abiotic-stress and ER-stress responses is discovered.
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Affiliation(s)
- Pengshan Zhao
- Laboratory of Plant Stress Ecophysiology and Biotechnology, Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
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Spang A. Retrograde traffic from the Golgi to the endoplasmic reticulum. Cold Spring Harb Perspect Biol 2013; 5:5/6/a013391. [PMID: 23732476 DOI: 10.1101/cshperspect.a013391] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Proteins to be secreted are transported from the endoplasmic reticulum (ER) to the Golgi apparatus. The transport of these proteins requires the localization and activity of proteins that create ER exit sites, coat proteins to collect cargo and to reshape the membrane into a transport container, and address labels--SNARE proteins--to target the vesicles specifically to the Golgi apparatus. In addition some proteins may need export chaperones or export receptors to enable their exit into transport vesicles. ER export factors, SNAREs, and misfolded Golgi-resident proteins must all be retrieved from the Golgi to the ER again. This retrieval is also part of the organellar homeostasis pathway essential to maintaining the identity of the ER and of the Golgi apparatus. In this review, I will discuss the different processes in retrograde transport from the Golgi to the ER and highlight the mechanistic insights we have obtained in the last couple of years.
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Affiliation(s)
- Anne Spang
- University of Basel, Biozentrum, Growth & Development, Klingelbergstrasse 70, 4056 Basel, Switzerland.
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Delic M, Valli M, Graf AB, Pfeffer M, Mattanovich D, Gasser B. The secretory pathway: exploring yeast diversity. FEMS Microbiol Rev 2013; 37:872-914. [PMID: 23480475 DOI: 10.1111/1574-6976.12020] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 02/14/2013] [Accepted: 02/17/2013] [Indexed: 12/11/2022] Open
Abstract
Protein secretion is an essential process for living organisms. In eukaryotes, this encompasses numerous steps mediated by several hundred cellular proteins. The core functions of translocation through the endoplasmic reticulum membrane, primary glycosylation, folding and quality control, and vesicle-mediated secretion are similar from yeasts to higher eukaryotes. However, recent research has revealed significant functional differences between yeasts and mammalian cells, and even among diverse yeast species. This review provides a current overview of the canonical protein secretion pathway in the model yeast Saccharomyces cerevisiae, highlighting differences to mammalian cells as well as currently unresolved questions, and provides a genomic comparison of the S. cerevisiae pathway to seven other yeast species where secretion has been investigated due to their attraction as protein production platforms, or for their relevance as pathogens. The analysis of Candida albicans, Candida glabrata, Kluyveromyces lactis, Pichia pastoris, Hansenula polymorpha, Yarrowia lipolytica, and Schizosaccharomyces pombe reveals that many - but not all - secretion steps are more redundant in S. cerevisiae due to duplicated genes, while some processes are even absent in this model yeast. Recent research obviates that even where homologous genes are present, small differences in protein sequence and/or differences in the regulation of gene expression may lead to quite different protein secretion phenotypes.
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Affiliation(s)
- Marizela Delic
- Department of Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria; Austrian Centre of Industrial Biotechnology (ACIB GmbH), Vienna, Austria
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New putative chloroplast vesicle transport components and cargo proteins revealed using a bioinformatics approach: an Arabidopsis model. PLoS One 2013; 8:e59898. [PMID: 23573218 PMCID: PMC3613420 DOI: 10.1371/journal.pone.0059898] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/19/2013] [Indexed: 11/23/2022] Open
Abstract
Proteins and lipids are known to be transported to targeted cytosolic compartments in vesicles. A similar system in chloroplasts is suggested to transfer lipids from the inner envelope to the thylakoids. However, little is known about both possible cargo proteins and the proteins required to build a functional vesicle transport system in chloroplasts. A few components have been suggested, but only one (CPSAR1) has a verified location in chloroplast vesicles. This protein is localized in the donor membrane (envelope) and vesicles, but not in the target membrane (thylakoids) suggesting it plays a similar role to a cytosolic homologue, Sar1, in the secretory pathway. Thus, we hypothesized that there may be more similarities, in addition to lipid transport, between the vesicle transport systems in the cytosol and chloroplast, i.e. similar vesicle transport components, possible cargo proteins and receptors. Therefore, using a bioinformatics approach we searched for putative chloroplast components in the model plant Arabidopsis thaliana, corresponding mainly to components of the cytosolic vesicle transport system that may act in coordination with previously proposed COPII chloroplast homologues. We found several additional possible components, supporting the notion of a fully functional vesicle transport system in chloroplasts. Moreover, we found motifs in thylakoid-located proteins similar to those of COPII vesicle cargo proteins, supporting the hypothesis that chloroplast vesicles may transport thylakoid proteins from the envelope to the thylakoid membrane. Several putative cargo proteins are involved in photosynthesis, thus we propose the existence of a novel thylakoid protein pathway that is important for construction and maintenance of the photosynthetic machinery.
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Laufman O, Hong W, Lev S. The COG complex interacts with multiple Golgi SNAREs and enhances fusogenic assembly of SNARE complexes. J Cell Sci 2013; 126:1506-16. [PMID: 23378023 DOI: 10.1242/jcs.122101] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Multisubunit tethering complexes (MTCs) positively regulate vesicular fusion by as yet unclear mechanism. In this study we provide evidence that the MTC COG enhances the assembly of fusogenic Golgi SNARE complexes and concomitantly prevents nonfusogenic tSNARE interactions. This capability is possibly mediated by multiple direct interactions of COG subunits and specific Golgi SNAREs and SM (Sec1/Munc18) proteins. By using a systematic co-immunoprecipitation analysis, we identified seven new interactions between the COG subunits and components of the Golgi fusion machinery in mammalian cells. Our studies suggest that these multivalent interactions are critical for the assembly of fusogenic SNARE complexes on the Golgi apparatus and consequently for facilitating endosome-to-trans-Golgi network (TGN) and intra-Golgi retrograde transport, and also for coordinating these transport routes.
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Affiliation(s)
- Orly Laufman
- Molecular Cell Biology Department, Weizmann Institute of Science, Rehovot 76100, Israel
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Shiba Y, Randazzo PA. ArfGAP1 function in COPI mediated membrane traffic: currently debated models and comparison to other coat-binding ArfGAPs. Histol Histopathol 2012; 27:1143-53. [PMID: 22806901 DOI: 10.14670/hh-27.1143] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The ArfGAPs are a family of proteins containing an ArfGAP catalytic domain that induces the hydrolysis of GTP bound to the small guanine nucleotide binding-protein ADP-ribosylation factor (Arf). Functional models for Arfs, which are regulators of membrane traffic, are based on the idea that guanine nucleotide-binding proteins function as switches: Arf with GTP bound is active and binds to effector proteins; the conversion of GTP to GDP inactivates Arf. The cellular activities of ArfGAPs have been examined primarily as regulatory proteins that inactivate Arf; however, Arf function in membrane traffic does not strictly adhere to the concept of a simple switch, adding complexity to models explaining the role of ArfGAPs. Here, we review the literature addressing the function Arf and ArfGAP1 in COPI mediated transport, focusing on two critical and integrated functions of membrane traffic, cargo sorting and vesicle coat polymerization. We briefly discuss other ArfGAPs that may have similar function in Arf-dependent membrane traffic outside the ER-Golgi.
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Affiliation(s)
- Yoko Shiba
- National Cancer Institute, Laboratory of Cellular and Molecular Biology, Bethesda, MD 20892, USA
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Rizo J, Südhof TC. The Membrane Fusion Enigma: SNAREs, Sec1/Munc18 Proteins, and Their Accomplices—Guilty as Charged? Annu Rev Cell Dev Biol 2012; 28:279-308. [DOI: 10.1146/annurev-cellbio-101011-155818] [Citation(s) in RCA: 318] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Josep Rizo
- Departments of Biophysics, Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390;
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University Medical School, Stanford, California 94305;
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