1
|
Eisenack TJ, Trentini DB. Ending a bad start: Triggers and mechanisms of co-translational protein degradation. Front Mol Biosci 2023; 9:1089825. [PMID: 36660423 PMCID: PMC9846516 DOI: 10.3389/fmolb.2022.1089825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 12/15/2022] [Indexed: 01/05/2023] Open
Abstract
Proteins are versatile molecular machines that control and execute virtually all cellular processes. They are synthesized in a multilayered process requiring transfer of information from DNA to RNA and finally into polypeptide, with many opportunities for error. In addition, nascent proteins must successfully navigate a complex folding-energy landscape, in which their functional native state represents one of many possible outcomes. Consequently, newly synthesized proteins are at increased risk of misfolding and toxic aggregation. To maintain proteostasis-the state of proteome balance-cells employ a plethora of molecular chaperones that guide proteins along a productive folding pathway and quality control factors that direct misfolded species for degradation. Achieving the correct balance between folding and degradation therefore represents a fundamental task for the proteostasis network. While many chaperones act co-translationally, protein quality control is generally considered to be a post-translational process, as the majority of proteins will only achieve their final native state once translation is completed. Nevertheless, it has been observed that proteins can be ubiquitinated during synthesis. The extent and the relevance of co-translational protein degradation, as well as the underlying molecular mechanisms, remain areas of open investigation. Recent studies made seminal advances in elucidating ribosome-associated quality control processes, and how their loss of function can lead to proteostasis failure and disease. Here, we discuss current understanding of the situations leading to the marking of nascent proteins for degradation before synthesis is completed, and the emerging quality controls pathways engaged in this task in eukaryotic cells. We also highlight the methods used to study co-translational quality control.
Collapse
Affiliation(s)
- Tom Joshua Eisenack
- University of Cologne, Faculty of Medicine, University Hospital of Cologne, Center for Molecular Medicine Cologne (CMMC), Cologne, Germany
| | - Débora Broch Trentini
- University of Cologne, Faculty of Medicine, University Hospital of Cologne, Center for Molecular Medicine Cologne (CMMC), Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany,*Correspondence: Débora Broch Trentini,
| |
Collapse
|
2
|
English AM, Green KM, Moon SL. A (dis)integrated stress response: Genetic diseases of eIF2α regulators. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1689. [PMID: 34463036 DOI: 10.1002/wrna.1689] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 01/28/2023]
Abstract
The integrated stress response (ISR) is a conserved mechanism by which eukaryotic cells remodel gene expression to adapt to intrinsic and extrinsic stressors rapidly and reversibly. The ISR is initiated when stress-activated protein kinases phosphorylate the major translation initiation factor eukaryotic translation initiation factor 2ɑ (eIF2ɑ), which globally suppresses translation initiation activity and permits the selective translation of stress-induced genes including important transcription factors such as activating transcription factor 4 (ATF4). Translationally repressed messenger RNAs (mRNAs) and noncoding RNAs assemble into cytoplasmic RNA-protein granules and polyadenylated RNAs are concomitantly stabilized. Thus, regulated changes in mRNA translation, stability, and localization to RNA-protein granules contribute to the reprogramming of gene expression that defines the ISR. We discuss fundamental mechanisms of RNA regulation during the ISR and provide an overview of a growing class of genetic disorders associated with mutant alleles of key translation factors in the ISR pathway. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease Translation > Translation Regulation RNA in Disease and Development > RNA in Development.
Collapse
Affiliation(s)
- Alyssa M English
- Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Katelyn M Green
- Department of Chemistry, Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Stephanie L Moon
- Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
3
|
Pietschmann M, Tempel G, Halladjian M, Krogh N, Nielsen H. Use of a Lariat Capping Ribozyme to Study Cap Function In Vivo. Methods Mol Biol 2021; 2167:271-285. [PMID: 32712925 DOI: 10.1007/978-1-0716-0716-9_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A lariat cap is a naturally occurring substitute of a conventional mRNA cap and is found in a particular genomic setting in a few eukaryotic microorganisms. It is installed by the lariat capping ribozyme acting in cis. In principle, any RNA molecule in any organism can be equipped with a lariat cap in vivo when expressed downstream of a lariat capping ribozyme. Lariat capping is thus a versatile tool for studying the importance of the 5' end structure of RNA molecules. In this chapter, we present protocols to validate the presence of the lariat cap and measure the efficiency of in vivo cleavage by the lariat capping ribozyme.
Collapse
Affiliation(s)
- Max Pietschmann
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Gregor Tempel
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Maral Halladjian
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
4
|
Moon SL, Morisaki T, Stasevich TJ, Parker R. Coupling of translation quality control and mRNA targeting to stress granules. J Cell Biol 2021; 219:151851. [PMID: 32520986 PMCID: PMC7401812 DOI: 10.1083/jcb.202004120] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 02/07/2023] Open
Abstract
Stress granules are dynamic assemblies of proteins and nontranslating RNAs that form when translation is inhibited in response to diverse stresses. Defects in ubiquitin–proteasome system factors including valosin-containing protein (VCP) and the proteasome impact the kinetics of stress granule induction and dissolution as well as being implicated in neuropathogenesis. However, the impacts of dysregulated proteostasis on mRNA regulation and stress granules are not well understood. Using single mRNA imaging, we discovered ribosomes stall on some mRNAs during arsenite stress, and the release of transcripts from stalled ribosomes for their partitioning into stress granules requires the activities of VCP, components of the ribosome-associated quality control (RQC) complex, and the proteasome. This is an unexpected contribution of the RQC system in releasing mRNAs from translation under stress, thus identifying a new type of stress-activated RQC (saRQC) distinct from canonical RQC pathways in mRNA substrates, cellular context, and mRNA fate.
Collapse
Affiliation(s)
- Stephanie L Moon
- Department of Human Genetics, University of Michigan, Ann Arbor, MI.,Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI
| | - Tatsuya Morisaki
- Department of Biochemistry, Colorado State University, Fort Collins, CO
| | - Timothy J Stasevich
- Department of Biochemistry, Colorado State University, Fort Collins, CO.,World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO.,Howard Hughes Medical Institute, Chevy Chase, MD
| |
Collapse
|
5
|
Aroonsri A, Kongsee J, Gunawan JD, Aubry DA, Shaw PJ. A cell-based ribozyme reporter system employing a chromosomally-integrated 5' exonuclease gene. BMC Mol Cell Biol 2021; 22:20. [PMID: 33726662 PMCID: PMC7967978 DOI: 10.1186/s12860-021-00357-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 02/28/2021] [Indexed: 11/10/2022] Open
Abstract
Background Bioinformatic genome surveys indicate that self-cleaving ribonucleic acids (ribozymes) appear to be widespread among all domains of life, although the functions of only a small number have been validated by biochemical methods. Alternatively, cell-based reporter gene assays can be used to validate ribozyme function. However, reporter activity can be confounded by phenomena unrelated to ribozyme-mediated cleavage of RNA. Results We established a ribozyme reporter system in Escherichia coli in which a significant reduction of reporter activity is manifest when an active ribozyme sequence is fused to the reporter gene and the expression of a foreign Bacillus subtilis RNaseJ1 5′ exonuclease is induced from a chromosomally-integrated gene in the same cell. Conclusions The reporter system could be useful for validating ribozyme function in candidate sequences identified from bioinformatics. Supplementary Information The online version contains supplementary material available at 10.1186/s12860-021-00357-7.
Collapse
Affiliation(s)
- Aiyada Aroonsri
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand.
| | - Jindaporn Kongsee
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand
| | - Jeremy David Gunawan
- School of Life Science, Indonesia International Institute for Life Sciences (i3L), Jakarta, 13210, Indonesia
| | - Daniel Abidin Aubry
- School of Life Science, Indonesia International Institute for Life Sciences (i3L), Jakarta, 13210, Indonesia
| | - Philip James Shaw
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand
| |
Collapse
|
6
|
Abstract
Stalled protein synthesis produces defective nascent chains that can harm cells. In response, cells degrade these nascent chains via a process called ribosome-associated quality control (RQC). Here, we review the irregularities in the translation process that cause ribosomes to stall as well as how cells use RQC to detect stalled ribosomes, ubiquitylate their tethered nascent chains, and deliver the ubiquitylated nascent chains to the proteasome. We additionally summarize how cells respond to RQC failure.
Collapse
Affiliation(s)
- Cole S Sitron
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany;
| | - Onn Brandman
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA;
| |
Collapse
|
7
|
Sultana N, Hadas Y, Sharkar MTK, Kaur K, Magadum A, Kurian AA, Hossain N, Alburquerque B, Ahmed S, Chepurko E, Zangi L. Optimization of 5' Untranslated Region of Modified mRNA for Use in Cardiac or Hepatic Ischemic Injury. Mol Ther Methods Clin Dev 2020; 17:622-633. [PMID: 32300609 PMCID: PMC7150433 DOI: 10.1016/j.omtm.2020.03.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 03/23/2020] [Indexed: 02/06/2023]
Abstract
Modified mRNA (modRNA) is a gene-delivery platform for transiently introducing a single gene or several genes of interest to different cell types and tissues. modRNA is considered to be a safe vector for gene transfer, as it negligibly activates the innate immune system and does not compromise the genome integrity. The use of modRNA in basic and translational science is rising, due to the clinical potential of modRNA. We are currently using modRNA to induce cardiac regeneration post-ischemic injury. Major obstacles in using modRNA for cardiac ischemic disease include the need for the direct and single administration of modRNA to the heart and the inefficient translation of modRNA due to its short half-life. Modulation of the 5' untranslated region (5' UTR) to enhance translation efficiency in ischemic cardiac disease has great value, as it can reduce the amount of modRNA needed per delivery and will achieve higher and longer protein production post-single delivery. Here, we identified that 5' UTR, from the fatty acid metabolism gene carboxylesterase 1D (Ces1d), enhanced the translation of firefly luciferase (Luc) modRNA by 2-fold in the heart post-myocardial infarction (MI). Moreover, we identified, in the Ces1d, a specific RNA element (element D) that is responsible for the improvement of modRNA translation and leads to a 2.5-fold translation increment over Luc modRNA carrying artificial 5' UTR, post-MI. Importantly, we were able to show that 5' UTR Ces1d also enhances modRNA translation in the liver, but not in the kidney, post-ischemic injury, indicating that Ces1d 5' UTR and element D may play a wider role in translation of protein under an ischemic condition.
Collapse
Affiliation(s)
- Nishat Sultana
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yoav Hadas
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mohammad Tofael Kabir Sharkar
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Keerat Kaur
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ajit Magadum
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ann Anu Kurian
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nadia Hossain
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bremy Alburquerque
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sakib Ahmed
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Elena Chepurko
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Lior Zangi
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| |
Collapse
|
8
|
Lingaraju M, Schuller JM, Falk S, Gerlach P, Bonneau F, Basquin J, Benda C, Conti E. To Process or to Decay: A Mechanistic View of the Nuclear RNA Exosome. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2020; 84:155-163. [PMID: 32493762 DOI: 10.1101/sqb.2019.84.040295] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The RNA exosome was originally discovered in yeast as an RNA-processing complex required for the maturation of 5.8S ribosomal RNA (rRNA), one of the constituents of the large ribosomal subunit. The exosome is now known in eukaryotes as the major 3'-5' RNA degradation machine involved in numerous processing, turnover, and surveillance pathways, both in the nucleus and the cytoplasm. Yet its role in maturing the 5.8S rRNA in the pre-60S ribosomal particle remains probably the most intricate and emblematic among its functions, as it involves all the RNA unwinding, degradation, and trimming activities embedded in this macromolecular complex. Here, we propose a comprehensive mechanistic model, based on current biochemical and structural data, explaining the dual functions of the nuclear exosome-the constructive versus the destructive mode.
Collapse
Affiliation(s)
- Mahesh Lingaraju
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Jan M Schuller
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Sebastian Falk
- Max Perutz Labs, Department of Structural and Computational Biology, University of Vienna, 1030, Vienna, Austria
| | - Piotr Gerlach
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Fabien Bonneau
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Jérôme Basquin
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Christian Benda
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| | - Elena Conti
- Max-Planck-Institute of Biochemistry, Department of Structural Cell Biology, D-82152 Martinsried/Munich, Germany
| |
Collapse
|
9
|
Lander N, Cruz-Bustos T, Docampo R. A CRISPR/Cas9-riboswitch-Based Method for Downregulation of Gene Expression in Trypanosoma cruzi. Front Cell Infect Microbiol 2020; 10:68. [PMID: 32175288 PMCID: PMC7056841 DOI: 10.3389/fcimb.2020.00068] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/11/2020] [Indexed: 12/18/2022] Open
Abstract
Few genetic tools were available to work with Trypanosoma cruzi until the recent introduction of the CRISPR/Cas9 technique for gene knockout, gene knock-in, gene complementation, and endogenous gene tagging. Riboswitches are naturally occurring self-cleaving RNAs (ribozymes) that can be ligand-activated. Results from our laboratory recently demonstrated the usefulness of the glmS ribozyme from Bacillus subtilis, which has been shown to control reporter gene expression in response to exogenous glucosamine, for gene silencing in Trypanosoma brucei. In this work we used the CRISPR/Cas9 system for endogenously tagging T. cruzi glycoprotein 72 (TcGP72) and vacuolar proton pyrophosphatase (TcVP1) with the active (glmS) or inactive (M9) ribozyme. Gene tagging was confirmed by PCR and protein downregulation was verified by western blot analyses. Further phenotypic characterization was performed by immunofluorescence analysis and quantification of growth in vitro. Our results indicate that the method was successful in silencing the expression of both genes without the need of glucosamine in the medium, suggesting that T. cruzi produces enough levels of endogenous glucosamine 6-phosphate to stimulate the glmS ribozyme activity under normal growth conditions. This method could be useful to obtain knockdowns of essential genes in T. cruzi and to validate potential drug targets in this parasite.
Collapse
Affiliation(s)
- Noelia Lander
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Teresa Cruz-Bustos
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States.,Department of Cellular Biology, University of Georgia, Athens, GA, United States
| |
Collapse
|
10
|
Inada T. Quality controls induced by aberrant translation. Nucleic Acids Res 2020; 48:1084-1096. [PMID: 31950154 PMCID: PMC7026593 DOI: 10.1093/nar/gkz1201] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 12/01/2019] [Accepted: 12/18/2019] [Indexed: 12/31/2022] Open
Abstract
During protein synthesis, translating ribosomes encounter many challenges imposed by various types of defective mRNAs that can lead to reduced cellular fitness and, in some cases, even threaten cell viability. Aberrant translation leads to activation of one of several quality control pathways depending on the nature of the problem. These pathways promote the degradation of the problematic mRNA as well as the incomplete translation product, the nascent polypeptide chain. Many of these quality control systems feature critical roles for specialized regulatory factors that work in concert with conventional factors. This review focuses on the mechanisms used by these quality control pathways to recognize aberrant ribosome stalling and discusses the conservation of these systems.
Collapse
Affiliation(s)
- Toshifumi Inada
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| |
Collapse
|
11
|
Navickas A, Chamois S, Saint-Fort R, Henri J, Torchet C, Benard L. No-Go Decay mRNA cleavage in the ribosome exit tunnel produces 5'-OH ends phosphorylated by Trl1. Nat Commun 2020; 11:122. [PMID: 31913314 PMCID: PMC6949252 DOI: 10.1038/s41467-019-13991-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/11/2019] [Indexed: 11/24/2022] Open
Abstract
The No-Go Decay (NGD) mRNA surveillance pathway degrades mRNAs containing stacks of stalled ribosomes. Although an endoribonuclease has been proposed to initiate cleavages upstream of the stall sequence, the production of two RNA fragments resulting from a unique cleavage has never been demonstrated. Here we use mRNAs expressing a 3'-ribozyme to produce truncated transcripts in vivo to mimic naturally occurring truncated mRNAs known to trigger NGD. This technique allows us to analyse endonucleolytic cleavage events at single-nucleotide resolution starting at the third collided ribosome, which we show to be Hel2-dependent. These cleavages map precisely in the mRNA exit tunnel of the ribosome, 8 nucleotides upstream of the first P-site residue and release 5'-hydroxylated RNA fragments requiring 5'-phosphorylation prior to digestion by the exoribonuclease Xrn1, or alternatively by Dxo1. Finally, we identify the RNA kinase Trl1, alias Rlg1, as an essential player in the degradation of NGD RNAs.
Collapse
Affiliation(s)
- Albertas Navickas
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Université, Laboratoire de Biologie moléculaire et Cellulaire des Eucaryotes, Paris, France
| | - Sébastien Chamois
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Université, Laboratoire de Biologie moléculaire et Cellulaire des Eucaryotes, Paris, France
| | - Rénette Saint-Fort
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Université, Laboratoire de Biologie moléculaire et Cellulaire des Eucaryotes, Paris, France
| | - Julien Henri
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Université, Laboratoire de Biologie moléculaire et Cellulaire des Eucaryotes, Paris, France
| | - Claire Torchet
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Université, Laboratoire de Biologie moléculaire et Cellulaire des Eucaryotes, Paris, France
| | - Lionel Benard
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Université, Laboratoire de Biologie moléculaire et Cellulaire des Eucaryotes, Paris, France.
| |
Collapse
|
12
|
Xiang JS, Kaplan M, Dykstra P, Hinks M, McKeague M, Smolke CD. Massively parallel RNA device engineering in mammalian cells with RNA-Seq. Nat Commun 2019; 10:4327. [PMID: 31548547 PMCID: PMC6757056 DOI: 10.1038/s41467-019-12334-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 08/28/2019] [Indexed: 12/21/2022] Open
Abstract
Synthetic RNA-based genetic devices dynamically control a wide range of gene-regulatory processes across diverse cell types. However, the limited throughput of quantitative assays in mammalian cells has hindered fast iteration and interrogation of sequence space needed to identify new RNA devices. Here we report developing a quantitative, rapid and high-throughput mammalian cell-based RNA-Seq assay to efficiently engineer RNA devices. We identify new ribozyme-based RNA devices that respond to theophylline, hypoxanthine, cyclic-di-GMP, and folinic acid from libraries of ~22,700 sequences in total. The small molecule responsive devices exhibit low basal expression and high activation ratios, significantly expanding our toolset of highly functional ribozyme switches. The large datasets obtained further provide conserved sequence and structure motifs that may be used for rationally guided design. The RNA-Seq approach offers a generally applicable strategy for developing broad classes of RNA devices, thereby advancing the engineering of genetic devices for mammalian systems.
Collapse
Affiliation(s)
- Joy S Xiang
- Department of Bioengineering, 443 Via Ortega, MC 4245, Stanford University, Stanford, CA, 94305, USA
| | - Matias Kaplan
- Department of Bioengineering, 443 Via Ortega, MC 4245, Stanford University, Stanford, CA, 94305, USA
| | - Peter Dykstra
- Department of Bioengineering, 443 Via Ortega, MC 4245, Stanford University, Stanford, CA, 94305, USA
| | - Michaela Hinks
- Department of Bioengineering, 443 Via Ortega, MC 4245, Stanford University, Stanford, CA, 94305, USA
| | - Maureen McKeague
- Department of Pharmacology and Therapeutics, McGill University, 3655 Prom. Sir-William-Osler, Montreal, Quebec, H3G 1Y6, Canada
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada
| | - Christina D Smolke
- Department of Bioengineering, 443 Via Ortega, MC 4245, Stanford University, Stanford, CA, 94305, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA.
| |
Collapse
|
13
|
CAT tails drive degradation of stalled polypeptides on and off the ribosome. Nat Struct Mol Biol 2019; 26:450-459. [PMID: 31133701 PMCID: PMC6554034 DOI: 10.1038/s41594-019-0230-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 04/16/2019] [Indexed: 12/12/2022]
Abstract
Stalled translation produces incomplete, ribosome-tethered polypeptides that the Ribosome-associated Quality Control (RQC) pathway targets for degradation via the E3 ubiquitin ligase Ltn1. During this process, the protein Rqc2 and the large ribosomal subunit elongate stalled polypeptides with carboxy-terminal alanine and threonine residues (CAT tails). Failure to degrade CAT-tailed proteins disrupts global protein homeostasis, as CAT-tailed proteins can aggregate and sequester chaperones. Why cells employ such a potentially toxic process during RQC is unclear. Here, we developed quantitative techniques to assess how CAT tails affect stalled polypeptide degradation in Saccharomyces cerevisiae. We found that CAT tails enhance Ltn1’s efficiency in targeting structured polypeptides, which are otherwise poor Ltn1 substrates. If Ltn1 fails to ubiquitylate those stalled polypeptides or becomes limiting, CAT tails act as degrons, marking proteins for proteasomal degradation off the ribosome. Thus, CAT tails functionalize the carboxy-termini of stalled polypeptides to drive their degradation on and off the ribosome.
Collapse
|
14
|
Arthur LL, Djuranovic S. PolyA tracks, polybasic peptides, poly-translational hurdles. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1486. [PMID: 29869837 PMCID: PMC6281860 DOI: 10.1002/wrna.1486] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 12/26/2022]
Abstract
The abundance of messenger RNA (mRNA) is one of the major determinants of protein synthesis. As such, factors that influence mRNA stability often contribute to gene regulation. Polyadenylation of the 3' end of mRNA transcripts, the poly(A) tail, has long been recognized as one of these regulatory elements given its influence on translation efficiency and mRNA stability. Unwanted translation of the poly(A) tail signals to the cell an aberrant polyadenylation event or the lack of stop codons, which makes this sequence an important element in translation fidelity and mRNA surveillance response. Consequently, investigations into the effects of the poly(A) tail lead to the discoveries that poly-lysine as well as other polybasic peptide sequences and, to a much greater extent, polyA mRNA sequences within the open reading frame influence mRNA stability and translational efficiency. Conservation and evolutionary selection of codon usage in polyA track sequences across multiple organisms suggests a biological significance for coding polyA tracks in the regulation of gene expression. Here, we discuss the cellular responses and consequences of coding polyA track translation and synthesis of polybasic peptides. This article is categorized under: Translation > Translation Mechanisms Translation > Translation Regulation RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms.
Collapse
Affiliation(s)
- Laura L Arthur
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - Sergej Djuranovic
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| |
Collapse
|
15
|
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: 74] [Impact Index Per Article: 12.3] [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.
Collapse
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.
| |
Collapse
|
16
|
Han J, van Hoof A. The RNA Exosome Channeling and Direct Access Conformations Have Distinct In Vivo Functions. Cell Rep 2018; 16:3348-3358. [PMID: 27653695 DOI: 10.1016/j.celrep.2016.08.059] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 06/06/2016] [Accepted: 08/18/2016] [Indexed: 10/21/2022] Open
Abstract
The RNA exosome is a 3'-5' ribonuclease complex that is composed of nine core subunits and an essential catalytic subunit, Rrp44. Two distinct conformations of Rrp44 were revealed in previous structural studies, suggesting that Rrp44 may change its conformation to exert its function. In the channeling conformation, (Rrp44(ch)), RNA accesses the active site after traversing the central channel of the RNA exosome, whereas in the other conformation, (Rrp44(da)), RNA gains direct access to the active site. Here, we show that the Rrp44(da) exosome is important for nuclear function of the RNA exosome. Defects caused by disrupting the direct access conformation are distinct from those caused by channel-occluding mutations, indicating specific functions for each conformation. Our genetic analyses provide in vivo evidence that the RNA exosome employs a direct-access route to recruit specific substrates, indicating that the RNA exosome uses alternative conformations to act on different RNA substrates.
Collapse
Affiliation(s)
- Jaeil Han
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA; The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA; The University of Texas Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 1.212, Houston, TX 77030, USA.
| |
Collapse
|
17
|
Cruz-Bustos T, Ramakrishnan S, Cordeiro CD, Ahmed MA, Docampo R. A Riboswitch-based Inducible Gene Expression System for Trypanosoma brucei. J Eukaryot Microbiol 2018; 65:412-421. [PMID: 29265590 DOI: 10.1111/jeu.12493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 12/08/2017] [Accepted: 12/08/2017] [Indexed: 01/13/2023]
Abstract
Generation of conditional mutants in Trypanosoma brucei can be done by the use of RNA interference (RNAi). However, RNAi frequently produces off target effects. Here, we present an alternative strategy in which the glmS ribozyme is inserted in the C-terminal region of one allele of a GOI and effectively knocks it down in response to the presence of glucosamine in the culture medium. Using several endogenous genes, we show that the glmS ribozyme cleaves the mRNA in vivo leading to reduction in mRNA and protein expression following glucosamine treatment in both T. brucei procyclic and bloodstream forms. Glucosamine-induced ribozyme activation can be rapidly reversed by removing the inducer. In summary, the glmS ribozyme could be used as a tool to study essential genes in T. brucei.
Collapse
Affiliation(s)
- Teresa Cruz-Bustos
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, 30602
| | - Srinivasan Ramakrishnan
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, 30602
| | - Ciro D Cordeiro
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, 30602
| | - Michael A Ahmed
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, 30602
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, 30602
| |
Collapse
|
18
|
Wurmthaler LA, Klauser B, Hartig JS. Highly motif- and organism-dependent effects of naturally occurring hammerhead ribozyme sequences on gene expression. RNA Biol 2017; 15:231-241. [PMID: 29106331 DOI: 10.1080/15476286.2017.1397870] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Recent bioinformatics studies have demonstrated a wide-spread occurrence of the hammerhead ribozyme (HHR) and similar small endonucleolytic RNA motifs in all domains of life. It is becoming increasingly evident that such ribozyme motifs participate in important genetic processes in diverse organisms. Although the HHR motif has been studied for more than three decades, only little is known about the consequences of ribozyme activity on gene expression. In the present study we analysed eight different naturally occurring HHR sequences in diverse genetic and organismal contexts. We investigated the influence of active ribozymes incorporated into mRNAs in mammalian, yeast and bacterial expression systems. The experiments show an unexpectedly high degree of organism-specific variability of ribozyme-mediated effects on gene expression. The presented findings demonstrate that ribozyme cleavage profoundly affect gene expression. However, the extent of this effect varies and depends strongly on the respective genetic context. The fast-cleaving type 3 HHRs [CChMVd(-) and sLTSV(-)] generally tended to cause the strongest effects on intracellular gene expression. The presented results are important in order to address potential functions of naturally occurring ribozymes in RNA processing and post-transcriptional regulation of gene expression. Additionally, our results are of interest for biotechnology and synthetic biology approaches that aim at the utilisation of self-cleaving ribozymes as widely applicable tools for controlling genetic processes.
Collapse
Affiliation(s)
- Lena A Wurmthaler
- a Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB) , University of Konstanz , Konstanz , Germany
| | - Benedikt Klauser
- a Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB) , University of Konstanz , Konstanz , Germany
| | - Jörg S Hartig
- a Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB) , University of Konstanz , Konstanz , Germany
| |
Collapse
|
19
|
Dohno C, Kimura M, Nakatani K. Restoration of Ribozyme Tertiary Contact and Function by Using a Molecular Glue for RNA. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201709041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Chikara Dohno
- Department of Regulatory Bioorganic Chemistry; The Institute of Scientific and Industrial Research; Osaka University; 8-1 Mihogaoka Ibaraki, Osaka 567-0047 Japan
| | - Maki Kimura
- Department of Regulatory Bioorganic Chemistry; The Institute of Scientific and Industrial Research; Osaka University; 8-1 Mihogaoka Ibaraki, Osaka 567-0047 Japan
| | - Kazuhiko Nakatani
- Department of Regulatory Bioorganic Chemistry; The Institute of Scientific and Industrial Research; Osaka University; 8-1 Mihogaoka Ibaraki, Osaka 567-0047 Japan
| |
Collapse
|
20
|
Restoration of Ribozyme Tertiary Contact and Function by Using a Molecular Glue for RNA. Angew Chem Int Ed Engl 2017; 57:506-510. [DOI: 10.1002/anie.201709041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/14/2017] [Indexed: 11/07/2022]
|
21
|
Joazeiro CAP. Ribosomal Stalling During Translation: Providing Substrates for Ribosome-Associated Protein Quality Control. Annu Rev Cell Dev Biol 2017; 33:343-368. [PMID: 28715909 DOI: 10.1146/annurev-cellbio-111315-125249] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells of all organisms survey problems during translation elongation, which may happen as a consequence of mRNA aberrations, inefficient decoding, or other sources. In eukaryotes, ribosome-associated quality control (RQC) senses elongation-stalled ribosomes and promotes dissociation of ribosomal subunits. This so-called ribosomal rescue releases the mRNA for degradation and allows 40S subunits to be recycled for new rounds of translation. However, the nascent polypeptide chains remain linked to tRNA and associated with the rescued 60S subunits. As a final critical step in this pathway, the Ltn1/Listerin E3 ligase subunit of the RQC complex (RQCc) ubiquitylates the nascent chain, which promotes clearance of the 60S subunit while simultaneously marking the nascent chain for elimination. Here we review the ribosomal stalling and rescue steps upstream of the RQCc, where one witnesses intersection with cellular machineries implicated in translation elongation, translation termination, ribosomal subunit recycling, and mRNA quality control. We emphasize both recent progress and future directions in this area, as well as examples linking ribosomal rescue with the production of Ltn1-RQCc substrates.
Collapse
Affiliation(s)
- Claudio A P Joazeiro
- ZMBH, University of Heidelberg, 69120 Heidelberg, Germany; .,The Scripps Research Institute, La Jolla, California 92037
| |
Collapse
|
22
|
Guydosh NR, Green R. Translation of poly(A) tails leads to precise mRNA cleavage. RNA (NEW YORK, N.Y.) 2017; 23:749-761. [PMID: 28193672 PMCID: PMC5393183 DOI: 10.1261/rna.060418.116] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/09/2017] [Indexed: 05/07/2023]
Abstract
Translation of poly(A) tails leads to mRNA cleavage but the mechanism and global pervasiveness of this "nonstop/no-go" decay process is not understood. Here we performed ribosome profiling (in a yeast strain lacking exosome function) of short 15-18 nucleotides mRNA footprints to identify ribosomes stalled at 3' ends of mRNA decay intermediates. In this background, we found mRNA cleavage extending hundreds of nucleotides upstream of ribosome stalling in poly(A) and predominantly in one reading frame. These observations suggest that decay-triggering endonucleolytic cleavage is closely associated with the ribosome. Surprisingly, ribosomes appeared to accumulate (i.e., stall) in the transcriptome when as few as three consecutive ORF-internal lysine codons were positioned in the A, P, and E sites though significant mRNA degradation was not observed. Endonucleolytic cleavage was found, however, at sites of premature polyadenylation (encoding polylysine) and rescue of the ribosomes stalled at these sites was dependent on Dom34. These results suggest this process may be critical when changes in the polyadenylation site occur during development, tumorigenesis, or when translation termination/recycling is impaired.
Collapse
Affiliation(s)
- Nicholas R Guydosh
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Rachel Green
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| |
Collapse
|
23
|
Sitron CS, Park JH, Brandman O. Asc1, Hel2, and Slh1 couple translation arrest to nascent chain degradation. RNA (NEW YORK, N.Y.) 2017; 23:798-810. [PMID: 28223409 PMCID: PMC5393187 DOI: 10.1261/rna.060897.117] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 02/17/2017] [Indexed: 05/17/2023]
Abstract
Premature arrest of protein synthesis within the open reading frame elicits a protective response that degrades the incomplete nascent chain. In this response, arrested 80S ribosomes are split into their large and small subunits, allowing assembly of the ribosome quality control complex (RQC), which targets nascent chains for degradation. How the cell recognizes arrested nascent chains among the vast pool of actively translating polypeptides is poorly understood. We systematically examined translation arrest and modification of nascent chains in Saccharomyces cerevisiae to characterize the steps that couple arrest to RQC targeting. We focused our analysis on two poorly understood 80S ribosome-binding proteins previously implicated in the response to failed translation, Asc1 and Hel2, as well as a new component of the pathway, Slh1, that we identified here. We found that premature arrest at ribosome stalling sequences still occurred robustly in the absence of Asc1, Hel2, and Slh1. However, these three factors were required for the RQC to modify the nascent chain. We propose that Asc1, Hel2, and Slh1 target arresting ribosomes and that this targeting event is a precondition for the RQC to engage the incomplete nascent chain and facilitate its degradation.
Collapse
Affiliation(s)
- Cole S Sitron
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Joseph H Park
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Onn Brandman
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| |
Collapse
|
24
|
Krogh N, Pietschmann M, Schmid M, Jensen TH, Nielsen H. Lariat capping as a tool to manipulate the 5' end of individual yeast mRNA species in vivo. RNA (NEW YORK, N.Y.) 2017; 23:683-695. [PMID: 28159804 PMCID: PMC5393178 DOI: 10.1261/rna.059337.116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 01/31/2017] [Indexed: 06/06/2023]
Abstract
The 5' cap structure of eukaryotic mRNA is critical for its processing, transport, translation, and stability. The many functions of the cap and the fact that most, if not all, mRNA carries the same type of cap makes it difficult to analyze cap function in vivo at individual steps of gene expression. We have used the lariat capping ribozyme (LCrz) from the myxomycete Didymium to replace the mRNA m7G cap of a single reporter mRNA species with a tiny lariat in which the first and the third nucleotide are joined by a 2', 5' phosphodiester bond. We show that the ribozyme functions in vivo in the budding yeast Saccharomyces cerevisiae presumably without cofactors and that lariat capping occurs cotranscriptionally. The lariat-capped reporter mRNA is efficiently exported to the cytoplasm where it is found to be oligoadenylated and evenly distributed. Both the oligoadenylated form and a lariat-capped mRNA with a templated poly(A) tail translates poorly, underlining the critical importance of the m7G cap in translation. Finally, the lariat-capped RNA exhibits a threefold longer half-life compared to its m7G-capped counterpart, consistent with a key role for the m7G cap in mRNA turnover. Our study emphasizes important activities of the m7G cap and suggests new utilities of lariat capping as a molecular tool in vivo.
Collapse
Affiliation(s)
- Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Max Pietschmann
- Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Manfred Schmid
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| |
Collapse
|
25
|
Hilal T, Yamamoto H, Loerke J, Bürger J, Mielke T, Spahn CM. Structural insights into ribosomal rescue by Dom34 and Hbs1 at near-atomic resolution. Nat Commun 2016; 7:13521. [PMID: 27995908 PMCID: PMC5187420 DOI: 10.1038/ncomms13521] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/11/2016] [Indexed: 01/13/2023] Open
Abstract
The surveillance of mRNA translation is imperative for homeostasis. Monitoring the integrity of the message is essential, as the translation of aberrant mRNAs leads to stalling of the translational machinery. During ribosomal rescue, arrested ribosomes are specifically recognized by the conserved eukaryotic proteins Dom34 and Hbs1, to initiate their recycling. Here we solve the structure of Dom34 and Hbs1 bound to a yeast ribosome programmed with a nonstop mRNA at 3.3 Å resolution using cryo-electron microscopy. The structure shows that Domain N of Dom34 is inserted into the upstream mRNA-binding groove via direct stacking interactions with conserved nucleotides of 18S rRNA. It senses the absence of mRNA at the A-site and part of the mRNA entry channel by direct competition. Thus, our analysis establishes the structural foundation for the recognition of aberrantly stalled 80S ribosomes by the Dom34·Hbs1·GTP complex during Dom34-mediated mRNA surveillance pathways.
Collapse
Affiliation(s)
- Tarek Hilal
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Hiroshi Yamamoto
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Justus Loerke
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Jörg Bürger
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
- Max-Planck Institut für Molekulare Genetik, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Thorsten Mielke
- Max-Planck Institut für Molekulare Genetik, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Christian M.T. Spahn
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| |
Collapse
|
26
|
Callesen MM, Berthelsen MF, Lund S, Füchtbauer AC, Füchtbauer EM, Jakobsen JE. Recombinase-Mediated Cassette Exchange (RMCE)-in Reporter Cell Lines as an Alternative to the Flp-in System. PLoS One 2016; 11:e0161471. [PMID: 27541869 PMCID: PMC4991790 DOI: 10.1371/journal.pone.0161471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/06/2016] [Indexed: 11/18/2022] Open
Abstract
Recombinase mediated cassette exchange (RMCE) is a powerful tool for targeted insertion of transgenes. Here we describe non-proprietary 'RMCE-in' cell lines as an alternative to the 'Flp-in' system and cell lines. RMCE-in cell lines offer a number of advantages including increased efficiency of integration of the genetic element of interest (GEI) at a single docking site, lack of bacterial backbone at the docking site both before and after GEI integration, removal of selection and visual markers initially present at the docking site upon GEI integration and the possibility to validate GEI integration by loss of a red fluorescence reporter. Moreover, the RMCE-in cell lines are compatible with GEI donors used for the Flp-in system. We demonstrate a three-step procedure for generating RMCE-in cell lines, (I) RMCE-in transposon and SB10 transposase transfection, (II) clone isolation, and (III) selecting single integrated clones with highest RFP level, which could in principle be used to turn any cell line into an RMCE-in cell line. The RMCE-in system was used as a proof of concept to produce three new RMCE-in cell lines using HEK293, HeLa, and murine embryonic stem (mES) cells. The established RMCE-in cell lines and vector are freely available from the ATCC cell bank and Addgene respectively.
Collapse
Affiliation(s)
- Morten M. Callesen
- Department of Biomedicine, Faculty of Health, Aarhus University, Aarhus C, Denmark
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus N, Denmark
| | - Martin F. Berthelsen
- Department of Biomedicine, Faculty of Health, Aarhus University, Aarhus C, Denmark
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus N, Denmark
| | - Sira Lund
- Department of Biomedicine, Faculty of Health, Aarhus University, Aarhus C, Denmark
| | | | | | - Jannik E. Jakobsen
- Department of Biomedicine, Faculty of Health, Aarhus University, Aarhus C, Denmark
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Aarhus N, Denmark
| |
Collapse
|
27
|
Rissland OS. The organization and regulation of mRNA-protein complexes. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27324829 PMCID: PMC5213448 DOI: 10.1002/wrna.1369] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 12/21/2022]
Abstract
In a eukaryotic cell, each messenger RNA (mRNA) is bound to a variety of proteins to form an mRNA-protein complex (mRNP). Together, these proteins impact nearly every step in the life cycle of an mRNA and are critical for the proper control of gene expression. In the cytoplasm, for instance, mRNPs affect mRNA translatability and stability and provide regulation of specific transcripts as well as global, transcriptome-wide control. mRNPs are complex, diverse, and dynamic, and so they have been a challenge to understand. But the advent of high-throughput sequencing technology has heralded a new era in the study of mRNPs. Here, I will discuss general principles of cytoplasmic mRNP organization and regulation. Using microRNA-mediated repression as a case study, I will focus on common themes in mRNPs and highlight the interplay between mRNP composition and posttranscriptional regulation. mRNPs are an important control point in regulating gene expression, and while the study of these fascinating complexes presents remaining challenges, recent advances provide a critical lens for deciphering gene regulation. WIREs RNA 2017, 8:e1369. doi: 10.1002/wrna.1369 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Olivia S Rissland
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
28
|
Simms CL, Thomas EN, Zaher HS. Ribosome-based quality control of mRNA and nascent peptides. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27193249 DOI: 10.1002/wrna.1366] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 11/06/2022]
Abstract
Quality control processes are widespread and play essential roles in detecting defective molecules and removing them in order to maintain organismal fitness. Aberrant messenger RNA (mRNA) molecules, unless properly managed, pose a significant hurdle to cellular proteostasis. Often mRNAs harbor premature stop codons, possess structures that present a block to the translational machinery, or lack stop codons entirely. In eukaryotes, the three cytoplasmic mRNA-surveillance processes, nonsense-mediated decay (NMD), no-go decay (NGD), and nonstop decay (NSD), evolved to cope with these aberrant mRNAs, respectively. Nonstop mRNAs and mRNAs that inhibit translation elongation are especially problematic as they sequester valuable ribosomes from the translating ribosome pool. As a result, in addition to RNA degradation, NSD and NGD are intimately coupled to ribosome rescue in all domains of life. Furthermore, protein products produced from all three classes of defective mRNAs are more likely to malfunction. It is not surprising then that these truncated nascent protein products are subject to degradation. Over the past few years, many studies have begun to document a central role for the ribosome in initiating the RNA and protein quality control processes. The ribosome appears to be responsible for recognizing the target mRNAs as well as for recruiting the factors required to carry out the processes of ribosome rescue and nascent protein decay. WIREs RNA 2017, 8:e1366. doi: 10.1002/wrna.1366 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Carrie L Simms
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Erica N Thomas
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Hani S Zaher
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| |
Collapse
|
29
|
Ribosome-associated protein quality control. Nat Struct Mol Biol 2016; 23:7-15. [PMID: 26733220 DOI: 10.1038/nsmb.3147] [Citation(s) in RCA: 298] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/23/2015] [Indexed: 12/18/2022]
Abstract
Protein synthesis by the ribosome can fail for numerous reasons including faulty mRNA, insufficient availability of charged tRNAs and genetic errors. All organisms have evolved mechanisms to recognize stalled ribosomes and initiate pathways for recycling, quality control and stress signaling. Here we review the discovery and molecular dissection of the eukaryotic ribosome-associated quality-control pathway for degradation of nascent polypeptides arising from interrupted translation.
Collapse
|
30
|
Strobel B, Klauser B, Hartig JS, Lamla T, Gantner F, Kreuz S. Riboswitch-mediated Attenuation of Transgene Cytotoxicity Increases Adeno-associated Virus Vector Yields in HEK-293 Cells. Mol Ther 2015; 23:1582-91. [PMID: 26137851 DOI: 10.1038/mt.2015.123] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/21/2015] [Indexed: 01/24/2023] Open
Abstract
Cytotoxicity of transgenes carried by adeno-associated virus (AAV) vectors might be desired, for instance, in oncolytic virotherapy or occur unexpectedly in exploratory research when studying sparsely characterized genes. To date, most AAV-based studies use constitutively active promoters (e.g., the CMV promoter) to drive transgene expression, which often hampers efficient AAV production due to cytotoxic, antiproliferative, or unknown transgene effects interfering with producer cell performance. Therefore, we explored artificial riboswitches as novel tools to control transgene expression during AAV production in mammalian cells. Our results demonstrate that the guanine-responsive GuaM8HDV aptazyme efficiently attenuates transgene expression and associated detrimental effects, thereby boosting AAV vector yields up to 23-fold after a single addition of guanine. Importantly, riboswitch-harboring vectors preserved their ability to express functional transgene at high levels in the absence of ligand, as demonstrated in a mouse model of AAV-TGFβ1-induced pulmonary fibrosis. Thus, our study provides the first application-ready biotechnological system-based on aptazymes, which should enable high viral vector yields largely independent of the transgene used. Moreover, the RNA-intrinsic, small-molecule regulatable mode of action of riboswitches provides key advantages over conventional transcription factor-based regulatory systems. Therefore, such riboswitch vectors might be ultimately applied to temporally control therapeutic transgene expression in vivo.
Collapse
Affiliation(s)
- Benjamin Strobel
- Target Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Benedikt Klauser
- Department of Chemistry, University of Konstanz, Konstanz, Germany
| | - Jörg S Hartig
- Department of Chemistry, University of Konstanz, Konstanz, Germany
| | - Thorsten Lamla
- Target Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Florian Gantner
- Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Sebastian Kreuz
- Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| |
Collapse
|
31
|
Losh JS, King AK, Bakelar J, Taylor L, Loomis J, Rosenzweig JA, Johnson SJ, van Hoof A. Interaction between the RNA-dependent ATPase and poly(A) polymerase subunits of the TRAMP complex is mediated by short peptides and important for snoRNA processing. Nucleic Acids Res 2015; 43:1848-58. [PMID: 25589546 PMCID: PMC4330371 DOI: 10.1093/nar/gkv005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The RNA exosome is one of the main 3′ to 5′ exoribonucleases in eukaryotic cells. Although it is responsible for degradation or processing of a wide variety of substrate RNAs, it is very specific and distinguishes between substrate and non-substrate RNAs as well as between substrates that need to be 3′ processed and those that need to be completely degraded. This specificity does not appear to be determined by the exosome itself but rather by about a dozen other proteins. Four of these exosome cofactors have enzymatic activity, namely, the nuclear RNA-dependent ATPase Mtr4, its cytoplasmic paralog Ski2 and the nuclear non-canonical poly(A) polymerases, Trf4 and Trf5. Mtr4 and either Trf4 or Trf5 assemble into a TRAMP complex. However, how these enzymes assemble into a TRAMP complex and the functional consequences of TRAMP complex assembly remain unknown. Here, we identify an important interaction site between Mtr4 and Trf5, and show that disrupting the Mtr4/Trf interaction disrupts specific TRAMP and exosome functions, including snoRNA processing.
Collapse
Affiliation(s)
- Jillian S. Losh
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
| | - Alejandra Klauer King
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
| | - Jeremy Bakelar
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322–0300, USA
| | - Lacy Taylor
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322–0300, USA
| | - John Loomis
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | - Jason A. Rosenzweig
- Department of Biology and Department of Environmental and Interdisciplinary Sciences, Texas Southern University, Houston, TX 77004, USA
| | - Sean J. Johnson
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322–0300, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
- To whom correspondence should be addressed. Tel: +1 713 500 5234;
| |
Collapse
|
32
|
Klauser B, Atanasov J, Siewert LK, Hartig JS. Ribozyme-based aminoglycoside switches of gene expression engineered by genetic selection in S. cerevisiae. ACS Synth Biol 2015; 4:516-25. [PMID: 24871672 DOI: 10.1021/sb500062p] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Systems for conditional gene expression are powerful tools in basic research as well as in biotechnology. For future applications, it is of great importance to engineer orthogonal genetic switches that function reliably in diverse contexts. RNA-based switches have the advantage that effector molecules interact immediately with regulatory modules inserted into the target RNAs, getting rid of the need of transcription factors usually mediating genetic control. Artificial riboswitches are characterized by their simplicity and small size accompanied by a high degree of modularity. We have recently reported a series of hammerhead ribozyme-based artificial riboswitches that allow for post-transcriptional regulation of gene expression via switching mRNA, tRNA, or rRNA functions. A more widespread application was so far hampered by moderate switching performances and a limited set of effector molecules available. Here, we report the re-engineering of hammerhead ribozymes in order to respond efficiently to aminoglycoside antibiotics. We first established an in vivo selection protocol in Saccharomyces cerevisiae that enabled us to search large sequence spaces for optimized switches. We then envisioned and characterized a novel strategy of attaching the aptamer to the ribozyme catalytic core, increasing the design options for rendering the ribozyme ligand-dependent. These innovations enabled the development of neomycin-dependent RNA modules that switch gene expression up to 25-fold. The presented aminoglycoside-responsive riboswitches belong to the best-performing RNA-based genetic regulators reported so far. The developed in vivo selection protocol should allow for sampling of large sequence spaces for engineering of further optimized riboswitches.
Collapse
Affiliation(s)
- Benedikt Klauser
- Department of Chemistry, Konstanz Research School Chemical
Biology (KoRSCB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Janina Atanasov
- Department of Chemistry, Konstanz Research School Chemical
Biology (KoRSCB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Lena K. Siewert
- Department of Chemistry, Konstanz Research School Chemical
Biology (KoRSCB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Jörg S. Hartig
- Department of Chemistry, Konstanz Research School Chemical
Biology (KoRSCB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| |
Collapse
|
33
|
Saito K, Horikawa W, Ito K. Inhibiting K63 polyubiquitination abolishes no-go type stalled translation surveillance in Saccharomyces cerevisiae. PLoS Genet 2015; 11:e1005197. [PMID: 25909477 PMCID: PMC4409330 DOI: 10.1371/journal.pgen.1005197] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 04/08/2015] [Indexed: 12/02/2022] Open
Abstract
Incidental ribosome stalling during translation elongation is an aberrant phenomenon during protein synthesis and is subjected to quality control by surveillance systems, in which mRNA and a nascent protein are rapidly degraded. Their detailed molecular mechanisms as well as responsible factors for these processes are beginning to be understood. However, the initial processes for detecting stalled translation that result in degradation remain to be determined. Among the factors identified to date, two E3 ubiquitin ligases have been reported to function in distinct manners. Because ubiquitination is one of the most versatile of cellular signals, these distinct functions of E3 ligases suggested diverse ubiquitination pathways during surveillance for stalled translation. In this study, we report experimental evidences for a unique role of non-proteasomal K63 polyubiquitination during quality control for stalled translation. Inhibiting K63 polyubiquitination by expressing a K63R ubiquitin mutation in Saccharomyces cerevisiae cells markedly abolished the quality control responses for stalled translation. More detailed analyses indicated that the effects of K63R mutants were independent of the proteasome and that K63 polyubiquitination is dependent on Hel2, one of the E3 ligases. Moreover, a K63R ubiquitin mutant barely inhibited the quality control pathway for nonstop translation, indicating distinct mechanisms for these highly related quality control pathways. Our results suggest that non-proteasomal K63 polyubiquitination is included in the initial surveillance process of stalled translation and presumably triggers protein degradation steps upon translational stall. These findings provide crucial information regarding the detailed molecular mechanisms for the initial steps involved in quality control systems and their classification. Stalled translation during elongation is an aberrant phenomenon during protein synthesis. Thus, once detected, it is subjected to quality control in which mRNA and a nascent protein are rapidly degraded. Although the mechanism of degradation for stalled translation is reasonably well understood, the initial processes, including those for detecting stalled translation, have not been determined. The ubiquitin proteasome pathway has been determined to function in the degradation of a nascent protein during stalled translation. Because a ubiquitin signal is one of the most versatile of cellular signals, we investigated the roles of various ubiquitination mechanisms in the budding yeast Saccharomyces cerevisiae using ubiquitin mutants that inhibited the polymerization of specific ubiquitin chains. We identified a role of non-proteasomal K63 polyubiquitination in stalled translation surveillance. Moreover, a K63R ubiquitin mutant barely inhibited the quality control pathway for nonstop translation, indicating distinct mechanisms for these highly related quality control pathways. These findings provide insights into the fundamental mechanisms for the initial processes of stalled translation surveillance and further emphasize the versatility of ubiquitin signals in cellular systems.
Collapse
Affiliation(s)
- Kazuki Saito
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-city, Chiba, Japan
- * E-mail:
| | - Wataru Horikawa
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-city, Chiba, Japan
| | - Koichi Ito
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-city, Chiba, Japan
| |
Collapse
|
34
|
Raju KK, Natarajan S, Kumar NS, Kumar DA, NM R. Role of cytoplasmic deadenylation and mRNA decay factors in yeast apoptosis. FEMS Yeast Res 2015; 15:fou006. [DOI: 10.1093/femsyr/fou006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
35
|
Yu AQ, Pratomo Juwono NK, Leong SSJ, Chang MW. Production of Fatty Acid-derived valuable chemicals in synthetic microbes. Front Bioeng Biotechnol 2014; 2:78. [PMID: 25566540 PMCID: PMC4275033 DOI: 10.3389/fbioe.2014.00078] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 12/10/2014] [Indexed: 12/18/2022] Open
Abstract
Fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. Currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. Metabolic engineering of microorganisms has provided a platform for effective production of these valuable biochemicals. Notably, synthetic biology-based metabolic engineering strategies have been extensively applied to refactor microorganisms for improved biochemical production. Here, we reviewed: (i) the current status of metabolic engineering of microbes that produce fatty acid-derived valuable chemicals, and (ii) the recent progress of synthetic biology approaches that assist metabolic engineering, such as mRNA secondary structure engineering, sensor-regulator system, regulatable expression system, ultrasensitive input/output control system, and computer science-based design of complex gene circuits. Furthermore, key challenges and strategies were discussed. Finally, we concluded that synthetic biology provides useful metabolic engineering strategies for economically viable production of fatty acid-derived valuable chemicals in engineered microbes.
Collapse
Affiliation(s)
- Ai-Qun Yu
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore ; Synthetic Biology Research Program, National University of Singapore , Singapore , Singapore
| | - Nina Kurniasih Pratomo Juwono
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore ; Synthetic Biology Research Program, National University of Singapore , Singapore , Singapore
| | - Susanna Su Jan Leong
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore ; Synthetic Biology Research Program, National University of Singapore , Singapore , Singapore ; Singapore Institute of Technology , Singapore , Singapore
| | - Matthew Wook Chang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore ; Synthetic Biology Research Program, National University of Singapore , Singapore , Singapore
| |
Collapse
|
36
|
Kashima I, Takahashi M, Hashimoto Y, Sakota E, Nakamura Y, Inada T. A functional involvement of ABCE1, eukaryotic ribosome recycling factor, in nonstop mRNA decay in Drosophila melanogaster cells. Biochimie 2014; 106:10-6. [DOI: 10.1016/j.biochi.2014.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 08/02/2014] [Indexed: 11/25/2022]
|
37
|
Release factor eRF3 mediates premature translation termination on polylysine-stalled ribosomes in Saccharomyces cerevisiae. Mol Cell Biol 2014; 34:4062-76. [PMID: 25154418 DOI: 10.1128/mcb.00799-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ribosome stalling is an important incident enabling the cellular quality control machinery to detect aberrant mRNA. Saccharomyces cerevisiae Hbs1-Dom34 and Ski7 are homologs of the canonical release factor eRF3-eRF1, which recognize stalled ribosomes, promote ribosome release, and induce the decay of aberrant mRNA. Polyadenylated nonstop mRNA encodes aberrant proteins containing C-terminal polylysine segments which cause ribosome stalling due to electrostatic interaction with the ribosomal exit tunnel. Here we describe a novel mechanism, termed premature translation termination, which releases C-terminally truncated translation products from ribosomes stalled on polylysine segments. Premature termination during polylysine synthesis was abolished when ribosome stalling was prevented due to the absence of the ribosomal protein Asc1. In contrast, premature termination was enhanced, when the general rate of translation elongation was lowered. The unconventional termination event was independent of Hbs1-Dom34 and Ski7, but it was dependent on eRF3. Moreover, premature termination during polylysine synthesis was strongly increased in the absence of the ribosome-bound chaperones ribosome-associated complex (RAC) and Ssb (Ssb1 and Ssb2). On the basis of the data, we suggest a model in which eRF3-eRF1 can catalyze the release of nascent polypeptides even though the ribosomal A-site contains a sense codon when the rate of translation is abnormally low.
Collapse
|
38
|
Tsanova B, Spatrick P, Jacobson A, van Hoof A. The RNA exosome affects iron response and sensitivity to oxidative stress. RNA (NEW YORK, N.Y.) 2014; 20:1057-1067. [PMID: 24860016 PMCID: PMC4114685 DOI: 10.1261/rna.043257.113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 04/01/2014] [Indexed: 06/03/2023]
Abstract
RNA degradation plays important roles for maintaining temporal control and fidelity of gene expression, as well as processing of transcripts. In Saccharomyces cerevisiae the RNA exosome is a major 3'-to-5' exoribonuclease and also has an endonuclease domain of unknown function. Here we report a physiological role for the exosome in response to a stimulus. We show that inactivating the exoribonuclease active site of Rrp44 up-regulates the iron uptake regulon. This up-regulation is caused by increased levels of reactive oxygen species (ROS) in the mutant. Elevated ROS also causes hypersensitivity to H2O2, which can be reduced by the addition of iron to H2O2 stressed cells. Finally, we show that the previously characterized slow growth phenotype of rrp44-exo(-) is largely ameliorated during fermentative growth. While the molecular functions of Rrp44 and the RNA exosome have been extensively characterized, our studies characterize how this molecular function affects the physiology of the organism.
Collapse
Affiliation(s)
- Borislava Tsanova
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center–Houston and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030, USA
| | - Phyllis Spatrick
- Department of Microbiology and Physiological Systems, Albert Sherman Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, Albert Sherman Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center–Houston and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030, USA
| |
Collapse
|
39
|
Lykke-Andersen J, Bennett EJ. Protecting the proteome: Eukaryotic cotranslational quality control pathways. ACTA ACUST UNITED AC 2014; 204:467-76. [PMID: 24535822 PMCID: PMC3926952 DOI: 10.1083/jcb.201311103] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The correct decoding of messenger RNAs (mRNAs) into proteins is an essential cellular task. The translational process is monitored by several quality control (QC) mechanisms that recognize defective translation complexes in which ribosomes are stalled on substrate mRNAs. Stalled translation complexes occur when defects in the mRNA template, the translation machinery, or the nascent polypeptide arrest the ribosome during translation elongation or termination. These QC events promote the disassembly of the stalled translation complex and the recycling and/or degradation of the individual mRNA, ribosomal, and/or nascent polypeptide components, thereby clearing the cell of improper translation products and defective components of the translation machinery.
Collapse
Affiliation(s)
- Jens Lykke-Andersen
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
| | | |
Collapse
|
40
|
Prommana P, Uthaipibull C, Wongsombat C, Kamchonwongpaisan S, Yuthavong Y, Knuepfer E, Holder AA, Shaw PJ. Inducible knockdown of Plasmodium gene expression using the glmS ribozyme. PLoS One 2013; 8:e73783. [PMID: 24023691 PMCID: PMC3758297 DOI: 10.1371/journal.pone.0073783] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 07/23/2013] [Indexed: 01/07/2023] Open
Abstract
Conventional reverse genetic approaches for study of Plasmodium malaria parasite gene function are limited, or not applicable. Hence, new inducible systems are needed. Here we describe a method to control P. falciparum gene expression in which target genes bearing a glmS ribozyme in the 3' untranslated region are efficiently knocked down in transgenic P. falciparum parasites in response to glucosamine inducer. Using reporter genes, we show that the glmS ribozyme cleaves reporter mRNA in vivo leading to reduction in mRNA expression following glucosamine treatment. Glucosamine-induced ribozyme activation led to efficient reduction of reporter protein, which could be rapidly reversed by removing the inducer. The glmS ribozyme was validated as a reverse-genetic tool by integration into the essential gene and antifolate drug target dihydrofolate reductase-thymidylate synthase (PfDHFR-TS). Glucosamine treatment of transgenic parasites led to rapid and efficient knockdown of PfDHFR-TS mRNA and protein. PfDHFR-TS knockdown led to a growth/arrest mutant phenotype and hypersensitivity to pyrimethamine. The glmS ribozyme may thus be a tool for study of essential genes in P. falciparum and other parasite species amenable to transfection.
Collapse
Affiliation(s)
- Parichat Prommana
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Khlong Nueng, Khlong Luang, Pathum Thani, Thailand
| | - Chairat Uthaipibull
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Khlong Nueng, Khlong Luang, Pathum Thani, Thailand
| | - Chayaphat Wongsombat
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Khlong Nueng, Khlong Luang, Pathum Thani, Thailand
| | - Sumalee Kamchonwongpaisan
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Khlong Nueng, Khlong Luang, Pathum Thani, Thailand
| | - Yongyuth Yuthavong
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Khlong Nueng, Khlong Luang, Pathum Thani, Thailand
| | - Ellen Knuepfer
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Anthony A. Holder
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Philip J. Shaw
- National Center for Genetic Engineering and Biotechnology (BIOTEC), Khlong Nueng, Khlong Luang, Pathum Thani, Thailand
| |
Collapse
|
41
|
Sandler I, Medalia O, Aharoni A. Experimental analysis of co-evolution within protein complexes: the yeast exosome as a model. Proteins 2013; 81:1997-2006. [PMID: 23852635 DOI: 10.1002/prot.24360] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/12/2013] [Accepted: 06/25/2013] [Indexed: 11/07/2022]
Abstract
Extensive bioinformatics analysis suggests that the stability and function of protein complexes are maintained throughout evolution by coordinated changes (co-evolution) of complex subunits. Yet, relatively little is known regarding the actual dynamics of such processes and the functional implications of co-evolution within protein complexes, since most of the bioinformatics predictions were not analyzed experimentally. Here, we describe a systematic experimental approach that allows a step-by-step observation of the co-evolution process in protein complexes. The exosome complex, an essential complex exhibiting a 3'→5' RNA degradation activity, served as a model system. In this study, we show that exosome subunits diverged very early during fungal evolution. Interestingly, we found that despite significant differences in conservation between Rrp41 and Mtr3 both subunits exhibit similar divergence pattern and co-evolutionary behavior through fungi evolution. Activity analysis of mutated exosomes exposes another layer of co-evolution between the core subunits and RNA substrates. Overall, our approach allows the experimental analysis of co-evolution within protein complexes and together with bioinformatics analysis can significantly deepen our understanding of the evolution of these complexes.
Collapse
Affiliation(s)
- Inga Sandler
- Departments of Life Sciences, Ben-Gurion University of the Negev, Be'er Sheva, 84105, Israel
| | | | | |
Collapse
|
42
|
Charneski CA, Hurst LD. Positively charged residues are the major determinants of ribosomal velocity. PLoS Biol 2013; 11:e1001508. [PMID: 23554576 PMCID: PMC3595205 DOI: 10.1371/journal.pbio.1001508] [Citation(s) in RCA: 200] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 02/01/2013] [Indexed: 11/18/2022] Open
Abstract
Both for understanding mechanisms of disease and for the design of transgenes, it is important to understand the determinants of ribosome velocity, as changes in the rate of translation are important for protein folding, error attenuation, and localization. While there is great variation in ribosomal occupancy along even a single transcript, what determines a ribosome's occupancy is unclear. We examine this issue using data from a ribosomal footprinting assay in yeast. While codon usage is classically considered a major determinant, we find no evidence for this. By contrast, we find that positively charged amino acids greatly retard ribosomes downstream from where they are encoded, consistent with the suggestion that positively charged residues interact with the negatively charged ribosomal exit tunnel. Such slowing is independent of and greater than the average effect owing to mRNA folding. The effect of charged amino acids is additive, with ribosomal occupancy well-predicted by a linear fit to the density of positively charged residues. We thus expect that a translated poly-A tail, encoding for positively charged lysines regardless of the reading frame, would act as a sandtrap for the ribosome, consistent with experimental data.
Collapse
Affiliation(s)
| | - Laurence D. Hurst
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- * E-mail:
| |
Collapse
|
43
|
Inada T. Quality control systems for aberrant mRNAs induced by aberrant translation elongation and termination. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:634-42. [PMID: 23416749 DOI: 10.1016/j.bbagrm.2013.02.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 02/01/2013] [Accepted: 02/02/2013] [Indexed: 10/27/2022]
Abstract
RNA processing is an essential gene expression step and plays a crucial role to achieve diversity of gene products in eukaryotes. Various aberrant mRNAs transiently produced during RNA processing reactions are recognized and eliminated by specific quality control systems. It has been demonstrated that these mRNA quality control systems stimulate the degradation of aberrant mRNA to prevent the potentially harmful products derived from aberrant mRNAs. Recent studies on quality control systems induced by abnormal translation elongation and termination have revealed that both aberrant mRNAs and proteins are subjected to rapid degradation. In NonStop Decay (NSD) quality control system, a poly(A) tail of nonstop mRNA is translated and the synthesis of poly-lysine sequence results in translation arrest followed by co-translational degradation of aberrant nonstop protein. In No-Go Decay (NGD) quality control system, the specific amino acid sequences of the nascent polypeptide induce ribosome stalling, and the arrest products are ubiquitinated and rapidly degraded by the proteasome. In Nonfunctional rRNA Decay (NRD) quality control system, aberrant ribosomes composed of nonfunctional ribosomal RNAs are also eliminated when aberrant translation elongation complexes are formed on mRNA. I describe recent progresses on the mechanisms of quality control systems and the relationships between quality control systems. This article is part of a Special issue entitled: RNA Decay mechanisms.
Collapse
|
44
|
Graille M, Séraphin B. Surveillance pathways rescuing eukaryotic ribosomes lost in translation. Nat Rev Mol Cell Biol 2012; 13:727-35. [DOI: 10.1038/nrm3457] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
45
|
Boyce M, Celma CCP, Roy P. Bluetongue virus non-structural protein 1 is a positive regulator of viral protein synthesis. Virol J 2012; 9:178. [PMID: 22931514 PMCID: PMC3479040 DOI: 10.1186/1743-422x-9-178] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 08/24/2012] [Indexed: 11/29/2022] Open
Abstract
Background Bluetongue virus (BTV) is a double-stranded RNA (dsRNA) virus of the Reoviridae family, which encodes its genes in ten linear dsRNA segments. BTV mRNAs are synthesised by the viral RNA-dependent RNA polymerase (RdRp) as exact plus sense copies of the genome segments. Infection of mammalian cells with BTV rapidly replaces cellular protein synthesis with viral protein synthesis, but the regulation of viral gene expression in the Orbivirus genus has not been investigated. Results Using an mRNA reporter system based on genome segment 10 of BTV fused with GFP we identify the protein characteristic of this genus, non-structural protein 1 (NS1) as sufficient to upregulate translation. The wider applicability of this phenomenon among the viral genes is demonstrated using the untranslated regions (UTRs) of BTV genome segments flanking the quantifiable Renilla luciferase ORF in chimeric mRNAs. The UTRs of viral mRNAs are shown to be determinants of the amount of protein synthesised, with the pre-expression of NS1 increasing the quantity in each case. The increased expression induced by pre-expression of NS1 is confirmed in virus infected cells by generating a replicating virus which expresses the reporter fused with genome segment 10, using reverse genetics. Moreover, NS1-mediated upregulation of expression is restricted to mRNAs which lack the cellular 3′ poly(A) sequence identifying the 3′ end as a necessary determinant in specifically increasing the translation of viral mRNA in the presence of cellular mRNA. Conclusions NS1 is identified as a positive regulator of viral protein synthesis. We propose a model of translational regulation where NS1 upregulates the synthesis of viral proteins, including itself, and creates a positive feedback loop of NS1 expression, which rapidly increases the expression of all the viral proteins. The efficient translation of viral reporter mRNAs among cellular mRNAs can account for the observed replacement of cellular protein synthesis with viral protein synthesis during infection.
Collapse
Affiliation(s)
- Mark Boyce
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | | | | |
Collapse
|
46
|
Schaeffer D, Reis FP, Johnson SJ, Arraiano CM, van Hoof A. The CR3 motif of Rrp44p is important for interaction with the core exosome and exosome function. Nucleic Acids Res 2012; 40:9298-307. [PMID: 22833611 PMCID: PMC3467083 DOI: 10.1093/nar/gks693] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The 10-subunit RNA exosome is involved in a large number of diverse RNA processing and degradation events in eukaryotes. These reactions are carried out by the single catalytic subunit, Rrp44p/Dis3p, which is composed of three parts that are conserved throughout eukaryotes. The exosome is named for the 3' to 5' exoribonuclease activity provided by a large C-terminal region of the Rrp44p subunit that resembles other exoribonucleases. Rrp44p also contains an endoribonuclease domain. Finally, the very N-terminus of Rrp44p contains three Cys residues (CR3 motif) that are conserved in many eukaryotes but have no known function. These three conserved Cys residues cluster with a previously unrecognized conserved His residue in what resembles a metal-ion-binding site. Genetic and biochemical data show that this CR3 motif affects both endo- and exonuclease activity in vivo and both the nuclear and cytoplasmic exosome, as well as the ability of Rrp44p to associate with the other exosome subunits. These data provide the first direct evidence that the exosome-Rrp44p interaction is functionally important and also provides a molecular explanation for the functional defects when the conserved Cys residues are mutated.
Collapse
Affiliation(s)
- Daneen Schaeffer
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, TX 77030, USA
| | | | | | | | | |
Collapse
|
47
|
Abstract
All RNA species in yeast cells are subject to turnover. Work over the past 20 years has defined degradation mechanisms for messenger RNAs, transfer RNAs, ribosomal RNAs, and noncoding RNAs. In addition, numerous quality control mechanisms that target aberrant RNAs have been identified. Generally, each decay mechanism contains factors that funnel RNA substrates to abundant exo- and/or endonucleases. Key issues for future work include determining the mechanisms that control the specificity of RNA degradation and how RNA degradation processes interact with translation, RNA transport, and other cellular processes.
Collapse
Affiliation(s)
- Roy Parker
- Department of Molecular and Cellular Biology, University of Arizona and Howard Hughes Medical Institute, Tucson, AZ 85721, USA.
| |
Collapse
|
48
|
Klauer AA, van Hoof A. Degradation of mRNAs that lack a stop codon: a decade of nonstop progress. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 3:649-60. [PMID: 22740367 DOI: 10.1002/wrna.1124] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nonstop decay is the mechanism of identifying and disposing aberrant transcripts that lack in-frame stop codons. It is hypothesized that these transcripts are identified during translation when the ribosome arrives at the 3' end of the mRNA and stalls. Presumably, the ribosome stalling recruits additional cofactors, Ski7 and the exosome complex. The exosome degrades the transcript using either one of its ribonucleolytic activities, and the ribosome and the peptide are both released. Additional precautionary measures by the nonstop decay pathway may include translational repression of the nonstop transcript after translation, and proteolysis of the released peptide by the proteasome. This surveillance mechanism protects the cells from potentially harmful truncated proteins, but it may also be involved in mediating critical cellular functions of transcripts that are prone to stop codon read-through. Important advances have been made in the past decade as we learn that nonstop decay may have implications in human disease.
Collapse
Affiliation(s)
- A Alejandra Klauer
- Microbiology and Molecular Genetics, University of Texas Health Science University-Houston, Houston, TX, USA
| | | |
Collapse
|
49
|
Dom34:Hbs1 Plays a General Role in Quality-Control Systems by Dissociation of a Stalled Ribosome at the 3′ End of Aberrant mRNA. Mol Cell 2012; 46:518-29. [DOI: 10.1016/j.molcel.2012.03.013] [Citation(s) in RCA: 201] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 02/14/2012] [Accepted: 03/12/2012] [Indexed: 11/24/2022]
|
50
|
Lemieux C, Marguerat S, Lafontaine J, Barbezier N, Bähler J, Bachand F. A Pre-mRNA degradation pathway that selectively targets intron-containing genes requires the nuclear poly(A)-binding protein. Mol Cell 2011; 44:108-19. [PMID: 21981922 DOI: 10.1016/j.molcel.2011.06.035] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 05/20/2011] [Accepted: 06/29/2011] [Indexed: 01/06/2023]
Abstract
General discard pathways eliminate unprocessed and irregular pre-mRNAs to control the quality of gene expression. In contrast to such general pre-mRNA decay, we describe here a nuclear pre-mRNA degradation pathway that controls the expression of select intron-containing genes. We show that the fission yeast nuclear poly(A)-binding protein, Pab2, and the nuclear exosome subunit, Rrp6, are the main factors involved in this polyadenylation-dependent pre-mRNA degradation pathway. Transcriptome analysis and intron swapping experiments revealed that inefficient splicing is important to dictate susceptibility to Pab2-dependent pre-mRNA decay. We also show that negative splicing regulation can promote the poor splicing efficiency required for this pre-mRNA decay pathway, and in doing so, we identified a mechanism of cross-regulation between paralogous ribosomal proteins through nuclear pre-mRNA decay. Our findings unveil a layer of regulation in the nucleus in which the turnover of specific pre-mRNAs, besides the turnover of mature mRNAs, is used to control gene expression.
Collapse
Affiliation(s)
- Caroline Lemieux
- RNA Group, Department of Biochemistry, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | | | | | | | | | | |
Collapse
|