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Abstract
The translation of messenger RNA (mRNA) into proteins represents the culmination of gene expression. Recent technological advances have revolutionized our ability to investigate this process with unprecedented precision, enabling the study of translation at the single-molecule level in real time within live cells. In this review, we provide an overview of single-mRNA translation reporters. We focus on the core technology, as well as the rapid development of complementary probes, tags, and accessories that enable the visualization and quantification of a wide array of translation dynamics. We then highlight notable studies that have utilized these reporters in model systems to address key biological questions. The high spatiotemporal resolution of these studies is shedding light on previously unseen phenomena, uncovering the full heterogeneity and complexity of translational regulation.
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Affiliation(s)
- Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
| | - O'Neil Wiggan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
- Cell Biology Center and World Research Hub Initiative, Tokyo Institute of Technology, Yokohama, Japan
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2
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Martin-Solana E, Carter SD, Donahue EK, Ning J, Glausier JR, Preisegger MA, Eisenman L, Joseph PN, Bouchet-Marquis C, Wu K, Mobini CL, Frantz AN, Puig S, Hampton CM, Kabbani N, Jensen GJ, Watkins SC, Deisseroth K, Fenno LE, Gold MS, Wills ZP, Burkewitz K, Das S, Freyberg Z. Ribosome-Associated Vesicles promote activity-dependent local translation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.598007. [PMID: 38895376 PMCID: PMC11185778 DOI: 10.1101/2024.06.07.598007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Local protein synthesis in axons and dendrites underpins synaptic plasticity. However, the composition of the protein synthesis machinery in distal neuronal processes and the mechanisms for its activity-driven deployment to local translation sites remain unclear. Here, we employed cryo-electron tomography, volume electron microscopy, and live-cell imaging to identify Ribosome-Associated Vesicles (RAVs) as a dynamic platform for moving ribosomes to distal processes. Stimulation via chemically-induced long-term potentiation causes RAV accumulation in distal sites to drive local translation. We also demonstrate activity-driven changes in RAV generation and dynamics in vivo, identifying tubular ER shaping proteins in RAV biogenesis. Together, our work identifies a mechanism for ribosomal delivery to distal sites in neurons to promote activity-dependent local translation.
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Affiliation(s)
- Eva Martin-Solana
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen D. Carter
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, UK
| | - Eric K.F. Donahue
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Jiying Ning
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jill R. Glausier
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Leanna Eisenman
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Paul N. Joseph
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Ken Wu
- Materials and Structural Analysis, Thermo Fisher Scientific, Hillsboro, OR, USA
| | | | - Amber N. Frantz
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephanie Puig
- Department of Psychiatry, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Cheri M. Hampton
- UES, Inc., Dayton, OH, USA
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, USA
| | - Nadine Kabbani
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA, USA
- School of Systems Biology, George Mason University, Fairfax, VA, USA
| | - Grant J. Jensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Simon C. Watkins
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
| | - Lief E. Fenno
- Departments of Psychiatry and Neuroscience, University of Texas Austin Dell Medical School, Austin, TX, USA
| | - Michael S. Gold
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zachary P. Wills
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kristopher Burkewitz
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Sulagna Das
- Department of Cell Biology, Albert Einstein College of Medicine, NY
- Department of Cell Biology, Emory University, Atlanta, GA, USA
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
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3
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Baymukhametov TN, Lyabin DN, Chesnokov YM, Sorokin II, Pechnikova E, Vasiliev A, Afonina Z. Polyribosomes of circular topology are prevalent in mammalian cells. Nucleic Acids Res 2022; 51:908-918. [PMID: 36583341 PMCID: PMC9881139 DOI: 10.1093/nar/gkac1208] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 12/02/2022] [Accepted: 12/06/2022] [Indexed: 12/31/2022] Open
Abstract
Polyribosomes, the groups of ribosomes simultaneously translating a single mRNA molecule, are very common in both, prokaryotic and eukaryotic cells. Even in early EM studies, polyribosomes have been shown to possess various spatial conformations, including a ring-shaped configuration which was considered to be functionally important. However, a recent in situ cryo-ET analysis of predominant regular inter-ribosome contacts did not confirm the abundance of ring-shaped polyribosomes in a cell cytoplasm. To address this discrepancy, here we analyzed the cryo-ET structure of polyribosomes in diluted lysates of HeLa cells. It was shown that the vast majority of the ribosomes were combined into polysomes and were proven to be translationally active. Tomogram analysis revealed that circular polyribosomes are indeed very common in the cytoplasm, but they mostly possess pseudo-regular structures without specific inter-ribosomal contacts. Although the size of polyribosomes varied widely, most circular polysomes were relatively small in size (4-8 ribosomes). Our results confirm the recent data that it is cellular mRNAs with short ORF that most commonly form circular structures providing an enhancement of translation.
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Affiliation(s)
- Timur N Baymukhametov
- Structural biology department, National Research Center ‘Kurchatov Institute’, Moscow 123182, Russia
| | - Dmitry N Lyabin
- Institute of Protein Research RAS, Pushchino, Moscow Region 142290, Russia
| | - Yury M Chesnokov
- Probe and Electron Microscopy Resource Center, National Research Center ‘Kurchatov Institute’, Moscow 123182, Russia
| | - Ivan I Sorokin
- Institute of Protein Research RAS, Pushchino, Moscow Region 142290, Russia
| | - Evgeniya V Pechnikova
- Probe and Electron Microscopy Resource Center, National Research Center ‘Kurchatov Institute’, Moscow 123182, Russia,Electron Microscopy Laboratory, Shubnikov Institute of Crystallography of Federal Scientific Research Centre ‘Crystallography and Photonics’ RAS, Moscow 119333, Russia
| | - Alexander L Vasiliev
- Probe and Electron Microscopy Resource Center, National Research Center ‘Kurchatov Institute’, Moscow 123182, Russia,Electron Microscopy Laboratory, Shubnikov Institute of Crystallography of Federal Scientific Research Centre ‘Crystallography and Photonics’ RAS, Moscow 119333, Russia
| | - Zhanna A Afonina
- To whom correspondence should be addressed. Tel: +7 985 7232812; Fax: +7 4967 318435;
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4
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Biziaev NS, Egorova TV, Alkalaeva EZ. Dynamics of Eukaryotic mRNA Structure during Translation. Mol Biol 2022. [DOI: 10.1134/s0026893322030037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Biswas B, Guemiri R, Cadix M, Labbé CM, Chakraborty A, Dutertre M, Robert C, Vagner S. Differential Effects on the Translation of Immune-Related Alternatively Polyadenylated mRNAs in Melanoma and T Cells by eIF4A Inhibition. Cancers (Basel) 2022; 14:cancers14051177. [PMID: 35267483 PMCID: PMC8909304 DOI: 10.3390/cancers14051177] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/20/2022] [Accepted: 02/21/2022] [Indexed: 02/05/2023] Open
Abstract
Targeting the translation initiation complex eIF4F, which binds the 5' cap of mRNAs, is a promising anti-cancer approach. Silvestrol, a small molecule inhibitor of eIF4A, the RNA helicase component of eIF4F, inhibits the translation of the mRNA encoding the signal transducer and activator of transcription 1 (STAT1) transcription factor, which, in turn, reduces the transcription of the gene encoding one of the major immune checkpoint proteins, i.e., programmed death ligand-1 (PD-L1) in melanoma cells. A large proportion of human genes produce multiple mRNAs differing in their 3'-ends through the use of alternative polyadenylation (APA) sites, which, when located in alternative last exons, can generate protein isoforms, as in the STAT1 gene. Here, we provide evidence that the STAT1α, but not STAT1β protein isoform generated by APA, is required for silvestrol-dependent inhibition of PD-L1 expression in interferon-γ-treated melanoma cells. Using polysome profiling in activated T cells we find that, beyond STAT1, eIF4A inhibition downregulates the translation of some important immune-related mRNAs, such as the ones encoding TIM-3, LAG-3, IDO1, CD27 or CD137, but with little effect on the ones for BTLA and ADAR-1 and no effect on the ones encoding CTLA-4, PD-1 and CD40-L. We next apply RT-qPCR and 3'-seq (RNA-seq focused on mRNA 3' ends) on polysomal RNAs to analyze in a high throughput manner the effect of eIF4A inhibition on the translation of APA isoforms. We identify about 150 genes, including TIM-3, LAG-3, AHNAK and SEMA4D, for which silvestrol differentially inhibits the translation of APA isoforms in T cells. It is therefore crucial to consider 3'-end mRNA heterogeneity in the understanding of the anti-tumor activities of eIF4A inhibitors.
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Affiliation(s)
- Biswendu Biswas
- Institut Curie, PSL Research University, CNRS UMR 3348, INSERM U1278, 91401 Orsay, France; (B.B.); (M.C.); (C.M.L.); (A.C.); (M.D.)
- Biologie de l’ARN, Signalisation et Cancer, Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, 91401 Orsay, France
- Équipe Labellisée Ligue Contre le Cancer, 91401 Orsay, France
- INSERM U981, Gustave Roussy Cancer Campus, 94805 Villejuif, France;
- Faculté de Médecine, Université Paris Sud, Université Paris-Saclay, 94270 Kremlin-Bicêtre, France
| | - Ramdane Guemiri
- INSERM U981, Gustave Roussy Cancer Campus, 94805 Villejuif, France;
- Faculté de Médecine, Université Paris Sud, Université Paris-Saclay, 94270 Kremlin-Bicêtre, France
| | - Mandy Cadix
- Institut Curie, PSL Research University, CNRS UMR 3348, INSERM U1278, 91401 Orsay, France; (B.B.); (M.C.); (C.M.L.); (A.C.); (M.D.)
- Biologie de l’ARN, Signalisation et Cancer, Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, 91401 Orsay, France
- Équipe Labellisée Ligue Contre le Cancer, 91401 Orsay, France
| | - Céline M. Labbé
- Institut Curie, PSL Research University, CNRS UMR 3348, INSERM U1278, 91401 Orsay, France; (B.B.); (M.C.); (C.M.L.); (A.C.); (M.D.)
- Biologie de l’ARN, Signalisation et Cancer, Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, 91401 Orsay, France
- Équipe Labellisée Ligue Contre le Cancer, 91401 Orsay, France
| | - Alina Chakraborty
- Institut Curie, PSL Research University, CNRS UMR 3348, INSERM U1278, 91401 Orsay, France; (B.B.); (M.C.); (C.M.L.); (A.C.); (M.D.)
- Biologie de l’ARN, Signalisation et Cancer, Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, 91401 Orsay, France
- Équipe Labellisée Ligue Contre le Cancer, 91401 Orsay, France
| | - Martin Dutertre
- Institut Curie, PSL Research University, CNRS UMR 3348, INSERM U1278, 91401 Orsay, France; (B.B.); (M.C.); (C.M.L.); (A.C.); (M.D.)
- Biologie de l’ARN, Signalisation et Cancer, Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, 91401 Orsay, France
- Équipe Labellisée Ligue Contre le Cancer, 91401 Orsay, France
| | - Caroline Robert
- INSERM U981, Gustave Roussy Cancer Campus, 94805 Villejuif, France;
- Faculté de Médecine, Université Paris Sud, Université Paris-Saclay, 94270 Kremlin-Bicêtre, France
- Correspondence: (C.R.); (S.V.)
| | - Stéphan Vagner
- Institut Curie, PSL Research University, CNRS UMR 3348, INSERM U1278, 91401 Orsay, France; (B.B.); (M.C.); (C.M.L.); (A.C.); (M.D.)
- Biologie de l’ARN, Signalisation et Cancer, Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, 91401 Orsay, France
- Équipe Labellisée Ligue Contre le Cancer, 91401 Orsay, France
- Correspondence: (C.R.); (S.V.)
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6
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De Silva D, Ferguson L, Chin GH, Smith BE, Apathy RA, Roth TL, Blaeschke F, Kudla M, Marson A, Ingolia NT, Cate JHD. Robust T cell activation requires an eIF3-driven burst in T cell receptor translation. eLife 2021; 10:e74272. [PMID: 34970966 PMCID: PMC8758144 DOI: 10.7554/elife.74272] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/30/2021] [Indexed: 11/13/2022] Open
Abstract
Activation of T cells requires a rapid surge in cellular protein synthesis. However, the role of translation initiation in the early induction of specific genes remains unclear. Here, we show human translation initiation factor eIF3 interacts with select immune system related mRNAs including those encoding the T cell receptor (TCR) subunits TCRA and TCRB. Binding of eIF3 to the TCRA and TCRB mRNA 3'-untranslated regions (3'-UTRs) depends on CD28 coreceptor signaling and regulates a burst in TCR translation required for robust T cell activation. Use of the TCRA or TCRB 3'-UTRs to control expression of an anti-CD19 chimeric antigen receptor (CAR) improves the ability of CAR-T cells to kill tumor cells in vitro. These results identify a new mechanism of eIF3-mediated translation control that can aid T cell engineering for immunotherapy applications.
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Affiliation(s)
- Dasmanthie De Silva
- Department of Molecular and Cell Biology, University of California-BerkeleyBerkeleyUnited States
- The J. David Gladstone InstitutesSan FranciscoUnited States
| | - Lucas Ferguson
- Department of Molecular and Cell Biology, University of California-BerkeleyBerkeleyUnited States
| | - Grant H Chin
- Department of Molecular and Cell Biology, University of California-BerkeleyBerkeleyUnited States
| | - Benjamin E Smith
- School of Optometry, University of California, BerkeleyBerkeleyUnited States
| | - Ryan A Apathy
- Department of Microbiology and Immunology, University of California, San FranciscoSan FranciscoUnited States
| | - Theodore L Roth
- Department of Microbiology and Immunology, University of California, San FranciscoSan FranciscoUnited States
| | | | - Marek Kudla
- Department of Molecular and Cell Biology, University of California-BerkeleyBerkeleyUnited States
| | - Alexander Marson
- Department of Microbiology and Immunology, University of California, San FranciscoSan FranciscoUnited States
- Gladstone-UCSF Institute of Genomic ImmunologySan FranciscoUnited States
- Diabetes Center, University of California, San FranciscoSan FranciscoUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
- Department of Medicine, University of California, San FranciscoSan FranciscoUnited States
- Parker Institute for Cancer ImmunotherapySan FranciscoUnited States
- Innovative Genomics Institute, University of California, BerkeleyBerkeleyUnited States
| | - Nicholas T Ingolia
- Department of Molecular and Cell Biology, University of California-BerkeleyBerkeleyUnited States
- California Institute for Quantitative Biosciences, University of California, BerkeleyBerkeleyUnited States
| | - Jamie HD Cate
- Department of Molecular and Cell Biology, University of California-BerkeleyBerkeleyUnited States
- The J. David Gladstone InstitutesSan FranciscoUnited States
- Innovative Genomics Institute, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative Biosciences, University of California, BerkeleyBerkeleyUnited States
- Department of Chemistry, University of California-BerkeleyBerkeleyUnited States
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
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7
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Wilkinson M, Yllanes D, Huber G. Polysomally protected viruses. Phys Biol 2021; 18. [PMID: 33827061 DOI: 10.1088/1478-3975/abf5b5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/07/2021] [Indexed: 11/12/2022]
Abstract
It is conceivable that an RNA virus could use a polysome, that is, a string of ribosomes covering the RNA strand, to protect the genetic material from degradation inside a host cell. This paper discusses how such a virus might operate, and how its presence might be detected by ribosome profiling. There are two possible forms for such apolysomally protected virus, depending upon whether just the forward strand or both the forward and complementary strands can be encased by ribosomes (these will be termed type 1 and type 2, respectively). It is argued that in the type 2 case the viral RNA would evolve anambigrammaticproperty, whereby the viral genes are free of stop codons in a reverse reading frame (with forward and reverse codons aligned). Recent observations of ribosome profiles of ambigrammatic narnavirus sequences are consistent with our predictions for the type 2 case.
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Affiliation(s)
- Michael Wilkinson
- Chan Zuckerberg Biohub, 499 Illinois Street, San Francisco, CA 94158, United States of America.,School of Mathematics and Statistics, The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom
| | - David Yllanes
- Chan Zuckerberg Biohub, 499 Illinois Street, San Francisco, CA 94158, United States of America
| | - Greg Huber
- Chan Zuckerberg Biohub, 499 Illinois Street, San Francisco, CA 94158, United States of America
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8
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Probing the Conformational State of mRNPs Using smFISH and SIM. Methods Mol Biol 2020. [PMID: 33201475 DOI: 10.1007/978-1-0716-0935-4_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
mRNAs and lncRNAs assemble with RNA-binding proteins (RBPs) to form ribonucleoprotein complexes (RNPs ). The assembly of RNPs initiates co-transcriptionally, and their composition and organization is thought to change during the different steps of an RNP life cycle. Modulation of RNP structural organization has been implicated in the regulation of different aspects of RNA metabolism, including establishing interactions between the 5' and 3' ends in regulating mRNA translation and turnover. In this chapter, we describe a single-molecule microscopy approach that combines fluorescent RNA in situ hybridization (smFISH) and structured illumination microscopy (SIM ) and allows to measure different aspects of RNP organization in cells, including distances between different regions within individual mRNAs, as well as the overall compaction state of RNAs in different subcellular compartments and environmental conditions. Moreover, we describe a detailed workflow required for image registration and analysis that allows determining distances at sub-diffraction resolution.
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9
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Carter SD, Hampton CM, Langlois R, Melero R, Farino ZJ, Calderon MJ, Li W, Wallace CT, Tran NH, Grassucci RA, Siegmund SE, Pemberton J, Morgenstern TJ, Eisenman L, Aguilar JI, Greenberg NL, Levy ES, Yi E, Mitchell WG, Rice WJ, Wigge C, Pilli J, George EW, Aslanoglou D, Courel M, Freyberg RJ, Javitch JA, Wills ZP, Area-Gomez E, Shiva S, Bartolini F, Volchuk A, Murray SA, Aridor M, Fish KN, Walter P, Balla T, Fass D, Wolf SG, Watkins SC, Carazo JM, Jensen GJ, Frank J, Freyberg Z. Ribosome-associated vesicles: A dynamic subcompartment of the endoplasmic reticulum in secretory cells. SCIENCE ADVANCES 2020; 6:eaay9572. [PMID: 32270040 PMCID: PMC7112762 DOI: 10.1126/sciadv.aay9572] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/13/2020] [Indexed: 05/21/2023]
Abstract
The endoplasmic reticulum (ER) is a highly dynamic network of membranes. Here, we combine live-cell microscopy with in situ cryo-electron tomography to directly visualize ER dynamics in several secretory cell types including pancreatic β-cells and neurons under near-native conditions. Using these imaging approaches, we identify a novel, mobile form of ER, ribosome-associated vesicles (RAVs), found primarily in the cell periphery, which is conserved across different cell types and species. We show that RAVs exist as distinct, highly dynamic structures separate from the intact ER reticular architecture that interact with mitochondria via direct intermembrane contacts. These findings describe a new ER subcompartment within cells.
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Affiliation(s)
- Stephen D. Carter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Cheri M. Hampton
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Robert Langlois
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Roberto Melero
- Biocomputing Unit, Centro Nacional de Biotecnología–CSIC, Darwin 3, Campus Universidad Autónoma, 28049 Madrid, Spain
| | - Zachary J. Farino
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Michael J. Calderon
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Wen Li
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Callen T. Wallace
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ngoc Han Tran
- HHMI, Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Robert A. Grassucci
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Stephanie E. Siegmund
- Department of Cellular, Molecular and Biophysical Studies, Columbia University Medical Center, New York, NY 10032, USA
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Joshua Pemberton
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Travis J. Morgenstern
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Leanna Eisenman
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jenny I. Aguilar
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Nili L. Greenberg
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Elana S. Levy
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Edward Yi
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - William G. Mitchell
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | | | | | - Jyotsna Pilli
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Emily W. George
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Despoina Aslanoglou
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Maïté Courel
- CNRS-UMR7622, Institut de Biologie Paris-Seine, Université Pierre & Marie Curie, 75252 Paris, France
| | - Robin J. Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jonathan A. Javitch
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Zachary P. Wills
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Estela Area-Gomez
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Francesca Bartolini
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Allen Volchuk
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sandra A. Murray
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Meir Aridor
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kenneth N. Fish
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Peter Walter
- HHMI, Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Sharon G. Wolf
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Simon C. Watkins
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - José María Carazo
- Biocomputing Unit, Centro Nacional de Biotecnología–CSIC, Darwin 3, Campus Universidad Autónoma, 28049 Madrid, Spain
| | - Grant J. Jensen
- HHMI, Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Joachim Frank
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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10
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Abstract
The proper regulation of mRNA processing, localization, translation, and degradation occurs on mRNPs. However, the global principles of mRNP organization are poorly understood. We utilize the limited, but existing, information available to present a speculative synthesis of mRNP organization with the following key points. First, mRNPs form a compacted structure due to the inherent folding of RNA. Second, the ribosome is the principal mechanism by which mRNA regions are partially decompacted. Third, mRNPs are 50%-80% protein by weight, consistent with proteins modulating mRNP organization, but also suggesting the majority of mRNA sequences are not directly interacting with RNA-binding proteins. Finally, the ratio of mRNA-binding proteins to mRNAs is higher in the nucleus to allow effective RNA processing and limit the potential for nuclear RNA based aggregation. This synthesis of mRNP understanding provides a model for mRNP biogenesis, structure, and regulation with multiple implications.
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Affiliation(s)
- Anthony Khong
- Department of Biochemistry and Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Roy Parker
- Department of Biochemistry and Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado 80303, USA
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11
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Component of splicing factor SF3b plays a key role in translational control of polyribosomes on the endoplasmic reticulum. Proc Natl Acad Sci U S A 2019; 116:9340-9349. [PMID: 31004060 DOI: 10.1073/pnas.1901742116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One of the morphological hallmarks of terminally differentiated secretory cells is highly proliferated membrane of the rough endoplasmic reticulum (ER), but the molecular basis for the high rate of protein biosynthesis in these cells remains poorly documented. An important aspect of ER translational control is the molecular mechanism that supports efficient use of targeted mRNAs in polyribosomes. Here, we identify an enhancement system for ER translation promoted by p180, an integral ER membrane protein we previously reported as an essential factor for the assembly of ER polyribosomes. We provide evidence that association of target mRNAs with p180 is critical for efficient translation, and that SF3b4, an RNA-binding protein in the splicing factor SF3b, functions as a cofactor for p180 at the ER and plays a key role in enhanced translation of secretory proteins. A cis-element in the 5' untranslated region of collagen and fibronectin genes is important to increase translational efficiency in the presence of p180 and SF3b4. These data demonstrate that a unique system comprising a p180-SF3b4-mRNA complex facilitates the selective assembly of polyribosomes on the ER.
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12
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Adivarahan S, Zenklusen D. Lessons from (pre-)mRNA Imaging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:247-284. [DOI: 10.1007/978-3-030-31434-7_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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13
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Adivarahan S, Livingston N, Nicholson B, Rahman S, Wu B, Rissland OS, Zenklusen D. Spatial Organization of Single mRNPs at Different Stages of the Gene Expression Pathway. Mol Cell 2018; 72:727-738.e5. [PMID: 30415950 PMCID: PMC6592633 DOI: 10.1016/j.molcel.2018.10.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/24/2018] [Accepted: 10/04/2018] [Indexed: 12/21/2022]
Abstract
mRNAs form ribonucleoprotein complexes (mRNPs) by association with proteins that are crucial for mRNA metabolism. While the mRNP proteome has been well characterized, little is known about mRNP organization. Using a single-molecule approach, we show that mRNA conformation changes depending on its cellular localization and translational state. Compared to nuclear mRNPs and lncRNPs, association with ribosomes decompacts individual mRNAs, while pharmacologically dissociating ribosomes or sequestering them into stress granules leads to increased compaction. Moreover, translating mRNAs rarely show co-localized 5' and 3' ends, indicating either that mRNAs are not translated in a closed-loop configuration, or that mRNA circularization is transient, suggesting that a stable closed-loop conformation is not a universal state for all translating mRNAs.
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Affiliation(s)
- Srivathsan Adivarahan
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Nathan Livingston
- The Department of Biophysics and Biophysical Chemistry, the Solomon Snyder Department of Neuroscience, Center for Cell Dynamics, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Beth Nicholson
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Samir Rahman
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Bin Wu
- The Department of Biophysics and Biophysical Chemistry, the Solomon Snyder Department of Neuroscience, Center for Cell Dynamics, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Olivia S Rissland
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Daniel Zenklusen
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC H3T 1J4, Canada.
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14
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The Structural and Functional Organization of Ribosomal Compartment in the Cell: A Mystery or a Reality? Trends Biochem Sci 2018; 43:938-950. [PMID: 30337135 DOI: 10.1016/j.tibs.2018.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/21/2018] [Accepted: 09/21/2018] [Indexed: 11/23/2022]
Abstract
Great progress has been made toward solving the atomic structure of the ribosome, which is the main biosynthetic machine in cells, but we still do not have a full picture of exactly how cellular ribosomes function. Based on the analysis of crystallographic and electron microscopy data, we propose a basic model of the structural organization of ribosomes into a compartment. This compartment is regularly formed by arrays of ribosomal tetramers made up of two dimers that are actually facing in opposite directions. The compartment functions as the main 'factory' for the production of cellular proteins. The model is consistent with the existing biochemical and genetic data. We also consider the functional connections of such a compartment with cellular transcription and ribosomal biogenesis.
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15
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Juszkiewicz S, Chandrasekaran V, Lin Z, Kraatz S, Ramakrishnan V, Hegde RS. ZNF598 Is a Quality Control Sensor of Collided Ribosomes. Mol Cell 2018; 72:469-481.e7. [PMID: 30293783 PMCID: PMC6224477 DOI: 10.1016/j.molcel.2018.08.037] [Citation(s) in RCA: 244] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/07/2018] [Accepted: 08/22/2018] [Indexed: 01/30/2023]
Abstract
Aberrantly slow translation elicits quality control pathways initiated by the ubiquitin ligase ZNF598. How ZNF598 discriminates physiologic from pathologic translation complexes and ubiquitinates stalled ribosomes selectively is unclear. Here, we find that the minimal unit engaged by ZNF598 is the collided di-ribosome, a molecular species that arises when a trailing ribosome encounters a slower leading ribosome. The collided di-ribosome structure reveals an extensive 40S-40S interface in which the ubiquitination targets of ZNF598 reside. The paucity of 60S interactions allows for different ribosome rotation states, explaining why ZNF598 recognition is indifferent to how the leading ribosome has stalled. The use of ribosome collisions as a proxy for stalling allows the degree of tolerable slowdown to be tuned by the initiation rate on that mRNA; hence, the threshold for triggering quality control is substrate specific. These findings illustrate how higher-order ribosome architecture can be exploited by cellular factors to monitor translation status. ZNF598 is a direct sensor of ribosome collisions incurred by many unrelated causes The minimal target recognized and ubiquitinated by ZNF598 is a collided di-ribosome Collided di-ribosome structure shows that ZNF598 ubiquitin sites are near the interface Collisions are required to terminally arrest translation in ZNF598-dependent manner
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Affiliation(s)
| | | | - Zhewang Lin
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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16
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Shirokikh NE, Preiss T. Translation initiation by cap-dependent ribosome recruitment: Recent insights and open questions. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1473. [PMID: 29624880 DOI: 10.1002/wrna.1473] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/02/2018] [Accepted: 02/14/2018] [Indexed: 12/14/2022]
Abstract
Gene expression universally relies on protein synthesis, where ribosomes recognize and decode the messenger RNA template by cycling through translation initiation, elongation, and termination phases. All aspects of translation have been studied for decades using the tools of biochemistry and molecular biology available at the time. Here, we focus on the mechanism of translation initiation in eukaryotes, which is remarkably more complex than prokaryotic initiation and is the target of multiple types of regulatory intervention. The "consensus" model, featuring cap-dependent ribosome entry and scanning of mRNA leader sequences, represents the predominantly utilized initiation pathway across eukaryotes, although several variations of the model and alternative initiation mechanisms are also known. Recent advances in structural biology techniques have enabled remarkable molecular-level insights into the functional states of eukaryotic ribosomes, including a range of ribosomal complexes with different combinations of translation initiation factors that are thought to represent bona fide intermediates of the initiation process. Similarly, high-throughput sequencing-based ribosome profiling or "footprinting" approaches have allowed much progress in understanding the elongation phase of translation, and variants of them are beginning to reveal the remaining mysteries of initiation, as well as aspects of translation termination and ribosomal recycling. A current view on the eukaryotic initiation mechanism is presented here with an emphasis on how recent structural and footprinting results underpin axioms of the consensus model. Along the way, we further outline some contested mechanistic issues and major open questions still to be addressed. This article is categorized under: Translation > Translation Mechanisms Translation > Translation Regulation RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Nikolay E Shirokikh
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
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17
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Miller ML, Porollo A, Wert S. Ultrastructure of Highly Ordered Granules in Alveolar Type II Cells in Several Species. Anat Rec (Hoboken) 2018; 301:1290-1302. [PMID: 29544026 DOI: 10.1002/ar.23805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 11/30/2017] [Accepted: 02/02/2018] [Indexed: 01/26/2023]
Abstract
Alveolar Type II cells from seven mammalian species were examined for a protein in the rough endoplasmic reticulum (RER), which showed a multilayered, repeating motif. Each motif, 100 nm in width, comprised two parallel outer dense layers, a less dense central layer, and often 1-3 faint layers on either side of the latter. Outer layers showed periodicities at 3-4 densities/100 nm of width, while layers on either side of the central layer showed 5-7 densities/100 nm of width. RER membranes were ribosome-free when parallel to these layers, but showed four ribosomes per motif at the growing ends: one ribosome at each outer dense layer, and one on either side of the less dense central layer. Granules appeared as single or as multiple motifs, stacked, curved, folded, or branching together within the same RER profile. Hexagons of around 30 nm in diameter with central densities were seen in tangential cuts of outer dense layers. Granule incidence varied: guinea pig > ferret > dog. Possible homologous structures occurred in rabbit and cat, but not in rat or mouse. Surfactant protein A (SP-A), a C-type lectin produced in Type II cells, forms trimers and bouquet-like 18-mer and can oligomerize further. Two pairs of SP-A 18-mers with carbohydrate recognition domains pointing inwardly and outwardly, stacked vertically as a column of four molecules, then repeated side by side in rows, approximated the size and layering patterns observed in these granules. Sequence analyses of SP-A from these species showed phylogenetic distances consistent with the observed occurrence and frequency of patterned granules. Anat Rec, 301:1290-1302, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Marian L Miller
- Department of Environmental Health, University of Cincinnati, College of Medicine, Cincinnati, Ohio
| | - Aleksey Porollo
- Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio.,Center for Autoimmune Genomics and Etiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio
| | - Susan Wert
- Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio.,Division of Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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18
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Afonina ZA, Shirokov VA. Three-Dimensional Organization of Polyribosomes–A Modern Approach. BIOCHEMISTRY (MOSCOW) 2018; 83:S48-S55. [DOI: 10.1134/s0006297918140055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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19
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Morisaki T, Lyon K, DeLuca KF, DeLuca JG, English BP, Zhang Z, Lavis LD, Grimm JB, Viswanathan S, Looger LL, Lionnet T, Stasevich TJ. Real-time quantification of single RNA translation dynamics in living cells. Science 2016; 352:1425-9. [PMID: 27313040 DOI: 10.1126/science.aaf0899] [Citation(s) in RCA: 246] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 04/28/2016] [Indexed: 12/14/2022]
Abstract
Although messenger RNA (mRNA) translation is a fundamental biological process, it has never been imaged in real time in vivo with single-molecule precision. To achieve this, we developed nascent chain tracking (NCT), a technique that uses multi-epitope tags and antibody-based fluorescent probes to quantify protein synthesis dynamics at the single-mRNA level. NCT reveals an elongation rate of ~10 amino acids per second, with initiation occurring stochastically every ~30 seconds. Polysomes contain ~1 ribosome every 200 to 900 nucleotides and are globular rather than elongated in shape. By developing multicolor probes, we showed that most polysomes act independently; however, a small fraction (~5%) form complexes in which two distinct mRNAs can be translated simultaneously. The sensitivity and versatility of NCT make it a powerful new tool for quantifying mRNA translation kinetics.
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Affiliation(s)
- Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology and Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
| | - Kenneth Lyon
- Department of Biochemistry and Molecular Biology and Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
| | - Keith F DeLuca
- Department of Biochemistry and Molecular Biology and Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
| | - Jennifer G DeLuca
- Department of Biochemistry and Molecular Biology and Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
| | - Brian P English
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Zhengjian Zhang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jonathan B Grimm
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Sarada Viswanathan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Timothee Lionnet
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology and Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
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20
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Archer SK, Shirokikh NE, Hallwirth CV, Beilharz TH, Preiss T. Probing the closed-loop model of mRNA translation in living cells. RNA Biol 2015; 12:248-54. [PMID: 25826658 PMCID: PMC4615164 DOI: 10.1080/15476286.2015.1017242] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mRNA closed-loop, formed through interactions between the cap structure, poly(A) tail, eIF4E, eIF4G and PAB, features centrally in models of eukaryotic translation initiation, although direct support for its existence in vivo is not well established. Here, we investigated the closed-loop using a combination of mRNP isolation from rapidly cross-linked cells and high-throughput qPCR. Using the interaction between these factors and the opposing ends of mRNAs as a proxy for the closed-loop, we provide evidence that it is prevalent for eIF4E/4G-bound but unexpectedly sparse for PAB1-bound mRNAs, suggesting it primarily occurs during a distinct phase of polysome assembly. We observed mRNA-specific variation in the extent of closed-loop formation, consistent with a role for polysome topology in the control of gene expression.
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Affiliation(s)
- Stuart K Archer
- a Genome Biology Department; The John Curtin School of Medical Research (JCSMR); The Australian National University ; Acton (Canberra), Australian Capital Territory , Australia
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21
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Hassler JR, Scheuner DL, Wang S, Han J, Kodali VK, Li P, Nguyen J, George JS, Davis C, Wu SP, Bai Y, Sartor M, Cavalcoli J, Malhi H, Baudouin G, Zhang Y, Yates III JR, Itkin-Ansari P, Volkmann N, Kaufman RJ. The IRE1α/XBP1s Pathway Is Essential for the Glucose Response and Protection of β Cells. PLoS Biol 2015; 13:e1002277. [PMID: 26469762 PMCID: PMC4607427 DOI: 10.1371/journal.pbio.1002277] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 09/08/2015] [Indexed: 12/11/2022] Open
Abstract
Although glucose uniquely stimulates proinsulin biosynthesis in β cells, surprisingly little is known of the underlying mechanism(s). Here, we demonstrate that glucose activates the unfolded protein response transducer inositol-requiring enzyme 1 alpha (IRE1α) to initiate X-box-binding protein 1 (Xbp1) mRNA splicing in adult primary β cells. Using mRNA sequencing (mRNA-Seq), we show that unconventional Xbp1 mRNA splicing is required to increase and decrease the expression of several hundred mRNAs encoding functions that expand the protein secretory capacity for increased insulin production and protect from oxidative damage, respectively. At 2 wk after tamoxifen-mediated Ire1α deletion, mice develop hyperglycemia and hypoinsulinemia, due to defective β cell function that was exacerbated upon feeding and glucose stimulation. Although previous reports suggest IRE1α degrades insulin mRNAs, Ire1α deletion did not alter insulin mRNA expression either in the presence or absence of glucose stimulation. Instead, β cell failure upon Ire1α deletion was primarily due to reduced proinsulin mRNA translation primarily because of defective glucose-stimulated induction of a dozen genes required for the signal recognition particle (SRP), SRP receptors, the translocon, the signal peptidase complex, and over 100 other genes with many other intracellular functions. In contrast, Ire1α deletion in β cells increased the expression of over 300 mRNAs encoding functions that cause inflammation and oxidative stress, yet only a few of these accumulated during high glucose. Antioxidant treatment significantly reduced glucose intolerance and markers of inflammation and oxidative stress in mice with β cell-specific Ire1α deletion. The results demonstrate that glucose activates IRE1α-mediated Xbp1 splicing to expand the secretory capacity of the β cell for increased proinsulin synthesis and to limit oxidative stress that leads to β cell failure.
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Affiliation(s)
- Justin R. Hassler
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Donalyn L. Scheuner
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
- Lilly Research Laboratories, Eli Lilly & Company, Lilly Corporate Center, Indianapolis, Indiana, United States of America
| | - Shiyu Wang
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Jaeseok Han
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Vamsi K. Kodali
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Philip Li
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Julie Nguyen
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Jenny S. George
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Cory Davis
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Shengyang P. Wu
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Yongsheng Bai
- NCIBI Department of Bioinformatics, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
- Department of Biology, Indiana State University, Terre Haute, Indiana, United States of America
| | - Maureen Sartor
- NCIBI Department of Bioinformatics, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - James Cavalcoli
- NCIBI Department of Bioinformatics, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Harmeet Malhi
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Gregory Baudouin
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Yaoyang Zhang
- Department of Chemical Physiology and Cell Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - John R. Yates III
- Department of Chemical Physiology and Cell Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Pamela Itkin-Ansari
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Niels Volkmann
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Randal J. Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
- * E-mail:
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Mrazek J, Toso D, Ryazantsev S, Zhang X, Zhou ZH, Fernandez BC, Kickhoefer VA, Rome LH. Polyribosomes are molecular 3D nanoprinters that orchestrate the assembly of vault particles. ACS NANO 2014; 8:11552-9. [PMID: 25354757 PMCID: PMC4245718 DOI: 10.1021/nn504778h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Ribosomes are molecular machines that function in polyribosome complexes to translate genetic information, guide the synthesis of polypeptides, and modulate the folding of nascent proteins. Here, we report a surprising function for polyribosomes as a result of a systematic examination of the assembly of a large ribonucleoprotein complex, the vault particle. Structural and functional evidence points to a model of vault assembly whereby the polyribosome acts like a 3D nanoprinter to direct the ordered translation and assembly of the multi-subunit vault homopolymer, a process which we refer to as polyribosome templating. Structure-based mutagenesis and cell-free in vitro expression studies further demonstrated the critical importance of the polyribosome in vault assembly. Polyribosome templating prevents chaos by ensuring efficiency and order in the production of large homopolymeric protein structures in the crowded cellular environment and might explain the origin of many polyribosome-associated molecular assemblies inside the cell.
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Affiliation(s)
- Jan Mrazek
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
- Address correspondence to ,
| | - Daniel Toso
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
| | - Sergey Ryazantsev
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
| | - Xing Zhang
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
| | - Z. Hong Zhou
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
| | - Beatriz Campo Fernandez
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
| | - Valerie A. Kickhoefer
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
| | - Leonard H. Rome
- Department of Biological Chemistry, David Geffen School of Medicine, Department of Microbiology, Immunology & Molecular Genetics, and California Nanosystems Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
- Address correspondence to ,
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23
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Afonina ZA, Myasnikov AG, Shirokov VA, Klaholz BP, Spirin AS. Formation of circular polyribosomes on eukaryotic mRNA without cap-structure and poly(A)-tail: a cryo electron tomography study. Nucleic Acids Res 2014; 42:9461-9. [PMID: 25016525 PMCID: PMC4132722 DOI: 10.1093/nar/gku599] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The polyribosomes newly formed on recombinant GFP-encoding mRNAs in a wheat germ cell-free translation system were analyzed using cryo-electron tomography, with sub-tomogram averaging of polysomal ribosomes and reconstruction of 3D structures of individual polyribosomes. The achieved level of resolution in the reconstructed polyribosomes allowed deducing the mRNA path by connecting adjacent exit and entry sites at the ribosomes inside each polyribosome. In this way, the circularity of a significant fraction (about 50%) of translating polyribosomes was proved in the case of the capped poly(A)-tailed mRNA, in agreement with the existing paradigm of the circularization via interaction of cap-bound initiation factor eIF4F with poly(A)-binding protein. However, translation of the capped mRNA construct without poly(A) tail, but with unspecific 3′-UTR derived from non-coding plasmid sequence, also led to the formation of circular polyribosomes in similar proportion (40%). Moreover, the polyribosomes formed on the uncapped non-polyadenylated mRNA with non-synergistic 5′- and 3′-UTRs proved to be circular as well, and appeared in the same proportion as in the previous cases. Thus, the formation of circular polyribosomes was found to be virtually independent of the presence of cap structure and poly(A) tail in mRNA, in contrast to the longstanding paradigm in the field.
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Affiliation(s)
- Zhanna A Afonina
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Alexander G Myasnikov
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Centre National de la Recherche Scientifique (CNRS) UMR 7104 / Institut National de la Santé de la Recherche Médicale (INSERM) U964 / Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Vladimir A Shirokov
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| | - Bruno P Klaholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), Centre National de la Recherche Scientifique (CNRS) UMR 7104 / Institut National de la Santé de la Recherche Médicale (INSERM) U964 / Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Alexander S Spirin
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
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Arl6IP1 has the ability to shape the mammalian ER membrane in a reticulon-like fashion. Biochem J 2014; 458:69-79. [DOI: 10.1042/bj20131186] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The present study characterizes Arl6IP1, an anti-apoptotic regulator, in the context of a protein harbouring the reticulon-homology domain. We demonstrate that Arl6IP1 has the ability to bind to atlastin and shape the ER tubules in a reticulon-like fashion.
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25
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Afonina ZA, Myasnikov AG, Khabibullina NF, Belorusova AY, Menetret JF, Vasiliev VD, Klaholz BP, Shirokov VA, Spirin AS. Topology of mRNA chain in isolated eukaryotic double-row polyribosomes. BIOCHEMISTRY (MOSCOW) 2013; 78:445-54. [PMID: 23848146 DOI: 10.1134/s0006297913050027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In the process of protein synthesis, the translating ribosomes of eukaryotic cells form polyribosomes that are found to be multiplex functional complexes possessing elements of ordered spatial organization. As revealed by a number of electron microscopy studies, the predominant visible configurations of the eukaryotic polyribosomes are circles (circular polyribosomes) and two-stranded formations (so-called double-row polyribosomes). The "long" (i.e. heavy loaded) polyribosomes are usually represented by double-row structures, which can be interpreted as either topologically circular ("collapsed rings"), or topologically linear (zigzags or helices). In the present work we have analyzed the mRNA path within the eukaryotic polyribosomes, isolated from a wheat germ cell-free translation system, by integrating two approaches: the visualization of mRNA ends in polyribosomes by marking them with gold nanoparticles (3'-end) and initiating 40S subunits (5'-end), as well as by the cryoelectron tomography. Examination of the location of the mRNA markers in polyribosomes and mutual orientation of ribosomes in them has shown that the double-row polyribosomes of the same sample can have both circular and linear arrangements of their mRNA.
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Affiliation(s)
- Zh A Afonina
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
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26
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Cougot N, Molza AE, Delesques J, Giudice E, Cavalier A, Rolland JP, Ermel G, Blanco C, Thomas D, Gillet R. Visualizing compaction of polysomes in bacteria. J Mol Biol 2013; 426:377-88. [PMID: 24095898 DOI: 10.1016/j.jmb.2013.09.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/25/2013] [Accepted: 09/25/2013] [Indexed: 10/26/2022]
Abstract
During protein synthesis, many translating ribosomes are bound together with an mRNA molecule to form polysomes (or polyribosomes). While the spatial organization of bacterial polysomes has been well studied in vitro, little is known about how they cluster when cellular conditions are highly constrained. To better understand this, we used electron tomography, template matching, and three-dimensional modeling to analyze the supramolecular network of ribosomes after induction of translational pauses. In Escherichia coli, we overexpressed an mRNA carrying a polyproline motif known to induce pausing during translation. When working with a strain lacking transfer-messenger RNA, the principle actor in the "trans-translation" rescuing system, the cells survived the hijacking of the translation machinery but this resulted in a sharp modification of the ribosomal network. The results of our experiments demonstrate that single ribosomes are replaced with large amounts of compacted polysomes. These polysomes are highly organized, principally forming hairpins and dimers of hairpins that stack together. We propose that these spatial arrangements help maintain translation efficiency when the rescue systems are absent or overwhelmed.
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Affiliation(s)
- Nicolas Cougot
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Anne-Elisabeth Molza
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Jérémy Delesques
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Emmanuel Giudice
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Annie Cavalier
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Jean-Paul Rolland
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Gwennola Ermel
- Université de Rennes 1, EA 1254, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Carlos Blanco
- Université de Rennes 1, EA 1254, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Daniel Thomas
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Reynald Gillet
- Team Translation and Folding, Université de Rennes 1, UMR CNRS 6290 IGDR, Campus de Beaulieu, 35042 Rennes Cedex, France; Institut Universitaire de France.
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27
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Mandon EC, Trueman SF, Gilmore R. Protein translocation across the rough endoplasmic reticulum. Cold Spring Harb Perspect Biol 2013; 5:cshperspect.a013342. [PMID: 23251026 DOI: 10.1101/cshperspect.a013342] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The rough endoplasmic reticulum is a major site of protein biosynthesis in all eukaryotic cells, serving as the entry point for the secretory pathway and as the initial integration site for the majority of cellular integral membrane proteins. The core components of the protein translocation machinery have been identified, and high-resolution structures of the targeting components and the transport channel have been obtained. Research in this area is now focused on obtaining a better understanding of the molecular mechanism of protein translocation and membrane protein integration.
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Affiliation(s)
- Elisabet C Mandon
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605-2324, USA
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28
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Cougot N, Molza AE, Giudice E, Cavalier A, Thomas D, Gillet R. Structural organization of the polysomes adjacent to mammalian processing bodies (P-bodies). RNA Biol 2013; 10:314-20. [PMID: 23324601 DOI: 10.4161/rna.23342] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A finely tuned balance of translation, storage and decay of mRNAs (mRNAs) is important for the regulation of gene expression. In eukaryotic cells, this takes place in dynamic cytoplasmic RNA-protein granules termed Processing bodies (P-bodies). In this study, by using immunoelectron tomography, 3D modeling and template matching, we analyze the size and the organization of the polysomes in the vicinity of human P-bodies. Our results show the presence of several polysomes that are compatible with a translational activity around P-bodies. Therefore, movement of mRNAs between polysomes and P-bodies can take place when the two compartments are in close contact. The presence of initiation factors in the proximity of P-bodies also suggests that translation of mRNAs can resume at the periphery of these granules.
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Affiliation(s)
- Nicolas Cougot
- Université de Rennes 1, UMR, CNRS 6290 IGDR, Translation and Folding Team, Campus de Beaulieu, Rennes Cedex, France
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29
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Lu W, Chai Q, Zhong M, Yu L, Fang J, Wang T, Li H, Zhu H, Wei Y. Assembling of AcrB trimer in cell membrane. J Mol Biol 2012; 423:123-34. [PMID: 22766312 PMCID: PMC5699209 DOI: 10.1016/j.jmb.2012.06.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 06/26/2012] [Accepted: 06/26/2012] [Indexed: 11/16/2022]
Abstract
Many membrane proteins exist and function as oligomers, but how monomers oligomerize in the cell membrane remains poorly understood. AcrB is an obligate homo-trimer. We previously found that the folding of individual subunit precedes oligomerization. Following folding, individual AcrB subunits must locate and interact with each other in order to dimerize and eventually trimerize. It has been unclear if AcrB trimerization is a spontaneous process following the "chance encounter and random assembling" mechanism. In other words, it is currently unknown whether monomeric subunits diffuse freely to "search" for each other after they are co-translationally inserted and folded into the cell membrane. Using four sets of experiments exploiting AcrB variants with different fusion tags, disulfide trapping, and activity measurement, here we showed that AcrB variants co-expressed in the same Escherichia coli cell did co-assemble into hybrid trimers in vivo. However, the level of co-assembly measured experimentally was not consistent with calculations derived from random assembling. The potential role of the polysome structure during protein translation and the resultant clustering effect were discussed as a potential explanation for the observed bias in AcrB subunit assembling in vivo. Our results provide new insights into the dynamic assembling and equilibration process of obligate homo-oligomeric membrane proteins in the cell membrane.
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Affiliation(s)
- Wei Lu
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Qian Chai
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Meng Zhong
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Linliang Yu
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Jun Fang
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Tong Wang
- Department of Biology, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Huilin Li
- Department of Biology, Brookhaven National Laboratory, Upton, NY 11973, USA
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Haining Zhu
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40506, USA
| | - Yinan Wei
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
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30
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Ueno T, Kaneko K, Sata T, Hattori S, Ogawa-Goto K. Regulation of polysome assembly on the endoplasmic reticulum by a coiled-coil protein, p180. Nucleic Acids Res 2011; 40:3006-17. [PMID: 22156060 PMCID: PMC3326322 DOI: 10.1093/nar/gkr1197] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A coiled-coil microtubule-bundling protein, p180, was originally identified as one of the ribosome receptor candidates on the rough endoplasmic reticulum (ER) and is highly expressed in secretory tissues. Recently, we reported that p180 plays crucial roles in upregulating collagen biosynthesis, mainly by facilitating ribosome association on the ER. Here, we provide evidence that p180 is required to form translationally active polysome/translocon complexes on the ER. Assembly of highly-developed polysomes on the ER was severely perturbed upon loss of p180. p180 associates with polysome/translocon complexes through multiple contact sites: it was coimmunoprecipitated with the translocon complex independently of ribosomes, while it can also bind to ribosomal large subunit specifically. The responsible domain of p180 for membrane polysome assembly was identified in the C-terminal coiled-coil region. The degree of ribosome occupation of collagen and fibronectin mRNAs was regulated in response to increased traffic demands. This effect appears to be exerted in a manner specific for a specified set of mRNAs. Collectively, our data suggest that p180 is required to form translationally active polysome/translocon complexes on the ER membrane, and plays a pivotal role in highly efficient biosynthesis on the ER membrane through facilitating polysome formation in professional secretory cells.
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Affiliation(s)
- Tomonori Ueno
- Nippi Research Institute of Biomatrix, Toride, Ibaraki 302-0017, Japan
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31
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Suchard MA, Lange K, Sinsheimer JS. Efficiency of Protein Production from mRNA. JOURNAL OF STATISTICAL THEORY AND PRACTICE 2011. [DOI: 10.1080/15598608.2008.10411869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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32
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Shibata Y, Shemesh T, Prinz WA, Palazzo AF, Kozlov MM, Rapoport TA. Mechanisms determining the morphology of the peripheral ER. Cell 2010; 143:774-88. [PMID: 21111237 PMCID: PMC3008339 DOI: 10.1016/j.cell.2010.11.007] [Citation(s) in RCA: 387] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 09/03/2010] [Accepted: 10/26/2010] [Indexed: 01/08/2023]
Abstract
The endoplasmic reticulum (ER) consists of the nuclear envelope and a peripheral network of tubules and membrane sheets. The tubules are shaped by the curvature-stabilizing proteins reticulons and DP1/Yop1p, but how the sheets are formed is unclear. Here, we identify several sheet-enriched membrane proteins in the mammalian ER, including proteins that translocate and modify newly synthesized polypeptides, as well as coiled-coil membrane proteins that are highly upregulated in cells with proliferated ER sheets, all of which are localized by membrane-bound polysomes. These results indicate that sheets and tubules correspond to rough and smooth ER, respectively. One of the coiled-coil proteins, Climp63, serves as a "luminal ER spacer" and forms sheets when overexpressed. More universally, however, sheet formation appears to involve the reticulons and DP1/Yop1p, which localize to sheet edges and whose abundance determines the ratio of sheets to tubules. These proteins may generate sheets by stabilizing the high curvature of edges.
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Affiliation(s)
- Yoko Shibata
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
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33
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Abstract
Nonsense-mediated mRNA decay (NMD) is a translation-coupled mechanism that eliminates mRNAs containing premature translation-termination codons (PTCs). In mammalian cells, NMD is also linked to pre-mRNA splicing, as in many instances strong mRNA reduction occurs only when the PTC is located upstream of an intron. It is proposed that in these systems, the exon junction complex (EJC) mediates the link between splicing and NMD. Recent studies have questioned the role of splicing and the EJC in initiating NMD. Instead, they put forward a general and evolutionarily conserved mechanism in which the main regulator of NMD is the distance between a PTC and the poly(A) tail of an mRNA. Here we discuss the limitations of the new NMD model and the EJC concept; we argue that neither satisfactorily accounts for all of the available data and offer a new model to test in future studies.
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Affiliation(s)
- Saverio Brogna
- University of Birmingham, School of Biosciences, Edgbaston, Birmingham B15 2TT, UK.
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34
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Kopeina GS, Afonina ZA, Gromova KV, Shirokov VA, Vasiliev VD, Spirin AS. Step-wise formation of eukaryotic double-row polyribosomes and circular translation of polysomal mRNA. Nucleic Acids Res 2008; 36:2476-88. [PMID: 18310103 PMCID: PMC2377419 DOI: 10.1093/nar/gkm1177] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The time course of polysome formation was studied in a long-term wheat germ cell-free translation system using sedimentation and electron microscopy techniques. The polysomes were formed on uncapped luciferase mRNA with translation-enhancing 5' and 3' UTRs. The formation of fully loaded polysomes was found to be a long process that required many rounds of translation and proceeded via several phases. First, short linear polysomes containing no more than six ribosomes were formed. Next, folding of these polysomes into short double-row clusters occurred. Subsequent gradual elongation of the clusters gave rise to heavy-loaded double-row strings containing up to 30-40 ribosomes. The formation of the double-row polysomes was considered to be equivalent to circularization of polysomes, with antiparallel halves of the circle being laterally stuck together by ribosome interactions. A slow exchange with free ribosomes and free mRNA observed in the double-row type polysomes, as well as the resistance of translation in them to AMP-PNP, provided evidence that most polysomal ribosomes reinitiate translation within the circularized polysomes without scanning of 5' UTR, while de novo initiation including 5' UTR scanning proceeds at a much slower rate. Removal or replacements of 5' and 3' UTRs affected the initial phase of translation, but did not prevent the formation of the double-row polysomes during translation.
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Affiliation(s)
- Gelina S Kopeina
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
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35
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Nikonov AV, Hauri HP, Lauring B, Kreibich G. Climp-63-mediated binding of microtubules to the ER affects the lateral mobility of translocon complexes. J Cell Sci 2007; 120:2248-58. [PMID: 17567679 DOI: 10.1242/jcs.008979] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microtubules are frequently seen in close proximity to membranes of the endoplasmic reticulum (ER), and the membrane protein CLIMP-63 is thought to mediate specific interaction between these two structures. It was, therefore, of interest to investigate whether these microtubules are in fact responsible for the highly restricted lateral mobility of the translocon complexes in M3/18 cells as described before. As determined by fluorescence recovery after photobleaching, the breakdown of microtubules caused by drug treatment or by overexpression of the microtubule-severing protein spastin, resulted in an increased lateral mobility of the translocons that are assembled into polysomes. Also, the expression of a CLIMP-63 mutant lacking the microtubule-binding domain resulted in a significant increase of the lateral mobility of the translocon complexes. The most striking increase in the diffusion rate of the translocon complexes was observed in M3/18 cells transfected with a siRNA that effectively knocked down the expression of the endogenous CLIMP-63. It appears, therefore, that interaction of microtubules with the ER results in the immobilization of translocon complexes that are part of membrane-bound polysomes, and may play a role in the mechanism that segregates the rough and smooth domains of the ER.
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Affiliation(s)
- Andrei V Nikonov
- Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
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36
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Abstract
The endoplasmic reticulum (ER) has distinct morphological domains composed of sheets and tubules, which differ in their characteristic membrane curvature. Key proteins may drive the formation of these structural morphologies, which in turn could generate the rough and smooth functional domains of the ER.
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Affiliation(s)
- Yoko Shibata
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
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37
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Mikamo E, Tanaka C, Kanno T, Akiyama H, Jung G, Tanaka H, Kawai T. Native polysomes of Saccharomyces cerevisiae in liquid solution observed by atomic force microscopy. J Struct Biol 2005; 151:106-10. [PMID: 15964206 DOI: 10.1016/j.jsb.2005.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 04/29/2005] [Accepted: 05/05/2005] [Indexed: 11/29/2022]
Abstract
The native polysomes of Saccharomyces cerevisiae were visualized in liquid solution by atomic force microscopy without external contrasting, such as shadowing and negative staining. This study showed native polysomes as lined particle with a height of ca. 27 nm, which is agreement with the height of 80S ribosomes in previous study. We found a small subparticle, located in a ring-shape or at the end of a linear structure, and visualized mRNA chains between adjacent ribosomes. Although the structures of polysomes have been studied for decades, it has remained difficult to visualize the native three-dimensional form. By the observation in liquid solution, we temporarily stopped the translation using an antibiotic to presenting the native three-dimensional structure and function of the polysomes. Our results provide not only new findings on native eukaryotic polysomes, but also great potential to visualize the influence of various environmental conditions on polysomes.
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Affiliation(s)
- Eriko Mikamo
- Toray Industries, Inc., New Frontiers Research Laboratories, 1111 Tebiro, Kamakura, Kanagawa 248-8555, Japan
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38
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Madin K, Sawasaki T, Kamura N, Takai K, Ogasawara T, Yazaki K, Takei T, Miura KI, Endo Y. Formation of circular polyribosomes in wheat germ cell-free protein synthesis system. FEBS Lett 2004; 562:155-9. [PMID: 15044017 DOI: 10.1016/s0014-5793(04)00221-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2003] [Revised: 02/20/2004] [Accepted: 02/24/2004] [Indexed: 10/26/2022]
Abstract
We report a morphological study of functioning ribosomes in a efficient and robust cell-free protein synthesis system prepared from wheat embryos. Sucrose density gradient analysis of translated mixtures programmed with luciferase mRNAs having different 5' and 3' untranslated regions showed formation of large polysomes. Electron microscopic examination of translation mixtures programmed with those of capped and polyadenylated mRNA revealed that ribosomes assemble into a circular-type polysome in vitro. Furthermore, a series of experiments using mRNAs lacking either cap, poly(A) tail or both also resulted in the formation of circular polysomes, which are indistinguishable from those with the original mRNA. The wheat germ cell-free system may provide a good experimental system for understanding functional ribosomes at the molecular level.
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Affiliation(s)
- Kairat Madin
- Cell-free Science and Technology Research Center, and The Venture Business Laboratory, Ehime University, Matsuyama 790-8577, Japan
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39
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Nikonov AV, Snapp E, Lippincott-Schwartz J, Kreibich G. Active translocon complexes labeled with GFP-Dad1 diffuse slowly as large polysome arrays in the endoplasmic reticulum. J Cell Biol 2002; 158:497-506. [PMID: 12163472 PMCID: PMC2173836 DOI: 10.1083/jcb.200201116] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the ER, the translocon complex (TC) functions in the translocation and cotranslational modification of proteins made on membrane-bound ribosomes. The oligosaccharyltransferase (OST) complex is associated with the TC, and performs the cotranslational N-glycosylation of nascent polypeptide chains. Here we use a GFP-tagged subunit of the OST complex (GFP-Dad1) that rescues the temperature-sensitive (ts) phenotype of tsBN7 cells, where Dad1 is degraded and N-glycosylation is inhibited, to study the lateral mobility of the TC by FRAP. GFP-Dad1 that is functionally incorporated into TCs diffuses extremely slow, exhibiting an effective diffusion constant (Deff) about seven times lower than that of GFP-tagged ER membrane proteins unhindered in their lateral mobility. Termination of protein synthesis significantly increases the lateral mobility of GFP-Dad1 in the ER membranes, but to a level that is still lower than that of free GFP-Dad1. This suggests that GFP-Dad1 as part of the OST remains associated with inactive TCs. Our findings that TCs assembled into membrane-bound polysomes diffuse slowly within the ER have mechanistic implications for the segregation of the ER into smooth and rough domains.
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Affiliation(s)
- Andrei V Nikonov
- Department of Cell Biology, New York University School of Medicine, New York 10016, USA
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40
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Seiser RM, Nicchitta CV. The fate of membrane-bound ribosomes following the termination of protein synthesis. J Biol Chem 2000; 275:33820-7. [PMID: 10931837 DOI: 10.1074/jbc.m004462200] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Contemporary models for protein translocation in the mammalian endoplasmic reticulum (ER) identify the termination of protein synthesis as the signal for ribosome release from the ER membrane. We have utilized morphometric and biochemical methods to assess directly the fate of membrane-bound ribosomes following the termination of protein synthesis. In these studies, tissue culture cells were treated with cycloheximide to inhibit elongation, with pactamycin to inhibit initiation, or with puromycin to induce premature chain termination, and ribosome-membrane interactions were subsequently analyzed. It was found that following the termination of protein synthesis, the majority of ribosomal particles remained membrane-associated. Analysis of the subunit structure of the membrane-bound ribosomal particles remaining after termination was conducted by negative stain electron microscopy and sucrose gradient sedimentation. By both methods of analysis, the termination of protein synthesis on membrane-bound ribosomes was accompanied by the release of small ribosomal subunits from the ER membrane; the majority of the large subunits remained membrane-bound. On the basis of these results, we propose that large ribosomal subunit release from the ER membrane is regulated independently of protein translocation.
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Affiliation(s)
- R M Seiser
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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