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Cantu F, Cao S, Hernandez C, Dhungel P, Spradlin J, Yang Z. Poxvirus-encoded decapping enzymes promote selective translation of viral mRNAs. PLoS Pathog 2020; 16:e1008926. [PMID: 33031446 PMCID: PMC7575113 DOI: 10.1371/journal.ppat.1008926] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/20/2020] [Accepted: 08/24/2020] [Indexed: 12/24/2022] Open
Abstract
Cellular decapping enzymes negatively regulate gene expression by removing the methylguanosine cap at the 5’ end of eukaryotic mRNA, rendering mRNA susceptible to degradation and repressing mRNA translation. Vaccinia virus (VACV), the prototype poxvirus, encodes two decapping enzymes, D9 and D10, that induce the degradation of both cellular and viral mRNAs. Using a genome-wide survey of translation efficiency, we analyzed vaccinia virus mRNAs in cells infected with wild type VACV and mutant VACVs with inactivated decapping enzymes. We found that VACV decapping enzymes are required for selective translation of viral post-replicative mRNAs (transcribed after viral DNA replication) independent of PKR- and RNase L-mediated translation repression. Further molecular characterization demonstrated that VACV decapping enzymes are necessary for efficient translation of mRNA with a 5'-poly(A) leader, which are present in all viral post-replicative mRNAs. Inactivation of D10 alone in VACV significantly impairs poly(A)-leader-mediated translation. Remarkably, D10 stimulates mRNA translation in the absence of VACV infection with a preference for RNA containing a 5’-poly(A) leader. We further revealed that VACV decapping enzymes are needed for 5’-poly(A) leader-mediated cap-independent translation enhancement during infection. Our findings identified a mechanism by which VACV mRNAs are selectively translated through subverting viral decapping enzymes to stimulate 5’-poly(A) leader-mediated translation. Decapping enzymes are encoded in eukaryotic cells and some viruses. Previous studies indicated that decapping enzymes are negative gene expression regulators by accelerating mRNA degradation and repressing translation. Surprisingly however, in this study we found that vaccinia virus (VACV) encoded-decapping enzymes, D9 and D10, are required to promote selective synthesis of viral proteins, although they are known to promote both cellular and viral mRNA degradation. We further showed that the unusual 5'-UTR of VACV mRNA, the 5'-poly(A) leader, confers an advantage to mRNA translation promoted by the decapping enzymes during vaccinia virus infection. Moreover, D9 and D10 are necessary for stimulating poly(A)-leader-mediated cap-independent translation enhancement during VACV infection. In the absence of VACV infection, D10 alone stimulates mRNA translation in a decapping activity-dependent manner, with a preference for mRNA that contains a poly(A) leader. The stimulation of mRNA translation by D10 is unique among decapping enzymes. Therefore, we identified a new mechanism to selectively synthesize VACV proteins through a coordination of viral mRNA 5’-UTR and virus-encoded decapping enzymes.
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Affiliation(s)
- Fernando Cantu
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Shuai Cao
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Candy Hernandez
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Pragyesh Dhungel
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Joshua Spradlin
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Zhilong Yang
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
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52
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Schieweck R, Ninkovic J, Kiebler MA. RNA-binding proteins balance brain function in health and disease. Physiol Rev 2020; 101:1309-1370. [PMID: 33000986 DOI: 10.1152/physrev.00047.2019] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Posttranscriptional gene expression including splicing, RNA transport, translation, and RNA decay provides an important regulatory layer in many if not all molecular pathways. Research in the last decades has positioned RNA-binding proteins (RBPs) right in the center of posttranscriptional gene regulation. Here, we propose interdependent networks of RBPs to regulate complex pathways within the central nervous system (CNS). These are involved in multiple aspects of neuronal development and functioning, including higher cognition. Therefore, it is not sufficient to unravel the individual contribution of a single RBP and its consequences but rather to study and understand the tight interplay between different RBPs. In this review, we summarize recent findings in the field of RBP biology and discuss the complex interplay between different RBPs. Second, we emphasize the underlying dynamics within an RBP network and how this might regulate key processes such as neurogenesis, synaptic transmission, and synaptic plasticity. Importantly, we envision that dysfunction of specific RBPs could lead to perturbation within the RBP network. This would have direct and indirect (compensatory) effects in mRNA binding and translational control leading to global changes in cellular expression programs in general and in synaptic plasticity in particular. Therefore, we focus on RBP dysfunction and how this might cause neuropsychiatric and neurodegenerative disorders. Based on recent findings, we propose that alterations in the entire regulatory RBP network might account for phenotypic dysfunctions observed in complex diseases including neurodegeneration, epilepsy, and autism spectrum disorders.
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Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Jovica Ninkovic
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Michael A Kiebler
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
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53
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Turner-Bridger B, Caterino C, Cioni JM. Molecular mechanisms behind mRNA localization in axons. Open Biol 2020; 10:200177. [PMID: 32961072 PMCID: PMC7536069 DOI: 10.1098/rsob.200177] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/01/2020] [Indexed: 12/12/2022] Open
Abstract
Messenger RNA (mRNA) localization allows spatiotemporal regulation of the proteome at the subcellular level. This is observed in the axons of neurons, where mRNA localization is involved in regulating neuronal development and function by orchestrating rapid adaptive responses to extracellular cues and the maintenance of axonal homeostasis through local translation. Here, we provide an overview of the key findings that have broadened our knowledge regarding how specific mRNAs are trafficked and localize to axons. In particular, we review transcriptomic studies investigating mRNA content in axons and the molecular principles underpinning how these mRNAs arrived there, including cis-acting mRNA sequences and trans-acting proteins playing a role. Further, we discuss evidence that links defective axonal mRNA localization and pathological outcomes.
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Affiliation(s)
- Benita Turner-Bridger
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, UK
| | - Cinzia Caterino
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Jean-Michel Cioni
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
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54
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Karousis ED, Gurzeler LA, Annibaldis G, Dreos R, Mühlemann O. Human NMD ensues independently of stable ribosome stalling. Nat Commun 2020; 11:4134. [PMID: 32807779 PMCID: PMC7431590 DOI: 10.1038/s41467-020-17974-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 07/20/2020] [Indexed: 12/18/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a translation-dependent RNA degradation pathway that is important for the elimination of faulty, and the regulation of normal, mRNAs. The molecular details of the early steps in NMD are not fully understood but previous work suggests that NMD activation occurs as a consequence of ribosome stalling at the termination codon (TC). To test this hypothesis, we established an in vitro translation-coupled toeprinting assay based on lysates from human cells that allows monitoring of ribosome occupancy at the TC of reporter mRNAs. In contrast to the prevailing NMD model, our in vitro system reveals similar ribosomal occupancy at the stop codons of NMD-sensitive and NMD-insensitive reporter mRNAs. Moreover, ribosome profiling reveals a similar density of ribosomes at the TC of endogenous NMD-sensitive and NMD-insensitive mRNAs in vivo. Together, these data show that NMD activation is not accompanied by stable stalling of ribosomes at TCs. Nonsense-mediated mRNA decay (NMD) was thought to ensue when ribosomes fail to terminate translation properly. However, the authors observe similar ribosome occupancy at stop codons of NMD sensitive and insensitive mRNAs, showing that human NMD is not activated by stable ribosome stalling as previously suggested.
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Affiliation(s)
- Evangelos D Karousis
- Department of Chemistry and Biochemistry, University of Bern, CH-3012, Bern, Switzerland
| | - Lukas-Adrian Gurzeler
- Department of Chemistry and Biochemistry, University of Bern, CH-3012, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, CH-3012, Bern, Switzerland
| | - Giuditta Annibaldis
- Department of Chemistry and Biochemistry, University of Bern, CH-3012, Bern, Switzerland
| | - René Dreos
- Center for Integrative Genomics, Université de Lausanne, CH-1015, Lausanne, Switzerland
| | - Oliver Mühlemann
- Department of Chemistry and Biochemistry, University of Bern, CH-3012, Bern, Switzerland.
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55
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Bajak K, Leiss K, Clayton C, Erben E. A potential role for a novel ZC3H5 complex in regulating mRNA translation in Trypanosoma brucei. J Biol Chem 2020; 295:14291-14304. [PMID: 32763974 DOI: 10.1074/jbc.ra120.014346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/29/2020] [Indexed: 11/06/2022] Open
Abstract
In Trypanosoma brucei and related kinetoplastids, gene expression regulation occurs mostly posttranscriptionally. Consequently, RNA-binding proteins play a critical role in the regulation of mRNA and protein abundance. Yet, the roles of many RNA-binding proteins are not understood. Our previous research identified the RNA-binding protein ZC3H5 as possibly involved in gene repression, but its role in controlling gene expression was unknown. We here show that ZC3H5 is an essential cytoplasmic RNA-binding protein. RNAi targeting ZC3H5 causes accumulation of precytokinetic cells followed by rapid cell death. Affinity purification and pairwise yeast two-hybrid analysis suggest that ZC3H5 forms a complex with three other proteins, encoded by genes Tb927.11.4900, Tb927.8.1500, and Tb927.7.3040. RNA immunoprecipitation revealed that ZC3H5 is preferentially associated with poorly translated, low-stability mRNAs, the 5'-untranslated regions and coding regions of which are enriched in the motif (U/A)UAG(U/A). As previously found in high-throughput analyses, artificial tethering of ZC3H5 to a reporter mRNA or other complex components repressed reporter expression. However, depletion of ZC3H5 in vivo caused only very minor decreases in a few targets, marked increases in the abundances of very stable mRNAs, an increase in monosomes at the expense of large polysomes, and appearance of "halfmer" disomes containing two 80S subunits and one 40S subunit. We speculate that the ZC3H5 complex might be implicated in quality control during the translation of suboptimal open reading frames.
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Affiliation(s)
- Kathrin Bajak
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany.,Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Kevin Leiss
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| | - Esteban Erben
- Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
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56
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Lavysh D, Neu-Yilik G. UPF1-Mediated RNA Decay-Danse Macabre in a Cloud. Biomolecules 2020; 10:E999. [PMID: 32635561 PMCID: PMC7407380 DOI: 10.3390/biom10070999] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/18/2020] [Accepted: 06/29/2020] [Indexed: 12/21/2022] Open
Abstract
Nonsense-mediated RNA decay (NMD) is the prototype example of a whole family of RNA decay pathways that unfold around a common central effector protein called UPF1. While NMD in yeast appears to be a linear pathway, NMD in higher eukaryotes is a multifaceted phenomenon with high variability with respect to substrate RNAs, degradation efficiency, effector proteins and decay-triggering RNA features. Despite increasing knowledge of the mechanistic details, it seems ever more difficult to define NMD and to clearly distinguish it from a growing list of other UPF1-mediated RNA decay pathways (UMDs). With a focus on mammalian, we here critically examine the prevailing NMD models and the gaps and inconsistencies in these models. By exploring the minimal requirements for NMD and other UMDs, we try to elucidate whether they are separate and definable pathways, or rather variations of the same phenomenon. Finally, we suggest that the operating principle of the UPF1-mediated decay family could be considered similar to that of a computing cloud providing a flexible infrastructure with rapid elasticity and dynamic access according to specific user needs.
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Affiliation(s)
- Daria Lavysh
- Department of Pediatric Oncology, Hematology and Immunology, University of Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany;
- Molecular Medicine Partnership Unit, University of Heidelberg and European Molecular Biology Laboratory, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany
- Department Clinical Pediatric Oncology, Hopp Kindertumorzentrum am NCT Heidelberg, 69120 Heidelberg, Germany
| | - Gabriele Neu-Yilik
- Department of Pediatric Oncology, Hematology and Immunology, University of Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany;
- Molecular Medicine Partnership Unit, University of Heidelberg and European Molecular Biology Laboratory, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany
- Department Clinical Pediatric Oncology, Hopp Kindertumorzentrum am NCT Heidelberg, 69120 Heidelberg, Germany
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57
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Mahadevan V, Peltekian A, McBain CJ. Translatome Analyses Using Conditional Ribosomal Tagging in GABAergic Interneurons and Other Sparse Cell Types. CURRENT PROTOCOLS IN NEUROSCIENCE 2020; 92:e93. [PMID: 32584517 PMCID: PMC7317066 DOI: 10.1002/cpns.93] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
GABAergic interneurons comprise a small but diverse subset of neurons in the mammalian brain that tightly regulate neuronal circuit maturation and information flow and, ultimately, behavior. Because of their centrality in the etiology of numerous neurological disorders, examining the molecular architecture of these neurons under different physiological scenarios has piqued the interest of the broader neuroscience community. The last few years have seen an explosion in next-generation sequencing (NGS) approaches aimed at identifying genetic and state-dependent subtypes in neuronal diversity. Although several approaches are employed to address neuronal molecular diversity, ribosomal tagging has emerged at the forefront of identifying the translatomes of neuronal subtypes. This approach primarily relies on Cre recombinase-driven expression of hemagglutinin A (HA)-tagged RiboTag mice exclusively in the neuronal subtype of interest. This allows the immunoprecipitation of cell-type-specific, ribosome-engaged mRNA, expressed both in the soma and the neuronal processes, for targeted quantitative real-time PCR (qRT-PCR) or high-throughput RNA sequencing analyses. Here we detail the typical technical caveats associated with successful application of the RiboTag technique for analyzing GABAergic interneurons, and in theory other sparse cell types, in the central nervous system. Published 2020. U.S. Government. Basic Protocol 1: Breeding mice to obtain RiboTag homozygosity Support Protocol 1: Detection of ectopic Cre recombinase expression Basic Protocol 2: The RiboTag assay Support Protocol 2: Real-time quantitative PCR (qRT-PCR) assay of RiboTag-derived cell-type-specific RNA Support Protocol 3: Construction of cell-type-specific RNA-seq library Support Protocol 4: Secondary analyses of RiboTag-derived RNA-seq dataset.
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Affiliation(s)
- Vivek Mahadevan
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, 20892
| | - Areg Peltekian
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, 20892
| | - Chris J. McBain
- Section on Cellular and Synaptic Physiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, 20892
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58
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Ho JJD, Balukoff NC, Theodoridis PR, Wang M, Krieger JR, Schatz JH, Lee S. A network of RNA-binding proteins controls translation efficiency to activate anaerobic metabolism. Nat Commun 2020; 11:2677. [PMID: 32472050 PMCID: PMC7260222 DOI: 10.1038/s41467-020-16504-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 04/30/2020] [Indexed: 01/30/2023] Open
Abstract
Protein expression evolves under greater evolutionary constraint than mRNA levels, and translation efficiency represents a primary determinant of protein levels during stimuli adaptation. This raises the question as to the translatome remodelers that titrate protein output from mRNA populations. Here, we uncover a network of RNA-binding proteins (RBPs) that enhances the translation efficiency of glycolytic proteins in cells responding to oxygen deprivation. A system-wide proteomic survey of translational engagement identifies a family of oxygen-regulated RBPs that functions as a switch of glycolytic intensity. Tandem mass tag-pulse SILAC (TMT-pSILAC) and RNA sequencing reveals that each RBP controls a unique but overlapping portfolio of hypoxic responsive proteins. These RBPs collaborate with the hypoxic protein synthesis apparatus, operating as a translation efficiency checkpoint that integrates upstream mRNA signals to activate anaerobic metabolism. This system allows anoxia-resistant animals and mammalian cells to initiate anaerobic glycolysis and survive hypoxia. We suggest that an oxygen-sensitive RBP cluster controls anaerobic metabolism to confer hypoxia tolerance. mRNA translation efficiency is regulated in response to stimuli. Here the authors employ mass spectrometry analysis of ribosome fractions and show that under hypoxia, oxygen-sensitive RNA binding proteins enhance the translation efficiency of glycolysis pathway transcripts.
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Affiliation(s)
- J J David Ho
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.,Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.,Division of Hematology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Nathan C Balukoff
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.,Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Phaedra R Theodoridis
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.,Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Miling Wang
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.,Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Jonathan R Krieger
- The SickKids Proteomics, Analytics, Robotics & Chemical Biology Centre (SPARC Biocentre), The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.,Bioinformatics Solutions Inc., Waterloo, ON, N2L 6J2, Canada
| | - Jonathan H Schatz
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.,Division of Hematology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Stephen Lee
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA. .,Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA. .,Department of Urology, Miller School of Medicine, University of Miami, Miami, 33136, USA.
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59
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Patraquim P, Mumtaz MAS, Pueyo JI, Aspden JL, Couso JP. Developmental regulation of canonical and small ORF translation from mRNAs. Genome Biol 2020; 21:128. [PMID: 32471506 PMCID: PMC7260771 DOI: 10.1186/s13059-020-02011-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/08/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Ribosomal profiling has revealed the translation of thousands of sequences outside annotated protein-coding genes, including small open reading frames of less than 100 codons, and the translational regulation of many genes. Here we present an improved version of Poly-Ribo-Seq and apply it to Drosophila melanogaster embryos to extend the catalog of in vivo translated small ORFs, and to reveal the translational regulation of both small and canonical ORFs from mRNAs across embryogenesis. RESULTS We obtain highly correlated samples across five embryonic stages, with nearly 500 million putative ribosomal footprints mapped to mRNAs, and compare them to existing Ribo-Seq and proteomic data. Our analysis reveals, for the first time in Drosophila, footprints mapping to codons in a phased pattern, the hallmark of productive translation. We propose a simple binomial probability metric to ascertain translation probability. Our results also reveal reproducible ribosomal binding apparently not resulting in productive translation. This non-productive ribosomal binding seems to be especially prevalent amongst upstream short ORFs located in the 5' mRNA leaders, and amongst canonical ORFs during the activation of the zygotic translatome at the maternal-to zygotic transition. CONCLUSIONS We suggest that this non-productive ribosomal binding might be due to cis-regulatory ribosomal binding and to defective ribosomal scanning of ORFs outside periods of productive translation. Our results are compatible with the main function of upstream short ORFs being to buffer the translation of canonical canonical ORFs; and show that, in general, small ORFs in mRNAs display markers compatible with an evolutionary transitory state towards full coding function.
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Affiliation(s)
- Pedro Patraquim
- Centro Andaluz de Biologia del Desarrollo, CSIC-UPO, Seville, Spain
| | | | | | - Julie Louise Aspden
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Juan-Pablo Couso
- Centro Andaluz de Biologia del Desarrollo, CSIC-UPO, Seville, Spain. .,Previous address: Brighton and Sussex Medical School, Brighton, East Sussex, UK.
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60
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Emerging Roles of Gemin5: From snRNPs Assembly to Translation Control. Int J Mol Sci 2020; 21:ijms21113868. [PMID: 32485878 PMCID: PMC7311978 DOI: 10.3390/ijms21113868] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/22/2020] [Accepted: 05/27/2020] [Indexed: 02/07/2023] Open
Abstract
RNA-binding proteins (RBPs) play a pivotal role in the lifespan of RNAs. The disfunction of RBPs is frequently the cause of cell disorders which are incompatible with life. Furthermore, the ordered assembly of RBPs and RNAs in ribonucleoprotein (RNP) particles determines the function of biological complexes, as illustrated by the survival of the motor neuron (SMN) complex. Defects in the SMN complex assembly causes spinal muscular atrophy (SMA), an infant invalidating disease. This multi-subunit chaperone controls the assembly of small nuclear ribonucleoproteins (snRNPs), which are the critical components of the splicing machinery. However, the functional and structural characterization of individual members of the SMN complex, such as SMN, Gemin3, and Gemin5, have accumulated evidence for the additional roles of these proteins, unveiling their participation in other RNA-mediated events. In particular, Gemin5 is a multidomain protein that comprises tryptophan-aspartic acid (WD) repeat motifs at the N-terminal region, a dimerization domain at the middle region, and a non-canonical RNA-binding domain at the C-terminal end of the protein. Beyond small nuclear RNA (snRNA) recognition, Gemin5 interacts with a selective group of mRNA targets in the cell environment and plays a key role in reprogramming translation depending on the RNA partner and the cellular conditions. Here, we review recent studies on the SMN complex, with emphasis on the individual components regarding their involvement in cellular processes critical for cell survival.
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61
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O'Loughlin S, Capece MC, Klimova M, Wills NM, Coakley A, Samatova E, O'Connor PBF, Loughran G, Weissman JS, Baranov PV, Rodnina MV, Puglisi JD, Atkins JF. Polysomes Bypass a 50-Nucleotide Coding Gap Less Efficiently Than Monosomes Due to Attenuation of a 5' mRNA Stem-Loop and Enhanced Drop-off. J Mol Biol 2020; 432:4369-4387. [PMID: 32454154 PMCID: PMC7245268 DOI: 10.1016/j.jmb.2020.05.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/08/2020] [Accepted: 05/11/2020] [Indexed: 01/03/2023]
Abstract
Efficient translational bypassing of a 50-nt non-coding gap in a phage T4 topoisomerase subunit gene (gp60) requires several recoding signals. Here we investigate the function of the mRNA stem–loop 5′ of the take-off codon, as well as the importance of ribosome loading density on the mRNA for efficient bypassing. We show that polysomes are less efficient at mediating bypassing than monosomes, both in vitro and in vivo, due to their preventing formation of a stem–loop 5′ of the take-off codon and allowing greater peptidyl-tRNA drop off. A ribosome profiling analysis of phage T4-infected Escherichia coli yielded protected mRNA fragments within the normal size range derived from ribosomes stalled at the take-off codon. However, ribosomes at this position also yielded some 53-nucleotide fragments, 16 longer. These were due to protection of the nucleotides that form the 5′ stem–loop. NMR shows that the 5′ stem–loop is highly dynamic. The importance of different nucleotides in the 5′ stem–loop is revealed by mutagenesis studies. These data highlight the significance of the 5′ stem–loop for the 50-nt bypassing and further enhance appreciation of relevance of the extent of ribosome loading for recoding. Monosomes are more efficient than polysome in mediating 50-nt translational bypassing. A 5′ mRNA stem–loop facilitates translational bypassing by monosomes. Ribosome profiling yields an extra-long, 53-nt, protected fragment of mRNA.
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Affiliation(s)
- Sinéad O'Loughlin
- School of Biochemistry, University College Cork, Western Gateway Building, Western Road, Cork, T12 XF62, Ireland; School of Microbiology, University College Cork, Western Gateway Building, Western Road, Cork, T12 YT57, Ireland
| | - Mark C Capece
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-4090, USA
| | - Mariia Klimova
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Norma M Wills
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112-5330, USA
| | - Arthur Coakley
- School of Biochemistry, University College Cork, Western Gateway Building, Western Road, Cork, T12 XF62, Ireland
| | - Ekaterina Samatova
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Patrick B F O'Connor
- School of Biochemistry, University College Cork, Western Gateway Building, Western Road, Cork, T12 XF62, Ireland
| | - Gary Loughran
- School of Biochemistry, University College Cork, Western Gateway Building, Western Road, Cork, T12 XF62, Ireland
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Pavel V Baranov
- School of Biochemistry, University College Cork, Western Gateway Building, Western Road, Cork, T12 XF62, Ireland; Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow 117997, Russia
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-4090, USA
| | - John F Atkins
- School of Biochemistry, University College Cork, Western Gateway Building, Western Road, Cork, T12 XF62, Ireland; School of Microbiology, University College Cork, Western Gateway Building, Western Road, Cork, T12 YT57, Ireland; Department of Human Genetics, University of Utah, Salt Lake City, UT 84112-5330, USA.
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62
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Reixachs-Solé M, Ruiz-Orera J, Albà MM, Eyras E. Ribosome profiling at isoform level reveals evolutionary conserved impacts of differential splicing on the proteome. Nat Commun 2020; 11:1768. [PMID: 32286305 PMCID: PMC7156646 DOI: 10.1038/s41467-020-15634-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 03/11/2020] [Indexed: 12/14/2022] Open
Abstract
The differential production of transcript isoforms from gene loci is a key cellular mechanism. Yet, its impact in protein production remains an open question. Here, we describe ORQAS (ORF quantification pipeline for alternative splicing), a pipeline for the translation quantification of individual transcript isoforms using ribosome-protected mRNA fragments (ribosome profiling). We find evidence of translation for 40-50% of the expressed isoforms in human and mouse, with 53% of the expressed genes having more than one translated isoform in human, and 33% in mouse. Differential splicing analysis revealed that about 40% of the splicing changes at RNA level are concordant with changes in translation. Furthermore, orthologous cassette exons between human and mouse preserve the directionality of the change, and are enriched in microexons in a comparison between glia and glioma. ORQAS leverages ribosome profiling to uncover a widespread and evolutionarily conserved impact of differential splicing on translation, particularly of microexon-containing isoforms.
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Affiliation(s)
- Marina Reixachs-Solé
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, 2601, Australia
- EMBL Australia Partner Laboratory Network at the Australian National University, Canberra, ACT, 2601, Australia
| | - Jorge Ruiz-Orera
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, 13125, Germany
| | - M Mar Albà
- IMIM - Hospital del Mar Medical Research Institute, E08003, Barcelona, Spain
- Catalan Institution for Research and Advanced Studies, E08010, Barcelona, Spain
- Pompeu Fabra University, E08003, Barcelona, Spain
| | - Eduardo Eyras
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, 2601, Australia.
- EMBL Australia Partner Laboratory Network at the Australian National University, Canberra, ACT, 2601, Australia.
- IMIM - Hospital del Mar Medical Research Institute, E08003, Barcelona, Spain.
- Catalan Institution for Research and Advanced Studies, E08010, Barcelona, Spain.
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63
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Biever A, Glock C, Tushev G, Ciirdaeva E, Dalmay T, Langer JD, Schuman EM. Monosomes actively translate synaptic mRNAs in neuronal processes. Science 2020; 367:367/6477/eaay4991. [PMID: 32001627 DOI: 10.1126/science.aay4991] [Citation(s) in RCA: 143] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/29/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022]
Abstract
To accommodate their complex morphology, neurons localize messenger RNAs (mRNAs) and ribosomes near synapses to produce proteins locally. However, a relative paucity of polysomes (considered the active sites of translation) detected in electron micrographs of neuronal processes has suggested a limited capacity for local protein synthesis. In this study, we used polysome profiling together with ribosome footprinting of microdissected rodent synaptic regions to reveal a surprisingly high number of dendritic and/or axonal transcripts preferentially associated with monosomes (single ribosomes). Furthermore, the neuronal monosomes were in the process of active protein synthesis. Most mRNAs showed a similar translational status in the cell bodies and neurites, but some transcripts exhibited differential ribosome occupancy in the compartments. Monosome-preferring transcripts often encoded high-abundance synaptic proteins. Thus, monosome translation contributes to the local neuronal proteome.
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Affiliation(s)
- Anne Biever
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Caspar Glock
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Georgi Tushev
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | | | - Tamas Dalmay
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt, Germany.,Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany.
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64
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Sato H, Das S, Singer RH, Vera M. Imaging of DNA and RNA in Living Eukaryotic Cells to Reveal Spatiotemporal Dynamics of Gene Expression. Annu Rev Biochem 2020; 89:159-187. [PMID: 32176523 DOI: 10.1146/annurev-biochem-011520-104955] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review focuses on imaging DNA and single RNA molecules in living cells to define eukaryotic functional organization and dynamic processes. The latest advances in technologies to visualize individual DNA loci and RNAs in real time are discussed. Single-molecule fluorescence microscopy provides the spatial and temporal resolution to reveal mechanisms regulating fundamental cell functions. Novel insights into the regulation of nuclear architecture, transcription, posttranscriptional RNA processing, and RNA localization provided by multicolor fluorescence microscopy are reviewed. A perspective on the future use of live imaging technologies and overcoming their current limitations is provided.
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Affiliation(s)
- Hanae Sato
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , ,
| | - Sulagna Das
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , ,
| | - Robert H Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , , .,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA
| | - Maria Vera
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , , .,Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada;
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65
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Herrmannová A, Prilepskaja T, Wagner S, Šikrová D, Zeman J, Poncová K, Valášek LS. Adapted formaldehyde gradient cross-linking protocol implicates human eIF3d and eIF3c, k and l subunits in the 43S and 48S pre-initiation complex assembly, respectively. Nucleic Acids Res 2020; 48:1969-1984. [PMID: 31863585 PMCID: PMC7039009 DOI: 10.1093/nar/gkz1185] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/04/2019] [Accepted: 12/09/2019] [Indexed: 12/18/2022] Open
Abstract
One of the key roles of the 12-subunit eukaryotic translation initiation factor 3 (eIF3) is to promote the formation of the 43S and 48S pre-initiation complexes (PICs). However, particular contributions of its individual subunits to these two critical initiation reactions remained obscure. Here, we adapted formaldehyde gradient cross-linking protocol to translation studies and investigated the efficiency of the 43S and 48S PIC assembly in knockdowns of individual subunits of human eIF3 known to produce various partial subcomplexes. We revealed that eIF3d constitutes an important intermolecular bridge between eIF3 and the 40S subunit as its elimination from the eIF3 holocomplex severely compromised the 43S PIC assembly. Similarly, subunits eIF3a, c and e were found to represent an important binding force driving eIF3 binding to the 40S subunit. In addition, we demonstrated that eIF3c, and eIF3k and l subunits alter the efficiency of mRNA recruitment to 43S PICs in an opposite manner. Whereas the eIF3c knockdown reduces it, downregulation of eIF3k or eIF3l increases mRNA recruitment, suggesting that the latter subunits possess a regulatory potential. Altogether this study provides new insights into the role of human eIF3 in the initial assembly steps of the translational machinery.
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Affiliation(s)
- Anna Herrmannová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Terezie Prilepskaja
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Susan Wagner
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Darina Šikrová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Jakub Zeman
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Kristýna Poncová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
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66
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Lee KM, Wu CC, Wu SE, Lin YH, Wang LT, Chang CR, Huang PN, Shih SR, Kuo RL. The RNA-dependent RNA polymerase of enterovirus A71 associates with ribosomal proteins and positively regulates protein translation. RNA Biol 2020; 17:608-622. [PMID: 32009553 DOI: 10.1080/15476286.2020.1722448] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Enteroviruses, which may cause neurological complications, have become a public health threat worldwide in recent years. Interactions between cellular proteins and enteroviral proteins could interfere with cellular biological processes to facilitate viral replication in infected cells. Enteroviral RNA-dependent RNA polymerase (RdRP), known as 3D protein, mainly functions as a replicase for viral RNA synthesis in infected cells. However, the 3D protein encoded by enterovirus A71 (EV-A71) could also interact with several cellular proteins to regulate cellular events and responses during infection. To globally investigate the functions of the EV-A71 3D protein in regulating biological processes in host cells, we performed immunoprecipitation coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify host proteins that may associate with the 3D protein. We found that the 3D protein interacts with factors involved in translation-related biological processes, including ribosomal proteins. In addition, polysome profiling analysis showed that the 3D protein cosediments with small and large subunits of ribosomes. We further discovered that the EV-A71 3D protein could enhance EV-A71 internal ribosome entry site (IRES)-dependent translation as well as cap-dependent translation. Collectively, this research demonstrated that the RNA polymerase encoded by EV-A71 could join a functional ribosomal complex and positively regulate viral and host translation.
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Affiliation(s)
- Kuo-Ming Lee
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Ching Wu
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Otolaryngology-Head & Neck Surgery, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Shang-En Wu
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ya-Han Lin
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Li-Ting Wang
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chun-Ru Chang
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Peng-Nien Huang
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shin-Ru Shih
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Clinical Virology Laboratory, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Rei-Lin Kuo
- Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
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67
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Ribosomal Protein L13 Promotes IRES-Driven Translation of Foot-and-Mouth Disease Virus in a Helicase DDX3-Dependent Manner. J Virol 2020; 94:JVI.01679-19. [PMID: 31619563 DOI: 10.1128/jvi.01679-19] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 10/11/2019] [Indexed: 12/22/2022] Open
Abstract
Internal ribosome entry site (IRES)-driven translation is a common strategy among positive-sense, single-stranded RNA viruses for bypassing the host cell requirement of a 5' cap structure. In the current study, we identified the ribosomal protein L13 (RPL13) as a critical regulator of IRES-driven translation of foot-and-mouth disease virus (FMDV) but found that it is not essential for cellular global translation. RPL13 is also a determinant for translation and infection of Seneca Valley virus (SVV) and classical swine fever virus (CSFV), and this suggests that its function may also be conserved in unrelated IRES-containing viruses. We further showed that depletion of DEAD box helicase DDX3 disrupts binding of RPL13 to the FMDV IRES, whereas the reduction in RPL13 expression impairs the ability of DDX3 to promote IRES-driven translation directly. DDX3 cooperates with RPL13 to support the assembly of 80S ribosomes for optimal translation initiation of viral mRNA. Finally, we demonstrated that DDX3 affects the recruitment of the eukaryotic initiation factor eIF3 subunits e and j to the viral IRES. This work provides the first connection between DDX3 and eIF3e/j and recognition of the role of RPL13 in modulating viral IRES-dependent translation. This previously uncharacterized process may be involved in selective mRNA translation.IMPORTANCE Accumulating evidence has unveiled the roles of ribosomal proteins (RPs) belonging to the large 60S subunit in regulating selective translation of specific mRNAs. The translation specificity of the large-subunit RPs in this process is thought provoking, given the role they play canonically in catalyzing peptide bond formation. Here, we have identified the ribosomal protein L13 (RPL13) as a critical regulator of IRES-driven translation during FMDV infection. Our study supports a model whereby the FMDV IRESs recruit helicase DDX3 recognizing RPL13 to facilitate IRES-driven translation, with the assistance of eIF3e and eIF3j. A better understanding of these specific interactions surrounding IRES-mediated translation initiation could have important implications for the selective translation of viral mRNA and thus for the development of effective prevention of viral infection.
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68
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Ostroff LE, Santini E, Sears R, Deane Z, Kanadia RN, LeDoux JE, Lhakhang T, Tsirigos A, Heguy A, Klann E. Axon TRAP reveals learning-associated alterations in cortical axonal mRNAs in the lateral amgydala. eLife 2019; 8:e51607. [PMID: 31825308 PMCID: PMC6924958 DOI: 10.7554/elife.51607] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/10/2019] [Indexed: 12/11/2022] Open
Abstract
Local translation can support memory consolidation by supplying new proteins to synapses undergoing plasticity. Translation in adult forebrain dendrites is an established mechanism of synaptic plasticity and is regulated by learning, yet there is no evidence for learning-regulated protein synthesis in adult forebrain axons, which have traditionally been believed to be incapable of translation. Here, we show that axons in the adult rat amygdala contain translation machinery, and use translating ribosome affinity purification (TRAP) with RNASeq to identify mRNAs in cortical axons projecting to the amygdala, over 1200 of which were regulated during consolidation of associative memory. Mitochondrial and translation-related genes were upregulated, whereas synaptic, cytoskeletal, and myelin-related genes were downregulated; the opposite effects were observed in the cortex. Our results demonstrate that axonal translation occurs in the adult forebrain and is altered after learning, supporting the likelihood that local translation is more a rule than an exception in neuronal processes.
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Affiliation(s)
- Linnaea E Ostroff
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | | | - Robert Sears
- Center for Neural ScienceNew York UniversityNew YorkUnited States
- Emotional Brain InstituteNathan Kline Institute for Psychiatry ResearchOrangeburgUnited States
- Department of Child and Adolescent PsychiatryNew York University School of MedicineNew YorkUnited States
| | - Zachary Deane
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Rahul N Kanadia
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Joseph E LeDoux
- Center for Neural ScienceNew York UniversityNew YorkUnited States
- Emotional Brain InstituteNathan Kline Institute for Psychiatry ResearchOrangeburgUnited States
| | - Tenzin Lhakhang
- Applied Bioinformatics LaboratoriesNew York University School of MedicineNew YorkUnited States
| | - Aristotelis Tsirigos
- Applied Bioinformatics LaboratoriesNew York University School of MedicineNew YorkUnited States
- Department of PathologyNew York University School of MedicineNew YorkUnited States
| | - Adriana Heguy
- Department of PathologyNew York University School of MedicineNew YorkUnited States
- Genome Technology CenterNew York University School of MedicineNew YorkUnited States
| | - Eric Klann
- Center for Neural ScienceNew York UniversityNew YorkUnited States
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69
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Carneiro RL, Requião RD, Rossetto S, Domitrovic T, Palhano FL. Codon stabilization coefficient as a metric to gain insights into mRNA stability and codon bias and their relationships with translation. Nucleic Acids Res 2019; 47:2216-2228. [PMID: 30698781 PMCID: PMC6412131 DOI: 10.1093/nar/gkz033] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/05/2018] [Accepted: 01/14/2019] [Indexed: 12/11/2022] Open
Abstract
The codon stabilization coefficient (CSC) is derived from the correlation between each codon frequency in transcripts and mRNA half-life experimental data. In this work, we used this metric as a reference to compare previously published Saccharomyces cerevisiae mRNA half-life datasets and investigate how codon composition related to protein levels. We generated CSCs derived from nine studies. Four datasets produced similar CSCs, which also correlated with other independent parameters that reflected codon optimality, such as the tRNA abundance and ribosome residence time. By calculating the average CSC for each gene, we found that most mRNAs tended to have more non-optimal codons. Conversely, a high proportion of optimal codons was found for genes coding highly abundant proteins, including proteins that were only transiently overexpressed in response to stress conditions. We also used CSCs to identify and locate mRNA regions enriched in non-optimal codons. We found that these stretches were usually located close to the initiation codon and were sufficient to slow ribosome movement. However, in contrast to observations from reporter systems, we found no position-dependent effect on the mRNA half-life. These analyses underscore the value of CSCs in studies of mRNA stability and codon bias and their relationships with protein expression.
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Affiliation(s)
- Rodolfo L Carneiro
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil
| | - Rodrigo D Requião
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil
| | - Silvana Rossetto
- Departamento de Ciência da Computação, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil
| | - Tatiana Domitrovic
- Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil
| | - Fernando L Palhano
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil
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70
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Wang J, Johnson AG, Lapointe CP, Choi J, Prabhakar A, Chen DH, Petrov AN, Puglisi JD. eIF5B gates the transition from translation initiation to elongation. Nature 2019; 573:605-608. [PMID: 31534220 PMCID: PMC6763361 DOI: 10.1038/s41586-019-1561-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 08/13/2019] [Indexed: 01/10/2023]
Abstract
Translation initiation determines both the quantity and identity of the protein encoded in an mRNA by establishing the reading frame for protein synthesis. In eukaryotic cells, numerous translation initiation factors (eIFs) prepare ribosomes for polypeptide synthesis, yet the underlying dynamics of this process remain enigmatic1,2. A central question is how eukaryotic ribosomes transition from translation initiation to elongation. Here, we applied in vitro single-molecule fluorescence microscopy approaches to monitor directly in real time the pathways of late translation initiation and the transition to elongation using a purified yeast Saccharomyces cerevisiae translation system. This transition was remarkably slower in our eukaryotic system than that reported for Escherichia coli3–5. The slow entry to elongation was defined by a long residence time of eIF5B on the 80S ribosome after joining of individual ribosomal subunits, which is catalyzed by this universally conserved initiation factor. Inhibition of eIF5B GTPase activity following subunit joining prevented eIF5B dissociation from the 80S complex, thereby preventing elongation. Our findings illustrate how eIF5B dissociation serves as a kinetic checkpoint for the transition from initiation to elongation, and its release may be governed by a conformation of the ribosome complex that triggers GTP hydrolysis.
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Affiliation(s)
- Jinfan Wang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Alex G Johnson
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Christopher P Lapointe
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Junhong Choi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Arjun Prabhakar
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Program in Biophysics, Stanford University, Stanford, CA, USA
| | - Dong-Hua Chen
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Alexey N Petrov
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Biological Sciences, Auburn University, Auburn, AL, USA
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.
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71
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Kim SH, Vieira M, Shim JY, Choi H, Park HY. Recent progress in single-molecule studies of mRNA localization in vivo. RNA Biol 2019; 16:1108-1118. [PMID: 30336727 PMCID: PMC6693552 DOI: 10.1080/15476286.2018.1536592] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/28/2018] [Accepted: 10/08/2018] [Indexed: 12/26/2022] Open
Abstract
From biogenesis to degradation, mRNA goes through diverse types of regulation and interaction with other biomolecules. Uneven distribution of mRNA transcripts and the diverse isoforms and modifications of mRNA make us wonder how cells manage the complexity and keep the functional integrity for the normal development of cells and organisms. Single-molecule microscopy tools have expanded the scope of RNA research with unprecedented spatiotemporal resolution. In this review, we highlight the recent progress in the methods for labeling mRNA targets and analyzing the quantitative information from fluorescence images of single mRNA molecules. In particular, the MS2 system and its various applications are the main focus of this article. We also review how recent studies have addressed biological questions related to the significance of mRNA localization in vivo. Efforts to visualize the dynamics of single mRNA molecules in live cells will push forward our knowledge on the nature of heterogeneity in RNA sequence, structure, and distribution as well as their molecular function and coordinated interaction with RNA binding proteins.
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Affiliation(s)
- Songhee H. Kim
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea
| | - Melissa Vieira
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
| | - Jae Youn Shim
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Hongyoung Choi
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Hye Yoon Park
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
- Institute of Applied Physics, Seoul National University, Seoul, Korea
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72
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Ghoneim DH, Zhang X, Brule CE, Mathews DH, Grayhack EJ. Conservation of location of several specific inhibitory codon pairs in the Saccharomyces sensu stricto yeasts reveals translational selection. Nucleic Acids Res 2019; 47:1164-1177. [PMID: 30576464 PMCID: PMC6379720 DOI: 10.1093/nar/gky1262] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/19/2018] [Accepted: 12/06/2018] [Indexed: 12/30/2022] Open
Abstract
Synonymous codons provide redundancy in the genetic code that influences translation rates in many organisms, in which overall codon use is driven by selection for optimal codons. It is unresolved if or to what extent translational selection drives use of suboptimal codons or codon pairs. In Saccharomyces cerevisiae, 17 specific inhibitory codon pairs, each comprised of adjacent suboptimal codons, inhibit translation efficiency in a manner distinct from their constituent codons, and many are translated slowly in native genes. We show here that selection operates within Saccharomyces sensu stricto yeasts to conserve nine of these codon pairs at defined positions in genes. Conservation of these inhibitory codon pairs is significantly greater than expected, relative to conservation of their constituent codons, with seven pairs more highly conserved than any other synonymous pair. Conservation is strongly correlated with slow translation of the pairs. Conservation of suboptimal codon pairs extends to two related Candida species, fungi that diverged from Saccharomyces ∼270 million years ago, with an enrichment for codons decoded by I•A and U•G wobble in both Candida and Saccharomyces. Thus, conservation of inhibitory codon pairs strongly implies selection for slow translation at particular gene locations, executed by suboptimal codon pairs.
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Affiliation(s)
- Dalia H Ghoneim
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Xiaoju Zhang
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Christina E Brule
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - David H Mathews
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
| | - Elizabeth J Grayhack
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
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73
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Puleston DJ, Buck MD, Klein Geltink RI, Kyle RL, Caputa G, O'Sullivan D, Cameron AM, Castoldi A, Musa Y, Kabat AM, Zhang Y, Flachsmann LJ, Field CS, Patterson AE, Scherer S, Alfei F, Baixauli F, Austin SK, Kelly B, Matsushita M, Curtis JD, Grzes KM, Villa M, Corrado M, Sanin DE, Qiu J, Pällman N, Paz K, Maccari ME, Blazar BR, Mittler G, Buescher JM, Zehn D, Rospert S, Pearce EJ, Balabanov S, Pearce EL. Polyamines and eIF5A Hypusination Modulate Mitochondrial Respiration and Macrophage Activation. Cell Metab 2019; 30:352-363.e8. [PMID: 31130465 PMCID: PMC6688828 DOI: 10.1016/j.cmet.2019.05.003] [Citation(s) in RCA: 216] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/05/2019] [Accepted: 04/30/2019] [Indexed: 12/26/2022]
Abstract
How cells adapt metabolism to meet demands is an active area of interest across biology. Among a broad range of functions, the polyamine spermidine is needed to hypusinate the translation factor eukaryotic initiation factor 5A (eIF5A). We show here that hypusinated eIF5A (eIF5AH) promotes the efficient expression of a subset of mitochondrial proteins involved in the TCA cycle and oxidative phosphorylation (OXPHOS). Several of these proteins have mitochondrial targeting sequences (MTSs) that in part confer an increased dependency on eIF5AH. In macrophages, metabolic switching between OXPHOS and glycolysis supports divergent functional fates stimulated by activation signals. In these cells, hypusination of eIF5A appears to be dynamically regulated after activation. Using in vivo and in vitro models, we show that acute inhibition of this pathway blunts OXPHOS-dependent alternative activation, while leaving aerobic glycolysis-dependent classical activation intact. These results might have implications for therapeutically controlling macrophage activation by targeting the polyamine-eIF5A-hypusine axis.
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Affiliation(s)
- Daniel J Puleston
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany; The Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK
| | - Michael D Buck
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | | | - Ryan L Kyle
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - George Caputa
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - David O'Sullivan
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Alanna M Cameron
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Angela Castoldi
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Yaarub Musa
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Agnieszka M Kabat
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Ying Zhang
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, and BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg 79104, Germany
| | - Lea J Flachsmann
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Cameron S Field
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Annette E Patterson
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Stefanie Scherer
- Department of Animal Physiology and Immunology, Technical University of Munich, Freising, Germany
| | - Francesca Alfei
- Department of Animal Physiology and Immunology, Technical University of Munich, Freising, Germany
| | - Francesc Baixauli
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - S Kyle Austin
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Beth Kelly
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Mai Matsushita
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Jonathan D Curtis
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Katarzyna M Grzes
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Matteo Villa
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Mauro Corrado
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - David E Sanin
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Jing Qiu
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Nora Pällman
- Division of Haematology, University Hospital Zurich and University of Zurich, Zurich 8091, Switzerland
| | - Katelyn Paz
- Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Maria Elena Maccari
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency, Center for Pediatrics, and Faculty of Medicine, Medical Center - University of Freiburg, Freiburg 79106, Germany
| | - Bruce R Blazar
- Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, Minneapolis, MN, USA
| | - Gerhard Mittler
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Joerg M Buescher
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Dietmar Zehn
- Department of Animal Physiology and Immunology, Technical University of Munich, Freising, Germany
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, and BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg 79104, Germany
| | - Edward J Pearce
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany; Faculty of Biology, University of Freiburg, Freiburg 79104, Germany
| | - Stefan Balabanov
- Division of Haematology, University Hospital Zurich and University of Zurich, Zurich 8091, Switzerland
| | - Erika L Pearce
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany.
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Aryanpur PP, Renner DM, Rodela E, Mittelmeier TM, Byrd A, Bolger TA. The DEAD-box RNA helicase Ded1 has a role in the translational response to TORC1 inhibition. Mol Biol Cell 2019; 30:2171-2184. [PMID: 31141444 PMCID: PMC6743465 DOI: 10.1091/mbc.e18-11-0702] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 12/26/2022] Open
Abstract
Ded1 is a DEAD-box RNA helicase with essential roles in translation initiation. It binds to the eukaryotic initiation factor 4F (eIF4F) complex and promotes 48S preinitiation complex assembly and start-site scanning of 5' untranslated regions of mRNAs. Most prior studies of Ded1 cellular function were conducted in steady-state conditions during nutrient-rich growth. In this work, however, we examine its role in the translational response during target of rapamycin (TOR)C1 inhibition and identify a novel function of Ded1 as a translation repressor. We show that C-terminal mutants of DED1 are defective in down-regulating translation following TORC1 inhibition using rapamycin. Furthermore, following TORC1 inhibition, eIF4G1 normally dissociates from translation complexes and is degraded, and this process is attenuated in mutant cells. Mapping of the functional requirements for Ded1 in this translational response indicates that Ded1 enzymatic activity and interaction with eIF4G1 are required, while homo-oligomerization may be dispensable. Our results are consistent with a model wherein Ded1 stalls translation and specifically removes eIF4G1 from translation preinitiation complexes, thus removing eIF4G1 from the translating mRNA pool and leading to the codegradation of both proteins. Shared features among DED1 orthologues suggest that this role is conserved and may be implicated in pathologies such as oncogenesis.
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Affiliation(s)
- Peyman P. Aryanpur
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Tucson, AZ 85721
| | - David M. Renner
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Tucson, AZ 85721
| | - Emily Rodela
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Tucson, AZ 85721
| | - Telsa M. Mittelmeier
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Tucson, AZ 85721
| | - Aaron Byrd
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Tucson, AZ 85721
| | - Timothy A. Bolger
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Tucson, AZ 85721
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75
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Bucca G, Pothi R, Hesketh A, Möller-Levet C, Hodgson DA, Laing EE, Stewart GR, Smith CP. Translational control plays an important role in the adaptive heat-shock response of Streptomyces coelicolor. Nucleic Acids Res 2019; 46:5692-5703. [PMID: 29746664 PMCID: PMC6009599 DOI: 10.1093/nar/gky335] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/18/2018] [Indexed: 12/29/2022] Open
Abstract
Stress-induced adaptations require multiple levels of regulation in all organisms to repair cellular damage. In the present study we evaluated the genome-wide transcriptional and translational changes following heat stress exposure in the soil-dwelling model actinomycete bacterium, Streptomyces coelicolor. The combined analysis revealed an unprecedented level of translational control of gene expression, deduced through polysome profiling, in addition to transcriptional changes. Our data show little correlation between the transcriptome and ‘translatome’; while an obvious downward trend in genome wide transcription was observed, polysome associated transcripts following heat-shock showed an opposite upward trend. A handful of key protein players, including the major molecular chaperones and proteases were highly induced at both the transcriptional and translational level following heat-shock, a phenomenon known as ‘potentiation’. Many other transcripts encoding cold-shock proteins, ABC-transporter systems, multiple transcription factors were more highly polysome-associated following heat stress; interestingly, these protein families were not induced at the transcriptional level and therefore were not previously identified as part of the stress response. Thus, stress coping mechanisms at the level of gene expression in this bacterium go well beyond the induction of a relatively small number of molecular chaperones and proteases in order to ensure cellular survival at non-physiological temperatures.
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Affiliation(s)
- Giselda Bucca
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
| | - Radhika Pothi
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, UK
| | - Andrew Hesketh
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
| | - Carla Möller-Levet
- Bioinformatics facility, Faculty of Health and Medical Sciences, University of Surrey, UK
| | | | - Emma E Laing
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, UK
| | - Graham R Stewart
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, UK
| | - Colin P Smith
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
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76
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Local translation in neurons: visualization and function. Nat Struct Mol Biol 2019; 26:557-566. [PMID: 31270476 DOI: 10.1038/s41594-019-0263-5] [Citation(s) in RCA: 288] [Impact Index Per Article: 57.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 05/30/2019] [Indexed: 01/01/2023]
Abstract
Neurons are among the most compartmentalized and interactive of all cell types. Like all cells, neurons use proteins as the main sensors and effectors. The modification of the proteome in axons and dendrites is used to guide the formation of synaptic connections and to store information. In this Review, we discuss the data indicating that an important source of protein for dendrites, axons and their associated elements is provided by the local synthesis of proteins. We review the data indicating the presence of the machinery required for protein synthesis, the direct visualization and demonstration of protein synthesis, and the established functional roles for local translation for many different neuronal functions. Finally, we consider the open questions and future directions in this field.
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77
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Translatome analysis reveals altered serine and glycine metabolism in T-cell acute lymphoblastic leukemia cells. Nat Commun 2019; 10:2542. [PMID: 31186416 PMCID: PMC6559966 DOI: 10.1038/s41467-019-10508-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/10/2019] [Indexed: 12/26/2022] Open
Abstract
Somatic ribosomal protein mutations have recently been described in cancer, yet their impact on cellular transcription and translation remains poorly understood. Here, we integrate mRNA sequencing, ribosome footprinting, polysomal RNA sequencing and mass spectrometry datasets from a mouse lymphoid cell model to characterize the T-cell acute lymphoblastic leukemia (T-ALL) associated ribosomal RPL10 R98S mutation. Surprisingly, RPL10 R98S induces changes in protein levels primarily through transcriptional rather than translation efficiency changes. Phosphoserine phosphatase (PSPH), encoding a key serine biosynthesis enzyme, was the only gene with elevated transcription and translation leading to protein overexpression. PSPH upregulation is a general phenomenon in T-ALL patient samples, associated with elevated serine and glycine levels in xenograft mice. Reduction of PSPH expression suppresses proliferation of T-ALL cell lines and their capacity to expand in mice. We identify ribosomal mutation driven induction of serine biosynthesis and provide evidence supporting dependence of T-ALL cells on PSPH. The ribosomal protein RPL10 is frequently mutated in T-cell acute lymphoblastic leukemia (T-ALL). Here, the authors show that it promotes proliferation of T-ALL cells by upregulating the serine biosynthesis enzyme phosphoserine phosphatase which in turn modulates serine and glycine metabolism.
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78
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Abstract
In trypanosomes, RNA polymerase II transcription is polycistronic and individual mRNAs are excised by trans-splicing and polyadenylation. The lack of individual gene transcription control is compensated by control of mRNA processing, translation and degradation. Although the basic mechanisms of mRNA decay and translation are evolutionarily conserved, there are also unique aspects, such as the existence of six cap-binding translation initiation factor homologues, a novel decapping enzyme and an mRNA stabilizing complex that is recruited by RNA-binding proteins. High-throughput analyses have identified nearly a hundred regulatory mRNA-binding proteins, making trypanosomes valuable as a model system to investigate post-transcriptional regulation.
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Affiliation(s)
- Christine Clayton
- University of Heidelberg Center for Molecular Biology (ZMBH), Im Neuenheimer Feld 282, D69120 Heidelberg, Germany
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79
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Marcon BH, Shigunov P, Spangenberg L, Pereira IT, de Aguiar AM, Amorín R, Rebelatto CK, Correa A, Dallagiovanna B. Cell cycle genes are downregulated after adipogenic triggering in human adipose tissue-derived stem cells by regulation of mRNA abundance. Sci Rep 2019; 9:5611. [PMID: 30948750 PMCID: PMC6449374 DOI: 10.1038/s41598-019-42005-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 03/20/2019] [Indexed: 12/18/2022] Open
Abstract
The adipogenic process is characterized by the expression of adipocyte differentiation markers that lead to changes in cell metabolism and to the accumulation of lipid droplets. Moreover, during early adipogenesis, cells undergo a strong downregulation of translational activity with a decrease in cell size, proliferation and migration. In the present study, we identified that after 24 hours of adipogenic induction, human adipose tissue-derived stem cells (hASCs) undergo a G1-cell cycle arrest consistent with reduced proliferation, and this effect was correlated with a shift in polysome profile with an enrichment of the monosomal fraction and a reduction of the polysomal fraction. Polysome profiling analysis also revealed that this change in the monosomal/polysomal ratio was related to a strong downregulation of cell cycle and proliferation genes, such as cyclins and cyclin-dependent kinases (CDKs). Comparing total and polysome-associated mRNA sequencing, we also observed that this downregulation was mostly due to a reduction of cell cycle and proliferation transcripts via control of total mRNA abundance, rather than by translational control.
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Affiliation(s)
- Bruna H Marcon
- Instituto Carlos Chagas, Fiocruz-Paraná. Rua Professor Algacyr Munhoz Mader, 3775, Curitiba, PR, 81350-010, Brazil
| | - Patrícia Shigunov
- Instituto Carlos Chagas, Fiocruz-Paraná. Rua Professor Algacyr Munhoz Mader, 3775, Curitiba, PR, 81350-010, Brazil
| | - Lucia Spangenberg
- Unidad de Bioinformática, Institut Pasteur Montevideo. Mataojo 2020, Montevideo, 11400, Uruguay
| | - Isabela Tiemy Pereira
- Instituto Carlos Chagas, Fiocruz-Paraná. Rua Professor Algacyr Munhoz Mader, 3775, Curitiba, PR, 81350-010, Brazil
| | - Alessandra Melo de Aguiar
- Instituto Carlos Chagas, Fiocruz-Paraná. Rua Professor Algacyr Munhoz Mader, 3775, Curitiba, PR, 81350-010, Brazil
| | - Rocío Amorín
- Unidad de Bioinformática, Institut Pasteur Montevideo. Mataojo 2020, Montevideo, 11400, Uruguay
| | - Carmen K Rebelatto
- Núcleo de Tecnologia Celular, Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição, 1155, Curitiba, PR, 80215-901, Brazil
| | - Alejandro Correa
- Instituto Carlos Chagas, Fiocruz-Paraná. Rua Professor Algacyr Munhoz Mader, 3775, Curitiba, PR, 81350-010, Brazil.
| | - Bruno Dallagiovanna
- Instituto Carlos Chagas, Fiocruz-Paraná. Rua Professor Algacyr Munhoz Mader, 3775, Curitiba, PR, 81350-010, Brazil.
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80
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Biever A, Donlin-Asp PG, Schuman EM. Local translation in neuronal processes. Curr Opin Neurobiol 2019; 57:141-148. [PMID: 30861464 DOI: 10.1016/j.conb.2019.02.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 02/07/2019] [Indexed: 12/19/2022]
Abstract
Neurons exhibit a unique degree of spatial compartmentalization and are able to maintain and remodel their proteomes independently from the cell body. While much effort has been devoted to understanding the capacity and role for local protein synthesis in dendrites and spines, local mRNA translation in mature axons, projecting over distances up to a meter, has received much less attention. Also, little is known about the spatio-temporal dynamics of axonal and dendritic gene expression as function of mRNA abundance, protein synthesis and degradation. Here, we summarize key recent findings that have shaped our knowledge of the precise location of local protein production and discuss unique strategies used by neurons to shape presynaptic and postsynaptic proteomes.
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Affiliation(s)
- Anne Biever
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | | | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany.
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81
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Regulation of NGF Signaling by an Axonal Untranslated mRNA. Neuron 2019; 102:553-563.e8. [PMID: 30853298 PMCID: PMC6509357 DOI: 10.1016/j.neuron.2019.02.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 11/26/2018] [Accepted: 02/06/2019] [Indexed: 11/20/2022]
Abstract
Neurons are extraordinarily large and highly polarized cells that require rapid and efficient communication between cell bodies and axons over long distances. In peripheral neurons, transcripts are transported along axons to growth cones, where they are rapidly translated in response to extrinsic signals. While studying Tp53inp2, a transcript highly expressed and enriched in sympathetic neuron axons, we unexpectedly discovered that Tp53inp2 is not translated. Instead, the transcript supports axon growth in a coding-independent manner. Increasing evidence indicates that mRNAs may function independently of their coding capacity; for example, acting as a scaffold for functionally related proteins. The Tp53inp2 transcript interacts with the nerve growth factor (NGF) receptor TrkA, regulating TrkA endocytosis and signaling. Deletion of Tp53inp2 inhibits axon growth in vivo, and the defects are rescued by a non-translatable form of the transcript. Tp53inp2 is an atypical mRNA that regulates axon growth by enhancing NGF-TrkA signaling in a translation-independent manner. Tp53inp2 is the most abundant mRNA in SN axons but is not translated Tp53inp2 transcript interacts with the TrkA receptor to regulate NGF signaling In SNs, Tp53inp2 functions independently of its protein-coding capacity Tp53inp2 transcript is essential for axon growth and target innervation in vivo
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82
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Chirillo MA, Waters MS, Lindsey LF, Bourne JN, Harris KM. Local resources of polyribosomes and SER promote synapse enlargement and spine clustering after long-term potentiation in adult rat hippocampus. Sci Rep 2019; 9:3861. [PMID: 30846859 PMCID: PMC6405867 DOI: 10.1038/s41598-019-40520-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 02/07/2019] [Indexed: 12/11/2022] Open
Abstract
Synapse clustering facilitates circuit integration, learning, and memory. Long-term potentiation (LTP) of mature neurons produces synapse enlargement balanced by fewer spines, raising the question of how clusters form despite this homeostatic regulation of total synaptic weight. Three-dimensional reconstruction from serial section electron microscopy (3DEM) revealed the shapes and distributions of smooth endoplasmic reticulum (SER) and polyribosomes, subcellular resources important for synapse enlargement and spine outgrowth. Compared to control stimulation, synapses were enlarged two hours after LTP on resource-rich spines containing polyribosomes (4% larger than control) or SER (15% larger). SER in spines shifted from a single tubule to complex spine apparatus after LTP. Negligible synapse enlargement (0.6%) occurred on resource-poor spines lacking SER and polyribosomes. Dendrites were divided into discrete synaptic clusters surrounded by asynaptic segments. Spine density was lowest in clusters having only resource-poor spines, especially following LTP. In contrast, resource-rich spines preserved neighboring resource-poor spines and formed larger clusters with elevated total synaptic weight following LTP. These clusters also had more shaft SER branches, which could sequester cargo locally to support synapse growth and spinogenesis. Thus, resources appear to be redistributed to synaptic clusters with LTP-related synapse enlargement while homeostatic regulation suppressed spine outgrowth in resource-poor synaptic clusters.
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Affiliation(s)
- Michael A Chirillo
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,Fulbright U.S. Scholar Program, University of Belgrade, Studentski trg 1, Belgrade, 11000, Serbia
| | - Mikayla S Waters
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,McGovern Medical School in Houston, 6431 Fannin St., Houston, TX, 77030, USA
| | - Laurence F Lindsey
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,Google Seattle, Seattle, Washington, 98103, USA
| | - Jennifer N Bourne
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.,Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Kristen M Harris
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712, USA.
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83
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Cardenas D, Sylvester C, Cao B, Nation CS, Pizarro JC, Lu H, Guidry J, Wojcik EJ, Kelly BL. Disruption of the Putative Ribosome-Binding Motif of a Scaffold Protein Impairs Cytochrome c Oxidase Subunit Expression in Leishmania major. mSphere 2019; 4:e00644-18. [PMID: 30842271 PMCID: PMC6403457 DOI: 10.1128/msphere.00644-18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 02/09/2019] [Indexed: 11/20/2022] Open
Abstract
During their parasitic life cycle, through sandflies and vertebrate hosts, Leishmania parasites confront strikingly different environments, including abrupt changes in pH and temperature, to which they must rapidly adapt. These adaptations include alterations in Leishmania gene expression, metabolism, and morphology, allowing them to thrive as promastigotes in the sandfly and as intracellular amastigotes in the vertebrate host. A critical aspect of Leishmania metabolic adaptation to these changes is maintenance of efficient mitochondrial function in the hostile vertebrate environment. Such functions, including generation of ATP, depend upon the expression of many mitochondrial proteins, including subunits of cytochrome c oxidase (COX). Significantly, under mammalian temperature conditions, expression of Leishmania major COX subunit IV (LmCOX4) and virulence are dependent upon two copies of LACK, a gene that encodes the ribosome-associated scaffold protein, LACK (Leishmania ortholog of RACK1 [receptor for activated C kinase]). Targeted replacement of an endogenous LACK copy with a putative ribosome-binding motif-disrupted variant (LACKR34D35G36→LACKD34D35E36) resulted in thermosensitive parasites that showed diminished LmCOX4 expression, mitochondrial fitness, and replication in macrophages. Surprisingly, despite these phenotypes, LACKD34D35E36 associated with monosomes and polysomes and showed no major impairment of global protein synthesis. Collectively, these data suggest that wild-type (WT) LACK orchestrates robust LmCOX4 expression and mitochondrial fitness to ensure parasite virulence, via optimized functional interactions with the ribosome.IMPORTANCELeishmania parasites are trypanosomatid protozoans that persist in infected human hosts to cause a spectrum of pathologies, from cutaneous and mucocutaneous manifestations to visceral leishmaniasis caused by Leishmania donovani The latter is usually fatal if not treated. Persistence of L. major in the mammalian host depends upon maintaining gene-regulatory programs to support essential parasite metabolic functions. These include expression and assembly of mitochondrial L. major cytochrome c oxidase (LmCOX) subunits, important for Leishmania ATP production. Significantly, under mammalian conditions, WT levels of LmCOX subunits require threshold levels of the Leishmania ribosome-associated scaffold protein, LACK. Unexpectedly, we find that although disruption of LACK's putative ribosome-binding motif does not grossly perturb ribosome association or global protein synthesis, it nonetheless impairs COX subunit expression, mitochondrial function, and virulence. Our data indicate that the quality of LACK's interaction with Leishmania ribosomes is critical for LmCOX subunit expression and parasite mitochondrial function in the mammalian host. Collectively, these findings validate LACK's ribosomal interactions as a potential therapeutic target.
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Affiliation(s)
- Daviel Cardenas
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Charity Sylvester
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Bo Cao
- Department of Biochemistry & Molecular Biology and Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Catherine S Nation
- Department of Tropical Medicine, Tulane University, New Orleans, Louisiana, USA
| | - Juan C Pizarro
- Department of Tropical Medicine, Tulane University, New Orleans, Louisiana, USA
| | - Hua Lu
- Department of Biochemistry & Molecular Biology and Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Jessie Guidry
- Department of Biochemistry & Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Edward J Wojcik
- Department of Biochemistry & Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Ben L Kelly
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
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Zhao J, Qin B, Nikolay R, Spahn CMT, Zhang G. Translatomics: The Global View of Translation. Int J Mol Sci 2019; 20:ijms20010212. [PMID: 30626072 PMCID: PMC6337585 DOI: 10.3390/ijms20010212] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/19/2018] [Accepted: 01/02/2019] [Indexed: 01/01/2023] Open
Abstract
In all kingdoms of life, proteins are synthesized by ribosomes in a process referred to as translation. The amplitude of translational regulation exceeds the sum of transcription, mRNA degradation and protein degradation. Therefore, it is essential to investigate translation in a global scale. Like the other “omics”-methods, translatomics investigates the totality of the components in the translation process, including but not limited to translating mRNAs, ribosomes, tRNAs, regulatory RNAs and nascent polypeptide chains. Technical advances in recent years have brought breakthroughs in the investigation of these components at global scale, both for their composition and dynamics. These methods have been applied in a rapidly increasing number of studies to reveal multifaceted aspects of translation control. The process of translation is not restricted to the conversion of mRNA coding sequences into polypeptide chains, it also controls the composition of the proteome in a delicate and responsive way. Therefore, translatomics has extended its unique and innovative power to many fields including proteomics, cancer research, bacterial stress response, biological rhythmicity and plant biology. Rational design in translation can enhance recombinant protein production for thousands of times. This brief review summarizes the main state-of-the-art methods of translatomics, highlights recent discoveries made in this field and introduces applications of translatomics on basic biological and biomedical research.
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Affiliation(s)
- Jing Zhao
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
| | - Bo Qin
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
| | - Rainer Nikolay
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
| | - Christian M T Spahn
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
| | - Gong Zhang
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
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85
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Ohmer M, Tzivelekidis T, Niedenführ N, Volceanov-Hahn L, Barth S, Vier J, Börries M, Busch H, Kook L, Biniossek ML, Schilling O, Kirschnek S, Häcker G. Infection of HeLa cells with Chlamydia trachomatis inhibits protein synthesis and causes multiple changes to host cell pathways. Cell Microbiol 2019; 21:e12993. [PMID: 30551267 DOI: 10.1111/cmi.12993] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 10/31/2018] [Accepted: 12/07/2018] [Indexed: 12/12/2022]
Abstract
The obligate intracellular bacterium Chlamydia trachomatis replicates in a cytosolic vacuole in human epithelial cells. Infection of human cells with C. trachomatis causes substantial changes to many host cell-signalling pathways, but the molecular basis of such influence is not well understood. Studies of gene transcription of the infected cell have shown altered transcription of many host cell genes, indicating a transcriptional response of the host cell to the infection. We here describe that infection of HeLa cells with C. trachomatis as well as infection of murine cells with Chlamydia muridarum substantially inhibits protein synthesis of the infected host cell. This inhibition was accompanied by changes to the ribosomal profile of the infected cell indicative of a block of translation initiation, most likely as part of a stress response. The Chlamydia protease-like activity factor (CPAF) also reduced protein synthesis in uninfected cells, although CPAF-deficient C. trachomatis showed no defect in this respect. Analysis of polysomal mRNA as a proxy of actively transcribed mRNA identified a number of biological processes differentially affected by chlamydial infection. Mapping of differentially regulated genes onto a protein interaction network identified nodes of up- and down-regulated networks during chlamydial infection. Proteomic analysis of protein synthesis further suggested translational regulation of host cell functions by chlamydial infection. These results demonstrate reprogramming of the host cell during chlamydial infection through the alteration of protein synthesis.
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Affiliation(s)
- Michaela Ohmer
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tina Tzivelekidis
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nora Niedenführ
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Larisa Volceanov-Hahn
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Svenja Barth
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Juliane Vier
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Melanie Börries
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,German Cancer Consortium (DKTK), Freiburg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Hauke Busch
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Luebeck Institute for Experimental Dermatology; Institute for Cardiogenetics, University of Lübeck, Lübeck, Germany
| | - Lucas Kook
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Martin L Biniossek
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Oliver Schilling
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Susanne Kirschnek
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Georg Häcker
- Institute for Microbiology and Hygiene, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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86
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Hato T, Maier B, Syed F, Myslinski J, Zollman A, Plotkin Z, Eadon MT, Dagher PC. Bacterial sepsis triggers an antiviral response that causes translation shutdown. J Clin Invest 2019; 129:296-309. [PMID: 30507610 PMCID: PMC6307966 DOI: 10.1172/jci123284] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/11/2018] [Indexed: 12/29/2022] Open
Abstract
In response to viral pathogens, the host upregulates antiviral genes that suppress translation of viral mRNAs. However, induction of such antiviral responses may not be exclusive to viruses, as the pathways lie at the intersection of broad inflammatory networks that can also be induced by bacterial pathogens. Using a model of Gram-negative sepsis, we show that propagation of kidney damage initiated by a bacterial origin ultimately involves antiviral responses that result in host translation shutdown. We determined that activation of the eukaryotic translation initiation factor 2-α kinase 2/eukaryotic translation initiation factor 2α (Eif2ak2/Eif2α) axis is the key mediator of translation initiation block in late-phase sepsis. Reversal of this axis mitigated kidney injury. Furthermore, temporal profiling of the kidney translatome revealed that multiple genes involved in formation of the initiation complex were translationally altered during bacterial sepsis. Collectively, our findings imply that translation shutdown is indifferent to the specific initiating pathogen and is an important determinant of tissue injury in sepsis.
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Affiliation(s)
| | | | - Farooq Syed
- Department of Pediatrics and the Herman B Wells Center, and
| | | | | | | | | | - Pierre C. Dagher
- Department of Medicine
- Department of Cellular and Integrative Physiology, Indiana University, Indianapolis, Indiana, USA
- Roudebush Indianapolis Veterans Affairs Medical Center, Indianapolis, Indiana, USA
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87
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Pringle ES, McCormick C, Cheng Z. Polysome Profiling Analysis of mRNA and Associated Proteins Engaged in Translation. ACTA ACUST UNITED AC 2018; 125:e79. [PMID: 30371019 DOI: 10.1002/cpmb.79] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Post-transcriptional regulation is an important aspect of the control of gene expression. mRNAs are translated with variable efficiencies, and these efficiencies can change rapidly during adaptation to diverse environmental factors, including cellular stresses and microbial infections. Polysome profiling analysis utilizes ultracentrifugation to isolate complexes of mRNAs in the process of translation and corresponding proteins on the basis of density. Here we describe polysome profiling analysis using a continuous ultraviolet spectrophotometer and a gradient fractionator. We provide protocols for processing sucrose gradient fractions for isolation of RNA for RT-qPCR analysis and isolation of protein for SDS-PAGE and immunoblot analysis. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Eric S Pringle
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.,Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
| | - Craig McCormick
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.,Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
| | - Zhenyu Cheng
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.,Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada
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88
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Dehecq M, Decourty L, Namane A, Proux C, Kanaan J, Le Hir H, Jacquier A, Saveanu C. Nonsense-mediated mRNA decay involves two distinct Upf1-bound complexes. EMBO J 2018; 37:embj.201899278. [PMID: 30275269 DOI: 10.15252/embj.201899278] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 08/10/2018] [Accepted: 08/22/2018] [Indexed: 11/09/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a translation-dependent RNA degradation pathway involved in many cellular pathways and crucial for telomere maintenance and embryo development. Core NMD factors Upf1, Upf2 and Upf3 are conserved from yeast to mammals, but a universal NMD model is lacking. We used affinity purification coupled with mass spectrometry and an improved data analysis protocol to characterize the composition and dynamics of yeast NMD complexes in yeast (112 experiments). Unexpectedly, we identified two distinct complexes associated with Upf1: Upf1-23 (Upf1, Upf2, Upf3) and Upf1-decapping Upf1-decapping contained the mRNA decapping enzyme, together with Nmd4 and Ebs1, two proteins that globally affected NMD and were critical for RNA degradation mediated by the Upf1 C-terminal helicase region. The fact that Nmd4 association with RNA was partially dependent on Upf1-23 components and the similarity between Nmd4/Ebs1 and mammalian Smg5-7 proteins suggest that NMD operates through conserved, successive Upf1-23 and Upf1-decapping complexes. This model can be extended to accommodate steps that are missing in yeast, to serve for further mechanistic studies of NMD in eukaryotes.
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Affiliation(s)
- Marine Dehecq
- Génétique des Interactions Macromoléculaires, Genomes and Genetics Department, Institut Pasteur, Paris, France.,Université Pierre et Marie Curie, Paris, France
| | - Laurence Decourty
- Génétique des Interactions Macromoléculaires, Genomes and Genetics Department, Institut Pasteur, Paris, France
| | - Abdelkader Namane
- Génétique des Interactions Macromoléculaires, Genomes and Genetics Department, Institut Pasteur, Paris, France
| | - Caroline Proux
- Transcriptome and Epigenome, CITECH, Institut Pasteur, Paris, France
| | - Joanne Kanaan
- Expression des ARN Messagers Eucaryotes, Biology Department, CNRS UMR8197, Inserm U1024, Institut de Biologie de l'Ecole Normale Supérieure, Paris, France
| | - Hervé Le Hir
- Expression des ARN Messagers Eucaryotes, Biology Department, CNRS UMR8197, Inserm U1024, Institut de Biologie de l'Ecole Normale Supérieure, Paris, France
| | - Alain Jacquier
- Génétique des Interactions Macromoléculaires, Genomes and Genetics Department, Institut Pasteur, Paris, France
| | - Cosmin Saveanu
- Génétique des Interactions Macromoléculaires, Genomes and Genetics Department, Institut Pasteur, Paris, France
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89
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Ji Z. RibORF: Identifying Genome-Wide Translated Open Reading Frames Using Ribosome Profiling. CURRENT PROTOCOLS IN MOLECULAR BIOLOGY 2018; 124:e67. [PMID: 30178897 PMCID: PMC6168376 DOI: 10.1002/cpmb.67] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ribosome profiling identifies RNA fragments associated with translating ribosomes. The technology provides an opportunity to examine genome-wide translation events at single-nucleotide resolution and in an unbiased manner. Here I present a computational pipeline named RibORF to systematically identify translated open reading frames (ORFs), based on read distribution features representing active translation, including 3-nt periodicity and uniformness across codons. Analyses using the computational tool revealed pervasive translation in putative 'noncoding' regions, such as lncRNAs, pseudogenes, and 5'UTRs. The computational tool is useful for studying functional roles of non-canonical translation events in various biological processes. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Zhe Ji
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL 60208, USA
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90
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Imami K, Milek M, Bogdanow B, Yasuda T, Kastelic N, Zauber H, Ishihama Y, Landthaler M, Selbach M. Phosphorylation of the Ribosomal Protein RPL12/uL11 Affects Translation during Mitosis. Mol Cell 2018; 72:84-98.e9. [PMID: 30220558 DOI: 10.1016/j.molcel.2018.08.019] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 06/09/2018] [Accepted: 08/10/2018] [Indexed: 12/22/2022]
Abstract
Emerging evidence indicates that heterogeneity in ribosome composition can give rise to specialized functions. Until now, research mainly focused on differences in core ribosomal proteins and associated factors. The effect of posttranslational modifications has not been studied systematically. Analyzing ribosome heterogeneity is challenging because individual proteins can be part of different subcomplexes (40S, 60S, 80S, and polysomes). Here we develop polysome proteome profiling to obtain unbiased proteomic maps across ribosomal subcomplexes. Our method combines extensive fractionation by sucrose gradient centrifugation with quantitative mass spectrometry. The high resolution of the profiles allows us to assign proteins to specific subcomplexes. Phosphoproteomics on the fractions reveals that phosphorylation of serine 38 in RPL12/uL11, a known mitotic CDK1 substrate, is strongly depleted in polysomes. Follow-up experiments confirm that RPL12/uL11 phosphorylation regulates the translation of specific subsets of mRNAs during mitosis. Together, our results show that posttranslational modification of ribosomal proteins can regulate translation.
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Affiliation(s)
- Koshi Imami
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany; Department of Molecular and Cellular BioAnalysis, Kyoto University, 606-8501 Kyoto, Japan.
| | - Miha Milek
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany
| | - Boris Bogdanow
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany
| | - Tomoharu Yasuda
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany
| | - Nicolai Kastelic
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany
| | - Henrik Zauber
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany
| | - Yasushi Ishihama
- Department of Molecular and Cellular BioAnalysis, Kyoto University, 606-8501 Kyoto, Japan
| | - Markus Landthaler
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany; IRI Life Sciences, Institute für Biologie, Humboldt Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany
| | - Matthias Selbach
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Str. 10, 13092 Berlin, Germany; Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
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91
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Wang YJ, Vaidyanathan PP, Rojas-Duran MF, Udeshi ND, Bartoli KM, Carr SA, Gilbert WV. Lso2 is a conserved ribosome-bound protein required for translational recovery in yeast. PLoS Biol 2018; 16:e2005903. [PMID: 30208026 PMCID: PMC6135351 DOI: 10.1371/journal.pbio.2005903] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 08/09/2018] [Indexed: 02/05/2023] Open
Abstract
Ribosome-binding proteins function broadly in protein synthesis, gene regulation, and cellular homeostasis, but the complete complement of functional ribosome-bound proteins remains unknown. Using quantitative mass spectrometry, we identified late-annotated short open reading frame 2 (Lso2) as a ribosome-associated protein that is broadly conserved in eukaryotes. Genome-wide crosslinking and immunoprecipitation of Lso2 and its human ortholog coiled-coil domain containing 124 (CCDC124) recovered 25S ribosomal RNA in a region near the A site that overlaps the GTPase activation center. Consistent with this location, Lso2 also crosslinked to most tRNAs. Ribosome profiling of yeast lacking LSO2 (lso2Δ) revealed global translation defects during recovery from stationary phase with translation of most genes reduced more than 4-fold. Ribosomes accumulated at start codons, were depleted from stop codons, and showed codon-specific changes in occupancy in lso2Δ. These defects, and the conservation of the specific ribosome-binding activity of Lso2/CCDC124, indicate broadly important functions in translation and physiology. Translation, or the production of protein from messenger RNA (mRNA), is catalyzed by a universally conserved macromolecular machine known as the ribosome. Ribosome-binding factors are also required for all substeps of translation, from initial recruitment of mRNA to peptide chain elongation to release of the mature polypeptide. However, many ribosome interactors have been identified whose effects on translation and physiology are unknown. Here, we show that the uncharacterized yeast protein late-annotated short open reading frame 2 (Lso2) crosslinks to a region of the ribosome that underlies accurate progression through all substeps of translation, the GTPase activation center. This specific binding activity is conserved in the human ortholog of Lso2, coiled-coil domain containing 124 (CCDC124). Null mutants of lso2 also show severe translation defects during recovery from extended starvation, including failure to initiate on most mRNAs and a general block to peptide chain elongation. We propose that these defects could arise from a function for Lso2 in modulating the activity or integrity of the ribosome GTPase activation center during challenging growth regimes.
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Affiliation(s)
- Yinuo J. Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | | | - Maria F. Rojas-Duran
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Namrata D. Udeshi
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Kristen M. Bartoli
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Steven A. Carr
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Wendy V. Gilbert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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92
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Yoshikawa H, Larance M, Harney DJ, Sundaramoorthy R, Ly T, Owen-Hughes T, Lamond AI. Efficient analysis of mammalian polysomes in cells and tissues using Ribo Mega-SEC. eLife 2018; 7:36530. [PMID: 30095066 PMCID: PMC6086667 DOI: 10.7554/elife.36530] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/28/2018] [Indexed: 12/14/2022] Open
Abstract
We describe Ribo Mega-SEC, a powerful approach for the separation and biochemical analysis of mammalian polysomes and ribosomal subunits using Size Exclusion Chromatography and uHPLC. Using extracts from either cells, or tissues, polysomes can be separated within 15 min from sample injection to fraction collection. Ribo Mega-SEC shows translating ribosomes exist predominantly in polysome complexes in human cell lines and mouse liver tissue. Changes in polysomes are easily quantified between treatments, such as the cellular response to amino acid starvation. Ribo Mega-SEC is shown to provide an efficient, convenient and highly reproducible method for studying functional translation complexes. We show that Ribo Mega-SEC is readily combined with high-throughput MS-based proteomics to characterize proteins associated with polysomes and ribosomal subunits. It also facilitates isolation of complexes for electron microscopy and structural studies.
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Affiliation(s)
- Harunori Yoshikawa
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mark Larance
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Dylan J Harney
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | | | - Tony Ly
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Angus I Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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93
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Identification of a 57S translation complex containing closed-loop factors and the 60S ribosome subunit. Sci Rep 2018; 8:11468. [PMID: 30065356 PMCID: PMC6068138 DOI: 10.1038/s41598-018-29832-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 07/19/2018] [Indexed: 01/14/2023] Open
Abstract
In eukaryotic translation the 60S ribosome subunit has not been proposed to interact with mRNA or closed-loop factors eIF4E, eIF4G, and PAB1. Using analytical ultracentrifugation with fluorescent detection system, we have identified a 57S translation complex that contains the 60S ribosome, mRNA, and the closed-loop factors. Previously published data by others also indicate the presence of a 50S-60S translation complex containing these same components. We have found that the abundance of this complex increased upon translational cessation, implying formation after ribosomal dissociation. Stoichiometric analyses of the abundances of the closed-loop components in the 57S complex indicate this complex is most similar to polysomal and monosomal translation complexes at the end of translation rather than at the beginning or middle of translation. In contrast, a 39S complex containing the 40S ribosome bound to mRNA and closed-loop factors was also identified with stoichiometries most similar to polysomal complexes engaged in translation, suggesting that the 39S complex is the previously studied 48S translation initiation complex. These results indicate that the 60S ribosome can associate with the closed-loop mRNA structure and plays a previously undetected role in the translation process.
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94
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Freimer JW, Hu TJ, Blelloch R. Decoupling the impact of microRNAs on translational repression versus RNA degradation in embryonic stem cells. eLife 2018; 7:38014. [PMID: 30044225 PMCID: PMC6086665 DOI: 10.7554/elife.38014] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/24/2018] [Indexed: 01/29/2023] Open
Abstract
Translation and mRNA degradation are intimately connected, yet the mechanisms that link them are not fully understood. Here, we studied these mechanisms in embryonic stem cells (ESCs). Transcripts showed a wide range of stabilities, which correlated with their relative translation levels and that did not change during early ESC differentiation. The protein DHH1 links translation to mRNA stability in yeast; however, loss of the mammalian homolog, DDX6, in ESCs did not disrupt the correlation across transcripts. Instead, the loss of DDX6 led to upregulated translation of microRNA targets, without concurrent changes in mRNA stability. The Ddx6 knockout cells were phenotypically and molecularly similar to cells lacking all microRNAs (Dgcr8 knockout ESCs). These data show that the loss of DDX6 can separate the two canonical functions of microRNAs: translational repression and transcript destabilization. Furthermore, these data uncover a central role for translational repression independent of transcript destabilization in defining the downstream consequences of microRNA loss.
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Affiliation(s)
- Jacob W Freimer
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, University of California, San Francisco, San Francisco, United States.,Department of Urology, University of California, San Francisco, San Francisco, United States
| | - T J Hu
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, University of California, San Francisco, San Francisco, United States.,Department of Urology, University of California, San Francisco, San Francisco, United States
| | - Robert Blelloch
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, University of California, San Francisco, San Francisco, United States.,Department of Urology, University of California, San Francisco, San Francisco, United States
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95
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Hutt DM, Loguercio S, Roth DM, Su AI, Balch WE. Correcting the F508del-CFTR variant by modulating eukaryotic translation initiation factor 3-mediated translation initiation. J Biol Chem 2018; 293:13477-13495. [PMID: 30006345 DOI: 10.1074/jbc.ra118.003192] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/05/2018] [Indexed: 12/31/2022] Open
Abstract
Inherited and somatic rare diseases result from >200,000 genetic variants leading to loss- or gain-of-toxic function, often caused by protein misfolding. Many of these misfolded variants fail to properly interact with other proteins. Understanding the link between factors mediating the transcription, translation, and protein folding of these disease-associated variants remains a major challenge in cell biology. Herein, we utilized the cystic fibrosis transmembrane conductance regulator (CFTR) protein as a model and performed a proteomics-based high-throughput screen (HTS) to identify pathways and components affecting the folding and function of the most common cystic fibrosis-associated mutation, the F508del variant of CFTR. Using a shortest-path algorithm we developed, we mapped HTS hits to the CFTR interactome to provide functional context to the targets and identified the eukaryotic translation initiation factor 3a (eIF3a) as a central hub for the biogenesis of CFTR. Of note, siRNA-mediated silencing of eIF3a reduced the polysome-to-monosome ratio in F508del-expressing cells, which, in turn, decreased the translation of CFTR variants, leading to increased CFTR stability, trafficking, and function at the cell surface. This finding suggested that eIF3a is involved in mediating the impact of genetic variations in CFTR on the folding of this protein. We posit that the number of ribosomes on a CFTR mRNA transcript is inversely correlated with the stability of the translated polypeptide. Polysome-based translation challenges the capacity of the proteostasis environment to balance message fidelity with protein folding, leading to disease. We suggest that this deficit can be corrected through control of translation initiation.
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Affiliation(s)
| | | | | | - Andrew I Su
- Integrative Structural and Computational Biology and
| | - William E Balch
- From the Departments of Molecular Medicine and .,the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037
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96
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Specialized ribosomes and the control of translation. Biochem Soc Trans 2018; 46:855-869. [PMID: 29986937 DOI: 10.1042/bst20160426] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 05/21/2018] [Accepted: 05/24/2018] [Indexed: 11/17/2022]
Abstract
The control of translation is increasingly recognized as a major factor in determining protein levels in the cell. The ribosome - the cellular machine that mediates protein synthesis - is typically seen as a key, but invariant, player in this process. This is because translational control is thought to be mediated by other auxiliary factors while ribosome recruitment is seen as the end-point of regulation. However, recent developments have made it clear that heterogeneous ribosome types can exist in different tissues, and more importantly, that these ribosomes can preferentially translate different subsets of mRNAs. In so doing, heterogeneous ribosomes could be key regulatory players in differentiation and development. Here, we examine current evidence for the existence of different ribosome types and how they might arise. In particular, we will take a close look at the mechanisms through which these ribosomes might mediate selective mRNA translation. We also summarize recently developed techniques/approaches that will aid in our understanding of the functions of such specialized ribosomes.
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The helicase Ded1p controls use of near-cognate translation initiation codons in 5' UTRs. Nature 2018; 559:130-134. [PMID: 29950728 PMCID: PMC6226265 DOI: 10.1038/s41586-018-0258-0] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/08/2018] [Indexed: 12/21/2022]
Abstract
The conserved and essential DEAD-box RNA helicase Ded1p from yeast and its mammalian orthologue DDX3 are critical for the initiation of translation1. Mutations in DDX3 are linked to tumorigenesis2-4 and intellectual disability5, and the enzyme is targeted by a range of viruses6. How Ded1p and its orthologues engage RNAs during the initiation of translation is unknown. Here we show, by integrating transcriptome-wide analyses of translation, RNA structure and Ded1p-RNA binding, that the effects of Ded1p on the initiation of translation are connected to near-cognate initiation codons in 5' untranslated regions. Ded1p associates with the translation pre-initiation complex at the mRNA entry channel and repressing the activity of Ded1p leads to the accumulation of RNA structure in 5' untranslated regions, the initiation of translation from near-cognate start codons immediately upstream of these structures and decreased protein synthesis from the corresponding main open reading frames. The data reveal a program for the regulation of translation that links Ded1p, the activation of near-cognate start codons and mRNA structure. This program has a role in meiosis, in which a marked decrease in the levels of Ded1p is accompanied by the activation of the alternative translation initiation sites that are seen when the activity of Ded1p is repressed. Our observations indicate that Ded1p affects translation initiation by controlling the use of near-cognate initiation codons that are proximal to mRNA structure in 5' untranslated regions.
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98
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Blair JD, Hockemeyer D, Doudna JA, Bateup HS, Floor SN. Widespread Translational Remodeling during Human Neuronal Differentiation. Cell Rep 2018; 21:2005-2016. [PMID: 29141229 DOI: 10.1016/j.celrep.2017.10.095] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/13/2017] [Accepted: 10/24/2017] [Indexed: 01/04/2023] Open
Abstract
Faithful cellular differentiation requires temporally precise activation of gene expression programs, which are coordinated at the transcriptional and translational levels. Neurons express the most complex set of mRNAs of any human tissue, but translational changes during neuronal differentiation remain incompletely understood. Here, we induced forebrain neuronal differentiation of human embryonic stem cells (hESCs) and measured genome-wide RNA and translation levels with transcript-isoform resolution. We found that thousands of genes change translation status during differentiation without a corresponding change in RNA level. Specifically, we identified mTOR signaling as a key driver for elevated translation of translation-related genes in hESCs. In contrast, translational repression in active neurons is mediated by regulatory sequences in 3' UTRs. Together, our findings identify extensive translational control changes during human neuronal differentiation and a crucial role of 3' UTRs in driving cell-type-specific translation.
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Affiliation(s)
- John D Blair
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Molecular Biophysics and Imaging Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Stephen N Floor
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA.
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99
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Martinez-Nunez RT, Rupani H, Platé M, Niranjan M, Chambers RC, Howarth PH, Sanchez-Elsner T. Genome-Wide Posttranscriptional Dysregulation by MicroRNAs in Human Asthma as Revealed by Frac-seq. THE JOURNAL OF IMMUNOLOGY 2018; 201:251-263. [PMID: 29769273 DOI: 10.4049/jimmunol.1701798] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 04/17/2018] [Indexed: 12/07/2022]
Abstract
MicroRNAs are small noncoding RNAs that inhibit gene expression posttranscriptionally, implicated in virtually all biological processes. Although the effect of individual microRNAs is generally studied, the genome-wide role of multiple microRNAs is less investigated. We assessed paired genome-wide expression of microRNAs with total (cytoplasmic) and translational (polyribosome-bound) mRNA levels employing subcellular fractionation and RNA sequencing (Frac-seq) in human primary bronchoepithelium from healthy controls and severe asthmatics. Severe asthma is a chronic inflammatory disease of the airways characterized by poor response to therapy. We found genes (i.e., isoforms of a gene) and mRNA isoforms differentially expressed in asthma, with novel inflammatory and structural pathophysiological mechanisms related to bronchoepithelium disclosed solely by polyribosome-bound mRNAs (e.g., IL1A and LTB genes or ITGA6 and ITGA2 alternatively spliced isoforms). Gene expression (i.e., isoforms of a gene) and mRNA expression analysis revealed different molecular candidates and biological pathways, with differentially expressed polyribosome-bound and total mRNAs also showing little overlap. We reveal a hub of six dysregulated microRNAs accounting for ∼90% of all microRNA targeting, displaying preference for polyribosome-bound mRNAs. Transfection of this hub in bronchial epithelial cells from healthy donors mimicked asthma characteristics. Our work demonstrates extensive posttranscriptional gene dysregulation in human asthma, in which microRNAs play a central role, illustrating the feasibility and importance of assessing posttranscriptional gene expression when investigating human disease.
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Affiliation(s)
- Rocio T Martinez-Nunez
- School of Immunology and Microbial Sciences, Medical Research Council and Asthma UK Centre in Allergic Mechanisms of Asthma, King's College London, London SE19RT, United Kingdom; .,Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Hitasha Rupani
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom.,Southampton National Institute for Health Research Respiratory Biomedical Research Unit, Southampton Centre for Biomedical Research, University Hospital Southampton National Health Service Foundation Trust, Southampton SO16 6YD, United Kingdom
| | - Manuela Platé
- Centre for Inflammation and Tissue Repair, Department of Respiratory Medicine, Rayne Institute, University College London, London WC1E 6JF, United Kingdom; and
| | - Mahesan Niranjan
- School of Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Rachel C Chambers
- Centre for Inflammation and Tissue Repair, Department of Respiratory Medicine, Rayne Institute, University College London, London WC1E 6JF, United Kingdom; and
| | - Peter H Howarth
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom.,Southampton National Institute for Health Research Respiratory Biomedical Research Unit, Southampton Centre for Biomedical Research, University Hospital Southampton National Health Service Foundation Trust, Southampton SO16 6YD, United Kingdom
| | - Tilman Sanchez-Elsner
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
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100
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Eastman G, Smircich P, Sotelo-Silveira JR. Following Ribosome Footprints to Understand Translation at a Genome Wide Level. Comput Struct Biotechnol J 2018; 16:167-176. [PMID: 30069283 PMCID: PMC6066590 DOI: 10.1016/j.csbj.2018.04.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 04/06/2018] [Accepted: 04/10/2018] [Indexed: 12/11/2022] Open
Abstract
Protein translation is a key step in gene expression. The development of Ribosome Profiling has allowed the global analysis of this process at sub-codon resolution. In the last years the method has been applied to several models ranging from bacteria to mammalian cells yielding a surprising amount of insight on the mechanism and the regulation of translation. In this review we describe the key aspects of the experimental protocol and comment on the main conclusions raised in different models.
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Affiliation(s)
- Guillermo Eastman
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Av. Italia 3318, Montevideo, CP 11600, Uruguay
| | - Pablo Smircich
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Av. Italia 3318, Montevideo, CP 11600, Uruguay
- Laboratory of Molecular Interactions, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, CP 11400, Uruguay
| | - José R. Sotelo-Silveira
- Department of Genomics, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Av. Italia 3318, Montevideo, CP 11600, Uruguay
- Department of Cell and Molecular Biology, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, CP 11400, Uruguay
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