1
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Cairo LV, Hong X, Müller MBD, Yuste-Checa P, Jagadeesan C, Bracher A, Park SH, Hayer-Hartl M, Hartl FU. Stress-dependent condensate formation regulated by the ubiquitin-related modifier Urm1. Cell 2024; 187:4656-4673.e28. [PMID: 38942013 DOI: 10.1016/j.cell.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 04/12/2024] [Accepted: 06/08/2024] [Indexed: 06/30/2024]
Abstract
The ability of proteins and RNA to coalesce into phase-separated assemblies, such as the nucleolus and stress granules, is a basic principle in organizing membraneless cellular compartments. While the constituents of biomolecular condensates are generally well documented, the mechanisms underlying their formation under stress are only partially understood. Here, we show in yeast that covalent modification with the ubiquitin-like modifier Urm1 promotes the phase separation of a wide range of proteins. We find that the drop in cellular pH induced by stress triggers Urm1 self-association and its interaction with both target proteins and the Urm1-conjugating enzyme Uba4. Urmylation of stress-sensitive proteins promotes their deposition into stress granules and nuclear condensates. Yeast cells lacking Urm1 exhibit condensate defects that manifest in reduced stress resilience. We propose that Urm1 acts as a reversible molecular "adhesive" to drive protective phase separation of functionally critical proteins under cellular stress.
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Affiliation(s)
- Lucas V Cairo
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Xiaoyu Hong
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Martin B D Müller
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Patricia Yuste-Checa
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Chandhuru Jagadeesan
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sae-Hun Park
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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2
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Lohmann J, Herzog O, Rosenzweig K, Weingartner M. Thermal adaptation in plants: understanding the dynamics of translation factors and condensates. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4258-4273. [PMID: 38630631 DOI: 10.1093/jxb/erae171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/16/2024] [Indexed: 04/19/2024]
Abstract
Plants, as sessile organisms, face the crucial challenge of adjusting growth and development with ever-changing environmental conditions. Protein synthesis is the fundamental process that enables growth of all organisms. Since elevated temperature presents a substantial threat to protein stability and function, immediate adjustments of protein synthesis rates are necessary to circumvent accumulation of proteotoxic stress and to ensure survival. This review provides an overview of the mechanisms that control translation under high-temperature stress by the modification of components of the translation machinery in plants, and compares them to yeast and metazoa. Recent research also suggests an important role for cytoplasmic biomolecular condensates, named stress granules, in these processes. Current understanding of the role of stress granules in translational regulation and of the molecular processes associated with translation that might occur within stress granules is also discussed.
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Affiliation(s)
- Julia Lohmann
- Institute of Plant Sciences and Microbiology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
| | - Oliver Herzog
- Institute of Plant Sciences and Microbiology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
| | - Kristina Rosenzweig
- Institute of Plant Sciences and Microbiology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
| | - Magdalena Weingartner
- Institute of Plant Sciences and Microbiology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
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3
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Creamer DR, Beynon RJ, Hubbard SJ, Ashe MP, Grant CM. Isoform-specific sequestration of protein kinase A fine-tunes intracellular signaling during heat stress. Cell Rep 2024; 43:114360. [PMID: 38865242 DOI: 10.1016/j.celrep.2024.114360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/24/2024] [Accepted: 05/30/2024] [Indexed: 06/14/2024] Open
Abstract
Protein kinase A (PKA) is a conserved kinase crucial for fundamental biological processes linked to growth, development, and metabolism. The PKA catalytic subunit is expressed as multiple isoforms in diverse eukaryotes; however, their contribution to ensuring signaling specificity in response to environmental cues remains poorly defined. Catalytic subunit activity is classically moderated via interaction with an inhibitory regulatory subunit. Here, a quantitative mass spectrometry approach is used to examine heat-stress-induced changes in the binding of yeast Tpk1-3 catalytic subunits to the Bcy1 regulatory subunit. We show that Tpk3 is not regulated by Bcy1 binding but, instead, is deactivated upon heat stress via reversible sequestration into cytoplasmic granules. These "Tpk3 granules" are enriched for multiple PKA substrates involved in various metabolic processes, with the Hsp42 sequestrase required for their formation. Hence, regulated sequestration of Tpk3 provides a mechanism to control isoform-specific kinase signaling activity during stress conditions.
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Affiliation(s)
- Declan R Creamer
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Robert J Beynon
- Centre for Proteome Research, Institute of Systems and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Simon J Hubbard
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Mark P Ashe
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Chris M Grant
- Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK.
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4
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Glauninger H, Bard JA, Wong Hickernell CJ, Airoldi EM, Li W, Singer RH, Paul S, Fei J, Sosnick TR, Wallace EWJ, Drummond DA. Transcriptome-wide mRNA condensation precedes stress granule formation and excludes stress-induced transcripts. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589678. [PMID: 38659805 PMCID: PMC11042329 DOI: 10.1101/2024.04.15.589678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Stress-induced condensation of mRNA and proteins into stress granules is conserved across eukaryotes, yet the function, formation mechanisms, and relation to well-studied conserved transcriptional responses remain largely unresolved. Stress-induced exposure of ribosome-free mRNA following translational shutoff is thought to cause condensation by allowing new multivalent RNA-dependent interactions, with RNA length and associated interaction capacity driving increased condensation. Here we show that, in striking contrast, virtually all mRNA species condense in response to multiple unrelated stresses in budding yeast, length plays a minor role, and instead, stress-induced transcripts are preferentially excluded from condensates, enabling their selective translation. Using both endogenous genes and reporter constructs, we show that translation initiation blockade, rather than resulting ribosome-free RNA, causes condensation. These translation initiation-inhibited condensates (TIICs) are biochemically detectable even when stress granules, defined as microscopically visible foci, are absent or blocked. TIICs occur in unstressed yeast cells, and, during stress, grow before the appearance of visible stress granules. Stress-induced transcripts are excluded from TIICs primarily due to the timing of their expression, rather than their sequence features. Together, our results reveal a simple system by which cells redirect translational activity to newly synthesized transcripts during stress, with broad implications for cellular regulation in changing conditions.
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Affiliation(s)
- Hendrik Glauninger
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL, USA
- Interdisciplinary Scientist Training Program, The University of Chicago, Chicago, IL, USA
| | - Jared A.M. Bard
- Department of Biology, Texas A&M University, College Station, TX, USA
| | | | - Edo M. Airoldi
- Fox School of Business and Management, Temple University, Philadelphia, PA, USA
| | - Weihan Li
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Robert H. Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Sneha Paul
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Jingyi Fei
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
| | - Tobin R. Sosnick
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | | | - D. Allan Drummond
- Department of Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, USA
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5
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Ali A, Garde R, Schaffer OC, Bard JAM, Husain K, Kik SK, Davis KA, Luengo-Woods S, Igarashi MG, Drummond DA, Squires AH, Pincus D. Adaptive preservation of orphan ribosomal proteins in chaperone-dispersed condensates. Nat Cell Biol 2023; 25:1691-1703. [PMID: 37845327 PMCID: PMC10868727 DOI: 10.1038/s41556-023-01253-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 09/12/2023] [Indexed: 10/18/2023]
Abstract
Ribosome biogenesis is among the most resource-intensive cellular processes, with ribosomal proteins accounting for up to half of all newly synthesized proteins in eukaryotic cells. During stress, cells shut down ribosome biogenesis in part by halting rRNA synthesis, potentially leading to massive accumulation of aggregation-prone 'orphan' ribosomal proteins (oRPs). Here we show that, during heat shock in yeast and human cells, oRPs accumulate as reversible peri-nucleolar condensates recognized by the Hsp70 co-chaperone Sis1/DnaJB6. oRP condensates are liquid-like in cell-free lysate but solidify upon depletion of Sis1 or inhibition of Hsp70. When cells recover from heat shock, oRP condensates disperse in a Sis1- and Hsp70-dependent manner, and the oRP constituents are incorporated into functional ribosomes in the cytosol, enabling cells to efficiently resume growth. Preserving biomolecules in reversible condensates-like mRNAs in cytosolic stress granules and oRPs at the nucleolar periphery-may be a primary function of the Hsp70 chaperone system.
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Affiliation(s)
- Asif Ali
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA.
| | - Rania Garde
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
| | - Olivia C Schaffer
- Pritzker School for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Jared A M Bard
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Kabir Husain
- Department of Physics, University of Chicago, Chicago, IL, USA
| | - Samantha Keyport Kik
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Kathleen A Davis
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Sofia Luengo-Woods
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Maya G Igarashi
- Graduate Program in Biophysical Sciences, University of Chicago, Chicago, IL, USA
| | - D Allan Drummond
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Department of Medicine, Section of Genetic Medicine, University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Center for Physics of Evolving Systems, University of Chicago, Chicago, IL, USA
| | - Allison H Squires
- Pritzker School for Molecular Engineering, University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Center for Physics of Evolving Systems, University of Chicago, Chicago, IL, USA
| | - David Pincus
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA.
- Center for Physics of Evolving Systems, University of Chicago, Chicago, IL, USA.
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6
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Grimes B, Jacob W, Liberman AR, Kim N, Zhao X, Masison DC, Greene LE. The Properties and Domain Requirements for Phase Separation of the Sup35 Prion Protein In Vivo. Biomolecules 2023; 13:1370. [PMID: 37759770 PMCID: PMC10526957 DOI: 10.3390/biom13091370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
The Sup35 prion protein of budding yeast has been reported to undergo phase separation to form liquid droplets both at low pH in vitro and when energy depletion decreases the intracellular pH in vivo. It also has been shown using purified proteins that this phase separation is driven by the prion domain of Sup35 and does not re-quire its C-terminal domain. In contrast, we now find that a Sup35 fragment consisting of only the N-terminal prion domain and the M-domain does not phase separate in vivo; this phase separation of Sup35 requires the C-terminal domain, which binds Sup45 to form the translation termination complex. The phase-separated Sup35 not only colocalizes with Sup45 but also with Pub1, a stress granule marker protein. In addition, like stress granules, phase separation of Sup35 appears to require mRNA since cycloheximide treatment, which inhibits mRNA release from ribosomes, prevents phase separation of Sup35. Finally, unlike Sup35 in vitro, Sup35 condensates do not disassemble in vivo when the intracellular pH is increased. These results suggest that, in energy-depleted cells, Sup35 forms supramolecular assemblies that differ from the Sup35 liquid droplets that form in vitro.
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Affiliation(s)
- Bryan Grimes
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Walter Jacob
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amanda R. Liberman
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nathan Kim
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiaohong Zhao
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Daniel C. Masison
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lois E. Greene
- Laboratory of Cell Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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7
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Lohmann J, de Luxán-Hernández C, Gao Y, Zoschke R, Weingartner M. Arabidopsis translation factor eEF1Bγ impacts plant development and is associated with heat-induced cytoplasmic foci. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:2585-2602. [PMID: 36749654 DOI: 10.1093/jxb/erad050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/02/2023] [Indexed: 06/06/2023]
Abstract
The important role of translational control for maintenance of proteostasis is well documented in plants, but the exact mechanisms that coordinate translation rates during plant development and stress response are not well understood. In Arabidopsis, the translation elongation complex eEF1B consists of three subunits: eEF1Bα, eEF1Bβ, and eEF1Bγ. While eEF1Bα and eEF1Bβ have a conserved GDP/GTP exchange function, the function of eEF1Bγ is still unknown. By generating Arabidopsis mutants with strongly reduced eEF1Bγ levels, we revealed its essential role during plant growth and development and analysed its impact on translation. To explore the function of the eEF1B subunits under high temperature stress, we analysed their dynamic localization as green fluorescent protein fusions under control and heat stress conditions. Each of these fusion proteins accumulated in heat-induced cytoplasmic foci and co-localized with the stress granule marker poly(A)-binding protein 8-mCherry. Protein-protein interaction studies and co-expression analyses indicated that eEF1Bβ physically interacted with both of the other subunits and promoted their recruitment to cytoplasmic foci. These data provide new insights into the mechanisms allowing for rapid adaptation of translation rates during heat stress response.
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Affiliation(s)
- Julia Lohmann
- Institute of Plant Sciences and Microbiology, University of Hamburg, Ohnhorststrasse 18, D-22609 Hamburg, Germany
| | - Cloe de Luxán-Hernández
- Institute of Plant Sciences and Microbiology, University of Hamburg, Ohnhorststrasse 18, D-22609 Hamburg, Germany
| | - Yang Gao
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Magdalena Weingartner
- Institute of Plant Sciences and Microbiology, University of Hamburg, Ohnhorststrasse 18, D-22609 Hamburg, Germany
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8
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Makeeva DS, Riggs CL, Burakov AV, Ivanov PA, Kushchenko AS, Bykov DA, Popenko VI, Prassolov VS, Ivanov PV, Dmitriev SE. Relocalization of Translation Termination and Ribosome Recycling Factors to Stress Granules Coincides with Elevated Stop-Codon Readthrough and Reinitiation Rates upon Oxidative Stress. Cells 2023; 12:259. [PMID: 36672194 PMCID: PMC9856671 DOI: 10.3390/cells12020259] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/27/2022] [Accepted: 01/03/2023] [Indexed: 01/11/2023] Open
Abstract
Upon oxidative stress, mammalian cells rapidly reprogram their translation. This is accompanied by the formation of stress granules (SGs), cytoplasmic ribonucleoprotein condensates containing untranslated mRNA molecules, RNA-binding proteins, 40S ribosomal subunits, and a set of translation initiation factors. Here we show that arsenite-induced stress causes a dramatic increase in the stop-codon readthrough rate and significantly elevates translation reinitiation levels on uORF-containing and bicistronic mRNAs. We also report the recruitment of translation termination factors eRF1 and eRF3, as well as ribosome recycling and translation reinitiation factors ABCE1, eIF2D, MCT-1, and DENR to SGs upon arsenite treatment. Localization of these factors to SGs may contribute to a rapid resumption of mRNA translation after stress relief and SG disassembly. It may also suggest the presence of post-termination, recycling, or reinitiation complexes in SGs. This new layer of translational control under stress conditions, relying on the altered spatial distribution of translation factors between cellular compartments, is discussed.
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Affiliation(s)
- Desislava S. Makeeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Claire L. Riggs
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Anton V. Burakov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Pavel A. Ivanov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Artem S. Kushchenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Dmitri A. Bykov
- Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Vladimir I. Popenko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Vladimir S. Prassolov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Pavel V. Ivanov
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sergey E. Dmitriev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
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9
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Glauninger H, Wong Hickernell CJ, Bard JAM, Drummond DA. Stressful steps: Progress and challenges in understanding stress-induced mRNA condensation and accumulation in stress granules. Mol Cell 2022; 82:2544-2556. [PMID: 35662398 PMCID: PMC9308734 DOI: 10.1016/j.molcel.2022.05.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/14/2022] [Accepted: 05/11/2022] [Indexed: 01/11/2023]
Abstract
Stress-induced condensation of mRNA and protein into massive cytosolic clusters is conserved across eukaryotes. Known as stress granules when visible by imaging, these structures remarkably have no broadly accepted biological function, mechanism of formation or dispersal, or even molecular composition. As part of a larger surge of interest in biomolecular condensation, studies of stress granules and related RNA/protein condensates have increasingly probed the biochemical underpinnings of condensation. Here, we review open questions and recent advances, including the stages from initial condensate formation to accumulation in mature stress granules, mechanisms by which stress-induced condensates form and dissolve, and surprising twists in understanding the RNA components of stress granules and their role in condensation. We outline grand challenges in understanding stress-induced RNA condensation, centering on the unique and substantial barriers in the molecular study of cellular structures, such as stress granules, for which no biological function has been firmly established.
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Affiliation(s)
- Hendrik Glauninger
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA
| | | | - Jared A M Bard
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA
| | - D Allan Drummond
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA.
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10
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Cañonero L, Pautasso C, Galello F, Sigaut L, Pietrasanta L, Arroyo J, Bermúdez-Moretti M, Portela P, Rossi S. Heat stress regulates the expression of TPK1 gene at transcriptional and post-transcriptional levels in Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119209. [PMID: 34999138 DOI: 10.1016/j.bbamcr.2021.119209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/16/2021] [Accepted: 12/28/2021] [Indexed: 12/11/2022]
Abstract
In Saccharomyces cerevisiae cAMP regulates different cellular processes through PKA. The specificity of the response of the cAMP-PKA pathway is highly regulated. Here we address the mechanism through which the cAMP-PKA pathway mediates its response to heat shock and thermal adaptation in yeast. PKA holoenzyme is composed of a regulatory subunit dimer (Bcy1) and two catalytic subunits (Tpk1, Tpk2, or Tpk3). PKA subunits are differentially expressed under certain growth conditions. Here we demonstrate the increased abundance and half-life of TPK1 mRNA and the assembly of this mRNA in cytoplasmic foci during heat shock at 37 °C. The resistance of the foci to cycloheximide-induced disassembly along with the polysome profiling analysis suggest that TPK1 mRNA is impaired for entry into translation. TPK1 expression was also evaluated during a recurrent heat shock and thermal adaptation. Tpk1 protein level is significantly increased during the recovery periods. The crosstalk of cAMP-PKA pathway and CWI signalling was also studied. Wsc3 sensor and some components of the CWI pathway are necessary for the TPK1 expression upon heat shock. The assembly in foci upon thermal stress depends on Wsc3. Tpk1 expression is lower in a wsc3∆ mutant than in WT strain during thermal adaptation and thus the PKA levels are also lower. An increase in Tpk1 abundance in the PKA holoenzyme in response to heat shock is presented, suggesting that a recurrent stress enhanced the fitness for the coming favourable conditions. Therefore, the regulation of TPK1 expression by thermal stress contributes to the specificity of cAMP-PKA signalling.
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Affiliation(s)
- Luciana Cañonero
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Constanza Pautasso
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Fiorella Galello
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Lorena Sigaut
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Física, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Física de Buenos Aires (IFIBA), Buenos Aires, Argentina
| | - Lia Pietrasanta
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Física, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Física de Buenos Aires (IFIBA), Buenos Aires, Argentina
| | - Javier Arroyo
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, Madrid, Spain
| | - Mariana Bermúdez-Moretti
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Paula Portela
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Silvia Rossi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina.
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11
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Grousl T, Vojtova J, Hasek J, Vomastek T. Yeast stress granules at a glance. Yeast 2021; 39:247-261. [PMID: 34791685 DOI: 10.1002/yea.3681] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/15/2021] [Accepted: 11/12/2021] [Indexed: 11/10/2022] Open
Abstract
The formation of stress granules (SGs), membrane-less organelles that are composed of mainly messenger ribonucleoprotein assemblies, is the result of a conserved evolutionary strategy to cellular stress. During their formation, which is triggered by robust environmental stress, SGs sequester translationally inactive mRNA molecules, which are either forwarded for further processing elsewhere or stored during a period of stress within SGs. Removal of mRNA molecules from active translation and their sequestration in SGs allows preferential translation of stress response transcripts. By affecting the specificity of mRNA translation, mRNA localization and stability, SGs are involved in the overall cellular reprogramming during periods of environmental stress and viral infection. Over the past two decades, we have learned which processes drive SGs assembly, how their composition varies under stress, and how they co-exist with other subcellular organelles. Yeast as a model has been instrumental in our understanding of SG biology. Despite the specific differences between the SGs of yeast and mammals, yeast have been shown to be a valuable tool to the study of SGs in translation-related stress response. This review summarizes the data surrounding SGs that are formed under different stress conditions in Saccharomyces cerevisiae and other yeast species. It offers a comprehensive and up-to-date view on these still somewhat mysterious entities.
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Affiliation(s)
- Tomas Grousl
- Laboratory of Cell Signalling, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jana Vojtova
- Laboratory of Cell Reproduction, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jiri Hasek
- Laboratory of Cell Reproduction, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Tomas Vomastek
- Laboratory of Cell Signalling, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
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12
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Shuvalova E, Egorova T, Ivanov A, Shuvalov A, Biziaev N, Mukba S, Pustogarov N, Terenin I, Alkalaeva E. Discovery of a novel role of tumor suppressor PDCD4 in stimulation of translation termination. J Biol Chem 2021; 297:101269. [PMID: 34606825 PMCID: PMC8551656 DOI: 10.1016/j.jbc.2021.101269] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 11/18/2022] Open
Abstract
Programmed cell death 4 protein (PDCD4) regulates many vital cell processes, although is classified as a tumor suppressor because it inhibits neoplastic transformation and tumor growth. For example, PCDC4 has been implicated in the regulation of transcription and mRNA translation. PDCD4 is known to inhibit translation initiation by binding to eukaryotic initiation factor 4A and elongation of oncogenic c- and A-myb mRNAs. Additionally, PDCD4 has been shown to interact with poly(A)-binding protein (PABP), which affects translation termination, although the significance of this interaction is not fully understood. Considering the interaction between PABP and PDCD4, we hypothesized that PDCD4 may also be involved in translation termination. Using in vitro translation systems, we revealed that PDCD4 directly activates translation termination. PDCD4 stimulates peptidyl-tRNA hydrolysis induced by a complex of eukaryotic release factors, eRF1-eRF3. Moreover, in combination with the PABP, which also stimulates peptide release, PDCD4 activity in translation termination increases. PDCD4 regulates translation termination by facilitating the binding of release factors to the ribosome, increasing the GTPase activity of eRF3, and dissociating eRF3 from the posttermination complex. Using a toe-printing assay, we determined the first stage at which PDCD4 functions-binding of release factors to the A-site of the ribosome. However, preventing binding of eRF3 with PABP, PDCD4 suppresses subsequent rounds of translation termination. Based on these data, we assumed that human PDCD4 controls protein synthesis during translation termination. The described mechanism of the activity of PDCD4 in translation termination provides a new insight into its functioning during suppression of protein biosynthesis.
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Affiliation(s)
- Ekaterina Shuvalova
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia
| | - Tatiana Egorova
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Alexander Ivanov
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia
| | - Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Nikita Biziaev
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia
| | - Sabina Mukba
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia
| | - Nikolay Pustogarov
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia
| | - Ilya Terenin
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia.
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13
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Dannenmaier S, Desroches Altamirano C, Schüler L, Zhang Y, Hummel J, Milanov M, Oeljeklaus S, Koch HG, Rospert S, Alberti S, Warscheid B. Quantitative proteomics identifies the universally conserved ATPase Ola1p as a positive regulator of heat shock response in Saccharomyces cerevisiae. J Biol Chem 2021; 297:101050. [PMID: 34571008 PMCID: PMC8531669 DOI: 10.1016/j.jbc.2021.101050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/24/2021] [Accepted: 08/04/2021] [Indexed: 12/02/2022] Open
Abstract
The universally conserved P-loop ATPase Ola1 is implicated in various cellular stress response pathways, as well as in cancer and tumor progression. However, Ola1p functions are divergent between species, and the involved mechanisms are only poorly understood. Here, we studied the role of Ola1p in the heat shock response of the yeast Saccharomyces cerevisiae using a combination of quantitative and pulse labeling-based proteomics approaches, in vitro studies, and cell-based assays. Our data show that when heat stress is applied to cells lacking Ola1p, the expression of stress-protective proteins is enhanced. During heat stress Ola1p associates with detergent-resistant protein aggregates and rapidly forms assemblies that localize to stress granules. The assembly of Ola1p was also observed in vitro using purified protein and conditions, which resembled those in living cells. We show that loss of Ola1p results in increased protein ubiquitination of detergent-insoluble aggregates recovered from heat-shocked cells. When cells lacking Ola1p were subsequently relieved from heat stress, reinitiation of translation was delayed, whereas, at the same time, de novo synthesis of central factors required for protein refolding and the clearance of aggregates was enhanced when compared with wild-type cells. The combined data suggest that upon acute heat stress, Ola1p is involved in the stabilization of misfolded proteins, which become sequestered in cytoplasmic stress granules. This function of Ola1p enables cells to resume translation in a timely manner as soon as heat stress is relieved.
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Affiliation(s)
- Stefan Dannenmaier
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Lisa Schüler
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ying Zhang
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Johannes Hummel
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Martin Milanov
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Silke Oeljeklaus
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Hans-Georg Koch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Simon Alberti
- BIOTEC and CMCB, Technische Universität Dresden, Dresden, Germany
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.
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14
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Malcova I, Senohrabkova L, Novakova L, Hasek J. eIF3a Destabilization and TDP-43 Alter Dynamics of Heat-Induced Stress Granules. Int J Mol Sci 2021; 22:ijms22105164. [PMID: 34068231 PMCID: PMC8153170 DOI: 10.3390/ijms22105164] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/04/2021] [Accepted: 05/08/2021] [Indexed: 12/17/2022] Open
Abstract
Stress granules (SGs) are membrane-less assemblies arising upon various stresses in eukaryotic cells. They sequester mRNAs and proteins from stressful conditions and modulate gene expression to enable cells to resume translation and growth after stress relief. SGs containing the translation initiation factor eIF3a/Rpg1 arise in yeast cells upon robust heat shock (HS) at 46 °C only. We demonstrate that the destabilization of Rpg1 within the PCI domain in the Rpg1-3 variant leads to SGs assembly already at moderate HS at 42 °C. These are bona fide SGs arising upon translation arrest containing mRNAs, which are components of the translation machinery, and associating with P-bodies. HS SGs associate with endoplasmatic reticulum and mitochondria and their contact sites ERMES. Although Rpg1-3-labeled SGs arise at a lower temperature, their disassembly is delayed after HS at 46 °C. Remarkably, the delayed disassembly of HS SGs after the robust HS is reversed by TDP-43, which is a human protein connected with amyotrophic lateral sclerosis. TDP-43 colocalizes with HS SGs in yeast cells and facilitates cell regrowth after the stress relief. Based on our results, we propose yeast HS SGs labeled by Rpg1 and its variants as a novel model system to study functions of TDP-43 in stress granules disassembly.
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Affiliation(s)
- Ivana Malcova
- Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (L.S.); (L.N.); (J.H.)
- Correspondence: ; Tel.: +420-241062769
| | - Lenka Senohrabkova
- Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (L.S.); (L.N.); (J.H.)
- First Faculty of Medicine, Charles University, Katerinska 42, 12108 Prague, Czech Republic
| | - Lenka Novakova
- Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (L.S.); (L.N.); (J.H.)
| | - Jiri Hasek
- Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic; (L.S.); (L.N.); (J.H.)
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15
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Nishimura K, Nakagawa R, Hachisuga C, Nakajima Munekage Y. Deciphering the Proteotoxic Stress Responses Triggered by the Perturbed Thylakoid Proteostasis in Arabidopsis. PLANTS 2021; 10:plants10030519. [PMID: 33802194 PMCID: PMC8001255 DOI: 10.3390/plants10030519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 11/30/2022]
Abstract
Here, we explored heat dependent thylakoid FtsH protease substrates and investigated proteotoxicity induced by thermal damage and processive protease dysfunction on the thylakoid membrane. Through our thylakoid enriched proteome analysis and biochemical experiments, carbonylated stromal proteins were suggested as possible FtsH targets. Furthermore, we observed in the thylakoid fractions in the absence of FtsH stromal reactive oxygen species-detoxifying enzymes, as well as heat shock proteins and chaperones, which are known to be upregulated at the transcriptional level when this protease is absent, which is called the damaged protein response, resembling unfolded protein response in eukaryotic cells. Interestingly, the thylakoid-enriched high-density fractions included stromal translation factors and RNA-binding proteins, along with aminoacyl-tRNA synthetase, reminiscent of the formation of stress granules. Unexpectedly, extraplastid proteins such as mitochondrial chaperones, peroxidase, tricarboxylic acid cycle and respiratory chain enzymes, as well as cytosolic ribosomes, translation factors, heat shock proteins, antioxidants and metabolic enzymes, were also found deposited in the high-density fractions depending on the loss of thylakoid FtsH, with more prominent effects of thermal stress on the cytosolic proteins. This may reflect intracellular adaptation to the proteotoxic influences from the organelle.
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Affiliation(s)
- Kenji Nishimura
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda 669-1337, Hyogo, Japan; (C.H.); (Y.N.M.)
- Correspondence: ; Tel.: +81-79-565-7351
| | - Reiko Nakagawa
- Laboratory for Phyloinformatics in RIKEN Center for Biosystems Dynamics Research (BDR), Kobe 650-0047, Hyogo, Japan;
| | - Chisato Hachisuga
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda 669-1337, Hyogo, Japan; (C.H.); (Y.N.M.)
| | - Yuri Nakajima Munekage
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda 669-1337, Hyogo, Japan; (C.H.); (Y.N.M.)
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16
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Ranjan N, Pochopien AA, Chih-Chien Wu C, Beckert B, Blanchet S, Green R, V Rodnina M, Wilson DN. Yeast translation elongation factor eEF3 promotes late stages of tRNA translocation. EMBO J 2021; 40:e106449. [PMID: 33555093 PMCID: PMC7957392 DOI: 10.15252/embj.2020106449] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 12/10/2020] [Accepted: 12/21/2020] [Indexed: 11/21/2022] Open
Abstract
In addition to the conserved translation elongation factors eEF1A and eEF2, fungi require a third essential elongation factor, eEF3. While eEF3 has been implicated in tRNA binding and release at the ribosomal A and E sites, its exact mechanism of action is unclear. Here, we show that eEF3 acts at the mRNA–tRNA translocation step by promoting the dissociation of the tRNA from the E site, but independent of aminoacyl‐tRNA recruitment to the A site. Depletion of eEF3 in vivo leads to a general slowdown in translation elongation due to accumulation of ribosomes with an occupied A site. Cryo‐EM analysis of native eEF3‐ribosome complexes shows that eEF3 facilitates late steps of translocation by favoring non‐rotated ribosomal states, as well as by opening the L1 stalk to release the E‐site tRNA. Additionally, our analysis provides structural insights into novel translation elongation states, enabling presentation of a revised yeast translation elongation cycle.
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Affiliation(s)
- Namit Ranjan
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Agnieszka A Pochopien
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany.,Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Colin Chih-Chien Wu
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bertrand Beckert
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Sandra Blanchet
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Daniel N Wilson
- Gene Center, Department for Biochemistry and Center for integrated Protein Science Munich (CiPSM), University of Munich, Munich, Germany.,Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
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17
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Park SK, Park S, Pentek C, Liebman SW. Tumor suppressor protein p53 expressed in yeast can remain diffuse, form a prion, or form unstable liquid-like droplets. iScience 2020; 24:102000. [PMID: 33490908 PMCID: PMC7811139 DOI: 10.1016/j.isci.2020.102000] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/20/2020] [Accepted: 12/23/2020] [Indexed: 01/08/2023] Open
Abstract
Mutations in the p53 tumor suppressor are frequent causes of cancer. Because p53 aggregates appear in some tumor cells, it has been suggested that p53 could also cause cancer by forming self-replicating protein aggregates (prions). Here, using yeast, we show that transient p53 overexpression induced the formation of p53 prion aggregates that were transmitted for >100 generations, found in lysate pellets, stained with Thioflavin T, and transmitted by cytoplasmic transfer, or transfection with lysates of cells carrying the prion or with p53 amyloid peptide. As predicted for a prion, transient interruption of p53 expression caused permanent p53 prion loss. Importantly, p53 transcription factor activity was reduced by prion formation suggesting that prion aggregation could cause cancer. p53 has also been found in liquid-like nuclear droplets in animal cell culture. In yeast, we found that liquid-like p53 foci appear in response to stress and disappear with stress removal. A published yeast model of functional nuclear human p53 tumor suppressor was used Upon transient overexpression p53 loses its transcription function and aggregates These p53 aggregates are cytoplasmic and behave like stable heritable prions Stress induces p53 to form liquid-like droplets that are unstable and not prion-like
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Affiliation(s)
- Sei-Kyoung Park
- Department of Pharmacology, University of Nevada, Reno, NV 89557, USA
| | - Sangeun Park
- Department of Pharmacology, University of Nevada, Reno, NV 89557, USA
| | - Christine Pentek
- Department of Pharmacology, University of Nevada, Reno, NV 89557, USA
| | - Susan W Liebman
- Department of Pharmacology, University of Nevada, Reno, NV 89557, USA
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18
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Määttä TA, Rettel M, Sridharan S, Helm D, Kurzawa N, Stein F, Savitski MM. Aggregation and disaggregation features of the human proteome. Mol Syst Biol 2020; 16:e9500. [PMID: 33022891 PMCID: PMC7538195 DOI: 10.15252/msb.20209500] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 08/25/2020] [Accepted: 09/09/2020] [Indexed: 12/15/2022] Open
Abstract
Protein aggregates have negative implications in disease. While reductionist experiments have increased our understanding of aggregation processes, the systemic view in biological context is still limited. To extend this understanding, we used mass spectrometry-based proteomics to characterize aggregation and disaggregation in human cells after non-lethal heat shock. Aggregation-prone proteins were enriched in nuclear proteins, high proportion of intrinsically disordered regions, high molecular mass, high isoelectric point, and hydrophilic amino acids. During recovery, most aggregating proteins disaggregated with a rate proportional to the aggregation propensity: larger loss in solubility was counteracted by faster disaggregation. High amount of intrinsically disordered regions were associated with faster disaggregation. However, other characteristics enriched in aggregating proteins did not correlate with the disaggregation rates. In addition, we analyzed changes in protein thermal stability after heat shock. Soluble remnants of aggregated proteins were more thermally stable compared with control condition. Therefore, our results provide a rich resource of heat stress-related protein solubility data and can foster further studies related to protein aggregation diseases.
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Affiliation(s)
- Tomi A Määttä
- Genome Biology UnitEuropean Molecular Biology LaboratoryHeidelbergGermany
- Faculty of BiosciencesCollaboration for Joint PhD Degree between EMBL and Heidelberg UniversityHeidelbergGermany
| | - Mandy Rettel
- Proteomics Core FacilityEuropean Molecular Biology LaboratoryHeidelbergGermany
| | - Sindhuja Sridharan
- Genome Biology UnitEuropean Molecular Biology LaboratoryHeidelbergGermany
| | - Dominic Helm
- Proteomics Core FacilityEuropean Molecular Biology LaboratoryHeidelbergGermany
| | - Nils Kurzawa
- Genome Biology UnitEuropean Molecular Biology LaboratoryHeidelbergGermany
- Faculty of BiosciencesCollaboration for Joint PhD Degree between EMBL and Heidelberg UniversityHeidelbergGermany
| | - Frank Stein
- Proteomics Core FacilityEuropean Molecular Biology LaboratoryHeidelbergGermany
| | - Mikhail M Savitski
- Genome Biology UnitEuropean Molecular Biology LaboratoryHeidelbergGermany
- Proteomics Core FacilityEuropean Molecular Biology LaboratoryHeidelbergGermany
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19
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Begovich K, Wilhelm JE. An In Vitro Assembly System Identifies Roles for RNA Nucleation and ATP in Yeast Stress Granule Formation. Mol Cell 2020; 79:991-1007.e4. [PMID: 32780990 DOI: 10.1016/j.molcel.2020.07.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 05/22/2020] [Accepted: 07/17/2020] [Indexed: 01/08/2023]
Abstract
Stress granules (SGs) are condensates of mRNPs that form in response to stress. SGs arise by multivalent protein-protein, protein-RNA, and RNA-RNA interactions. However, the role of RNA-RNA interactions in SG assembly remains understudied. Here, we describe a yeast SG reconstitution system that faithfully recapitulates SG assembly in response to trigger RNAs. SGs assembled by stem-loop RNA triggers are ATP-sensitive, regulated by helicase/chaperone activity, and exhibit the hallmarks of maturation observed for SG proteins that phase-separate in vitro. Additionally, the fraction of total RNA that phase-separates in vitro is sufficient to trigger SG formation. However, condensation of NFT1 mRNA, an enriched transcript in this population, can only assemble an incomplete SG. These results suggest that networks of distinct transcripts are required to form a canonical SG and provide a platform for dissecting the interplay between the transcriptome and ATP-dependent remodeling in SG formation.
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Affiliation(s)
- Kyle Begovich
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Howard Hughes Medical Institute (HHMI) Summer Institute Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - James E Wilhelm
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Howard Hughes Medical Institute (HHMI) Summer Institute Marine Biological Laboratory, Woods Hole, MA 02543, USA.
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20
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Si W, Li Y, Ye S, Li Z, Liu Y, Kuang W, Chen D, Zhu M. Methyltransferase 3 Mediated miRNA m6A Methylation Promotes Stress Granule Formation in the Early Stage of Acute Ischemic Stroke. Front Mol Neurosci 2020; 13:103. [PMID: 32581712 PMCID: PMC7289951 DOI: 10.3389/fnmol.2020.00103] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/13/2020] [Indexed: 12/21/2022] Open
Abstract
The modification of methyltransferase-like (METTL) enzymes plays important roles in various cellular responses by regulating microRNA expression. However, how m6A modification is involved in stress granule (SG) formation in the early stage of acute ischemic stroke by affecting the biogenesis processing of microRNAs remains unclear. Here, we established a middle cerebral artery occlusion (MCAO) model in rats and an oxygen-glucose deprivation/reperfusion (OGD/R) model in primary cortical neurons and PC12 cells to explore the potential mechanism between m6A modification and SG formation. The in vivo results showed that the level of infarction and apoptosis increased while SG formation decreased significantly within the ischemic cortex with improved reperfusion time after 2 h of ischemia. Consistent with the in vivo data, an inverse association between the apoptosis level and SG formation was observed in PC12 cells during the reperfusion period after 6 h of OGD stimulation. Both in vivo and in vitro results showed that the expression of METTL3 protein, m6A and miR-335 was significantly decreased with the reperfusion period. Overexpression of the METTL3 and METTL3 gene-knockdown in PC12 cells were achieved via plasmid transfection and CRISPR-Cas9 technology, respectively. Overexpression or knockdown of METTL3 in oxygen-glucose deprivation of PC12 cells resulted in functional maturation of miR-335, SG formation and apoptosis levels. In addition, we found that miR-335 enhanced SG formation through degradation of the mRNA of the eukaryotic translation termination factor (Erf1). In conclusion, we found that METTL3-mediated m6A methylation increases the maturation of miR-335, which promotes SG formation and reduces the apoptosis level of injury neurons and cells, and provides a potential therapeutic strategy for AIS.
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Affiliation(s)
- Wenwen Si
- Shenzhen Bao'an Traditional Chinese Medicine Hospital (Group), Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Yi Li
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Shanyu Ye
- Department of Anatomy, The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou Higher Education Mega Center, Guangzhou, China
| | - Zhen Li
- Department of Anatomy, The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou Higher Education Mega Center, Guangzhou, China
| | - Yangping Liu
- Department of Anatomy, The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou Higher Education Mega Center, Guangzhou, China
| | - Weihong Kuang
- The Second Clinical Medical College, Guangdong Medical University, Dongguan, China
| | - Dongfeng Chen
- Department of Anatomy, The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou Higher Education Mega Center, Guangzhou, China
| | - Meiling Zhu
- Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine, Shenzhen, China
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21
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Negrutskii B. Non-translational Connections of eEF1B in the Cytoplasm and Nucleus of Cancer Cells. Front Mol Biosci 2020; 7:56. [PMID: 32328499 PMCID: PMC7160314 DOI: 10.3389/fmolb.2020.00056] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/20/2020] [Indexed: 12/28/2022] Open
Abstract
The human translation machinery includes three types of supramolecular complexes involved in elongation of the polypeptide chain: the ribosome, complex of elongation factors eEF1B and multienzyme aminoacyl-tRNA synthetase complex. Of the above, eEF1B is the least investigated assembly. Recently, a number of studies provided some insights into the structure of different eEF1B subunits and changes in their expression in cancer and other diseases. There is increasing agreement that possible disease-related functions of eEF1B are not necessarily related to its role in translation. This mini-review focuses on structural and functional features of the eEF1B complex while paying special attention to possible non-canonical functions of its subunits in cancer cells.
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Affiliation(s)
- Boris Negrutskii
- Department of Structural and Functional Proteomics, Institute of Molecular Biology and Genetics, National Academy of Sciences, Kyiv, Ukraine
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22
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Álvarez-Cao ME, Cerdán ME, González-Siso MI, Becerra M. Bioconversion of Beet Molasses to Alpha-Galactosidase and Ethanol. Front Microbiol 2019; 10:405. [PMID: 30899250 PMCID: PMC6416216 DOI: 10.3389/fmicb.2019.00405] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/15/2019] [Indexed: 12/15/2022] Open
Abstract
Molasses are sub-products of the sugar industry, rich in sucrose and containing other sugars like raffinose, glucose, and fructose. Alpha-galactosidases (EC. 3.2.1.22) catalyze the hydrolysis of alpha-(1,6) bonds of galactose residues in galacto-oligosaccharides (melibiose, raffinose, and stachyose) and complex galactomannans. Alpha-galactosidases have important applications, mainly in the food industry but also in the pharmaceutical and bioenergy sectors. However, the cost of the enzyme limits the profitability of most of these applications. The use of cheap sub-products, such as molasses, as substrates for production of alpha-galactosidases, reduces the cost of the enzymes and contributes to the circular economy. Alpha-galactosidase is a specially indicated bioproduct since, at the same time, it allows to use the raffinose present in molasses. This work describes the development of a two-step system for the valuation of beet molasses, based on their use as substrate for alpha-galactosidase and bioethanol production by Saccharomyces cerevisiae. Since this yeast secretes high amounts of invertase, to avoid congest the secretory route and to facilitate alpha-galactosidase purification from the culture medium, a mutant in the SUC2 gene (encoding invertase) was constructed. After a statistical optimization of culture conditions, this mutant yielded a very high rate of molasses bioconversion to alpha-galactosidase. In the second step, the SUC2 wild type yeast strain fermented the remaining sucrose to ethanol. A procedure to recycle the yeast biomass, by using it as nitrogen source to supplement molasses, was also developed.
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Affiliation(s)
- María-Efigenia Álvarez-Cao
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, Universidade da Coruña, A Coruña, Spain
| | - María-Esperanza Cerdán
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, Universidade da Coruña, A Coruña, Spain
| | - María-Isabel González-Siso
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, Universidade da Coruña, A Coruña, Spain
| | - Manuel Becerra
- Grupo EXPRELA, Centro de Investigacións Científicas Avanzadas (CICA), Facultade de Ciencias, Universidade da Coruña, A Coruña, Spain
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Khan T, Kandola TS, Wu J, Venkatesan S, Ketter E, Lange JJ, Rodríguez Gama A, Box A, Unruh JR, Cook M, Halfmann R. Quantifying Nucleation In Vivo Reveals the Physical Basis of Prion-like Phase Behavior. Mol Cell 2019; 71:155-168.e7. [PMID: 29979963 PMCID: PMC6086602 DOI: 10.1016/j.molcel.2018.06.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 02/26/2018] [Accepted: 06/07/2018] [Indexed: 01/29/2023]
Abstract
Protein self-assemblies modulate protein activities over biological timescales that can exceed the lifetimes of the proteins or even the cells that harbor them. We hypothesized that these timescales relate to kinetic barriers inherent to the nucleation of ordered phases. To investigate nucleation barriers in living cells, we developed distributed amphifluoric FRET (DAmFRET). DAmFRET exploits a photoconvertible fluorophore, heterogeneous expression, and large cell numbers to quantify via flow cytometry the extent of a protein's self-assembly as a function of cellular concentration. We show that kinetic barriers limit the nucleation of ordered self-assemblies and that the persistence of the barriers with respect to concentration relates to structure. Supersaturation resulting from sequence-encoded nucleation barriers gave rise to prion behavior and enabled a prion-forming protein, Sup35 PrD, to partition into dynamic intracellular condensates or to form toxic aggregates. Our results suggest that nucleation barriers govern cytoplasmic inheritance, subcellular organization, and proteotoxicity.
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Affiliation(s)
- Tarique Khan
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Tejbir S Kandola
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Jianzheng Wu
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | | | - Ellen Ketter
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Jeffrey J Lange
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | | | - Andrew Box
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Malcolm Cook
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Randal Halfmann
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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Senohrabkova L, Malcova I, Hasek J. An aggregation-prone mutant of eIF3a forms reversible assemblies escaping spatial control in exponentially growing yeast cells. Curr Genet 2019; 65:919-940. [PMID: 30715564 DOI: 10.1007/s00294-019-00940-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/14/2019] [Accepted: 01/17/2019] [Indexed: 10/27/2022]
Abstract
Cells have elaborated a complex strategy to maintain protein homeostasis under physiological as well as stress conditions with the aim to ensure the smooth functioning of vital processes and producing healthy offspring. Impairment of one of the most important processes in living cells, translation, might have serious consequences including various brain disorders in humans. Here, we describe a variant of the translation initiation factor eIF3a, Rpg1-3, mutated in its PCI domain that displays an attenuated translation efficiency and formation of reversible assemblies at physiological growth conditions. Rpg1-3-GFP assemblies are not sequestered within mother cells only as usual for misfolded-protein aggregates and are freely transmitted from the mother cell into the bud although they are of non-amyloid nature. Their bud-directed transmission and the active movement within the cell area depend on the intact actin cytoskeleton and the related molecular motor Myo2. Mutations in the Rpg1-3 protein render not only eIF3a but, more importantly, also the eIF3 core complex prone to aggregation that is potentiated by the limited availability of Hsp70 and Hsp40 chaperones. Our results open the way to understand mechanisms yeast cells employ to cope with malfunction and aggregation of essential proteins and their complexes.
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Affiliation(s)
- Lenka Senohrabkova
- Laboratory of Cell Reproduction, Institute of Microbiology of the CAS, Videnska 1083, 14220, Prague 4, Czech Republic
- First Faculty of Medicine, Charles University, Katerinska 42, 12108, Prague 2, Czech Republic
| | - Ivana Malcova
- Laboratory of Cell Reproduction, Institute of Microbiology of the CAS, Videnska 1083, 14220, Prague 4, Czech Republic.
| | - Jiri Hasek
- Laboratory of Cell Reproduction, Institute of Microbiology of the CAS, Videnska 1083, 14220, Prague 4, Czech Republic.
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25
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Wilson CJ, Bommarius AS, Champion JA, Chernoff YO, Lynn DG, Paravastu AK, Liang C, Hsieh MC, Heemstra JM. Biomolecular Assemblies: Moving from Observation to Predictive Design. Chem Rev 2018; 118:11519-11574. [PMID: 30281290 PMCID: PMC6650774 DOI: 10.1021/acs.chemrev.8b00038] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Biomolecular assembly is a key driving force in nearly all life processes, providing structure, information storage, and communication within cells and at the whole organism level. These assembly processes rely on precise interactions between functional groups on nucleic acids, proteins, carbohydrates, and small molecules, and can be fine-tuned to span a range of time, length, and complexity scales. Recognizing the power of these motifs, researchers have sought to emulate and engineer biomolecular assemblies in the laboratory, with goals ranging from modulating cellular function to the creation of new polymeric materials. In most cases, engineering efforts are inspired or informed by understanding the structure and properties of naturally occurring assemblies, which has in turn fueled the development of predictive models that enable computational design of novel assemblies. This Review will focus on selected examples of protein assemblies, highlighting the story arc from initial discovery of an assembly, through initial engineering attempts, toward the ultimate goal of predictive design. The aim of this Review is to highlight areas where significant progress has been made, as well as to outline remaining challenges, as solving these challenges will be the key that unlocks the full power of biomolecules for advances in technology and medicine.
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Affiliation(s)
- Corey J. Wilson
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Andreas S. Bommarius
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Julie A. Champion
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Yury O. Chernoff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Laboratory of Amyloid Biology & Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
| | - David G. Lynn
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Anant K. Paravastu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Chen Liang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Ming-Chien Hsieh
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Jennifer M. Heemstra
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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26
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Hayashi H, Nagai R, Abe T, Wada M, Ito K, Takeuchi-Tomita N. Tight interaction of eEF2 in the presence of Stm1 on ribosome. J Biochem 2018; 163:177-185. [PMID: 29069440 DOI: 10.1093/jb/mvx070] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 09/07/2017] [Indexed: 11/14/2022] Open
Abstract
The stress-related protein Stm1 interacts with ribosomes, and is implicated in repressing translation. Stm1 was previously studied both in vivo and in vitro by cell-free translation systems using crude yeast lysates, but its precise functional mechanism remains obscure. Using an in vitro reconstituted translation system, we now show that Stm1 severely inhibits translation through its N-terminal region, aa 1 to 107, and this inhibition is antagonized by eEF3. We found that Stm1 stabilizes eEF2 on the 80 S ribosome in the GTP-bound form, independently of eEF2's diphthamide modification, a conserved post-translational modification at the tip of domain IV. Systematic analyses of N- or C-terminal truncated mutants revealed that the core region of Stm1, aa 47 to 143, is crucial for its ribosome binding and eEF2 stabilization. Stm1 does not inhibit the 80 S-dependent GTPase activity of eEF2, at least during the first round of GTP-hydrolysis. The mechanism and the role of the stable association of eEF2 with the ribosome in the presence of Stm1 are discussed in relation to the translation repression by Stm1.
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Affiliation(s)
- Hikari Hayashi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Riku Nagai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Taisho Abe
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Miki Wada
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Koichi Ito
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Nono Takeuchi-Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
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27
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Abstract
Prion-like proteins overlap with intrinsically disordered and low-complexity sequence families. These proteins are widespread, especially among mRNA-binding proteins. A salient feature of these proteins is the ability to form protein assemblies with distinct biophysical and functional properties. While prion-like proteins are involved in myriad of cellular processes, we propose potential roles for protein assemblies in regulated protein synthesis. Since proteins are the ultimate functional output of gene expression, when, where, and how much of a particular protein is made dictates the functional state of a cell. Recent finding suggests that the prion-like proteins offer unique advantages in translation regulation and also raises questions regarding formation and regulation of protein assemblies.
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Affiliation(s)
- Liying Li
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - J P McGinnis
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
| | - Kausik Si
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA.
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28
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Denis CL, Richardson R, Park S, Zhang C, Xi W, Laue TM, Wang X. Defining the protein complexome of translation termination factor eRF1: Identification of four novel eRF1-containing complexes that range from 20S to 57S in size. Proteins 2018; 86:177-191. [PMID: 29139201 PMCID: PMC5897186 DOI: 10.1002/prot.25422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/09/2017] [Accepted: 11/10/2017] [Indexed: 12/23/2022]
Abstract
The eukaryotic eRF1 translation termination factor plays an important role in recognizing stop codons and initiating the end to translation. However, which exact complexes contain eRF1 and at what abundance is not clear. We have used analytical ultracentrifugation with fluorescent detection system to identify the protein complexome of eRF1 in the yeast Saccharomyces cerevisiae. In addition to eRF1 presence in translating polysomes, we found that eRF1 associated with five other macromolecular complexes: 77S, 57S, 39S, 28S, and 20S in size. Generally equal abundances of each of these complexes were found. The 77S complex primarily contained the free 80S ribosome consistent with in vitro studies and did not appear to contain significant levels of the monosomal translating complex that co-migrates with the free 80S ribosome. The 57S and 39S complexes represented, respectively, free 60S and 40S ribosomal subunits bound to eRF1, associations not previously reported. The novel 28S and 20S complexes (containing minimal masses of 830 KDa and 500 KDa, respectively) lacked significant RNA components and appeared to be oligomeric, as eRF1 has a mass of 49 KDa. The majority of polysomal complexes containing eRF1 were both substantially deadenylated and lacking in closed-loop factors eIF4E and eIF4G. The thirteen percent of such translating polysomes that contained poly(A) tails had equivalent levels of eIF4E and eIF4G, suggesting these complexes were in a closed-loop structure. The identification of eRF1 in these unique and previously unrecognized complexes suggests a variety of new roles for eRF1 in the regulation of cellular processes.
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Affiliation(s)
- Clyde L. Denis
- Department of Molecular, Cellular, and Biomedical Sciences, 46 College Road, Rudman Hall, University of New Hampshire, Durham, NH 03824, 603-862-2427, FAX: 603-862-4013
| | - Roy Richardson
- Department of Molecular, Cellular, and Biomedical Sciences, 46 College Road, Rudman Hall, University of New Hampshire, Durham, NH 03824, 603-862-2427, FAX: 603-862-4013
| | - Shiwha Park
- Department of Molecular, Cellular, and Biomedical Sciences, 46 College Road, Rudman Hall, University of New Hampshire, Durham, NH 03824, 603-862-2427, FAX: 603-862-4013
| | - Chongxu Zhang
- Department of Molecular, Cellular, and Biomedical Sciences, 46 College Road, Rudman Hall, University of New Hampshire, Durham, NH 03824, 603-862-2427, FAX: 603-862-4013
| | - Wen Xi
- Department of Molecular, Cellular, and Biomedical Sciences, 46 College Road, Rudman Hall, University of New Hampshire, Durham, NH 03824, 603-862-2427, FAX: 603-862-4013
| | - Thomas M. Laue
- Department of Molecular, Cellular, and Biomedical Sciences, 46 College Road, Rudman Hall, University of New Hampshire, Durham, NH 03824, 603-862-2427, FAX: 603-862-4013
| | - Xin Wang
- Department of Molecular, Cellular, and Biomedical Sciences, 46 College Road, Rudman Hall, University of New Hampshire, Durham, NH 03824, 603-862-2427, FAX: 603-862-4013
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29
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Barraza CE, Solari CA, Marcovich I, Kershaw C, Galello F, Rossi S, Ashe MP, Portela P. The role of PKA in the translational response to heat stress in Saccharomyces cerevisiae. PLoS One 2017; 12:e0185416. [PMID: 29045428 PMCID: PMC5646765 DOI: 10.1371/journal.pone.0185416] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 09/12/2017] [Indexed: 11/18/2022] Open
Abstract
Cellular responses to stress stem from a variety of different mechanisms, including translation arrest and relocation of the translationally repressed mRNAs to ribonucleoprotein particles like stress granules (SGs) and processing bodies (PBs). Here, we examine the role of PKA in the S. cerevisiae heat shock response. Under mild heat stress Tpk3 aggregates and promotes aggregation of eIF4G, Pab1 and eIF4E, whereas severe heat stress leads to the formation of PBs and SGs that contain both Tpk2 and Tpk3 and a larger 48S translation initiation complex. Deletion of TPK2 or TPK3 impacts upon the translational response to heat stress of several mRNAs including CYC1, HSP42, HSP30 and ENO2. TPK2 deletion leads to a robust translational arrest, an increase in SGs/PBs aggregation and translational hypersensitivity to heat stress, whereas TPK3 deletion represses SGs/PBs formation, translational arrest and response for the analyzed mRNAs. Therefore, this work provides evidence indicating that Tpk2 and Tpk3 have opposing roles in translational adaptation during heat stress, and highlight how the same signaling pathway can be regulated to generate strikingly distinct physiological outputs.
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Affiliation(s)
- Carla E Barraza
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina
| | - Clara A Solari
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina
| | - Irina Marcovich
- Instituto de Investigaciones en Ingenieria Genetica y Biologia Molecular "Dr. Hector N. Torres", Buenos Aires, Argentina
| | - Christopher Kershaw
- The Michael Smith Building, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Fiorella Galello
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina
| | - Silvia Rossi
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina
| | - Mark P Ashe
- The Michael Smith Building, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Paula Portela
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas (IQUIBICEN-CONICET). Buenos Aires, Argentina
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30
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Brambilla M, Martani F, Branduardi P. The recruitment of the Saccharomyces cerevisiae poly(A)-binding protein into stress granules: new insights into the contribution of the different protein domains. FEMS Yeast Res 2017; 17:4061003. [DOI: 10.1093/femsyr/fox059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 08/02/2017] [Indexed: 12/17/2022] Open
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31
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Schuller AP, Wu CCC, Dever TE, Buskirk AR, Green R. eIF5A Functions Globally in Translation Elongation and Termination. Mol Cell 2017; 66:194-205.e5. [PMID: 28392174 PMCID: PMC5414311 DOI: 10.1016/j.molcel.2017.03.003] [Citation(s) in RCA: 286] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/10/2017] [Accepted: 03/03/2017] [Indexed: 12/11/2022]
Abstract
The eukaryotic translation factor eIF5A, originally identified as an initiation factor, was later shown to promote translation elongation of iterated proline sequences. Using a combination of ribosome profiling and in vitro biochemistry, we report a much broader role for eIF5A in elongation and uncover a critical function for eIF5A in termination. Ribosome profiling of an eIF5A-depleted strain reveals a global elongation defect, with abundant ribosomes stalling at many sequences, not limited to proline stretches. Our data also show ribosome accumulation at stop codons and in the 3' UTR, suggesting a global defect in termination in the absence of eIF5A. Using an in vitro reconstituted translation system, we find that eIF5A strongly promotes the translation of the stalling sequences identified by profiling and increases the rate of peptidyl-tRNA hydrolysis more than 17-fold. We conclude that eIF5A functions broadly in elongation and termination, rationalizing its high cellular abundance and essential nature.
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Affiliation(s)
- Anthony P Schuller
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Colin Chih-Chien Wu
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Thomas E Dever
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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32
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Seidel G, Meierhofer D, Şen NE, Guenther A, Krobitsch S, Auburger G. Quantitative Global Proteomics of Yeast PBP1 Deletion Mutants and Their Stress Responses Identifies Glucose Metabolism, Mitochondrial, and Stress Granule Changes. J Proteome Res 2016; 16:504-515. [PMID: 27966978 DOI: 10.1021/acs.jproteome.6b00647] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The yeast protein PBP1 is implicated in very diverse pathways. Intriguingly, its deletion mitigates the toxicity of human neurodegeneration factors. Here, we performed label-free quantitative global proteomics to identify crucial downstream factors, either without stress or under cell stress conditions (heat and NaN3). Compared to the wildtype BY4741 strain, PBP1 deletion always triggered downregulation of the key bioenergetics enzyme KGD2 and the prion protein RNQ1 as well as upregulation of the leucine biosynthesis enzyme LEU1. Without stress, enrichment of stress response factors was consistently detected for both deletion mutants; upon stress, these factors were more pronounced. The selective analysis of components of stress granules and P-bodies revealed a prominent downregulation of GIS2. Our yeast data are in good agreement with a global proteomics and metabolomics publication that the PBP1 ortholog ATAXIN-2 (ATXN2) knockout (KO) in mouse results in mitochondrial deficits in leucine/fatty acid catabolism and bioenergetics, with an obesity phenotype. Furthermore, our data provide the completely novel insight that PBP1 mutations in stress periods involve GIS2, a plausible scenario in view of previous data that both PBP1 and GIS2 relocalize from ribosomes to stress granules, interact with poly(A)-binding protein in translation regulation and prevent mitochondrial precursor overaccumulation stress (mPOS). This may be relevant for human diseases like spinocerebellar ataxias, amyotrophic lateral sclerosis, and the metabolic syndrome.
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Affiliation(s)
- Gunnar Seidel
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195 Berlin, Germany
| | - David Meierhofer
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195 Berlin, Germany
| | - Nesli-Ece Şen
- Experimental Neurology, Goethe University Medical School , Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| | - Anika Guenther
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195 Berlin, Germany
| | - Sylvia Krobitsch
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195 Berlin, Germany
| | - Georg Auburger
- Experimental Neurology, Goethe University Medical School , Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
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33
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Wang D, Wang S, He D, Gao S, Xue B, Wang L. Deletion of afpab1 Causes Increased Sensitivity to Oxidative Stress and Hypovirulence in Aspergillus fumigatus. Int J Mol Sci 2016; 17:ijms17111811. [PMID: 27801871 PMCID: PMC5133812 DOI: 10.3390/ijms17111811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/15/2016] [Accepted: 10/25/2016] [Indexed: 11/16/2022] Open
Abstract
Aspergillus fumigatus AFPAB1 is the ortholog of the Aspergillus oryzae cytoplasmic messenger ribonucleoprotein granules AOPAB1 that function to depress the initiation of translation during stress. A. fumigatus can regulate its cellular physiology in response to environmental stresses, but there has been no research on Pab1 in A. fumigatus. The associated gene afpab1 was replaced with a hygromycin-selectable marker to generate the strain Δafpab1. Phenotypic analysis showed that the Δafpab1 grew more weakly than the wild-type strain. Also the germination rate of Δafpab1 was decreased when exposed to oxidative stress. The morphology of Δafpab1 spores also showed great changes. The killing rate of Δafpab1 by RAW264.7 murine macrophage cells was increased, and the reactive oxygen species (ROS) scavenging ability of Δafpab1 was decreased. Pathogenicity testing showed that the deletion strain had decreased virulence. Therefore, we conclude that afpab1 activity is correlated with susceptibility to oxidative stress, and deletion of afpab1 from A. fumigatus possibly leads to observed hypovirulence in an immunosuppressed mouse model.
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Affiliation(s)
- Dongyang Wang
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, China.
| | - Shunan Wang
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, China.
| | - Dan He
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, China.
| | - Song Gao
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, China.
| | - Baiji Xue
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, China.
| | - Li Wang
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, China.
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Brink DP, Borgström C, Tueros FG, Gorwa-Grauslund MF. Real-time monitoring of the sugar sensing in Saccharomyces cerevisiae indicates endogenous mechanisms for xylose signaling. Microb Cell Fact 2016; 15:183. [PMID: 27776527 PMCID: PMC5078928 DOI: 10.1186/s12934-016-0580-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 10/14/2016] [Indexed: 12/03/2022] Open
Abstract
Background The sugar sensing and carbon catabolite repression in Baker’s yeast Saccharomyces cerevisiae is governed by three major signaling pathways that connect carbon source recognition with transcriptional regulation. Here we present a screening method based on a non-invasive in vivo reporter system for real-time, single-cell screening of the sugar signaling state in S. cerevisiae in response to changing carbon conditions, with a main focus on the response to glucose and xylose. Results The artificial reporter system was constructed by coupling a green fluorescent protein gene (yEGFP3) downstream of endogenous yeast promoters from the Snf3p/Rgt2p, SNF1/Mig1p and cAMP/PKA signaling pathways: HXT1p/2p/4p; SUC2p, CAT8p; TPS1p/2p and TEF4p respectively. A panel of eight biosensors strains was generated by single copy chromosomal integration of the different constructs in a W303-derived strain. The signaling biosensors were validated for their functionality with flow cytometry by comparing the fluorescence intensity (FI) response in the presence of high or nearly depleted glucose to the known induction/repression conditions of the eight different promoters. The FI signal correlated with the known patterns of the selected promoters while maintaining a non-invasive property on the cellular phenotype, as was demonstrated in terms of growth, metabolites and enzyme activity. Conclusions Once verified, the sensors were used to evaluate the signaling response to varying conditions of extracellular glucose, glycerol and xylose by screening in 96-well microtiter plates. We show that these yeast strains, which do not harbor any recombinant pathways for xylose utilization, are lacking a signaling response for extracellular xylose. However, for the HXT2p/4p sensors, a shift in the flow cytometry population dynamics indicated that internalized xylose does affect the signaling. These results suggest that the previously observed effects of this pentose on the S. cerevisiae physiology and gene regulation can be attributed to xylose and not only to a lack of glucose. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0580-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel P Brink
- Applied Microbiology, Department of Chemistry, Lund University, P.O. Box 124, 22100, Lund, Sweden.
| | - Celina Borgström
- Applied Microbiology, Department of Chemistry, Lund University, P.O. Box 124, 22100, Lund, Sweden
| | - Felipe G Tueros
- Applied Microbiology, Department of Chemistry, Lund University, P.O. Box 124, 22100, Lund, Sweden
| | - Marie F Gorwa-Grauslund
- Applied Microbiology, Department of Chemistry, Lund University, P.O. Box 124, 22100, Lund, Sweden
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35
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McLoughlin F, Basha E, Fowler ME, Kim M, Bordowitz J, Katiyar-Agarwal S, Vierling E. Class I and II Small Heat Shock Proteins Together with HSP101 Protect Protein Translation Factors during Heat Stress. PLANT PHYSIOLOGY 2016; 172:1221-1236. [PMID: 27474115 PMCID: PMC5047077 DOI: 10.1104/pp.16.00536] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 07/25/2016] [Indexed: 05/23/2023]
Abstract
The ubiquitous small heat shock proteins (sHSPs) are well documented to act in vitro as molecular chaperones to prevent the irreversible aggregation of heat-sensitive proteins. However, the in vivo activities of sHSPs remain unclear. To investigate the two most abundant classes of plant cytosolic sHSPs (class I [CI] and class II [CII]), RNA interference (RNAi) and overexpression lines were created in Arabidopsis (Arabidopsis thaliana) and shown to have reduced and enhanced tolerance, respectively, to extreme heat stress. Affinity purification of CI and CII sHSPs from heat-stressed seedlings recovered eukaryotic translation elongation factor (eEF) 1B (α-, β-, and γ-subunits) and eukaryotic translation initiation factor 4A (three isoforms), although the association with CI sHSPs was stronger and additional proteins involved in translation were recovered with CI sHSPs. eEF1B subunits became partially insoluble during heat stress and, in the CI and CII RNAi lines, showed reduced recovery to the soluble cell fraction after heat stress, which was also dependent on HSP101. Furthermore, after heat stress, CI sHSPs showed increased retention in the insoluble fraction in the CII RNAi line and vice versa. Immunolocalization revealed that both CI and CII sHSPs were present in cytosolic foci, some of which colocalized with HSP101 and with eEF1Bγ and eEF1Bβ. Thus, CI and CII sHSPs have both unique and overlapping functions and act either directly or indirectly to protect specific translation factors in cytosolic stress granules.
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Affiliation(s)
- Fionn McLoughlin
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (F.M., M.E.F., M.K., E.V.);Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (E.B., M.K., J.B., S.K.-A.); andDepartment of Botany, Tanta University, Tanta 31527, Egypt (E.B.)
| | - Eman Basha
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (F.M., M.E.F., M.K., E.V.);Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (E.B., M.K., J.B., S.K.-A.); andDepartment of Botany, Tanta University, Tanta 31527, Egypt (E.B.)
| | - Mary E Fowler
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (F.M., M.E.F., M.K., E.V.);Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (E.B., M.K., J.B., S.K.-A.); andDepartment of Botany, Tanta University, Tanta 31527, Egypt (E.B.)
| | - Minsoo Kim
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (F.M., M.E.F., M.K., E.V.);Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (E.B., M.K., J.B., S.K.-A.); andDepartment of Botany, Tanta University, Tanta 31527, Egypt (E.B.)
| | - Juliana Bordowitz
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (F.M., M.E.F., M.K., E.V.);Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (E.B., M.K., J.B., S.K.-A.); andDepartment of Botany, Tanta University, Tanta 31527, Egypt (E.B.)
| | - Surekha Katiyar-Agarwal
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (F.M., M.E.F., M.K., E.V.);Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (E.B., M.K., J.B., S.K.-A.); andDepartment of Botany, Tanta University, Tanta 31527, Egypt (E.B.)
| | - Elizabeth Vierling
- Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003 (F.M., M.E.F., M.K., E.V.);Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (E.B., M.K., J.B., S.K.-A.); andDepartment of Botany, Tanta University, Tanta 31527, Egypt (E.B.)
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36
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Malcova I, Farkasovsky M, Senohrabkova L, Vasicova P, Hasek J. New integrative modules for multicolor-protein labeling and live-cell imaging in Saccharomyces cerevisiae. FEMS Yeast Res 2016; 16:fow027. [PMID: 26994102 DOI: 10.1093/femsyr/fow027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2016] [Indexed: 12/30/2022] Open
Abstract
Live-imaging analysis is performed in many laboratories all over the world. Various tools have been developed to enable protein labeling either in plasmid or genomic context in live yeast cells. Here, we introduce a set of nine integrative modules for the C-terminal gene tagging that combines three fluorescent proteins (FPs)-ymTagBFP, mCherry and yTagRFP-T with three dominant selection markers: geneticin, nourseothricin and hygromycin. In addition, the construction of two episomal modules for Saccharomyces cerevisiae with photostable yTagRFP-T is also referred to. Our cassettes with orange, red and blue FPs can be combined with other fluorescent probes like green fluorescent protein to prepare double- or triple-labeled strains for multicolor live-cell imaging. Primers for PCR amplification of the cassettes were designed in such a way as to be fully compatible with the existing PCR toolbox representing over 50 various integrative modules and also with deletion cassettes either for single or repeated usage to enable a cost-effective and an easy exchange of tags. New modules can also be used for biochemical analysis since antibodies are available for all three fluorescent probes.
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Affiliation(s)
- Ivana Malcova
- Laboratory of Cell Reproduction, Institute of Microbiology CAS, v.v.i., 142 20 Prague 4, Czech Republic
| | - Marian Farkasovsky
- Laboratory of Molecular Microbiology, Institute of Molecular Biology SAS, 845 51 Bratislava, Slovakia
| | - Lenka Senohrabkova
- Laboratory of Cell Reproduction, Institute of Microbiology CAS, v.v.i., 142 20 Prague 4, Czech Republic
| | - Pavla Vasicova
- Laboratory of Cell Reproduction, Institute of Microbiology CAS, v.v.i., 142 20 Prague 4, Czech Republic
| | - Jiri Hasek
- Laboratory of Cell Reproduction, Institute of Microbiology CAS, v.v.i., 142 20 Prague 4, Czech Republic
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Wallace EWJ, Kear-Scott JL, Pilipenko EV, Schwartz MH, Laskowski PR, Rojek AE, Katanski CD, Riback JA, Dion MF, Franks AM, Airoldi EM, Pan T, Budnik BA, Drummond DA. Reversible, Specific, Active Aggregates of Endogenous Proteins Assemble upon Heat Stress. Cell 2015; 162:1286-98. [PMID: 26359986 DOI: 10.1016/j.cell.2015.08.041] [Citation(s) in RCA: 327] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/19/2015] [Accepted: 08/05/2015] [Indexed: 01/03/2023]
Abstract
Heat causes protein misfolding and aggregation and, in eukaryotic cells, triggers aggregation of proteins and RNA into stress granules. We have carried out extensive proteomic studies to quantify heat-triggered aggregation and subsequent disaggregation in budding yeast, identifying >170 endogenous proteins aggregating within minutes of heat shock in multiple subcellular compartments. We demonstrate that these aggregated proteins are not misfolded and destined for degradation. Stable-isotope labeling reveals that even severely aggregated endogenous proteins are disaggregated without degradation during recovery from shock, contrasting with the rapid degradation observed for many exogenous thermolabile proteins. Although aggregation likely inactivates many cellular proteins, in the case of a heterotrimeric aminoacyl-tRNA synthetase complex, the aggregated proteins remain active with unaltered fidelity. We propose that most heat-induced aggregation of mature proteins reflects the operation of an adaptive, autoregulatory process of functionally significant aggregate assembly and disassembly that aids cellular adaptation to thermal stress.
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Affiliation(s)
- Edward W J Wallace
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Jamie L Kear-Scott
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Evgeny V Pilipenko
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Michael H Schwartz
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Pawel R Laskowski
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Alexandra E Rojek
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Christopher D Katanski
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Joshua A Riback
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Michael F Dion
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | | | - Edoardo M Airoldi
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA; Department of Statistics, Harvard University, Cambridge, MA 02138, USA
| | - Tao Pan
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA
| | - Bogdan A Budnik
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | - D Allan Drummond
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57(th) Street, Chicago, IL 60637, USA.
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38
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Systemic control of protein synthesis through sequestration of translation and ribosome biogenesis factors during severe heat stress. FEBS Lett 2015; 589:3654-64. [PMID: 26484595 DOI: 10.1016/j.febslet.2015.10.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/16/2015] [Accepted: 10/11/2015] [Indexed: 12/22/2022]
Abstract
Environmental stress causes the sequestration of proteins into insoluble deposits including cytoplasmic stress granules (SGs), containing mRNA and a variety of translation factors. Here we systematically identified proteins sequestered in Saccharomyces cerevisiae at 46 °C by a SG co-localization screen and proteomic analysis of insoluble protein fractions. We identified novel SG components including essential aminoacyl-tRNA synthetases. Moreover, we discovered nucleus-associated deposits containing ribosome biogenesis factors. Our study suggests downregulation of cytosolic protein synthesis and nuclear ribosome production at multiple levels through heat shock induced protein sequestrations.
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39
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Cary GA, Vinh DBN, May P, Kuestner R, Dudley AM. Proteomic Analysis of Dhh1 Complexes Reveals a Role for Hsp40 Chaperone Ydj1 in Yeast P-Body Assembly. G3 (BETHESDA, MD.) 2015; 5:2497-511. [PMID: 26392412 PMCID: PMC4632068 DOI: 10.1534/g3.115.021444] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 09/16/2015] [Indexed: 12/18/2022]
Abstract
P-bodies (PB) are ribonucleoprotein (RNP) complexes that aggregate into cytoplasmic foci when cells are exposed to stress. Although the conserved mRNA decay and translational repression machineries are known components of PB, how and why cells assemble RNP complexes into large foci remain unclear. Using mass spectrometry to analyze proteins immunoisolated with the core PB protein Dhh1, we show that a considerable number of proteins contain low-complexity sequences, similar to proteins highly represented in mammalian RNP granules. We also show that the Hsp40 chaperone Ydj1, which contains an low-complexity domain and controls prion protein aggregation, is required for the formation of Dhh1-GFP foci on glucose depletion. New classes of proteins that reproducibly coenrich with Dhh1-GFP during PB induction include proteins involved in nucleotide or amino acid metabolism, glycolysis, transfer RNA aminoacylation, and protein folding. Many of these proteins have been shown to form foci in response to other stresses. Finally, analysis of RNA associated with Dhh1-GFP shows enrichment of mRNA encoding the PB protein Pat1 and catalytic RNAs along with their associated mitochondrial RNA-binding proteins. Thus, global characterization of PB composition has uncovered proteins important for PB assembly and evidence suggesting an active role for RNA in PB function.
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Affiliation(s)
- Gregory A Cary
- Institute for Systems Biology, Seattle, Washington 98109 Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
| | - Dani B N Vinh
- Institute for Systems Biology, Seattle, Washington 98109
| | - Patrick May
- Institute for Systems Biology, Seattle, Washington 98109 Luxembourg Centre for Systems Biomedicine, Université du Luxembourg, Esch-sur-Alzette, Luxembourg L-4362
| | - Rolf Kuestner
- Institute for Systems Biology, Seattle, Washington 98109
| | - Aimée M Dudley
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195 Pacific Northwest Diabetes Research Institute, Seattle, Washington 98122
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40
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Kroschwald S, Maharana S, Mateju D, Malinovska L, Nüske E, Poser I, Richter D, Alberti S. Promiscuous interactions and protein disaggregases determine the material state of stress-inducible RNP granules. eLife 2015; 4:e06807. [PMID: 26238190 PMCID: PMC4522596 DOI: 10.7554/elife.06807] [Citation(s) in RCA: 391] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/25/2015] [Indexed: 12/27/2022] Open
Abstract
RNA-protein (RNP) granules have been proposed to assemble by forming solid RNA/protein aggregates or through phase separation into a liquid RNA/protein phase. Which model describes RNP granules in living cells is still unclear. In this study, we analyze P bodies in budding yeast and find that they have liquid-like properties. Surprisingly, yeast stress granules adopt a different material state, which is reminiscent of solid protein aggregates and controlled by protein disaggregases. By using an assay to ectopically nucleate RNP granules, we further establish that RNP granule formation does not depend on amyloid-like aggregation but rather involves many promiscuous interactions. Finally, we show that stress granules have different properties in mammalian cells, where they show liquid-like behavior. Thus, we propose that the material state of RNP granules is flexible and that the solid state of yeast stress granules is an adaptation to extreme environments, made possible by the presence of a powerful disaggregation machine. DOI:http://dx.doi.org/10.7554/eLife.06807.001 Genes consist of long stretches of DNA that code for proteins. The DNA is first ‘transcribed’ to produce an RNA molecule, which is then translated into a protein. In most cells, RNA molecules are present within a structure called ribonucleoprotein (RNP for short) granules. These contain the protein machinery needed to transport, store, and break down RNAs. P bodies and stress granules are two types of RNP granules found in all cells, from yeast to human. P bodies are present at all times, whereas stress granules assemble when a cell experiences stressful conditions, such as a lack of nutrients or high temperatures. Once the stress has been overcome, the stress granules are disassembled. The precise details of how RNP granules assemble in cells remain poorly understood. One theory suggests that RNP granules form through a physical process called ‘phase separation’ in which RNA molecules and proteins above a certain critical concentration condense to form a liquid droplet. Other research has suggested that RNP granules arise when so-called prion-like proteins spontaneously clump together and start aggregating to form fibers. These granules would behave more like solids than liquids. Kroschwald et al. have now analyzed how P bodies and stress granules form in yeast and human cells using a chemical compound that can distinguish between liquid-like and solid-like structures. The results revealed that P bodies and stress granules behave very differently in yeast cells. While P bodies are indeed liquid droplets, stress granules are more solid in nature and act like protein aggregates. So why is there a difference between the two? It is known from previous work that when cells are stressed, many proteins misfold and start aggregating. Kroschwald et al. found that the formation of stress granules coincides with the formation of aggregates, suggesting that stress granules themselves are a type of aggregate. Furthermore, stress granule formation does not seem to involve prion-like fibers, but rather prion-like proteins can easily interact with other proteins in a promiscuous way, thus promoting the seeding of stress granules and their growth. Kroschwald et al. next studied human cells and observed that in these cells, both P bodies and stress granules were liquid droplets. These results together suggest that the physical properties and method of assembling P bodies and stress granules can vary from one organism to another. Future work will investigate whether the ability to form solid rather than liquid stress granules provides extra protection to yeast cells when they are stressed. It also remains to be tested whether and how stress granules convert into the pathological RNP aggregates that are often seen in neurodegenerative diseases. DOI:http://dx.doi.org/10.7554/eLife.06807.002
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Affiliation(s)
- Sonja Kroschwald
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Shovamayee Maharana
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Daniel Mateju
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Liliana Malinovska
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Elisabeth Nüske
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Doris Richter
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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Kroschwald S, Maharana S, Mateju D, Malinovska L, Nüske E, Poser I, Richter D, Alberti S. Promiscuous interactions and protein disaggregases determine the material state of stress-inducible RNP granules. eLife 2015; 4:e06807. [PMID: 26238190 DOI: 10.7554/elife.06807.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/25/2015] [Indexed: 05/23/2023] Open
Abstract
RNA-protein (RNP) granules have been proposed to assemble by forming solid RNA/protein aggregates or through phase separation into a liquid RNA/protein phase. Which model describes RNP granules in living cells is still unclear. In this study, we analyze P bodies in budding yeast and find that they have liquid-like properties. Surprisingly, yeast stress granules adopt a different material state, which is reminiscent of solid protein aggregates and controlled by protein disaggregases. By using an assay to ectopically nucleate RNP granules, we further establish that RNP granule formation does not depend on amyloid-like aggregation but rather involves many promiscuous interactions. Finally, we show that stress granules have different properties in mammalian cells, where they show liquid-like behavior. Thus, we propose that the material state of RNP granules is flexible and that the solid state of yeast stress granules is an adaptation to extreme environments, made possible by the presence of a powerful disaggregation machine.
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Affiliation(s)
- Sonja Kroschwald
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Shovamayee Maharana
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Daniel Mateju
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Liliana Malinovska
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Elisabeth Nüske
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Doris Richter
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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42
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Yeast mRNA localization: protein asymmetry, organelle localization and response to stress. Biochem Soc Trans 2015; 42:1256-60. [PMID: 25110034 DOI: 10.1042/bst20140086] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The localization of mRNA forms a key facet of the post-transcriptional control of gene expression and recent evidence suggests that it may be considerably more widespread than previously anticipated. For example, defined mRNA-containing granules can be associated with translational repression or activation. Furthermore, mRNA P-bodies (processing bodies) harbour much of the mRNA decay machinery and stress granules are thought to play a role in mRNA storage. In the present review, we explore the process of mRNA localization in the yeast Saccharomyces cerevisiae, examining connections between organellar mRNA localization and the response to stress. We also review recent data suggesting that even where there is a global relocalization of mRNA, the specificity and kinetics of this process can be regulated.
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Translational arrest due to cytoplasmic redox stress delays adaptation to growth on methanol and heterologous protein expression in a typical fed-batch culture of Pichia pastoris. PLoS One 2015; 10:e0119637. [PMID: 25785713 PMCID: PMC4364781 DOI: 10.1371/journal.pone.0119637] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 02/01/2015] [Indexed: 11/30/2022] Open
Abstract
Results We have followed a typical fed-batch induction regime for heterologous protein production under the control of the AOX1 promoter using both microarray and metabolomic analysis. The genetic constructs involved 1 and 3 copies of the TRY1 gene, encoding human trypsinogen. In small-scale laboratory cultures, expression of the 3 copy-number construct induced the unfolded protein response (UPR) sufficiently that titres of extracellular trypsinogen were lower in the 3-copy construct than with the 1-copy construct. In the fed-batch-culture, a similar pattern was observed, with higher expression from the 1-copy construct, but in this case there was no significant induction of UPR with the 3-copy strain. Analysis of the microarray and metabolomic information indicates that the 3-copy strain was undergoing cytoplasmic redox stress at the point of induction with methanol. In this Crabtree-negative yeast, this redox stress appeared to delay the adaptation to growth on methanol and supressed heterologous protein production, probably due to a block in translation. Conclusion Although redox imbalance as a result of artificially imposed hypoxia has previously been described, this is the first time that it has been characterised as a result of a transient metabolic imbalance and shown to involve a stress response which can lead to translational arrest. Without detailed analysis of the underlying processes it could easily have been mis-interpreted as secretion stress, transmitted through the UPR.
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44
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Yang X, Shen Y, Garre E, Hao X, Krumlinde D, Cvijović M, Arens C, Nyström T, Liu B, Sunnerhagen P. Stress granule-defective mutants deregulate stress responsive transcripts. PLoS Genet 2014; 10:e1004763. [PMID: 25375155 PMCID: PMC4222700 DOI: 10.1371/journal.pgen.1004763] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 09/18/2014] [Indexed: 01/28/2023] Open
Abstract
To reduce expression of gene products not required under stress conditions, eukaryotic cells form large and complex cytoplasmic aggregates of RNA and proteins (stress granules; SGs), where transcripts are kept translationally inert. The overall composition of SGs, as well as their assembly requirements and regulation through stress-activated signaling pathways remain largely unknown. We have performed a genome-wide screen of S. cerevisiae gene deletion mutants for defects in SG formation upon glucose starvation stress. The screen revealed numerous genes not previously implicated in SG formation. Most mutants with strong phenotypes are equally SG defective when challenged with other stresses, but a considerable fraction is stress-specific. Proteins associated with SG defects are enriched in low-complexity regions, indicating that multiple weak macromolecule interactions are responsible for the structural integrity of SGs. Certain SG-defective mutants, but not all, display an enhanced heat-induced mutation rate. We found several mutations affecting the Ran GTPase, regulating nucleocytoplasmic transport of RNA and proteins, to confer SG defects. Unexpectedly, we found stress-regulated transcripts to reach more extreme levels in mutants unable to form SGs: stress-induced mRNAs accumulate to higher levels than in the wild-type, whereas stress-repressed mRNAs are reduced further in such mutants. Our findings are consistent with the view that, not only are SGs being regulated by stress signaling pathways, but SGs also modulate the extent of stress responses. We speculate that nucleocytoplasmic shuttling of RNA-binding proteins is required for gene expression regulation during stress, and that SGs modulate this traffic. The absence of SGs thus leads the cell to excessive, and potentially deleterious, reactions to stress. When cells encounter harsh conditions, they face an energy crisis since the stress will reduce their energy production, and at the same time cause extra demands on energy expenditure. To tackle this dilemma, cells under stress form giant agglomerates of RNA and protein, called stress granules. In these, mRNA molecules are kept silent, preventing waste of energy on producing proteins not needed under these conditions. A few mRNAs, encoding proteins required for the cell to survive, stay outside of stress granules and escape this silencing. This mechanism can protect plants and microbes against cold spells or heat shocks, and human cells exposed to oxidative damage or toxic drugs. We have investigated which genes are necessary to form stress granules, and their impact on the stress response. We discovered that mutant cells unable to form stress granules overreacted to stress, in that they produced much higher levels of the induced mRNAs. We think this means that gene regulatory proteins are sequestered inside stress granules, inhibiting their action. Stress granules may thus function as moderators that dampen the stress response, safeguarding the cell against excessive reactions.
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Affiliation(s)
- Xiaoxue Yang
- School of Life Science and Engineering, Harbin Institute of Technology, Harbin, China
| | - Yi Shen
- School of Life Science and Engineering, Harbin Institute of Technology, Harbin, China
| | - Elena Garre
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Göteborg, Sweden
| | - Xinxin Hao
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Göteborg, Sweden
| | - Daniel Krumlinde
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Göteborg, Sweden
| | - Marija Cvijović
- Department of Mathematical Sciences, Chalmers University of Technology, Göteborg, Sweden
- Department of Mathematical Sciences, University of Gothenburg, Göteborg, Sweden
| | - Christina Arens
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Göteborg, Sweden
| | - Thomas Nyström
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Göteborg, Sweden
| | - Beidong Liu
- School of Life Science and Engineering, Harbin Institute of Technology, Harbin, China
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Göteborg, Sweden
- * E-mail: (BL); (PS)
| | - Per Sunnerhagen
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Göteborg, Sweden
- * E-mail: (BL); (PS)
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Nizhnikov AA, Antonets KS, Inge-Vechtomov SG, Derkatch IL. Modulation of efficiency of translation termination in Saccharomyces cerevisiae. Prion 2014; 8:247-60. [PMID: 25486049 DOI: 10.4161/pri.29851] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nonsense suppression is a readthrough of premature termination codons. It typically occurs either due to the recognition of stop codons by tRNAs with mutant anticodons, or due to a decrease in the fidelity of translation termination. In the latter case, suppressors usually promote the readthrough of different types of nonsense codons and are thus called omnipotent nonsense suppressors. Omnipotent nonsense suppressors were identified in yeast Saccharomyces cerevisiae in 1960s, and most of subsequent studies were performed in this model organism. Initially, omnipotent suppressors were localized by genetic analysis to different protein- and RNA-encoding genes, mostly the components of translational machinery. Later, nonsense suppression was found to be caused not only by genomic mutations, but also by epigenetic elements, prions. Prions are self-perpetuating protein conformations usually manifested by infectious protein aggregates. Modulation of translational accuracy by prions reflects changes in the activity of their structural proteins involved in different aspects of protein synthesis. Overall, nonsense suppression can be seen as a "phenotypic mirror" of events affecting the accuracy of the translational machine. However, the range of proteins participating in the modulation of translation termination fidelity is not fully elucidated. Recently, the list has been expanded significantly by findings that revealed a number of weak genetic and epigenetic nonsense suppressors, the effect of which can be detected only in specific genetic backgrounds. This review summarizes the data on the nonsense suppressors decreasing the fidelity of translation termination in S. cerevisiae, and discusses the functional significance of the modulation of translational accuracy.
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Affiliation(s)
- Anton A Nizhnikov
- a Department of Genetics and Biotechnology ; St. Petersburg State University ; St. Petersburg , Russia
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Zeng C, Chen Z, Xia J, Zhang K, Chen X, Zhou Y, Bo W, Song S, Deng D, Guo X, Wang B, Zhou J, Peng H, Wang W, Peng M, Zhang W. Chilling acclimation provides immunity to stress by altering regulatory networks and inducing genes with protective functions in cassava. BMC PLANT BIOLOGY 2014; 14:207. [PMID: 25090992 PMCID: PMC4236759 DOI: 10.1186/s12870-014-0207-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 07/22/2014] [Indexed: 05/23/2023]
Abstract
BACKGROUND Stress acclimation is an effective mechanism that plants acquired for adaption to dynamic environment. Even though generally considered to be sensitive to low temperature, Cassava, a major tropical crop, can be tolerant to much lower temperature after chilling acclimation. Improvement to chilling resistance could be beneficial to breeding. However, the underlying mechanism and the effects of chilling acclimation on chilling tolerance remain largely unexplored. RESULTS In order to understand the mechanism of chilling acclimation, we profiled and analyzed the transcriptome and microRNAome of Cassava, using high-throughput deep sequencing, across the normal condition, a moderate chilling stress (14°C), a harsh stress (4°C) after chilling acclimation (14°C), and a chilling shock from 24°C to 4°C. The results revealed that moderate stress and chilling shock triggered comparable degrees of transcriptional perturbation, and more importantly, about two thirds of differentially expressed genes reversed their expression from up-regulation to down-regulation or vice versa in response to hash stress after experiencing moderate stress. In addition, microRNAs played important roles in the process of this massive genetic circuitry rewiring. Furthermore, function analysis revealed that chilling acclimation helped the plant develop immunity to further harsh stress by exclusively inducing genes with function for nutrient reservation therefore providing protection, whereas chilling shock induced genes with function for viral reproduction therefore causing damage. CONCLUSIONS Our study revealed, for the first time, the molecular basis of chilling acclimation, and showed potential regulation role of microRNA in chilling response and acclimation in Euphorbia.
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Affiliation(s)
- Changying Zeng
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Zheng Chen
- Institute for Systems Biology, Jianghan University, Wuhan, 430056, Hubei, China
- Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, 63130, MO, USA
| | - Jing Xia
- Institute for Systems Biology, Jianghan University, Wuhan, 430056, Hubei, China
- Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, 63130, MO, USA
| | - Kevin Zhang
- Institute for Systems Biology, Jianghan University, Wuhan, 430056, Hubei, China
- Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, 63130, MO, USA
| | - Xin Chen
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Yufei Zhou
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Weiping Bo
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Shun Song
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Deli Deng
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Xin Guo
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Bin Wang
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Junfei Zhou
- Institute for Systems Biology, Jianghan University, Wuhan, 430056, Hubei, China
| | - Hai Peng
- Institute for Systems Biology, Jianghan University, Wuhan, 430056, Hubei, China
| | - Wenquan Wang
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Ming Peng
- The Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Weixiong Zhang
- Institute for Systems Biology, Jianghan University, Wuhan, 430056, Hubei, China
- Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, 63130, MO, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, 63110, MO, USA
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47
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Profilin 1 associates with stress granules and ALS-linked mutations alter stress granule dynamics. J Neurosci 2014; 34:8083-97. [PMID: 24920614 DOI: 10.1523/jneurosci.0543-14.2014] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mutations in the PFN1 gene encoding profilin 1 are a rare cause of familial amyotrophic lateral sclerosis (ALS). Profilin 1 is a well studied actin-binding protein but how PFN1 mutations cause ALS is unknown. The budding yeast, Saccharomyces cerevisiae, has one PFN1 ortholog. We expressed the ALS-linked profilin 1 mutant proteins in yeast, demonstrating a loss of protein stability and failure to restore growth to profilin mutant cells, without exhibiting gain-of-function toxicity. This model provides for simple and rapid screening of novel ALS-linked PFN1 variants. To gain insight into potential novel roles for profilin 1, we performed an unbiased, genome-wide synthetic lethal screen with yeast cells lacking profilin (pfy1Δ). Unexpectedly, deletion of several stress granule and processing body genes, including pbp1Δ, were found to be synthetic lethal with pfy1Δ. Mutations in ATXN2, the human ortholog of PBP1, are a known ALS genetic risk factor and ataxin 2 is a stress granule component in mammalian cells. Given this genetic interaction and recent evidence linking stress granule dynamics to ALS pathogenesis, we hypothesized that profilin 1 might also associate with stress granules. Here we report that profilin 1 and related protein profilin 2 are novel stress granule-associated proteins in mouse primary cortical neurons and in human cell lines and that ALS-linked mutations in profilin 1 alter stress granule dynamics, providing further evidence for the potential role of stress granules in ALS pathogenesis.
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Zhang C, Wang X, Park S, Chiang YC, Xi W, Laue TM, Denis CL. Only a subset of the PAB1-mRNP proteome is present in mRNA translation complexes. Protein Sci 2014; 23:1036-49. [PMID: 24838188 DOI: 10.1002/pro.2490] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 04/29/2014] [Accepted: 05/14/2014] [Indexed: 01/02/2023]
Abstract
We have previously identified 55 nonribosomal proteins in PAB1-mRNP complexes in Saccharomyces cerevisiae using mass spectrometric analysis. Because one of the inherent limitations of mass spectrometry is that it does not inform as to the size or type of complexes in which the proteins are present, we consequently used analytical ultracentrifugation with fluorescent detection system (AU-FDS) to determine which proteins are present in the 77S monosomal translation complex that contains minimally the closed-loop structure components (eIF4E, eIF4G, and PAB1), mRNA, and the 40S and 60S ribosomes. We assayed by AU-FDS analysis 33 additional PAB1-mRNP factors but found that only five of these proteins were present in the 77S translation complex: eRF1, SLF1, SSD1, PUB1, and SBP1. eRF1 is involved in translation termination, SBP1 is a translational repressor, and SLF1, SSD1, and PUB1 are known mRNA binding proteins. Many of the known P body/stress granule proteins that associate with the PAB1-mRNP were not present in the 77S translation complex, implying that P body/stress granules result from significant protein additions after translational cessation. These data inform that AU-FDS can clarify protein complex identification that remains undetermined after typical immunoprecipitation and mass spectrometric analyses.
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Affiliation(s)
- Chongxu Zhang
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, 03824
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49
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Zhang P, Li Y, Xia J, He J, Pu J, Xie J, Wu S, Feng L, Huang X, Zhang P. IPS-1 plays an essential role in dsRNA-induced stress granule formation by interacting with PKR and promoting its activation. J Cell Sci 2014; 127:2471-82. [PMID: 24659800 DOI: 10.1242/jcs.139626] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The formation of cytoplasmic stress granules and the innate immune response are two distinct cellular stress responses. Our study investigated the involvement of four innate immune proteins - retinoic-acid-inducible gene I (RIG-I, also known as DDX58), melanoma differentiation-associated gene 5 (MDA5, also known as IFIH1), IFN-β promoter stimulator (IPS-1, also known as MAVS) and protein kinase regulated by dsRNA (PKR, also known as EIF2AK2) in the formation of stress granules. Knockdown of IPS-1 or PKR significantly decreased the formation of stress granules induced by double-stranded (ds)RNA. IPS-1 depletion markedly attenuated the phosphorylation of PKR and eIF2α that was triggered by dsRNA, and IPS-1 facilitated the in vitro autophosphorylation of PKR. In IPS-1-depleted cells, the dsRNA-mediated dimerization of PKR through its dsRNA-binding domains was significantly abrogated, suggesting that IPS-1 might be involved in PKR dimerization. By co-immunoprecipitation and pulldown assays, our data demonstrate that IPS-1 directly binds to PKR through the IPS-1 caspase activation and recruitment domain (CARD), suggesting that the effect of IPS-1 on the formation of stress granules might be exerted through interacting with PKR and mediating its activation. PKR was recruited into stress granules upon activation, whereas the majority of IPS-1 protein formed clusters on mitochondrial membranes. Our work provides the first evidence that the innate signaling molecule IPS-1 plays an essential role in stress granule formation.
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Affiliation(s)
- Peifen Zhang
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Yuye Li
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Jun Xia
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Junfang He
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Jieying Pu
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Jiong Xie
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Siyu Wu
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Lianqiang Feng
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Xi Huang
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Ping Zhang
- Department of Immunology, Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
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50
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Simpson CE, Lui J, Kershaw CJ, Sims PFG, Ashe MP. mRNA localization to P-bodies in yeast is bi-phasic with many mRNAs captured in a late Bfr1p-dependent wave. J Cell Sci 2014; 127:1254-62. [PMID: 24424022 PMCID: PMC3953815 DOI: 10.1242/jcs.139055] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The relocalization of translationally repressed mRNAs to mRNA processing bodies Pbodies is a key consequence of cellular stress across many systems. Pbodies harbor mRNA degradation components and are implicated in mRNA decay, but the relative timing and control of mRNA relocalization to Pbodies is poorly understood. We used the MS2GFP system to follow the movement of specific endogenous mRNAs in live Saccharomyces cerevisiae cells after nutritional stress. It appears that the relocalization of mRNA to Pbodies after stress is biphasic some mRNAs are present early, whereas others are recruited much later concomitant with recruitment of translation initiation factors, such as eIF4E. We also find that Bfr1p is a latephaselocalizing Pbody protein that is important for the delayed entry of certain mRNAS to Pbodies. Therefore, for the mRNAs tested, relocalization to Pbodies varies both in terms of the kinetics and factor requirements. This work highlights a potential new regulatory juncture in gene expression that would facilitate the overall rationalization of protein content required for adaptation to stress.
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Affiliation(s)
- Clare E Simpson
- Department of Biochemistry, Downing Site, The University of Cambridge, Cambridge CB2 1QW, UK
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