1
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Koli S, Shetty S. Ribosomal dormancy at the nexus of ribosome homeostasis and protein synthesis. Bioessays 2024:e2300247. [PMID: 38769702 DOI: 10.1002/bies.202300247] [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: 12/28/2023] [Revised: 02/05/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024]
Abstract
Dormancy or hibernation is a non-proliferative state of cells with low metabolic activity and gene expression. Dormant cells sequester ribosomes in a translationally inactive state, called dormant/hibernating ribosomes. These dormant ribosomes are important for the preservation of ribosomes and translation shut-off. While recent studies attempted to elucidate their modes of formation, the regulation and roles of the diverse dormant ribosomal populations are still largely understudied. The mechanistic details of the formation of dormant ribosomes in stress and especially their disassembly during recovery remain elusive. In this review, we discuss the roles of dormant ribosomes and their potential regulatory mechanisms. Furthermore, we highlight the paradigms that need to be answered in the field of ribosomal dormancy.
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Affiliation(s)
- Saloni Koli
- Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai, India
| | - Sunil Shetty
- Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai, India
- Homi Bhabha National Institute, Mumbai, India
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2
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Helena-Bueno K, Chan LI, Melnikov SV. Rippling life on a dormant planet: hibernation of ribosomes, RNA polymerases, and other essential enzymes. Front Microbiol 2024; 15:1386179. [PMID: 38770025 PMCID: PMC11102965 DOI: 10.3389/fmicb.2024.1386179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/21/2024] [Indexed: 05/22/2024] Open
Abstract
Throughout the tree of life, cells and organisms enter states of dormancy or hibernation as a key feature of their biology: from a bacterium arresting its growth in response to starvation, to a plant seed anticipating placement in fertile ground, to a human oocyte poised for fertilization to create a new life. Recent research shows that when cells hibernate, many of their essential enzymes hibernate too: they disengage from their substrates and associate with a specialized group of proteins known as hibernation factors. Here, we summarize how hibernation factors protect essential cellular enzymes from undesired activity or irreparable damage in hibernating cells. We show how molecular hibernation, once viewed as rare and exclusive to certain molecules like ribosomes, is in fact a widespread property of biological molecules that is required for the sustained persistence of life on Earth.
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Affiliation(s)
| | | | - Sergey V. Melnikov
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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3
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Alagar Boopathy LR, Beadle E, Garcia-Bueno Rico A, Vera M. Proteostasis regulation through ribosome quality control and no-go-decay. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1809. [PMID: 37488089 DOI: 10.1002/wrna.1809] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 06/14/2023] [Accepted: 06/30/2023] [Indexed: 07/26/2023]
Abstract
Cell functionality relies on the existing pool of proteins and their folding into functional conformations. This is achieved through the regulation of protein synthesis, which requires error-free mRNAs and ribosomes. Ribosomes are quality control hubs for mRNAs and proteins. Problems during translation elongation slow down the decoding rate, leading to ribosome halting and the eventual collision with the next ribosome. Collided ribosomes form a specific disome structure recognized and solved by ribosome quality control (RQC) mechanisms. RQC pathways orchestrate the degradation of the problematic mRNA by no-go decay and the truncated nascent peptide, the repression of translation initiation, and the recycling of the stalled ribosomes. All these events maintain protein homeostasis and return valuable ribosomes to translation. As such, cell homeostasis and function are maintained at the mRNA level by preventing the production of aberrant or unnecessary proteins. It is becoming evident that the crosstalk between RQC and the protein homeostasis network is vital for cell function, as the absence of RQC components leads to the activation of stress response and neurodegenerative diseases. Here, we review the molecular events of RQC discovered through well-designed stalling reporters. Given the impact of RQC in proteostasis, we discuss the relevance of identifying endogenous mRNA regulated by RQC and their preservation in stress conditions. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms Translation > Regulation.
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Affiliation(s)
| | - Emma Beadle
- Department of Biochemistry, McGill University, Montreal, Canada
| | | | - Maria Vera
- Department of Biochemistry, McGill University, Montreal, Canada
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4
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Luo S, Alwattar B, Li Q, Bora K, Blomfield AK, Lin J, Fulton A, Chen J, Agrawal PB. Genetic deficiency of ribosomal rescue factor HBS1L causes retinal dystrophy associated with Pelota and EDF1 depletion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.18.562924. [PMID: 37905068 PMCID: PMC10614867 DOI: 10.1101/2023.10.18.562924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Inherited retinal diseases (IRDs) encompass a genetically diverse group of conditions in which mutations in genes critical to retinal function lead to progressive loss of photoreceptor cells and subsequent visual impairment. A handful of ribosome-associated genes have been implicated in retinal disorders alongside neurological phenotypes. This study focuses on the HBS1L gene, encoding HBS1 Like Translational GTPase which has been recognized as a critical ribosomal rescue factor. Previously, we have reported a female child carrying biallelic HBS1L mutations, manifesting growth restriction, developmental delay, and hypotonia. In this study, we describe her ophthalmologic findings, compare them with the Hbs1ltm1a/tm1a hypomorph mouse model, and evaluate the underlying microscopic and molecular perturbations. The patient was noted to have impaired visual function observed by electroretinogram (ERG), with dampened amplitudes of a- and b-waves in both rod- and cone-mediated responses. Hbs1ltm1a/tm1a mice exhibited profound retinal thinning of the entire retina, specifically of the outer retinal photoreceptor layer, detected using in vivo imaging of optical coherence tomography (OCT) and retinal cross sections. TUNEL assay revealed retinal degeneration due to extensive photoreceptor cell apoptosis. Loss of HBS1L resulted in comprehensive proteomic alterations in mass spectrometry analysis, with169 proteins increased and 480 proteins decreased including many critical IRD-related proteins. GO biological process and GSEA analyses reveal that these downregulated proteins are primarily involved in photoreceptor cell development, cilium assembly, phototransduction, and aerobic respiration. Furthermore, apart from the diminished level of PELO, a known partner protein, HBS1L depletion was accompanied by reduction in translation machinery associated 7 homolog (Tma7), and Endothelial differentiation-related factor 1(Edf1) proteins, the latter of which coordinates cellular responses to ribosome collisions. This novel connection between HBS1L and ribosome collision sensor (EDF1) further highlights the intricate mechanisms underpinning ribosomal rescue and quality control that are essential to maintain homeostasis of key proteins of retinal health, such as rhodopsin.
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Affiliation(s)
- Shiyu Luo
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine and Holtz Children’s Hospital, Jackson Health System, Miami, FL 33136, USA
- Division of Genetics and Genomics and The Manton Center for Orphan Disease Research, Boston, MA 02115, USA
| | - Bilal Alwattar
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School; Boston, MA 02115, USA
| | - Qifei Li
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine and Holtz Children’s Hospital, Jackson Health System, Miami, FL 33136, USA
- Division of Genetics and Genomics and The Manton Center for Orphan Disease Research, Boston, MA 02115, USA
| | - Kiran Bora
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School; Boston, MA 02115, USA
| | - Alexandra K. Blomfield
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School; Boston, MA 02115, USA
| | - Jasmine Lin
- Division of Genetics and Genomics and The Manton Center for Orphan Disease Research, Boston, MA 02115, USA
| | - Anne Fulton
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School; Boston, MA 02115, USA
| | - Jing Chen
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School; Boston, MA 02115, USA
| | - Pankaj B. Agrawal
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine and Holtz Children’s Hospital, Jackson Health System, Miami, FL 33136, USA
- Division of Genetics and Genomics and The Manton Center for Orphan Disease Research, Boston, MA 02115, USA
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5
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Nguyen T, Mills JC, Cho CJ. The coordinated management of ribosome and translation during injury and regeneration. Front Cell Dev Biol 2023; 11:1186638. [PMID: 37427381 PMCID: PMC10325863 DOI: 10.3389/fcell.2023.1186638] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/06/2023] [Indexed: 07/11/2023] Open
Abstract
Diverse acute and chronic injuries induce damage responses in the gastrointestinal (GI) system, and numerous cell types in the gastrointestinal tract demonstrate remarkable resilience, adaptability, and regenerative capacity in response to stress. Metaplasias, such as columnar and secretory cell metaplasia, are well-known adaptations that these cells make, the majority of which are epidemiologically associated with an elevated cancer risk. On a number of fronts, it is now being investigated how cells respond to injury at the tissue level, where diverse cell types that differ in proliferation capacity and differentiation state cooperate and compete with one another to participate in regeneration. In addition, the cascades or series of molecular responses that cells show are just beginning to be understood. Notably, the ribosome, a ribonucleoprotein complex that is essential for translation on the endoplasmic reticulum (ER) and in the cytoplasm, is recognized as the central organelle during this process. The highly regulated management of ribosomes as key translational machinery, and their platform, rough endoplasmic reticulum, are not only essential for maintaining differentiated cell identity, but also for achieving successful cell regeneration after injury. This review will cover in depth how ribosomes, the endoplasmic reticulum, and translation are regulated and managed in response to injury (e.g., paligenosis), as well as why this is essential for the proper adaptation of a cell to stress. For this, we will first discuss how multiple gastrointestinal organs respond to stress through metaplasia. Next, we will cover how ribosomes are generated, maintained, and degraded, in addition to the factors that govern translation. Finally, we will investigate how ribosomes and translation machinery are dynamically regulated in response to injury. Our increased understanding of this overlooked cell fate decision mechanism will facilitate the discovery of novel therapeutic targets for gastrointestinal tract tumors, focusing on ribosomes and translation machinery.
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Affiliation(s)
- Thanh Nguyen
- Department of Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Jason C. Mills
- Department of Medicine, Baylor College of Medicine, Houston, TX, United States
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, United States
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States
| | - Charles J. Cho
- Department of Medicine, Baylor College of Medicine, Houston, TX, United States
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6
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Smith PR, Loerch S, Kunder N, Stanowick AD, Lou TF, Campbell ZT. Functionally distinct roles for eEF2K in the control of ribosome availability and p-body abundance. Nat Commun 2021; 12:6789. [PMID: 34815424 PMCID: PMC8611098 DOI: 10.1038/s41467-021-27160-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 11/07/2021] [Indexed: 11/09/2022] Open
Abstract
Processing bodies (p-bodies) are a prototypical phase-separated RNA-containing granule. Their abundance is highly dynamic and has been linked to translation. Yet, the molecular mechanisms responsible for coordinate control of the two processes are unclear. Here, we uncover key roles for eEF2 kinase (eEF2K) in the control of ribosome availability and p-body abundance. eEF2K acts on a sole known substrate, eEF2, to inhibit translation. We find that the eEF2K agonist nelfinavir abolishes p-bodies in sensory neurons and impairs translation. To probe the latter, we used cryo-electron microscopy. Nelfinavir stabilizes vacant 80S ribosomes. They contain SERBP1 in place of mRNA and eEF2 in the acceptor site. Phosphorylated eEF2 associates with inactive ribosomes that resist splitting in vitro. Collectively, the data suggest that eEF2K defines a population of inactive ribosomes resistant to recycling and protected from degradation. Thus, eEF2K activity is central to both p-body abundance and ribosome availability in sensory neurons.
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Affiliation(s)
- Patrick R. Smith
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Sarah Loerch
- grid.443970.dJanelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA USA ,grid.205975.c0000 0001 0740 6917University of California, Santa Cruz, Department of Chemistry and Biochemistry, Santa Cruz, CA USA
| | - Nikesh Kunder
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Alexander D. Stanowick
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Tzu-Fang Lou
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Zachary T. Campbell
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA ,grid.267323.10000 0001 2151 7939The Center for Advanced Pain Studies (CAPS), University of Texas at Dallas, Richardson, TX USA
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7
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Korostelev AA. Diversity and Similarity of Termination and Ribosome Rescue in Bacterial, Mitochondrial, and Cytoplasmic Translation. BIOCHEMISTRY (MOSCOW) 2021; 86:1107-1121. [PMID: 34565314 DOI: 10.1134/s0006297921090066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
When a ribosome encounters the stop codon of an mRNA, it terminates translation, releases the newly made protein, and is recycled to initiate translation on a new mRNA. Termination is a highly dynamic process in which release factors (RF1 and RF2 in bacteria; eRF1•eRF3•GTP in eukaryotes) coordinate peptide release with large-scale molecular rearrangements of the ribosome. Ribosomes stalled on aberrant mRNAs are rescued and recycled by diverse bacterial, mitochondrial, or cytoplasmic quality control mechanisms. These are catalyzed by rescue factors with peptidyl-tRNA hydrolase activity (bacterial ArfA•RF2 and ArfB, mitochondrial ICT1 and mtRF-R, and cytoplasmic Vms1), that are distinct from each other and from release factors. Nevertheless, recent structural studies demonstrate a remarkable similarity between translation termination and ribosome rescue mechanisms. This review describes how these pathways rely on inherent ribosome dynamics, emphasizing the active role of the ribosome in all translation steps.
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Affiliation(s)
- Andrei A Korostelev
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, UMass Medical School, Worcester, MA, USA.
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8
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Arabidopsis REI-LIKE proteins activate ribosome biogenesis during cold acclimation. Sci Rep 2021; 11:2410. [PMID: 33510206 PMCID: PMC7844247 DOI: 10.1038/s41598-021-81610-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/06/2021] [Indexed: 12/11/2022] Open
Abstract
Arabidopsis REIL proteins are cytosolic ribosomal 60S-biogenesis factors. After shift to 10 °C, reil mutants deplete and slowly replenish non-translating eukaryotic ribosome complexes of root tissue, while controlling the balance of non-translating 40S- and 60S-subunits. Reil mutations respond by hyper-accumulation of non-translating subunits at steady-state temperature; after cold-shift, a KCl-sensitive 80S sub-fraction remains depleted. We infer that Arabidopsis may buffer fluctuating translation by pre-existing non-translating ribosomes before de novo synthesis meets temperature-induced demands. Reil1 reil2 double mutants accumulate 43S-preinitiation and pre-60S-maturation complexes and alter paralog composition of ribosomal proteins in non-translating complexes. With few exceptions, e.g. RPL3B and RPL24C, these changes are not under transcriptional control. Our study suggests requirement of de novo synthesis of eukaryotic ribosomes for long-term cold acclimation, feedback control of NUC2 and eIF3C2 transcription and links new proteins, AT1G03250, AT5G60530, to plant ribosome biogenesis. We propose that Arabidopsis requires biosynthesis of specialized ribosomes for cold acclimation.
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9
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Jungers CF, Elliff JM, Masson-Meyers DS, Phiel CJ, Origanti S. Regulation of eukaryotic translation initiation factor 6 dynamics through multisite phosphorylation by GSK3. J Biol Chem 2020; 295:12796-12813. [PMID: 32703900 DOI: 10.1074/jbc.ra120.013324] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/16/2020] [Indexed: 01/25/2023] Open
Abstract
Eukaryotic translation initiation factor 6 (eIF6) is essential for the synthesis of 60S ribosomal subunits and for regulating the association of 60S and 40S subunits. A mechanistic understanding of how eIF6 modulates translation in response to stress, specifically starvation-induced stress, is lacking. We here show a novel mode of eIF6 regulation by glycogen synthase kinase 3 (GSK3) that is predominantly active in response to serum starvation. Both GSK3α and GSK3β phosphorylate human eIF6. Multiple residues in the C terminus of eIF6 are phosphorylated by GSK3 in a sequential manner. In response to serum starvation, eIF6 accumulates in the cytoplasm, and this altered localization depends on phosphorylation by GSK3. Disruption of eIF6 phosphorylation exacerbates the translation inhibitory response to serum starvation and stalls cell growth. These results suggest that eIF6 regulation by GSK3 contributes to the attenuation of global protein synthesis that is critical for adaptation to starvation-induced stress.
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Affiliation(s)
- Courtney F Jungers
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Jonah M Elliff
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | | | - Christopher J Phiel
- Department of Integrative Biology, University of Colorado Denver, Colorado, USA
| | - Sofia Origanti
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA .,Department of Biology, Saint Louis University, St. Louis, Missouri, USA
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10
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Wells JN, Buschauer R, Mackens-Kiani T, Best K, Kratzat H, Berninghausen O, Becker T, Gilbert W, Cheng J, Beckmann R. Structure and function of yeast Lso2 and human CCDC124 bound to hibernating ribosomes. PLoS Biol 2020; 18:e3000780. [PMID: 32687489 PMCID: PMC7392345 DOI: 10.1371/journal.pbio.3000780] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/30/2020] [Accepted: 07/01/2020] [Indexed: 12/20/2022] Open
Abstract
Cells adjust to nutrient deprivation by reversible translational shutdown. This is accompanied by maintaining inactive ribosomes in a hibernation state, in which they are bound by proteins with inhibitory and protective functions. In eukaryotes, such a function was attributed to suppressor of target of Myb protein 1 (Stm1; SERPINE1 mRNA-binding protein 1 [SERBP1] in mammals), and recently, late-annotated short open reading frame 2 (Lso2; coiled-coil domain containing short open reading frame 124 [CCDC124] in mammals) was found to be involved in translational recovery after starvation from stationary phase. Here, we present cryo-electron microscopy (cryo-EM) structures of translationally inactive yeast and human ribosomes. We found Lso2/CCDC124 accumulating on idle ribosomes in the nonrotated state, in contrast to Stm1/SERBP1-bound ribosomes, which display a rotated state. Lso2/CCDC124 bridges the decoding sites of the small with the GTPase activating center (GAC) of the large subunit. This position allows accommodation of the duplication of multilocus region 34 protein (Dom34)-dependent ribosome recycling system, which splits Lso2-containing, but not Stm1-containing, ribosomes. We propose a model in which Lso2 facilitates rapid translation reactivation by stabilizing the recycling-competent state of inactive ribosomes.
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Affiliation(s)
- Jennifer N. Wells
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Robert Buschauer
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Timur Mackens-Kiani
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Katharina Best
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Hanna Kratzat
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Otto Berninghausen
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Thomas Becker
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Wendy Gilbert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Jingdong Cheng
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Roland Beckmann
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
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11
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Ghosh A, Williams LD, Pestov DG, Shcherbik N. Proteotoxic stress promotes entrapment of ribosomes and misfolded proteins in a shared cytosolic compartment. Nucleic Acids Res 2020; 48:3888-3905. [PMID: 32030400 PMCID: PMC7144922 DOI: 10.1093/nar/gkaa068] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 01/03/2020] [Accepted: 01/21/2020] [Indexed: 11/23/2022] Open
Abstract
Cells continuously monitor protein synthesis to prevent accumulation of aberrant polypeptides. Insufficient capacity of cellular degradative systems, chaperone shortage or high levels of mistranslation by ribosomes can result in proteotoxic stress and endanger proteostasis. One of the least explored reasons for mistranslation is the incorrect functioning of the ribosome itself. To understand how cells deal with ribosome malfunction, we introduced mutations in the Expansion Segment 7 (ES7L) of 25S rRNA that allowed the formation of mature, translationally active ribosomes but induced proteotoxic stress and compromised cell viability. The ES7L-mutated ribosomes escaped nonfunctional rRNA Decay (NRD) and remained stable. Remarkably, ES7L-mutated ribosomes showed increased segregation into cytoplasmic foci containing soluble misfolded proteins. This ribosome entrapment pathway, termed TRAP (Translational Relocalization with Aberrant Polypeptides), was generalizable beyond the ES7L mutation, as wild-type ribosomes also showed increased relocalization into the same compartments in cells exposed to proteotoxic stressors. We propose that during TRAP, assembled ribosomes associated with misfolded nascent chains move into cytoplasmic compartments enriched in factors that facilitate protein quality control. In addition, TRAP may help to keep translation at its peak efficiency by preventing malfunctioning ribosomes from active duty in translation.
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Affiliation(s)
- Arnab Ghosh
- Department for Cell Biology and Neuroscience, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
| | - Loren Dean Williams
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, GA 30332, USA
| | - Dimitri G Pestov
- Department for Cell Biology and Neuroscience, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
| | - Natalia Shcherbik
- Department for Cell Biology and Neuroscience, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
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12
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Nürenberg-Goloub E, Kratzat H, Heinemann H, Heuer A, Kötter P, Berninghausen O, Becker T, Tampé R, Beckmann R. Molecular analysis of the ribosome recycling factor ABCE1 bound to the 30S post-splitting complex. EMBO J 2020; 39:e103788. [PMID: 32064661 PMCID: PMC7196836 DOI: 10.15252/embj.2019103788] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 12/15/2022] Open
Abstract
Ribosome recycling by the twin‐ATPase ABCE1 is a key regulatory process in mRNA translation and surveillance and in ribosome‐associated protein quality control in Eukarya and Archaea. Here, we captured the archaeal 30S ribosome post‐splitting complex at 2.8 Å resolution by cryo‐electron microscopy. The structure reveals the dynamic behavior of structural motifs unique to ABCE1, which ultimately leads to ribosome splitting. More specifically, we provide molecular details on how conformational rearrangements of the iron–sulfur cluster domain and hinge regions of ABCE1 are linked to closure of its nucleotide‐binding sites. The combination of mutational and functional analyses uncovers an intricate allosteric network between the ribosome, regulatory domains of ABCE1, and its two structurally and functionally asymmetric ATP‐binding sites. Based on these data, we propose a refined model of how signals from the ribosome are integrated into the ATPase cycle of ABCE1 to orchestrate ribosome recycling.
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Affiliation(s)
- Elina Nürenberg-Goloub
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt a.M., Germany
| | - Hanna Kratzat
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, München, Germany
| | - Holger Heinemann
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt a.M., Germany
| | - André Heuer
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, München, Germany
| | - Peter Kötter
- Institute for Molecular Biosciences, Biocenter, Goethe University Frankfurt, Frankfurt a.M., Germany
| | - Otto Berninghausen
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, München, Germany
| | - Thomas Becker
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, München, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Frankfurt a.M., Germany
| | - Roland Beckmann
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, München, Germany
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13
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Rath S, Prangley E, Donovan J, Demarest K, Wingreen NS, Meir Y, Korennykh A. Concerted 2-5A-Mediated mRNA Decay and Transcription Reprogram Protein Synthesis in the dsRNA Response. Mol Cell 2019; 75:1218-1228.e6. [PMID: 31494033 DOI: 10.1016/j.molcel.2019.07.027] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/13/2019] [Accepted: 07/16/2019] [Indexed: 01/09/2023]
Abstract
Viral and endogenous double-stranded RNA (dsRNA) is a potent trigger for programmed RNA degradation by the 2-5A/RNase L complex in cells of all mammals. This 2-5A-mediated decay (2-5AMD) is a conserved stress response switching global protein synthesis from homeostasis to production of interferons (IFNs). To understand this mechanism, we examined 2-5AMD in human cells and found that it triggers polysome collapse characteristic of inhibited translation initiation. We determined that translation initiation complexes and ribosomes purified from translation-arrested cells remain functional. However, spike-in RNA sequencing (RNA-seq) revealed cell-wide decay of basal mRNAs accompanied by rapid accumulation of mRNAs encoding innate immune proteins. Our data attribute this 2-5AMD evasion to better stability of defense mRNAs and positive feedback in the IFN response amplified by RNase L-resistant molecules. We conclude that 2-5AMD and transcription act in concert to refill mammalian cells with defense mRNAs, thereby "prioritizing" the synthesis of innate immune proteins.
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Affiliation(s)
- Sneha Rath
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Eliza Prangley
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jesse Donovan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Kaitlin Demarest
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Yigal Meir
- Department of Physics, Ben Gurion University, Beer-Sheva 84105, Israel
| | - Alexei Korennykh
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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14
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Weisser M, Ban N. Extensions, Extra Factors, and Extreme Complexity: Ribosomal Structures Provide Insights into Eukaryotic Translation. Cold Spring Harb Perspect Biol 2019; 11:11/9/a032367. [PMID: 31481454 DOI: 10.1101/cshperspect.a032367] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although the basic aspects of protein synthesis are preserved in all kingdoms of life, there are many important structural and functional differences between bacterial and the more complex eukaryotic ribosomes. High-resolution cryo-electron microscopy (cryo-EM) and X-ray crystallography structures of eukaryotic ribosomes have revealed the complex architectures of eukaryotic ribosomes and species-specific variations in protein and ribosomal RNA (rRNA) extensions. They also enabled structural studies of a range of eukaryotic ribosomal complexes involved in translation initiation, elongation, and termination, revealing unique mechanistic features of the eukaryotic translation process, especially with respect to the identification and recognition of translation start and stop codons on messenger RNAs (mRNAs). Most recently, structural biology has provided insights into the eukaryotic ribosomal biogenesis pathway by visualizing several of its complex intermediates. This review highlights the past decade's structural work on eukaryotic ribosomes and its implications on our understanding of eukaryotic translation.
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Affiliation(s)
- Melanie Weisser
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Nenad Ban
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
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15
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Imai H, Abe T, Miyoshi T, Nishikawa SI, Ito K, Uchiumi T. The ribosomal stalk protein is crucial for the action of the conserved ATPase ABCE1. Nucleic Acids Res 2019; 46:7820-7830. [PMID: 30010948 PMCID: PMC6125642 DOI: 10.1093/nar/gky619] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/28/2018] [Indexed: 01/14/2023] Open
Abstract
The ATP-binding cassette (ABC) protein ABCE1 is an essential factor in ribosome recycling during translation. However, the detailed mechanochemistry of its recruitment to the ribosome, ATPase activation and subunit dissociation remain to be elucidated. Here, we show that the ribosomal stalk protein, which is known to participate in the actions of translational GTPase factors, plays an important role in these events. Biochemical and crystal structural data indicate that the conserved hydrophobic amino acid residues at the C-terminus of the archaeal stalk protein aP1 binds to the nucleotide-binding domain 1 (NBD1) of aABCE1, and that this binding is crucial for ATPase activation of aABCE1 on the ribosome. The functional role of the stalk•ABCE1 interaction in ATPase activation and the subunit dissociation is also investigated using mutagenesis in a yeast system. The data demonstrate that the ribosomal stalk protein likely participates in efficient actions of both archaeal and eukaryotic ABCE1 in ribosome recycling. The results also show that the stalk protein has a role in the function of ATPase as well as GTPase factors in translation.
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Affiliation(s)
- Hirotatsu Imai
- Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Takaya Abe
- Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Tomohiro Miyoshi
- Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Shuh-Ichi Nishikawa
- Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Kosuke Ito
- Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Toshio Uchiumi
- Department of Biology, Faculty of Science, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
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16
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O’Connell AE, Gerashchenko MV, O’Donohue MF, Rosen SM, Huntzinger E, Gleeson D, Galli A, Ryder E, Cao S, Murphy Q, Kazerounian S, Morton SU, Schmitz-Abe K, Gladyshev VN, Gleizes PE, Séraphin B, Agrawal PB. Mammalian Hbs1L deficiency causes congenital anomalies and developmental delay associated with Pelota depletion and 80S monosome accumulation. PLoS Genet 2019; 15:e1007917. [PMID: 30707697 PMCID: PMC6373978 DOI: 10.1371/journal.pgen.1007917] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 02/13/2019] [Accepted: 12/25/2018] [Indexed: 12/18/2022] Open
Abstract
Hbs1 has been established as a central component of the cell's translational quality control pathways in both yeast and prokaryotic models; however, the functional characteristics of its human ortholog (Hbs1L) have not been well-defined. We recently reported a novel human phenotype resulting from a mutation in the critical coding region of the HBS1L gene characterized by facial dysmorphism, severe growth restriction, axial hypotonia, global developmental delay and retinal pigmentary deposits. Here we further characterize downstream effects of the human HBS1L mutation. HBS1L has three transcripts in humans, and RT-PCR demonstrated reduced mRNA levels corresponding with transcripts V1 and V2 whereas V3 expression was unchanged. Western blot analyses revealed Hbs1L protein was absent in the patient cells. Additionally, polysome profiling revealed an abnormal aggregation of 80S monosomes in patient cells under baseline conditions. RNA and ribosomal sequencing demonstrated an increased translation efficiency of ribosomal RNA in Hbs1L-deficient fibroblasts, suggesting that there may be a compensatory increase in ribosome translation to accommodate the increased 80S monosome levels. This enhanced translation was accompanied by upregulation of mTOR and 4-EBP protein expression, suggesting an mTOR-dependent phenomenon. Furthermore, lack of Hbs1L caused depletion of Pelota protein in both patient cells and mouse tissues, while PELO mRNA levels were unaffected. Inhibition of proteasomal function partially restored Pelota expression in human Hbs1L-deficient cells. We also describe a mouse model harboring a knockdown mutation in the murine Hbs1l gene that shared several of the phenotypic elements observed in the Hbs1L-deficient human including facial dysmorphism, growth restriction and retinal deposits. The Hbs1lKO mice similarly demonstrate diminished Pelota levels that were rescued by proteasome inhibition.
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Affiliation(s)
- Amy E. O’Connell
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Maxim V. Gerashchenko
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Marie-Francoise O’Donohue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Samantha M. Rosen
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Eric Huntzinger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Université de Strasbourg, Centre National de La Recherche Scientifique UMR 7104, INSERM U964, Strasbourg, France
| | - Diane Gleeson
- Wellcome Sanger Institute, Cambridge, United Kingdom
| | | | - Edward Ryder
- Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Siqi Cao
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Quinn Murphy
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Shideh Kazerounian
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Sarah U. Morton
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Klaus Schmitz-Abe
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Vadim N. Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pierre-Emmanuel Gleizes
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Bertrand Séraphin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Université de Strasbourg, Centre National de La Recherche Scientifique UMR 7104, INSERM U964, Strasbourg, France
| | - Pankaj B. Agrawal
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
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17
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Brodiazhenko T, Johansson MJO, Takada H, Nissan T, Hauryliuk V, Murina V. Elimination of Ribosome Inactivating Factors Improves the Efficiency of Bacillus subtilis and Saccharomyces cerevisiae Cell-Free Translation Systems. Front Microbiol 2018; 9:3041. [PMID: 30619132 PMCID: PMC6305275 DOI: 10.3389/fmicb.2018.03041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/26/2018] [Indexed: 12/29/2022] Open
Abstract
Cell-free translation systems based on cellular lysates optimized for in vitro protein synthesis have multiple applications both in basic and applied science, ranging from studies of translational regulation to cell-free production of proteins and ribosome-nascent chain complexes. In order to achieve both high activity and reproducibility in a translation system, it is essential that the ribosomes in the cellular lysate are enzymatically active. Here we demonstrate that genomic disruption of genes encoding ribosome inactivating factors - HPF in Bacillus subtilis and Stm1 in Saccharomyces cerevisiae - robustly improve the activities of bacterial and yeast translation systems. Importantly, the elimination of B. subtilis HPF results in a complete loss of 100S ribosomes, which otherwise interfere with disome-based approaches for preparation of stalled ribosomal complexes for cryo-electron microscopy studies.
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Affiliation(s)
- Tetiana Brodiazhenko
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Institute of Technology, University of Tartu, Tartu, Estonia
| | | | - Hiraku Takada
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Tracy Nissan
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Vasili Hauryliuk
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Victoriia Murina
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
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18
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Simms CL, Kim KQ, Yan LL, Qiu J, Zaher HS. Interactions between the mRNA and Rps3/uS3 at the entry tunnel of the ribosomal small subunit are important for no-go decay. PLoS Genet 2018; 14:e1007818. [PMID: 30475795 PMCID: PMC6283612 DOI: 10.1371/journal.pgen.1007818] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/06/2018] [Accepted: 11/07/2018] [Indexed: 11/25/2022] Open
Abstract
No-go Decay (NGD) is a process that has evolved to deal with stalled ribosomes resulting from structural blocks or aberrant mRNAs. The process is distinguished by an endonucleolytic cleavage prior to degradation of the transcript. While many of the details of the pathway have been described, the identity of the endonuclease remains unknown. Here we identify residues of the small subunit ribosomal protein Rps3 that are important for NGD by affecting the cleavage reaction. Mutation of residues within the ribosomal entry tunnel that contact the incoming mRNA leads to significantly reduced accumulation of cleavage products, independent of the type of stall sequence, and renders cells sensitive to damaging agents thought to trigger NGD. These phenotypes are distinct from those seen in combination with other NGD factors, suggesting a separate role for Rps3 in NGD. Conversely, ribosomal proteins ubiquitination is not affected by rps3 mutations, indicating that upstream ribosome quality control (RQC) events are not dependent on these residues. Together, these results suggest that Rps3 is important for quality control on the ribosome and strongly supports the notion that the ribosome itself plays a central role in the endonucleolytic cleavage reaction during NGD. In all organisms, optimum cellular fitness depends on the ability of cells to recognize and degrade aberrant molecules. Messenger RNA is subject to alterations and, as a result, often presents roadblocks for the translating ribosomes. It is not surprising, then, that organisms evolved pathways to resolve these valuable stuck ribosomes. In eukaryotes, this process is called no-go decay (NGD) because it is coupled with decay of mRNAs that are associated with ribosomes that do not ‘go’. This decay process initiates with cleavage of the mRNA near the stall site, but some important details about this reaction are lacking. Here, we show that the ribosome itself is very central to the cleavage reaction. In particular, we identified a pair of residues of a ribosomal protein to be important for cleavage efficiency. These observations are consistent with prior structural studies showing that the residues make intimate contacts with the incoming mRNA in the entry tunnel. Altogether our data provide important clues about this quality-control pathway and suggest that the endonuclease not only recognizes stalled ribosomes but may have coevolved with the translation machinery to take advantage of certain residues of the ribosome to fulfill its function.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Amino Acid Sequence
- Amino Acid Substitution
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Endoribonucleases/genetics
- Endoribonucleases/metabolism
- GTP-Binding Proteins/genetics
- GTP-Binding Proteins/metabolism
- Genes, Fungal
- Models, Molecular
- Mutagenesis, Site-Directed
- Mutation
- Peptide Chain Elongation, Translational
- Protein Conformation
- RNA Stability
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Small/genetics
- Ribosome Subunits, Small/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae Proteins/chemistry
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Sequence Homology, Amino Acid
- Ubiquitination
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Affiliation(s)
- Carrie L. Simms
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Kyusik Q. Kim
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Liewei L. Yan
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Jessica Qiu
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Hani S. Zaher
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, United States of America
- * E-mail:
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19
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Brown A, Baird MR, Yip MC, Murray J, Shao S. Structures of translationally inactive mammalian ribosomes. eLife 2018; 7:40486. [PMID: 30355441 PMCID: PMC6226290 DOI: 10.7554/elife.40486] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/12/2018] [Indexed: 12/23/2022] Open
Abstract
The cellular levels and activities of ribosomes directly regulate gene expression during numerous physiological processes. The mechanisms that globally repress translation are incompletely understood. Here, we use electron cryomicroscopy to analyze inactive ribosomes isolated from mammalian reticulocytes, the penultimate stage of red blood cell differentiation. We identify two types of ribosomes that are translationally repressed by protein interactions. The first comprises ribosomes sequestered with elongation factor 2 (eEF2) by SERPINE mRNA binding protein 1 (SERBP1) occupying the ribosomal mRNA entrance channel. The second type are translationally repressed by a novel ribosome-binding protein, interferon-related developmental regulator 2 (IFRD2), which spans the P and E sites and inserts a C-terminal helix into the mRNA exit channel to preclude translation. IFRD2 binds ribosomes with a tRNA occupying a noncanonical binding site, the ‘Z site’, on the ribosome. These structures provide functional insights into how ribosomal interactions may suppress translation to regulate gene expression.
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Affiliation(s)
- Alan Brown
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Matthew R Baird
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Matthew Cj Yip
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Jason Murray
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Sichen Shao
- Department of Cell Biology, Harvard Medical School, Boston, United States
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20
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Ding W, Wu J, Ye J, Zheng W, Wang S, Zhu X, Zhou J, Pan Z, Zhang B, Zhu S. A Pelota-like gene regulates root development and defence responses in rice. ANNALS OF BOTANY 2018; 122:359-371. [PMID: 29771278 PMCID: PMC6110353 DOI: 10.1093/aob/mcy075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 04/19/2018] [Indexed: 05/17/2023]
Abstract
BACKGROUND AND AIMS Pelota (Pelo) are evolutionarily conserved genes reported to be involved in ribosome rescue, cell cycle control and meiotic cell division. However, there is little known about their function in plants. The aim of this study was to elucidate the function of an ethylmethane sulphonate (EMS)-derived mutation of a Pelo-like gene in rice (named Ospelo). METHODS A dysfunctional mutant was used to characterize the function of OsPelo. Analyses of its expression and sub-cellular localization were performed. The whole-genome transcriptomic change in leaves of Ospelo was also investigated by RNA sequencing. KEY RESULTS The Ospelo mutant showed defects in root system development and spotted leaves at early seedling stages. Map-based cloning revealed that the mutation occurred in the putative Pelo gene. OsPelo was found to be expressed in various tissues throughout the plant, and the protein was located in mitochondria. Defence responses were induced in the Ospelo mutant, as shown by enhanced resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae, coupled with upregulation of three pathogenesis-related marker genes. In addition, whole-genome transcriptome analysis showed that OsPelo was significantly associated with a number of biological processes, including translation, metabolism and biotic stress response. Detailed analysis showed that activation of a number of innate immunity-related genes might be responsible for the enhanced disease resistance in the Ospelo mutant. CONCLUSIONS These results demonstrate that OsPelo positively regulates root development while its loss of function enhances pathogen resistance by pre-activation of defence responses in rice.
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Affiliation(s)
- Wona Ding
- College of Science & Technology, Ningbo University, Ningbo, PR China
| | - Jing Wu
- School of Marine Sciences, Ningbo University, Ningbo, PR China
| | - Jin Ye
- School of Marine Sciences, Ningbo University, Ningbo, PR China
| | - Wenjuan Zheng
- College of Science & Technology, Ningbo University, Ningbo, PR China
| | - Shanshan Wang
- School of Marine Sciences, Ningbo University, Ningbo, PR China
| | - Xinni Zhu
- School of Marine Sciences, Ningbo University, Ningbo, PR China
| | - Jiaqin Zhou
- College of Science & Technology, Ningbo University, Ningbo, PR China
| | - Zhichong Pan
- College of Science & Technology, Ningbo University, Ningbo, PR China
| | - Botao Zhang
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, PR China
- For correspondence. E-mail or
| | - Shihua Zhu
- College of Science & Technology, Ningbo University, Ningbo, PR China
- For correspondence. E-mail or
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21
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Yoshikawa H, Larance M, Harney DJ, Sundaramoorthy R, Ly T, Owen-Hughes T, Lamond AI. Efficient analysis of mammalian polysomes in cells and tissues using Ribo Mega-SEC. eLife 2018; 7:36530. [PMID: 30095066 PMCID: PMC6086667 DOI: 10.7554/elife.36530] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/28/2018] [Indexed: 12/14/2022] Open
Abstract
We describe Ribo Mega-SEC, a powerful approach for the separation and biochemical analysis of mammalian polysomes and ribosomal subunits using Size Exclusion Chromatography and uHPLC. Using extracts from either cells, or tissues, polysomes can be separated within 15 min from sample injection to fraction collection. Ribo Mega-SEC shows translating ribosomes exist predominantly in polysome complexes in human cell lines and mouse liver tissue. Changes in polysomes are easily quantified between treatments, such as the cellular response to amino acid starvation. Ribo Mega-SEC is shown to provide an efficient, convenient and highly reproducible method for studying functional translation complexes. We show that Ribo Mega-SEC is readily combined with high-throughput MS-based proteomics to characterize proteins associated with polysomes and ribosomal subunits. It also facilitates isolation of complexes for electron microscopy and structural studies.
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Affiliation(s)
- Harunori Yoshikawa
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mark Larance
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Dylan J Harney
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | | | - Tony Ly
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Angus I Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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22
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Ho YH, Shishkova E, Hose J, Coon JJ, Gasch AP. Decoupling Yeast Cell Division and Stress Defense Implicates mRNA Repression in Translational Reallocation during Stress. Curr Biol 2018; 28:2673-2680.e4. [PMID: 30078561 DOI: 10.1016/j.cub.2018.06.044] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/24/2018] [Accepted: 06/19/2018] [Indexed: 12/29/2022]
Abstract
Stress tolerance and rapid growth are often competing interests in cells. Upon severe environmental stress, many organisms activate defense systems concurrent with growth arrest. There has been debate as to whether aspects of the stress-activated transcriptome are regulated by stress or an indirect byproduct of reduced proliferation. For example, stressed Saccharomyces cerevisiae cells mount a common gene expression program called the environmental stress response (ESR) [1] comprised of ∼300 induced (iESR) transcripts involved in stress defense and ∼600 reduced (rESR) mRNAs encoding ribosomal proteins (RPs) and ribosome biogenesis factors (RiBi) important for division. Because ESR activation also correlates with reduced growth rate in nutrient-restricted chemostats and prolonged G1 in slow-growing mutants, an alternate proposal is that the ESR is simply a consequence of reduced division [2-5]. A major challenge is that past studies did not separate effects of division arrest and stress defense; thus, the true responsiveness of the ESR-and the purpose of stress-dependent rESR repression in particular-remains unclear. Here, we decoupled cell division from the stress response by following transcriptome, proteome, and polysome changes in arrested cells responding to acute stress. We show that the ESR cannot be explained by changes in growth rate or cell-cycle phase during stress acclimation. Instead, failure to repress rESR transcripts reduces polysome association of induced transcripts, delaying production of their proteins. Our results suggest that stressed cells alleviate competition for translation factors by removing mRNAs and ribosomes from the translating pool, directing translational capacity toward induced transcripts to accelerate protein production.
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Affiliation(s)
- Yi-Hsuan Ho
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Evgenia Shishkova
- Genome Center of Wisconsin, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - James Hose
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Joshua J Coon
- Genome Center of Wisconsin, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Morgridge Institute for Research, Madison, WI 53715, USA
| | - Audrey P Gasch
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA; Genome Center of Wisconsin, University of Wisconsin-Madison, Madison, WI 53706, USA.
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23
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Abstract
During protein synthesis, ribosomes encounter many roadblocks, the outcomes of which are largely determined by substrate availability, amino acid features and reaction kinetics. Prolonged ribosome stalling is likely to be resolved by ribosome rescue or quality control pathways, whereas shorter stalling is likely to be resolved by ongoing productive translation. How ribosome function is affected by such hindrances can therefore have a profound impact on the translational output (yield) of a particular mRNA. In this Review, we focus on these roadblocks and the resumption of normal translation elongation rather than on alternative fates wherein the stalled ribosome triggers degradation of the mRNA and the incomplete protein product. We discuss the fundamental stages of the translation process in eukaryotes, from elongation through ribosome recycling, with particular attention to recent discoveries of the complexity of the genetic code and regulatory elements that control gene expression, including ribosome stalling during elongation, the role of mRNA context in translation termination and mechanisms of ribosome rescue that resemble recycling.
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Affiliation(s)
- Anthony P Schuller
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - 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.
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24
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Muto A, Sugihara Y, Shibakawa M, Oshima K, Matsuda T, Nadano D. The mRNA-binding protein Serbp1 as an auxiliary protein associated with mammalian cytoplasmic ribosomes. Cell Biochem Funct 2018; 36:312-322. [PMID: 30039520 DOI: 10.1002/cbf.3350] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 04/23/2018] [Accepted: 06/26/2018] [Indexed: 01/27/2023]
Abstract
While transcription plays an obviously important role in gene expression, translation has recently been emerged as a key step that defines the composition and quality of the proteome in the cell of higher eukaryotes including mammals. Selective translation is supposed to be regulated by the structural heterogeneity of cytoplasmic ribosomes including differences in protein composition and chemical modifications. However, the current knowledge on the heterogeneity of mammalian ribosomes is limited. Here, we report mammalian Serbp1 as a ribosome-associated protein. The translated products of Serbp1 gene, including the longest isoform, were found to be localized in the nucleolus as well as in the cytoplasm. Subcellular fractionation indicated that most of cytoplasmic Serbp1 molecules were precipitated by ultracentrifugation. Proteomic analysis identified Serbp1 in the cytoplasmic ribosomes of the rodent testis. Polysome profiling suggested that Serbp1, as a component of the small 40S subunit, was included in translating ribosomes (polysomes). Cosedimentation of Serbp1 with the 40S subunit was observed after dissociation of the ribosomal subunits. Serbp1 was also included in the ribosomes of human cancer cells, which may lead to a mechanistic understanding of an emerging link between Serbp1 and tumour progression. SIGNIFICANCE OF THE STUDY In mammalian cells, the final protein output of their genetic program is determined not only by controlling transcription but also by regulating the posttranscriptional events. Although mRNA-binding proteins and the cytoplasmic ribosome have long been recognized as central players in the posttranscriptional regulation, their physical and functional interactions are still far from a complete understanding. Here, we describe the intracellular localization of Serbp1, an mRNA-binding protein, and the inclusion of this protein in actively translating ribosomes in normal and cancer cells. These findings shed a new light into molecular mechanisms underlying Serbp1 action in translational gene regulation and tumour progression.
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Affiliation(s)
- Akiko Muto
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Yoshihiko Sugihara
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Minami Shibakawa
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Kenzi Oshima
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Tsukasa Matsuda
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Daita Nadano
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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Nürenberg-Goloub E, Heinemann H, Gerovac M, Tampé R. Ribosome recycling is coordinated by processive events in two asymmetric ATP sites of ABCE1. Life Sci Alliance 2018; 1. [PMID: 30198020 PMCID: PMC6124641 DOI: 10.26508/lsa.201800095] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The stepwise ribosome disassembly in the translation cycle of eukaryotes and archaea is scheduled by discrete molecular events within the asymmetric ribosome recycling factor ABCE1. Ribosome recycling orchestrated by ABCE1 is a fundamental process in protein translation and mRNA surveillance, connecting termination with initiation. Beyond the plenitude of well-studied translational GTPases, ABCE1 is the only essential factor energized by ATP, delivering the energy for ribosome splitting via two nucleotide-binding sites by a yet unknown mechanism. Here, we define how allosterically coupled ATP binding and hydrolysis events in ABCE1 empower ribosome recycling. ATP occlusion in the low-turnover control site II promotes formation of the pre-splitting complex and facilitates ATP engagement in the high-turnover site I, which in turn drives the structural reorganization required for ribosome splitting. ATP hydrolysis and ensuing release of ABCE1 from the small subunit terminate the post-splitting complex. Thus, ABCE1 runs through an allosterically coupled cycle of closure and opening at both sites, consistent with a processive clamp model. This study delineates the inner mechanics of ABCE1 and reveals why various ABCE1 mutants lead to defects in cell homeostasis, growth, and differentiation.
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Affiliation(s)
- Elina Nürenberg-Goloub
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
| | - Holger Heinemann
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
| | - Milan Gerovac
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
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26
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Zurita Rendón O, Fredrickson EK, Howard CJ, Van Vranken J, Fogarty S, Tolley ND, Kalia R, Osuna BA, Shen PS, Hill CP, Frost A, Rutter J. Vms1p is a release factor for the ribosome-associated quality control complex. Nat Commun 2018; 9:2197. [PMID: 29875445 PMCID: PMC5989216 DOI: 10.1038/s41467-018-04564-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 05/03/2018] [Indexed: 12/02/2022] Open
Abstract
Eukaryotic cells employ the ribosome-associated quality control complex (RQC) to maintain homeostasis despite defects that cause ribosomes to stall. The RQC comprises the E3 ubiquitin ligase Ltn1p, the ATPase Cdc48p, Rqc1p, and Rqc2p. Upon ribosome stalling and splitting, the RQC assembles on the 60S species containing unreleased peptidyl-tRNA (60S:peptidyl–tRNA). Ltn1p and Rqc1p facilitate ubiquitination of the incomplete nascent chain, marking it for degradation. Rqc2p stabilizes Ltn1p on the 60S and recruits charged tRNAs to the 60S to catalyze elongation of the nascent protein with carboxy-terminal alanine and threonine extensions (CAT tails). By mobilizing the nascent chain, CAT tailing can expose lysine residues that are hidden in the exit tunnel, thereby supporting efficient ubiquitination. If the ubiquitin–proteasome system is overwhelmed or unavailable, CAT-tailed nascent chains can aggregate in the cytosol or within organelles like mitochondria. Here we identify Vms1p as a tRNA hydrolase that releases stalled polypeptides engaged by the RQC. The ribosome-associated quality control complex (RQC) functions to disassemble stalled ribosomes. Here the authors find that the tRNA hydrolase Vms1 is involved in the release of nascent peptide from stalled ribosomes.
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Affiliation(s)
- Olga Zurita Rendón
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815-6789, USA.,Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Eric K Fredrickson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Conor J Howard
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94158, USA.,California Institute for Quantitative Biomedical Research, San Francisco, CA, 94158, USA
| | - Jonathan Van Vranken
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Sarah Fogarty
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815-6789, USA.,Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Neal D Tolley
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Raghav Kalia
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94158, USA.,California Institute for Quantitative Biomedical Research, San Francisco, CA, 94158, USA
| | - Beatriz A Osuna
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94158, USA.,Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Peter S Shen
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Christopher P Hill
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Adam Frost
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA. .,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94158, USA. .,California Institute for Quantitative Biomedical Research, San Francisco, CA, 94158, USA. .,Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA.
| | - Jared Rutter
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815-6789, USA. .,Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
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27
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Karamysheva ZN, Tikhonova EB, Grozdanov PN, Huffman JC, Baca KR, Karamyshev A, Denison RB, MacDonald CC, Zhang K, Karamyshev AL. Polysome Profiling in Leishmania, Human Cells and Mouse Testis. J Vis Exp 2018. [PMID: 29683462 DOI: 10.3791/57600] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Proper protein expression at the right time and in the right amounts is the basis of normal cell function and survival in a fast-changing environment. For a long time, the gene expression studies were dominated by research on the transcriptional level. However, the steady-state levels of mRNAs do not correlate well with protein production, and the translatability of mRNAs varies greatly depending on the conditions. In some organisms, like the parasite Leishmania, the protein expression is regulated mostly at the translational level. Recent studies demonstrated that protein translation dysregulation is associated with cancer, metabolic, neurodegenerative and other human diseases. Polysome profiling is a powerful method to study protein translation regulation. It allows to measure the translational status of individual mRNAs or examine translation on a genome-wide scale. The basis of this technique is the separation of polysomes, ribosomes, their subunits and free mRNAs during centrifugation of a cytoplasmic lysate through a sucrose gradient. Here, we present a universal polysome profiling protocol used on three different models - parasite Leishmania major, cultured human cells and animal tissues. Leishmania cells freely grow in suspension and cultured human cells grow in adherent monolayer, while mouse testis represents an animal tissue sample. Thus, the technique is adapted to all of these sources. The protocol for the analysis of polysomal fractions includes detection of individual mRNA levels by RT-qPCR, proteins by Western blot and analysis of ribosomal RNAs by electrophoresis. The method can be further extended by examination of mRNAs association with the ribosome on a transcriptome level by deep RNA-seq and analysis of ribosome-associated proteins by mass spectroscopy of the fractions. The method can be easily adjusted to other biological models.
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Affiliation(s)
| | - Elena B Tikhonova
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - Petar N Grozdanov
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - James C Huffman
- Department of Biological Sciences, Texas Tech University; CISER (Center for the Integration of STEM Education & Research), Texas Tech University
| | - Kristen R Baca
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center; CISER (Center for the Integration of STEM Education & Research), Texas Tech University
| | - Alexander Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - R Brian Denison
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - Clinton C MacDonald
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University
| | - Andrey L Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center;
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28
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Navarro-Quiles C, Mateo-Bonmatí E, Micol JL. ABCE Proteins: From Molecules to Development. FRONTIERS IN PLANT SCIENCE 2018; 9:1125. [PMID: 30127795 PMCID: PMC6088178 DOI: 10.3389/fpls.2018.01125] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/12/2018] [Indexed: 05/12/2023]
Abstract
Most members of the large family of ATP-Binding Cassette (ABC) proteins function as membrane transporters. However, the most evolutionarily conserved group, the ABCE protein subfamily, comprises soluble proteins that were initially denoted RNase L inhibitor (RLI) proteins. ABCE proteins are present in all eukaryotes and archaea and are encoded by a single gene in most genomes, or by two genes in a few cases. Functional analysis of ABCE genes, primarily in Saccharomyces cerevisiae, has shown that ABCE proteins have essential functions as part of the translational apparatus. In this review, we summarize the current understanding of ABCE protein function in ribosome biogenesis and recycling, with a particular focus on their known and proposed developmental roles in different species. The ABCE proteins might represent another class of factors contributing to the role of the ribosome in gene expression regulation.
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29
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Benchouaia M, Ripoche H, Sissoko M, Thiébaut A, Merhej J, Delaveau T, Fasseu L, Benaissa S, Lorieux G, Jourdren L, Le Crom S, Lelandais G, Corel E, Devaux F. Comparative Transcriptomics Highlights New Features of the Iron Starvation Response in the Human Pathogen Candida glabrata. Front Microbiol 2018; 9:2689. [PMID: 30505294 PMCID: PMC6250833 DOI: 10.3389/fmicb.2018.02689] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/22/2018] [Indexed: 11/21/2022] Open
Abstract
In this work, we used comparative transcriptomics to identify regulatory outliers (ROs) in the human pathogen Candida glabrata. ROs are genes that have very different expression patterns compared to their orthologs in other species. From comparative transcriptome analyses of the response of eight yeast species to toxic doses of selenite, a pleiotropic stress inducer, we identified 38 ROs in C. glabrata. Using transcriptome analyses of C. glabrata response to five different stresses, we pointed out five ROs which were more particularly responsive to iron starvation, a process which is very important for C. glabrata virulence. Global chromatin Immunoprecipitation and gene profiling analyses showed that four of these genes are actually new targets of the iron starvation responsive Aft2 transcription factor in C. glabrata. Two of them (HBS1 and DOM34b) are required for C. glabrata optimal growth in iron limited conditions. In S. cerevisiae, the orthologs of these two genes are involved in ribosome rescue by the NO GO decay (NGD) pathway. Hence, our results suggest a specific contribution of NGD co-factors to the C. glabrata adaptation to iron starvation.
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Affiliation(s)
- Médine Benchouaia
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Hugues Ripoche
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Mariam Sissoko
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Antonin Thiébaut
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Jawad Merhej
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Thierry Delaveau
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Laure Fasseu
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Sabrina Benaissa
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Geneviève Lorieux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Laurent Jourdren
- École Normale Supérieure, PSL Research University, CNRS, Inserm U1024, Institut de Biologie de l’École Normale Supérieure, Plateforme Génomique, Paris, France
| | - Stéphane Le Crom
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7138, Évolution, Paris, France
| | - Gaëlle Lelandais
- UMR 9198, Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, UPSay, Gif-sur-Yvette, France
| | - Eduardo Corel
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7138, Évolution, Paris, France
| | - Frédéric Devaux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
- *Correspondence: Frédéric Devaux,
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30
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Beaupere C, Chen RB, Pelosi W, Labunskyy VM. Genome-wide Quantification of Translation in Budding Yeast by Ribosome Profiling. JOURNAL OF VISUALIZED EXPERIMENTS : JOVE 2017:56820. [PMID: 29286414 PMCID: PMC5755679 DOI: 10.3791/56820] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Translation of mRNA into proteins is a complex process involving several layers of regulation. It is often assumed that changes in mRNA transcription reflect changes in protein synthesis, but many exceptions have been observed. Recently, a technique called ribosome profiling (or Ribo-Seq) has emerged as a powerful method that allows identification, with high accuracy, which regions of mRNA are translated into proteins and quantification of translation at the genome-wide level. Here, we present a generalized protocol for genome-wide quantification of translation using Ribo-Seq in budding yeast. In addition, combining Ribo-Seq data with mRNA abundance measurements allows us to simultaneously quantify translation efficiency of thousands of mRNA transcripts in the same sample and compare changes in these parameters in response to experimental manipulations or in different physiological states. We describe a detailed protocol for generation of ribosome footprints using nuclease digestion, isolation of intact ribosome-footprint complexes via sucrose gradient fractionation, and preparation of DNA libraries for deep sequencing along with appropriate quality controls necessary to ensure accurate analysis of in vivo translation.
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Affiliation(s)
- Carine Beaupere
- Department of Dermatology, Boston University School of Medicine
| | - Rosalyn B. Chen
- Department of Dermatology, Boston University School of Medicine
| | - William Pelosi
- Department of Dermatology, Boston University School of Medicine
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31
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Survival of the drowsiest: the hibernating 100S ribosome in bacterial stress management. Curr Genet 2017; 64:753-760. [PMID: 29243175 PMCID: PMC6060826 DOI: 10.1007/s00294-017-0796-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/09/2017] [Accepted: 12/11/2017] [Indexed: 11/24/2022]
Abstract
In response to nutrient deprivation and environmental insults, bacteria conjoin two copies of non-translating 70S ribosomes that form the translationally inactive 100S dimer. This widespread phenomenon is believed to prevent ribosome turnover and serves as a reservoir that, when conditions become favorable, allows the hibernating ribosomes to be disassembled and recycled for translation. New structural studies have revealed two distinct mechanisms for dimerizing 70S ribosomes, but the molecular basis of the disassembly process is still in its infancy. Many details regarding the sequence of dimerization-dissociation events with respect to the binding and departure of the hibernation factor and its antagonizing disassembly factor remain unclear.
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32
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Limoncelli KA, Merrikh CN, Moore MJ. ASC1 and RPS3: new actors in 18S nonfunctional rRNA decay. RNA (NEW YORK, N.Y.) 2017; 23:1946-1960. [PMID: 28956756 PMCID: PMC5689013 DOI: 10.1261/rna.061671.117] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 09/23/2017] [Indexed: 06/07/2023]
Abstract
In budding yeast, inactivating mutations within the 40S ribosomal subunit decoding center lead to 18S rRNA clearance by a quality control mechanism known as nonfunctional 18S rRNA decay (18S NRD). We previously showed that 18S NRD is functionally related to No-Go mRNA Decay (NGD), a pathway for clearing translation complexes stalled on aberrant mRNAs. Whereas the NGD factors Dom34p and Hbs1p contribute to 18S NRD, their genetic deletion (either singly or in combination) only partially stabilizes mutant 18S rRNA. Here we identify Asc1p (aka RACK1) and Rps3p, both stable 40S subunit components, as additional 18S NRD factors. Complete stabilization of mutant 18S rRNA in dom34Δ;asc1Δ and hbs1Δ;asc1Δ strains indicates the existence of two genetically separable 18S NRD pathways. A small region of the Rps3p C-terminal tail known to be subject to post-translational modification is also crucial for 18S NRD. We combine these findings with the effects of mutations in the 5' → 3' and 3' → 5' decay machinery to propose a model wherein multiple targeting and decay pathways kinetically contribute to 18S NRD.
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Affiliation(s)
- Kelly A Limoncelli
- Department of Biochemistry and Molecular Pharmacology, RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Christopher N Merrikh
- Department of Biochemistry and Molecular Pharmacology, RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Melissa J Moore
- Department of Biochemistry and Molecular Pharmacology, RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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33
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Opitz N, Schmitt K, Hofer-Pretz V, Neumann B, Krebber H, Braus GH, Valerius O. Capturing the Asc1p/ Receptor for Activated C Kinase 1 (RACK1) Microenvironment at the Head Region of the 40S Ribosome with Quantitative BioID in Yeast. Mol Cell Proteomics 2017; 16:2199-2218. [PMID: 28982715 DOI: 10.1074/mcp.m116.066654] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 09/29/2017] [Indexed: 12/13/2022] Open
Abstract
The Asc1 protein of Saccharomyces cerevisiae is a scaffold protein at the head region of ribosomal 40S that links mRNA translation to cellular signaling. In this study, proteins that colocalize with Asc1p were identified with proximity-dependent Biotin IDentification (BioID), an in vivo labeling technique described here for the first time for yeast. Biotinylated Asc1p-birA*-proximal proteins were identified and quantitatively verified against controls applying SILAC and mass spectrometry. The mRNA-binding proteins Sro9p and Gis2p appeared together with Scp160p, each providing ribosomes with nuclear transcripts. The cap-binding protein eIF4E (Cdc33p) and the eIF3/a-subunit (Rpg1p) were identified reflecting the encounter of proteins involved in the initiation of mRNA translation at the head region of ribosomal 40S. Unexpectedly, a protein involved in ribosome preservation (the clamping factor Stm1p), the deubiquitylation complex Ubp3p-Bre5p, the RNA polymerase II degradation factor 1 (Def1p), and transcription factors (Spt5p, Mbf1p) colocalize with Asc1p in exponentially growing cells. For Asc1R38D, K40Ep, a variant considered to be deficient in binding to ribosomes, BioID revealed its predominant ribosome localization. Glucose depletion replaced most of the Asc1p colocalizing proteins for additional ribosomal proteins, suggesting a ribosome aggregation process during early nutrient limitation, possibly concomitant with ribosomal subunit clamping. Overall, the characterization of the Asc1p microenvironment with BioID confirmed and substantiated our recent findings that the β-propeller broadly contributes to signal transduction influencing phosphorylation of colocalizing proteins (e.g. of Bre5p), and by that might affect nuclear gene transcription and the fate of ribosomes.
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Affiliation(s)
- Nadine Opitz
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Kerstin Schmitt
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Verena Hofer-Pretz
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Bettina Neumann
- §Department of Molecular Genetics, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Heike Krebber
- §Department of Molecular Genetics, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Gerhard H Braus
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Oliver Valerius
- From the ‡Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, 37077 Göttingen, Germany;
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Shedlovskiy D, Zinskie JA, Gardner E, Pestov DG, Shcherbik N. Endonucleolytic cleavage in the expansion segment 7 of 25S rRNA is an early marker of low-level oxidative stress in yeast. J Biol Chem 2017; 292:18469-18485. [PMID: 28939771 DOI: 10.1074/jbc.m117.800003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/13/2017] [Indexed: 12/29/2022] Open
Abstract
The ability to detect and respond to oxidative stress is crucial to the survival of living organisms. In cells, sensing of increased levels of reactive oxygen species (ROS) activates many defensive mechanisms that limit or repair damage to cell components. The ROS-signaling responses necessary for cell survival under oxidative stress conditions remain incompletely understood, especially for the translational machinery. Here, we found that drug treatments or a genetic deficiency in the thioredoxin system that increase levels of endogenous hydrogen peroxide in the yeast Saccharomyces cerevisiae promote site-specific endonucleolytic cleavage in 25S ribosomal RNA (rRNA) adjacent to the c loop of the expansion segment 7 (ES7), a putative regulatory region located on the surface of the 60S ribosomal subunit. Our data also show that ES7c is cleaved at early stages of the gene expression program that enables cells to successfully counteract oxidative stress and is not a prerequisite or consequence of apoptosis. Moreover, the 60S subunits containing ES7c-cleaved rRNA cofractionate with intact subunits in sucrose gradients and repopulate polysomes after a short starvation-induced translational block, indicating their active role in translation. These results demonstrate that ES7c cleavage in rRNA is an early and sensitive marker of increased ROS levels in yeast cells and suggest that changes in ribosomes may be involved in the adaptive response to oxidative stress.
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Affiliation(s)
| | | | - Ethan Gardner
- From the Department of Cell Biology and Neuroscience and.,the Graduate School for Biomedical Sciences, Rowan University, Stratford, New Jersey 08084
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35
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Metzl-Raz E, Kafri M, Yaakov G, Soifer I, Gurvich Y, Barkai N. Principles of cellular resource allocation revealed by condition-dependent proteome profiling. eLife 2017; 6:28034. [PMID: 28857745 PMCID: PMC5578734 DOI: 10.7554/elife.28034] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/08/2017] [Indexed: 12/23/2022] Open
Abstract
Growing cells coordinate protein translation with metabolic rates. Central to this coordination is ribosome production. Ribosomes drive cell growth, but translation of ribosomal proteins competes with production of non-ribosomal proteins. Theory shows that cell growth is maximized when all expressed ribosomes are constantly translating. To examine whether budding yeast function at this limit of full ribosomal usage, we profiled the proteomes of cells growing in different environments. We find that cells produce excess ribosomal proteins, amounting to a constant ≈8% of the proteome. Accordingly, ≈25% of ribosomal proteins expressed in rapidly growing cells does not contribute to translation. Further, this fraction increases as growth rate decreases and these excess ribosomal proteins are employed when translation demands unexpectedly increase. We suggest that steadily growing cells prepare for conditions that demand increased translation by producing excess ribosomes, at the expense of lower steady-state growth rate.
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Affiliation(s)
- Eyal Metzl-Raz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Moshe Kafri
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Gilad Yaakov
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ilya Soifer
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Yonat Gurvich
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Naama Barkai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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Structure of the 40S-ABCE1 post-splitting complex in ribosome recycling and translation initiation. Nat Struct Mol Biol 2017; 24:453-460. [PMID: 28368393 DOI: 10.1038/nsmb.3396] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 03/07/2017] [Indexed: 11/08/2022]
Abstract
The essential ATP-binding cassette protein ABCE1 splits 80S ribosomes into 60S and 40S subunits after canonical termination or quality-control-based mRNA surveillance processes. However, the underlying splitting mechanism remains enigmatic. Here, we present a cryo-EM structure of the yeast 40S-ABCE1 post-splitting complex at 3.9-Å resolution. Compared to the pre-splitting state, we observe repositioning of ABCE1's iron-sulfur cluster domain, which rotates 150° into a binding pocket on the 40S subunit. This repositioning explains a newly observed anti-association activity of ABCE1. Notably, the movement implies a collision with A-site factors, thus explaining the splitting mechanism. Disruption of key interactions in the post-splitting complex impairs cellular homeostasis. Additionally, the structure of a native post-splitting complex reveals ABCE1 to be part of the 43S initiation complex, suggesting a coordination of termination, recycling, and initiation.
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37
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Kiosze-Becker K, Ori A, Gerovac M, Heuer A, Nürenberg-Goloub E, Rashid UJ, Becker T, Beckmann R, Beck M, Tampé R. Structure of the ribosome post-recycling complex probed by chemical cross-linking and mass spectrometry. Nat Commun 2016; 7:13248. [PMID: 27824037 PMCID: PMC5105147 DOI: 10.1038/ncomms13248] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 09/15/2016] [Indexed: 02/03/2023] Open
Abstract
Ribosome recycling orchestrated by the ATP binding cassette (ABC) protein ABCE1 can be considered as the final—or the first—step within the cyclic process of protein synthesis, connecting translation termination and mRNA surveillance with re-initiation. An ATP-dependent tweezer-like motion of the nucleotide-binding domains in ABCE1 transfers mechanical energy to the ribosome and tears the ribosome subunits apart. The post-recycling complex (PRC) then re-initiates mRNA translation. Here, we probed the so far unknown architecture of the 1-MDa PRC (40S/30S·ABCE1) by chemical cross-linking and mass spectrometry (XL-MS). Our study reveals ABCE1 bound to the translational factor-binding (GTPase) site with multiple cross-link contacts of the helix–loop–helix motif to the S24e ribosomal protein. Cross-linking of the FeS cluster domain to the ribosomal protein S12 substantiates an extreme lever-arm movement of the FeS cluster domain during ribosome recycling. We were thus able to reconstitute and structurally analyse a key complex in the translational cycle, resembling the link between translation initiation and ribosome recycling. Ribosome recycling orchestrated by ABCE1 connects translation termination and mRNA surveillance mechanisms with re-initiation. Using a cross-linking and mass spectrometry approach, Kiosze-Becker et al. provide new information on the large conformational rearrangements that occur during ribosome recycling.
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Affiliation(s)
- Kristin Kiosze-Becker
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
| | - Alessandro Ori
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Milan Gerovac
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
| | - André Heuer
- Gene Center and Center for Integrated Protein Science Munich (CiPSM), Department of Biochemistry, University of Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Elina Nürenberg-Goloub
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
| | - Umar Jan Rashid
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
| | - Thomas Becker
- Gene Center and Center for Integrated Protein Science Munich (CiPSM), Department of Biochemistry, University of Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Roland Beckmann
- Gene Center and Center for Integrated Protein Science Munich (CiPSM), Department of Biochemistry, University of Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Martin Beck
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt a.M., Germany
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van Wijlick L, Geissen R, Hilbig JS, Lagadec Q, Cantero PD, Pfeifer E, Juchimiuk M, Kluge S, Wickert S, Alepuz P, Ernst JF. Dom34 Links Translation to Protein O-mannosylation. PLoS Genet 2016; 12:e1006395. [PMID: 27768707 PMCID: PMC5074521 DOI: 10.1371/journal.pgen.1006395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 09/29/2016] [Indexed: 11/25/2022] Open
Abstract
In eukaryotes, Dom34 upregulates translation by securing levels of activatable ribosomal subunits. We found that in the yeast Saccharomyces cerevisiae and the human fungal pathogen Candida albicans, Dom34 interacts genetically with Pmt1, a major isoform of protein O-mannosyltransferase. In C. albicans, lack of Dom34 exacerbated defective phenotypes of pmt1 mutants, while they were ameliorated by Dom34 overproduction that enhanced Pmt1 protein but not PMT1 transcript levels. Translational effects of Dom34 required the 5′-UTR of the PMT1 transcript, which bound recombinant Dom34 directly at a CA/AC-rich sequence and regulated in vitro translation. Polysomal profiling revealed that Dom34 stimulates general translation moderately, but that it is especially required for translation of transcripts encoding Pmt isoforms 1, 4 and 6. Because defective protein N- or O-glycosylation upregulates transcription of PMT genes, it appears that Dom34-mediated specific translational upregulation of the PMT transcripts optimizes cellular responses to glycostress. Its translational function as an RNA binding protein acting at the 5′-UTR of specific transcripts adds another facet to the known ribosome-releasing functions of Dom34 at the 3′-UTR of transcripts. Fungi respond to damages of their glycostructures in their cell wall by transcriptional upregulation of genes that specify compensatory activities. Upon block of protein N-glycosylation, the human fungal pathogen Candida albicans increases transcription of PMT1 encoding a major isoform of protein O-mannosyltransferase. Here we demonstrate that the Dom34 protein aids in glycostress responses by upregulating the translation of several PMT isoform transcripts. Dom34 has previously been implicated in mechanisms to secure high levels of ribosomal subunits that promote translation in general, e. g. by no-go decay at the 3′-UTR of transcripts. By binding to the 5′-UTR and activating translational initiation of PMT transcripts we add a novel mode of action and suggest a preferred class of targets for the translational activities of the Dom34 protein. The combination of transcriptional and Dom34-mediated translational upregulation of PMT genes optimizes effective recovery and survival of fungal cells upon glycostress.
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Affiliation(s)
- Lasse van Wijlick
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
- Manchot Graduate School Molecules of Infection, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - René Geissen
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Jessica S. Hilbig
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Quentin Lagadec
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Pilar D. Cantero
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Eugen Pfeifer
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Mateusz Juchimiuk
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Sven Kluge
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Stephan Wickert
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Paula Alepuz
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Burjassot Spain
- ERI Biotecmed. Universitat de València, Burjassot Spain
| | - Joachim F. Ernst
- Department Biologie, Molekulare Mykologie, Heinrich-Heine-Universität, Düsseldorf, Germany
- Manchot Graduate School Molecules of Infection, Heinrich-Heine-Universität, Düsseldorf, Germany
- * E-mail:
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39
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Shcherbik N, Chernova TA, Chernoff YO, Pestov DG. Distinct types of translation termination generate substrates for ribosome-associated quality control. Nucleic Acids Res 2016; 44:6840-52. [PMID: 27325745 PMCID: PMC5001609 DOI: 10.1093/nar/gkw566] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 06/13/2016] [Indexed: 11/24/2022] Open
Abstract
Cotranslational degradation of polypeptide nascent chains plays a critical role in quality control of protein synthesis and the rescue of stalled ribosomes. In eukaryotes, ribosome stalling triggers release of 60S subunits with attached nascent polypeptides, which undergo ubiquitination by the E3 ligase Ltn1 and proteasomal degradation facilitated by the ATPase Cdc48. However, the identity of factors acting upstream in this process is less clear. Here, we examined how the canonical release factors Sup45–Sup35 (eRF1–eRF3) and their paralogs Dom34-Hbs1 affect the total population of ubiquitinated nascent chains associated with yeast ribosomes. We found that the availability of the functional release factor complex Sup45–Sup35 strongly influences the amount of ubiquitinated polypeptides associated with 60S ribosomal subunits, while Dom34-Hbs1 generate 60S-associated peptidyl-tRNAs that constitute a relatively minor fraction of Ltn1 substrates. These results uncover two separate pathways that target nascent polypeptides for Ltn1-Cdc48-mediated degradation and suggest that in addition to canonical termination on stop codons, eukaryotic release factors contribute to cotranslational protein quality control.
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Affiliation(s)
- Natalia Shcherbik
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Tatiana A Chernova
- Department of Biochemistry, Emory University, School of Medicine, Atlanta, GA 30322, USA
| | - Yury O Chernoff
- School of Biology, Georgia Institute of Technology, Atlanta, GA 30322, USA Laboratory of Amyloid Biology & Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg 199034, Russia
| | - Dimitri G Pestov
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, Stratford, NJ 08084, USA
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40
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Rli1/ABCE1 Recycles Terminating Ribosomes and Controls Translation Reinitiation in 3'UTRs In Vivo. Cell 2016; 162:872-84. [PMID: 26276635 DOI: 10.1016/j.cell.2015.07.041] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/21/2015] [Accepted: 07/10/2015] [Indexed: 02/05/2023]
Abstract
To study the function of Rli1/ABCE1 in vivo, we used ribosome profiling and biochemistry to characterize its contribution to ribosome recycling. When Rli1 levels were diminished, 80S ribosomes accumulated both at stop codons and in the adjoining 3'UTRs of most mRNAs. Frequently, these ribosomes reinitiated translation without the need for a canonical start codon, as small peptide products predicted by 3'UTR ribosome occupancy in all three reading frames were confirmed by western analysis and mass spectrometry. Eliminating the ribosome-rescue factor Dom34 dramatically increased 3'UTR ribosome occupancy in Rli1 depleted cells, indicating that Dom34 clears the bulk of unrecycled ribosomes. Thus, Rli1 is crucial for ribosome recycling in vivo and controls ribosome homeostasis. 3'UTR translation occurs in wild-type cells as well, and observations of elevated 3'UTR ribosomes during stress suggest that modulating recycling and reinitiation is involved in responding to environmental changes.
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41
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Toompuu M, Kärblane K, Pata P, Truve E, Sarmiento C. ABCE1 is essential for S phase progression in human cells. Cell Cycle 2016; 15:1234-47. [PMID: 26985706 DOI: 10.1080/15384101.2016.1160972] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
ABCE1 is a highly conserved protein universally present in eukaryotes and archaea, which is crucial for the viability of different organisms. First identified as RNase L inhibitor, ABCE1 is currently recognized as an essential translation factor involved in several stages of eukaryotic translation and ribosome biogenesis. The nature of vital functions of ABCE1, however, remains unexplained. Here, we study the role of ABCE1 in human cell proliferation and its possible connection to translation. We show that ABCE1 depletion by siRNA results in a decreased rate of cell growth due to accumulation of cells in S phase, which is accompanied by inefficient DNA synthesis and reduced histone mRNA and protein levels. We infer that in addition to the role in general translation, ABCE1 is involved in histone biosynthesis and DNA replication and therefore is essential for normal S phase progression. In addition, we analyze whether ABCE1 is implicated in transcript-specific translation via its association with the eIF3 complex subunits known to control the synthesis of cell proliferation-related proteins. The expression levels of a few such targets regulated by eIF3A, however, were not consistently affected by ABCE1 depletion.
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Affiliation(s)
- Marina Toompuu
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Kairi Kärblane
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Pille Pata
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Erkki Truve
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Cecilia Sarmiento
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
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42
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Wang X, Xi W, Toomey S, Chiang YC, Hasek J, Laue TM, Denis CL. Stoichiometry and Change of the mRNA Closed-Loop Factors as Translating Ribosomes Transit from Initiation to Elongation. PLoS One 2016; 11:e0150616. [PMID: 26953568 PMCID: PMC4783044 DOI: 10.1371/journal.pone.0150616] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/17/2016] [Indexed: 01/06/2023] Open
Abstract
Protein synthesis is a highly efficient process and is under exacting control. Yet, the actual abundance of translation factors present in translating complexes and how these abundances change during the transit of a ribosome across an mRNA remains unknown. Using analytical ultracentrifugation with fluorescent detection we have determined the stoichiometry of the closed-loop translation factors for translating ribosomes. A variety of pools of translating polysomes and monosomes were identified, each containing different abundances of the closed-loop factors eIF4E, eIF4G, and PAB1 and that of the translational repressor, SBP1. We establish that closed-loop factors eIF4E/eIF4G dissociated both as ribosomes transited polyadenylated mRNA from initiation to elongation and as translation changed from the polysomal to monosomal state prior to cessation of translation. eIF4G was found to particularly dissociate from polyadenylated mRNA as polysomes moved to the monosomal state, suggesting an active role for translational repressors in this process. Consistent with this suggestion, translating complexes generally did not simultaneously contain eIF4E/eIF4G and SBP1, implying mutual exclusivity in such complexes. For substantially deadenylated mRNA, however, a second type of closed-loop structure was identified that contained just eIF4E and eIF4G. More than one eIF4G molecule per polysome appeared to be present in these complexes, supporting the importance of eIF4G interactions with the mRNA independent of PAB1. These latter closed-loop structures, which were particularly stable in polysomes, may be playing specific roles in both normal and disease states for specific mRNA that are deadenylated and/or lacking PAB1. These analyses establish a dynamic snapshot of molecular abundance changes during ribosomal transit across an mRNA in what are likely to be critical targets of regulation.
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Affiliation(s)
- Xin Wang
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, United States of America
| | - Wen Xi
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, United States of America
| | - Shaun Toomey
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, United States of America
| | - Yueh-Chin Chiang
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, United States of America
| | - Jiri Hasek
- Laboratory of Cell Reproduction, Institute of Microbiology of ASCR, Prague, Videnska 1083, Czech Republic
| | - Thomas M. Laue
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, United States of America
| | - Clyde L. Denis
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, United States of America
- * E-mail:
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43
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Zhang Y, Mandava CS, Cao W, Li X, Zhang D, Li N, Zhang Y, Zhang X, Qin Y, Mi K, Lei J, Sanyal S, Gao N. HflX is a ribosome-splitting factor rescuing stalled ribosomes under stress conditions. Nat Struct Mol Biol 2015; 22:906-13. [PMID: 26458047 DOI: 10.1038/nsmb.3103] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 09/04/2015] [Indexed: 12/16/2022]
Abstract
Adverse cellular conditions often lead to nonproductive translational stalling and arrest of ribosomes on mRNAs. Here, we used fast kinetics and cryo-EM to characterize Escherichia coli HflX, a GTPase with unknown function. Our data reveal that HflX is a heat shock-induced ribosome-splitting factor capable of dissociating vacant as well as mRNA-associated ribosomes with deacylated tRNA in the peptidyl site. Structural data demonstrate that the N-terminal effector domain of HflX binds to the peptidyl transferase center in a strikingly similar manner as that of the class I release factors and induces dramatic conformational changes in central intersubunit bridges, thus promoting subunit dissociation. Accordingly, loss of HflX results in an increase in stalled ribosomes upon heat shock. These results suggest a primary role of HflX in rescuing translationally arrested ribosomes under stress conditions.
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Affiliation(s)
- Yanqing Zhang
- Ministry of Education Key Laboratory of Protein Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | | | - Wei Cao
- Ministry of Education Key Laboratory of Protein Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaojing Li
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Dejiu Zhang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Ningning Li
- Ministry of Education Key Laboratory of Protein Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yixiao Zhang
- Ministry of Education Key Laboratory of Protein Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaoxiao Zhang
- Ministry of Education Key Laboratory of Protein Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yan Qin
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kaixia Mi
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jianlin Lei
- Ministry of Education Key Laboratory of Protein Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Suparna Sanyal
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Ning Gao
- Ministry of Education Key Laboratory of Protein Sciences, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
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44
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Basbouss-Serhal I, Soubigou-Taconnat L, Bailly C, Leymarie J. Germination Potential of Dormant and Nondormant Arabidopsis Seeds Is Driven by Distinct Recruitment of Messenger RNAs to Polysomes. PLANT PHYSIOLOGY 2015; 168:1049-65. [PMID: 26019300 PMCID: PMC4741348 DOI: 10.1104/pp.15.00510] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 05/21/2015] [Indexed: 05/19/2023]
Abstract
Dormancy is a complex evolutionary trait that temporally prevents seed germination, thus allowing seedling growth at a favorable season. High-throughput analyses of transcriptomes have led to significant progress in understanding the molecular regulation of this process, but the role of posttranscriptional mechanisms has received little attention. In this work, we have studied the dynamics of messenger RNA association with polysomes and compared the transcriptome with the translatome in dormant and nondormant seeds of Arabidopsis (Arabidopsis thaliana) during their imbibition at 25 °C in darkness, a temperature preventing germination of dormant seeds only. DNA microarray analysis revealed that 4,670 and 7,028 transcripts were differentially abundant in dormant and nondormant seeds in the transcriptome and the translatome, respectively. We show that there is no correlation between transcriptome and translatome and that germination regulation is also largely translational, implying a selective and dynamic recruitment of messenger RNAs to polysomes in both dormant and nondormant seeds. The study of 5' untranslated region features revealed that GC content and the number of upstream open reading frames could play a role in selective translation occurring during germination. Gene Ontology clustering showed that the functions of polysome-associated transcripts differed between dormant and nondormant seeds and revealed actors in seed dormancy and germination. In conclusion, our results demonstrate the essential role of selective polysome loading in this biological process.
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Affiliation(s)
- Isabelle Basbouss-Serhal
- Sorbonne Universités, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, F-75005 Paris, France (I.B.-S., C.B., J.L.);Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, Biologie du Développement, F-75005 Paris, France (I.B.-S., C.B., J.L.); andUnité de Recherche en Génomique Végétale, Unité Mixte de Recherche 1165, Institut National de la Recherche Agronomique, 91057 Evry, France (L.S.-T.)
| | - Ludivine Soubigou-Taconnat
- Sorbonne Universités, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, F-75005 Paris, France (I.B.-S., C.B., J.L.);Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, Biologie du Développement, F-75005 Paris, France (I.B.-S., C.B., J.L.); andUnité de Recherche en Génomique Végétale, Unité Mixte de Recherche 1165, Institut National de la Recherche Agronomique, 91057 Evry, France (L.S.-T.)
| | - Christophe Bailly
- Sorbonne Universités, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, F-75005 Paris, France (I.B.-S., C.B., J.L.);Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, Biologie du Développement, F-75005 Paris, France (I.B.-S., C.B., J.L.); andUnité de Recherche en Génomique Végétale, Unité Mixte de Recherche 1165, Institut National de la Recherche Agronomique, 91057 Evry, France (L.S.-T.)
| | - Juliette Leymarie
- Sorbonne Universités, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, F-75005 Paris, France (I.B.-S., C.B., J.L.);Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Unité Mixte de Recherche 7622, Biologie du Développement, F-75005 Paris, France (I.B.-S., C.B., J.L.); andUnité de Recherche en Génomique Végétale, Unité Mixte de Recherche 1165, Institut National de la Recherche Agronomique, 91057 Evry, France (L.S.-T.)
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45
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Simm S, Fragkostefanakis S, Paul P, Keller M, Einloft J, Scharf KD, Schleiff E. Identification and Expression Analysis of Ribosome Biogenesis Factor Co-orthologs in Solanum lycopersicum. Bioinform Biol Insights 2015; 9:1-17. [PMID: 25698879 PMCID: PMC4325683 DOI: 10.4137/bbi.s20751] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/17/2014] [Accepted: 11/21/2014] [Indexed: 12/12/2022] Open
Abstract
Ribosome biogenesis involves a large inventory of proteinaceous and RNA cofactors. More than 250 ribosome biogenesis factors (RBFs) have been described in yeast. These factors are involved in multiple aspects like rRNA processing, folding, and modification as well as in ribosomal protein (RP) assembly. Considering the importance of RBFs for particular developmental processes, we examined the complexity of RBF and RP (co-)orthologs by bioinformatic assignment in 14 different plant species and expression profiling in the model crop Solanum lycopersicum. Assigning (co-)orthologs to each RBF revealed that at least 25% of all predicted RBFs are encoded by more than one gene. At first we realized that the occurrence of multiple RBF co-orthologs is not globally correlated to the existence of multiple RP co-orthologs. The transcript abundance of genes coding for predicted RBFs and RPs in leaves and anthers of S. lycopersicum was determined by next generation sequencing (NGS). In combination with existing expression profiles, we can conclude that co-orthologs of RBFs by large account for a preferential function in different tissue or at distinct developmental stages. This notion is supported by the differential expression of selected RBFs during male gametophyte development. In addition, co-regulated clusters of RBF and RP coding genes have been observed. The relevance of these results is discussed.
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Affiliation(s)
- Stefan Simm
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany. ; Cluster of Excellence Frankfurt, Goethe University, Frankfurt/Main, Germany
| | - Sotirios Fragkostefanakis
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany. ; Cluster of Excellence Frankfurt, Goethe University, Frankfurt/Main, Germany
| | - Puneet Paul
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Mario Keller
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Jens Einloft
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Klaus-Dieter Scharf
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany
| | - Enrico Schleiff
- Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt/Main, Germany. ; Center of Membrane Proteomics, Goethe University, Frankfurt/Main, Germany. ; Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt/Main, Germany
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Simms CL, Hudson BH, Mosior JW, Rangwala AS, Zaher HS. An active role for the ribosome in determining the fate of oxidized mRNA. Cell Rep 2014; 9:1256-64. [PMID: 25456128 DOI: 10.1016/j.celrep.2014.10.042] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/23/2014] [Accepted: 10/15/2014] [Indexed: 11/30/2022] Open
Abstract
Chemical damage to RNA affects its functional properties and thus may pose a significant hurdle to the translational apparatus; however, the effects of damaged mRNA on the speed and accuracy of the decoding process and their interplay with quality-control processes are not known. Here, we systematically explore the effects of oxidative damage on the decoding process using a well-defined bacterial in vitro translation system. We find that the oxidative lesion 8-oxoguanosine (8-oxoG) reduces the rate of peptide-bond formation by more than three orders of magnitude independent of its position within the codon. Interestingly, 8-oxoG had little effect on the fidelity of the selection process, suggesting that the modification stalls the translational machinery. Consistent with these findings, 8-oxoG mRNAs were observed to accumulate and associate with polyribosomes in yeast strains in which no-go decay is compromised. Our data provide compelling evidence that mRNA-surveillance mechanisms have evolved to cope with damaged mRNA.
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Affiliation(s)
- Carrie L Simms
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Benjamin H Hudson
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - John W Mosior
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ali S Rangwala
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Hani S Zaher
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
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Mondal S, Pathak BK, Ray S, Barat C. Impact of P-Site tRNA and antibiotics on ribosome mediated protein folding: studies using the Escherichia coli ribosome. PLoS One 2014; 9:e101293. [PMID: 25000563 PMCID: PMC4085065 DOI: 10.1371/journal.pone.0101293] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/04/2014] [Indexed: 12/22/2022] Open
Abstract
Background The ribosome, which acts as a platform for mRNA encoded polypeptide synthesis, is also capable of assisting in folding of polypeptide chains. The peptidyl transferase center (PTC) that catalyzes peptide bond formation resides in the domain V of the 23S rRNA of the bacterial ribosome. Proper positioning of the 3′ –CCA ends of the A- and P-site tRNAs via specific interactions with the nucleotides of the PTC are crucial for peptidyl transferase activity. This RNA domain is also the center for ribosomal chaperoning activity. The unfolded polypeptide chains interact with the specific nucleotides of the PTC and are released in a folding competent form. In vitro transcribed RNA corresponding to this domain (bDV RNA) also displays chaperoning activity. Results The present study explores the effects of tRNAs, antibiotics that are A- and P-site PTC substrate analogs (puromycin and blasticidin) and macrolide antibiotics (erythromycin and josamycin) on the chaperoning ability of the E. coli ribosome and bDV RNA. Our studies using mRNA programmed ribosomes show that a tRNA positioned at the P-site effectively inhibits the ribosome's chaperoning function. We also show that the antibiotic blasticidin (that mimics the interaction between 3′–CCA end of P/P-site tRNA with the PTC) is more effective in inhibiting ribosome and bDV RNA chaperoning ability than either puromycin or the macrolide antibiotics. Mutational studies of the bDV RNA could identify the nucleotides U2585 and G2252 (both of which interact with P-site tRNA) to be important for its chaperoning ability. Conclusion Both protein synthesis and their proper folding are crucial for maintenance of a functional cellular proteome. The PTC of the ribosome is attributed with both these abilities. The silencing of the chaperoning ability of the ribosome in the presence of P-site bound tRNA might be a way to segregate these two important functions.
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Affiliation(s)
- Surojit Mondal
- Department of Biotechnology, St. Xavier's College, Kolkata, West Bengal, India
| | - Bani Kumar Pathak
- Department of Biotechnology, St. Xavier's College, Kolkata, West Bengal, India
| | - Sutapa Ray
- Dr. B.C Guha Centre for Genetic Engineering and Department of Biotechnology, Calcutta University, Kolkata, West Bengal, India
| | - Chandana Barat
- Department of Biotechnology, St. Xavier's College, Kolkata, West Bengal, India
- * E-mail:
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