1
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Lee H, Ozbulak U, Park H, Depuydt S, De Neve W, Vankerschaver J. Assessing the reliability of point mutation as data augmentation for deep learning with genomic data. BMC Bioinformatics 2024; 25:170. [PMID: 38689247 PMCID: PMC11059627 DOI: 10.1186/s12859-024-05787-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 04/15/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Deep neural networks (DNNs) have the potential to revolutionize our understanding and treatment of genetic diseases. An inherent limitation of deep neural networks, however, is their high demand for data during training. To overcome this challenge, other fields, such as computer vision, use various data augmentation techniques to artificially increase the available training data for DNNs. Unfortunately, most data augmentation techniques used in other domains do not transfer well to genomic data. RESULTS Most genomic data possesses peculiar properties and data augmentations may significantly alter the intrinsic properties of the data. In this work, we propose a novel data augmentation technique for genomic data inspired by biology: point mutations. By employing point mutations as substitutes for codons, we demonstrate that our newly proposed data augmentation technique enhances the performance of DNNs across various genomic tasks that involve coding regions, such as translation initiation and splice site detection. CONCLUSION Silent and missense mutations are found to positively influence effectiveness, while nonsense mutations and random mutations in non-coding regions generally lead to degradation. Overall, point mutation-based augmentations in genomic datasets present valuable opportunities for improving the accuracy and reliability of predictive models for DNA sequences.
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Affiliation(s)
| | - Utku Ozbulak
- Center for Biosystems and Biotech Data Science, Ghent University Global Campus, Incheon, South Korea
| | - Homin Park
- Center for Biosystems and Biotech Data Science, Ghent University Global Campus, Incheon, South Korea
- IDLab, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Stephen Depuydt
- Erasmus Brussels University of Applied Sciences and Arts, Brussels, Belgium
| | - Wesley De Neve
- Center for Biosystems and Biotech Data Science, Ghent University Global Campus, Incheon, South Korea
- IDLab, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Joris Vankerschaver
- Center for Biosystems and Biotech Data Science, Ghent University Global Campus, Incheon, South Korea.
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent, Belgium.
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2
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Kohl MP, Chane-Woon-Ming B, Bahena-Ceron R, Jaramillo-Ponce J, Antoine L, Herrgott L, Romby P, Marzi S. Ribosome Profiling Methods Adapted to the Study of RNA-Dependent Translation Regulation in Staphylococcus aureus. Methods Mol Biol 2024; 2741:73-100. [PMID: 38217649 DOI: 10.1007/978-1-0716-3565-0_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
Noncoding RNAs, including regulatory RNAs (sRNAs), are instrumental in regulating gene expression in pathogenic bacteria, allowing them to adapt to various stresses encountered in their host environments. Staphylococcus aureus is a well-studied model for RNA-mediated regulation of virulence and pathogenicity, with sRNAs playing significant roles in shaping S. aureus interactions with human and animal hosts. By modulating the translation and/or stability of target mRNAs, sRNAs regulate the synthesis of virulence factors and regulatory proteins required for pathogenesis. Moreover, perturbation of the levels of RNA modifications in two other classes of noncoding RNAs, rRNAs, and tRNAs, has been proposed to contribute to stress adaptation. However, the study of how these various factors affect translation regulation has often been restricted to specific genes, using in vivo reporters and/or in vitro translation systems. Genome-wide sequencing approaches offer novel perspectives for studying RNA-dependent regulation. In particular, ribosome profiling methods provide a powerful resource for characterizing the overall landscape of translational regulation, contributing to a better understanding of S. aureus physiopathology. Here, we describe protocols that we have adapted to perform ribosome profiling in S. aureus.
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Affiliation(s)
- Maximilian P Kohl
- Architecture et Réactivité de l'ARN, CNRS 9002, Université de Strasbourg, Strasbourg, France
| | | | - Roberto Bahena-Ceron
- Architecture et Réactivité de l'ARN, CNRS 9002, Université de Strasbourg, Strasbourg, France
| | - Jose Jaramillo-Ponce
- Architecture et Réactivité de l'ARN, CNRS 9002, Université de Strasbourg, Strasbourg, France
| | - Laura Antoine
- Architecture et Réactivité de l'ARN, CNRS 9002, Université de Strasbourg, Strasbourg, France
| | - Lucas Herrgott
- Architecture et Réactivité de l'ARN, CNRS 9002, Université de Strasbourg, Strasbourg, France
| | - Pascale Romby
- Architecture et Réactivité de l'ARN, CNRS 9002, Université de Strasbourg, Strasbourg, France
| | - Stefano Marzi
- Architecture et Réactivité de l'ARN, CNRS 9002, Université de Strasbourg, Strasbourg, France.
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3
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Mondal S, Rousseau S, Talenton V, Thiam CAB, Aznauryan M, Mackereth CD. Backbone resonance assignments of the C-terminal region of human translation initiation factor eIF4B. Biomol NMR Assign 2023; 17:199-203. [PMID: 37368134 DOI: 10.1007/s12104-023-10141-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/21/2023] [Indexed: 06/28/2023]
Abstract
Translation initiation in eukaryotes is an early step in protein synthesis, requiring multiple factors to recruit the ribosomal small subunit to the mRNA 5' untranslated region. One such protein factor is the eukaryotic translation initiation factor 4B (eIF4B), which increases the activity of the eIF4A RNA helicase, and is linked to cell survival and proliferation. We report here the protein backbone chemical shift assignments corresponding to the C-terminal 279 residues of human eIF4B. Analysis of the chemical shift values identifies one main helical region in the area previously linked to RNA binding, and confirms that the overall C-terminal region is intrinsically disordered.
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Affiliation(s)
- Somnath Mondal
- Univ. Bordeaux, Inserm U1212, CNRS UMR 5320, Institut Européen de Chimie et Biologie, Pessac, F-33600, France
| | - Sabrina Rousseau
- Univ. Bordeaux, Inserm U1212, CNRS UMR 5320, Institut Européen de Chimie et Biologie, Pessac, F-33600, France
| | - Vincent Talenton
- Univ. Bordeaux, Inserm U1212, CNRS UMR 5320, Institut Européen de Chimie et Biologie, Pessac, F-33600, France
| | - Cheikh Ahmadou Bamba Thiam
- Univ. Bordeaux, Inserm U1212, CNRS UMR 5320, Institut Européen de Chimie et Biologie, Pessac, F-33600, France
| | - Mikayel Aznauryan
- Univ. Bordeaux, Inserm U1212, CNRS UMR 5320, Institut Européen de Chimie et Biologie, Pessac, F-33600, France.
| | - Cameron D Mackereth
- Univ. Bordeaux, Inserm U1212, CNRS UMR 5320, Institut Européen de Chimie et Biologie, Pessac, F-33600, France.
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4
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Yonke JA, Seymour KA, El-Kadi SW. Branched-chain amino acid supplementation does not enhance lean tissue accretion in low birth weight neonatal pigs, despite lower Sestrin2 expression in skeletal muscle. Amino Acids 2023; 55:1389-1404. [PMID: 37743429 DOI: 10.1007/s00726-023-03319-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 08/18/2023] [Indexed: 09/26/2023]
Abstract
Postnatal muscle growth is impaired in low birth weight (L) neonatal pigs. Leucine supplementation has been established as a dietary intervention to enhance muscle growth in growing animals. The aim of this study was to investigate the efficacy of supplementing L neonatal pig formulas with branched-chain amino acids (B) to enhance the rate of protein accretion. Twenty-four 3-day old pigs were divided into two groups low (L) and normal birth weight (N) based on weight at birth. Pigs were assigned to a control (C) or 1% branched-chain amino acids (B) formulas, and fed at 250 mL·kg body weight -1·d-1 for 28 d. Body weight of pigs in the L group was less than those in the N group (P < 0.01). However, fractional body weight was greater for L pigs compared with their N siblings from day 24 to 28 of feeding regardless of formula (P < 0.01). In addition, feed efficiency (P < 0.0001) and efficiently of protein accretion (P < 0.0001) were greater for L than N pigs regardless of supplementation. Pigs fed the B formula had greater plasma leucine, isoleucine, and valine concentrations compared with those fed the C formula (P < 0.05). Longissimus dorsi Sestrin2 protein expression was less for pigs in the L group compared with those in the N group (P < 0.01), but did not result in a corresponding increase in translation initiation signaling. Longissimus dorsi mRNA expression of BCAT2 was less for LB pigs compared with those in the LC group, and was intermediate for NC and NB pigs (P < 0.05). Hepatic mRNA expression of BCKDHA was greater for pigs in the L compared with those in the N groups (P < 0.05). However, plasma branched-chain keto-acid concentration was reduced for C compared with those in the B group (P < 0.05). These data suggest that branched-chain amino acid supplementation does not improve lean tissue accretion of low and normal birth weight pigs, despite a reduction in Sestrin2 expression in skeletal muscle of low birth weight pigs. The modest improvement in fractional growth rate of low birth weight pigs compared with their normal birth weight siblings was likely due to a more efficient dietary protein utilization.
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Affiliation(s)
- Joseph A Yonke
- School of Animal Sciences, Virginia Tech, 175 West Campus Drive, Blacksburg, VA, 24061, USA
| | - Kacie A Seymour
- School of Animal Sciences, Virginia Tech, 175 West Campus Drive, Blacksburg, VA, 24061, USA
| | - Samer W El-Kadi
- School of Animal Sciences, Virginia Tech, 175 West Campus Drive, Blacksburg, VA, 24061, USA.
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5
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Wilkins KC, Schroeder T, Gu S, Revalde JL, Floor SN. Determinants of DDX3X sensitivity uncovered using a helicase activity in translation reporter. bioRxiv 2023:2023.09.14.557805. [PMID: 37745530 PMCID: PMC10515938 DOI: 10.1101/2023.09.14.557805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
DDX3X regulates the translation of a subset of human transcripts containing complex 5' untranslated regions (5' UTRs). In this study we developed the helicase activity reporter for translation (HART) which uses DDX3X-sensitive 5' UTRs to measure DDX3X mediated translational activity in cells. To dissect the structural underpinnings of DDX3X dependent translation, we first used SHAPE-MaP to determine the secondary structures present in DDX3X-sensitive 5' UTRs and then employed HART to investigate how their perturbation impacts DDX3X-sensitivity. Additionally, we identified residues 38-44 as potential mediators of DDX3X's interaction with the translational machinery. HART revealed that both DDX3X's association with the ribosome complex as well as its helicase activity are required for its function in promoting the translation of DDX3X-sensitive 5' UTRs. These findings suggest DDX3X plays a crucial role regulating translation through its interaction with the translational machinery during ribosome scanning, and establish the HART reporter as a robust, lentivirally encoded measurement of DDX3X-dependent translation in cells.
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Affiliation(s)
- Kevin C. Wilkins
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, 94143, USA
- Graduate Division, University of California, San Francisco, San Francisco, CA, United States
| | - Till Schroeder
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, 94143, USA
- Julius-Maximilians-University of Würzburg, Würzburg, 97070, Germany
| | - Sohyun Gu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, 94143, USA
| | - Jezrael L. Revalde
- Department of Pharmaceutical Chemistry, University of California, 600 16th Street, San Francisco, California 94143, United States
| | - Stephen N. Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, 94143, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California, 94143, USA
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6
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Wang S, Sun S. Translation dysregulation in neurodegenerative diseases: a focus on ALS. Mol Neurodegener 2023; 18:58. [PMID: 37626421 PMCID: PMC10464328 DOI: 10.1186/s13024-023-00642-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023] Open
Abstract
RNA translation is tightly controlled in eukaryotic cells to regulate gene expression and maintain proteome homeostasis. RNA binding proteins, translation factors, and cell signaling pathways all modulate the translation process. Defective translation is involved in multiple neurological diseases including amyotrophic lateral sclerosis (ALS). ALS is a progressive neurodegenerative disorder and poses a major public health challenge worldwide. Over the past few years, tremendous advances have been made in the understanding of the genetics and pathogenesis of ALS. Dysfunction of RNA metabolisms, including RNA translation, has been closely associated with ALS. Here, we first introduce the general mechanisms of translational regulation under physiological and stress conditions and review well-known examples of translation defects in neurodegenerative diseases. We then focus on ALS-linked genes and discuss the recent progress on how translation is affected by various mutant genes and the repeat expansion-mediated non-canonical translation in ALS.
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Affiliation(s)
- Shaopeng Wang
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Shuying Sun
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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7
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Cheng J, Li G, Wang W, Stovall DB, Sui G, Li D. Circular RNAs with protein-coding ability in oncogenesis. Biochim Biophys Acta Rev Cancer 2023; 1878:188909. [PMID: 37172651 DOI: 10.1016/j.bbcan.2023.188909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 05/08/2023] [Accepted: 05/08/2023] [Indexed: 05/15/2023]
Abstract
As ubiquitously expressed transcripts in eukaryotes, circular RNAs (circRNAs) are covalently closed and lack a 5'-cap and 3'-polyadenylation (poly (A)) tail. Initially, circRNAs were considered non-coding RNA (ncRNA), and their roles as sponging molecules to adsorb microRNAs have been extensively reported. However, in recent years, accumulating evidence has demonstrated that circRNAs could encode functional polypeptides through the initiation of translation mediated by internal ribosomal entry sites (IRESs) or N6-methyladenosine (m6A). In this review, we collectively discuss the biogenesis, cognate mRNA products, regulatory mechanisms, aberrant expression and biological phenotypes or clinical relevance of all currently reported, cancer-relevant protein-coding circRNAs. Overall, we provide a comprehensive overview of circRNA-encoded proteins and their physiological and pathological functions.
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Affiliation(s)
- Jiahui Cheng
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Guangyue Li
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Wenmeng Wang
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Daniel B Stovall
- College of Arts and Sciences, Winthrop University, Rock Hill, SC 29733, United States
| | - Guangchao Sui
- College of Life Science, Northeast Forestry University, Harbin 150040, China.
| | - Dangdang Li
- College of Life Science, Northeast Forestry University, Harbin 150040, China.
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8
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Abstract
A hexanucleotide repeat expansion in the C9ORF72 gene is the most common genetic alteration associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). These neurodegenerative diseases share genetic, clinical and pathological features. The mutation in C9ORF72 appears to drive pathogenesis through a combination of loss of C9ORF72 normal function and gain of toxic effects due to the repeat expansion, which result in aggregation prone expanded RNAs and dipeptide repeat (DPR) proteins. Studies in cellular and animal models indicate that the DPR proteins are the more toxic species. Thus, a large body of research has focused on identifying the cellular pathways most directly impacted by these toxic proteins, with the goal of characterizing disease pathogenesis and nominating potential targets for therapeutic development. The preventative block of the production of the toxic proteins before they can cause harm is a second strategy of intense focus. Despite the considerable amount of effort dedicated to this prophylactic approach, it is still unclear how the DPR proteins are synthesized from RNAs harboring repeat expansions. In this review, we summarize our current knowledge of the specific protein translation mechanisms shown to account for the synthesis of DPR proteins. We will then discuss how enhanced understanding of the composition of these toxic effectors could help in refining disease mechanisms, and paving the way to identify and design effective prophylactic therapies for C9ORF72 ALS-FTD.
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Affiliation(s)
- Heleen M Van't Spijker
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Sandra Almeida
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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9
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Dong HJ, Wang J, Zhang XZ, Li CC, Liu JF, Wang XJ. Proteomic screening identifies RPLp2 as a specific regulator for the translation of coronavirus. Int J Biol Macromol 2023; 230:123191. [PMID: 36632964 PMCID: PMC9827737 DOI: 10.1016/j.ijbiomac.2023.123191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023]
Abstract
Viral mRNA of coronavirus translates in an eIF4E-dependent manner, and the phosphorylation of eIF4E can modulate this process, but the role of p-eIF4E in coronavirus infection is not yet entirely evident. p-eIF4E favors the translation of selected mRNAs, specifically the mRNAs that encode proteins associated with cell proliferation, inflammation, the extracellular matrix, and tumor formation and metastasis. In the present work, two rounds of TMT relative quantitative proteomics were used to screen 77 cellular factors that are upregulated upon infection by coronavirus PEDV and are potentially susceptible to a high level of p-eIF4E. PEDV infection increased the translation level of ribosomal protein lateral stalk subunit RPLp2 (but not subunit RPLp0/1) in a p-eIF4E-dependent manner. The bicistronic dual-reporter assay and polysome profile showed that RPLp2 is essential for translating the viral mRNA of PEDV. RNA binding protein and immunoprecipitation assay showed that RPLp2 interacted with PEDV 5'UTR via association with eIF4E. Moreover, the cap pull-down assay showed that the viral nucleocapsid protein is recruited in m7GTP-precipitated complexes with the assistance of RPLp2. The heterogeneous ribosomes, which are different in composition, regulate the selective translation of specific mRNAs. Our study proves that viral mRNA and protein utilize translation factors and heterogeneous ribosomes for preferential translation initiation. This previously uncharacterized process may be involved in the selective translation of coronavirus.
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Affiliation(s)
- Hui-Jun Dong
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Jing Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Xiu-Zhong Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Cui-Cui Li
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Jian-Feng Liu
- College of Animal Science and Technol, China Agricultural University, Beijing 100193, China.
| | - Xiao-Jia Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
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10
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Takallou S, Puchacz N, Allard D, Said KB, Nokhbeh MR, Samanfar B, Golshani A. IRES-mediated translation in bacteria. Biochem Biophys Res Commun 2023; 641:110-115. [PMID: 36527744 DOI: 10.1016/j.bbrc.2022.12.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022]
Abstract
Despite the similarity in fundamental goals of translation initiation between different domains of life, it is one of the most phylogenetically diverse steps of the central dogma of molecular biology. In a classical view, the translation signals for prokaryotes and eukaryotes are distinct from each other. This idea was challenged by the finding that the Internal Ribosome Entry Site (IRES) belonging to Plautia stali intestine virus (PSIV) could bypass the domain-specific boundaries and effectively initiate translation in E. coli. This finding led us to investigate whether the ability of PSIV IRES to initiate translation in E. coli is specific to this IRES and also to study features that allow this viral IRES to mediate prokaryotic translation initiation. We observed that certain IRESs may also possess the ability to initiate E. coli translation. Our results also indicated that the structural integrity of the PSIV IRES in translation in prokaryotes does not appear to be as critical as it is in eukaryotes. We also demonstrated that two regions of the PSIV IRES with complementarity to 16S ribosomal RNA are important for the ability of this IRES to initiate translation in E. coli.
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Affiliation(s)
- Sarah Takallou
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada; Department of Biology, Carleton University, Ottawa, Ontario, Canada.
| | - Nathalie Puchacz
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada; Department of Biology, Carleton University, Ottawa, Ontario, Canada.
| | - Danielle Allard
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada; Department of Biology, Carleton University, Ottawa, Ontario, Canada.
| | - Kamaledin B Said
- Department of Pathology and Microbiology, College of Medicine, University of Hail, Saudi Arabia.
| | | | - Bahram Samanfar
- Department of Biology, Carleton University, Ottawa, Ontario, Canada; Agriculture and Agri-Food Canada, Ottawa Research and Development Centre (ORDC), Ottawa, Ontario, Canada.
| | - Ashkan Golshani
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada; Department of Biology, Carleton University, Ottawa, Ontario, Canada.
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11
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Remes C, Nguyen MD, Spahr H, Ng M, Fritsch C, Bhattacharya A, Li H, Cooperman B, Rorbach J. Assembly of the Mitochondrial Translation Initiation Complex. Methods Mol Biol 2023; 2661:217-232. [PMID: 37166640 DOI: 10.1007/978-1-0716-3171-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Mitochondria maintain their own translational machinery that is responsible for the synthesis of essential components of the oxidative phosphorylation system. The mammalian mitochondrial translation system differs significantly from its cytosolic and bacterial counterparts. Here, we describe detailed protocols for efficient in vitro reconstitution of the mammalian mitochondrial translation initiation complex, which can be further used for mechanistic analyses of different aspects of mitochondrial translation.
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Affiliation(s)
- Cristina Remes
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA.
| | - Minh Duc Nguyen
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solna, Sweden
| | - Henrik Spahr
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solna, Sweden
| | - Martin Ng
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Clark Fritsch
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Arpan Bhattacharya
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hong Li
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Barry Cooperman
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Joanna Rorbach
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solna, Sweden
- Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
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12
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Raneri M, Alvarez-Ruiz E, Mossakovska D, Briani F. Cell-Based Fluorescent Screen Amenable to HTS to Identify Inhibitors of Bacterial Translation Initiation. Methods Mol Biol 2023; 2601:303-312. [PMID: 36445591 DOI: 10.1007/978-1-0716-2855-3_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A strategy that can be applied to the research of new molecules with antibacterial activity is to look for inhibitors of essential bacterial processes within large collections of chemically heterogeneous compounds. The implementation of this approach requires the development of assays aimed at the identification of molecules interfering with specific cell pathways that can also be used in high-throughput analysis of large chemical libraries. Here, we describe a fluorescence-based whole-cell assay in Escherichia coli devised to find inhibitors of the translation initiation pathway. Translation is a complex and essential mechanism. It involves numerous sub-steps performed by factors that are in many cases sufficiently dissimilar in bacterial and eukaryotic cells to be targetable with domain-specific drugs. As a matter of fact, translation has been proven as one of the few bacterial mechanisms pharmacologically tractable with specific antibiotics. The assay described in this updated chapter is tailored to the identification of molecules affecting the first stage of translation initiation, which is the most dissimilar step in bacteria versus mammals. The effect of the compounds under analysis is measured in living cells, thus allowing evaluation of their in vivo performance as inhibitors of translation initiation. Compared with other assays for antibacterials, the major advantages of this screen are its simplicity, high mechanism specificity, and amenability to scaling up to high-throughput analyses.
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Affiliation(s)
- Matteo Raneri
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
- Sacco S.r.l., Cadorago, Italy
| | - Emilio Alvarez-Ruiz
- GlaxoSmithKline Platform Technologies and Science, Parque Tecnologico de Madrid, Madrid, Spain
| | - Danuta Mossakovska
- GlaxoSmithKline, Stevenage, Hertfordshire, UK
- Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy.
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13
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Li K, Kong J, Zhang S, Zhao T, Qian W. Distance-dependent inhibition of translation initiation by downstream out-of-frame AUGs is consistent with a Brownian ratchet process of ribosome scanning. Genome Biol 2022; 23:254. [PMID: 36510274 PMCID: PMC9743702 DOI: 10.1186/s13059-022-02829-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 12/01/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Eukaryotic ribosomes are widely presumed to scan mRNA for the AUG codon to initiate translation in a strictly 5'-3' movement (i.e., strictly unidirectional scanning model), so that ribosomes initiate translation exclusively at the 5' proximal AUG codon (i.e., the first-AUG rule). RESULTS We generate 13,437 yeast variants, each with an ATG triplet placed downstream (dATGs) of the annotated ATG (aATG) codon of a green fluorescent protein. We find that out-of-frame dATGs can inhibit translation at the aATG, but with diminishing strength over increasing distance between aATG and dATG, undetectable beyond ~17 nt. This phenomenon is best explained by a Brownian ratchet mechanism of ribosome scanning, in which the ribosome uses small-amplitude 5'-3' and 3'-5' oscillations with a net 5'-3' movement to scan the AUG codon, thereby leading to competition for translation initiation between aAUG and a proximal dAUG. This scanning model further predicts that the inhibitory effect induced by an out-of-frame upstream AUG triplet (uAUG) will diminish as uAUG approaches aAUG, which is indeed observed among the 15,586 uATG variants generated in this study. Computational simulations suggest that each triplet is scanned back and forth approximately ten times until the ribosome eventually migrates to downstream regions. Moreover, this scanning process could constrain the evolution of sequences downstream of the aATG to minimize proximal out-of-frame dATG triplets in yeast and humans. CONCLUSIONS Collectively, our findings uncover the basic process by which eukaryotic ribosomes scan for initiation codons, and how this process could shape eukaryotic genome evolution.
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Affiliation(s)
- Ke Li
- grid.418558.50000 0004 0596 2989State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101 China
| | - Jinhui Kong
- grid.418558.50000 0004 0596 2989State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Shuo Zhang
- grid.418558.50000 0004 0596 2989State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Tong Zhao
- grid.458488.d0000 0004 0627 1442Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Wenfeng Qian
- grid.418558.50000 0004 0596 2989State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
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14
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Shi JJ, Cao Y, Lang QH, Dong Y, Huang LY, Yang LJ, Li JJ, Zhang XX, Wang DY. The effect of the nucleotides immediately upstream of the AUG start codon on the efficiency of translation initiation in sperm cells. Plant Reprod 2022; 35:221-231. [PMID: 35674836 DOI: 10.1007/s00497-022-00442-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
It is widely known that an optimal nucleotide sequence context immediately upstream of the AUG start codon greatly improves the efficiency of translation initiation of mRNA in mammalian and plant somatic cells, which in turn increases protein levels. However, it is still unclear whether a similar regulatory mechanism is also present in highly differentiated cells. Here, we surveyed this issue in Arabidopsis thaliana sperm cells and found that the sequence context-mediated regulation of translation initiation in sperm cells is generally similar to that in somatic cells. A simple motif of four adenine nucleotides at positions - 1 to - 4 greatly improved the efficiency of translation initiation, and when the motif was present there, translation was even initiated at some non-AUG codons in sperm cells. However, unlike that in mammalian cells, a mainly effective nucleotide site to regulate the efficiency of translation initiation was not present at positions - 1 to - 4 in sperm cells. Meanwhile, different from somatic cells, sperm cells did not use eukaryotic translation initiation factor 1 to regulate the efficiency in a poor context consisting of the lowest frequency nucleotides. All these results contribute to our understanding of the cytoplasmic event of translation initiation in highly differentiated sperm cells.
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Affiliation(s)
- Jiao-Jiao Shi
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Yuan Cao
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Qiu-Hua Lang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Yao Dong
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Liu-Yuan Huang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Liu-Jie Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Jing-Jing Li
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Xue-Xin Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China
| | - Dan-Yang Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), College of Life Science, Northwest University, Xi'an, 710069, China.
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15
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Muñoz-Ayala A, Chimal-Vega B, García-González V. Translation initiation and its relationship with metabolic mechanisms in cancer development, progression and chemoresistance. Adv Protein Chem Struct Biol 2022; 132:111-141. [PMID: 36088073 DOI: 10.1016/bs.apcsb.2022.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Pathways that regulate protein homeostasis (proteostasis) in cells range from mRNA processing to protein degradation; perturbations in regulatory mechanisms of these pathways can lead to oncogenic cellular processes. Protein synthesis modulation failures are common phenomena in cancer cells, wherein specific conditions that promote the translation of protein factors promoting carcinogenesis are present. These specific conditions may be favored by metabolic lipid alterations like those found in metabolic syndrome and obesity. Protein translation modifications have been described in obesity, favoring the translation of protein targets that benefit lipid accumulation; a determining factor is the activity of the cap-binding eukaryotic translation initiation factor 4E (eIF4E), a crosstalk in protein translation and lipogenesis. Besides, alterations of protein translation initiation steps are critical participants for the development of both pathogenic conditions, cancer, and obesity. This chapter is focused on the regulation of recognition and processing of carcinogenic-mRNA and the connections among lipid metabolism and cell signaling pathways that promote oncogenesis, tumoral microenvironment generation and potentially the development of chemoresistance. We performed an in-depth analysis of events, such as those occurring in obesity and dyslipidemias, that may influence protein translation, driving the recognition of certain mRNAs and favoring cancer development and chemoresistance.
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Affiliation(s)
- Andrea Muñoz-Ayala
- Departamento de Bioquímica, Facultad de Medicina Mexicali, Universidad Autónoma de Baja California, Mexicali, México; Laboratorio Multidisciplinario de Estudios Metabólicos y Cáncer, Universidad Autónoma de Baja California, Mexicali, México
| | - Brenda Chimal-Vega
- Departamento de Bioquímica, Facultad de Medicina Mexicali, Universidad Autónoma de Baja California, Mexicali, México; Laboratorio Multidisciplinario de Estudios Metabólicos y Cáncer, Universidad Autónoma de Baja California, Mexicali, México
| | - Victor García-González
- Departamento de Bioquímica, Facultad de Medicina Mexicali, Universidad Autónoma de Baja California, Mexicali, México; Laboratorio Multidisciplinario de Estudios Metabólicos y Cáncer, Universidad Autónoma de Baja California, Mexicali, México.
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16
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Schaflinger E, Blatterer J, Khan AS, Kaufmann L, Auinger L, Tatrai B, Abbasi SW, Zeeshan Ali M, Abbasi AA, Al Kaissi A, Petek E, Wagner K, Ahmad Khan M, Windpassinger C. An exceptional biallelic N-terminal frame shift mutation in ZMPSTE24 leads to non-lethal progeria due to possible utilization of a downstream alternative start codon. Gene 2022; 833:146582. [PMID: 35597529 DOI: 10.1016/j.gene.2022.146582] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 03/29/2022] [Accepted: 05/16/2022] [Indexed: 11/16/2022]
Abstract
Biallelic mutations in ZMPSTE24 are known to be associated with autosomal recessive mandibuloacral dysplasia with type B lipodystrophy (MADB) and lethal restrictive dermopathy (RD), respectively. Disease manifestation is depending on the remaining enzyme activity of the mutated ZMPSTE24 protein. To date, complete loss of function has exclusively been reported in RD cases. In this study, we identified a novel N-terminal homozygous frameshift mutation (c.28_29insA) in a consanguineous family segregating with MADB. An in-depth analysis of the mutated sequence revealed, that the one base pair insertion creates a novel downstream in-frame start codon, which supposedly serves as an alternative translation initiation site (TIS). This possible rescue mechanism would explain the relatively mild clinical outcome in the studied individuals. Our findings demonstrate the necessity for careful interpretation of N-terminal variants potentially effecting translation initiation.
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Affiliation(s)
- Erich Schaflinger
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria
| | - Jasmin Blatterer
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria
| | - Aiman Saeed Khan
- Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I.Khan, Khyber Pakhtunkhwa, Pakistan
| | - Lukas Kaufmann
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria
| | - Lisa Auinger
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria
| | - Benjamin Tatrai
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria
| | - Sumra Wajid Abbasi
- NUMS Department of Biological Sciences, National University of Medical Sciences, The Mall, Abid Majeed Road, Rawalpindi, Punjab, Pakistan
| | - Muhammad Zeeshan Ali
- Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I.Khan, Khyber Pakhtunkhwa, Pakistan
| | - Ansar Ahmad Abbasi
- Department of Zoology, Mirpur University of Science and Technology, Mirpur, AJK 10250, Pakistan
| | - Ali Al Kaissi
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Med. Dept. Hanusch Hospital, Vienna, Austria
| | - Erwin Petek
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria
| | - Klaus Wagner
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria
| | - Muzammil Ahmad Khan
- Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I.Khan, Khyber Pakhtunkhwa, Pakistan.
| | - Christian Windpassinger
- Diagnostic and Research Institute of Human Genetics, Medical University of Graz, Graz 8010, Austria.
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17
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Li Z, Wu Y, Fu Y, Chen X, Zhao X, Wu X, Lu Y, He H, Shen C, Zheng B, Yu J, Sun F. Cyst stem cell lineage eIF5 non-autonomously prevents testicular germ cell tumor formation via eIF1A/eIF2γ-mediated pre-initiation complex. Stem Cell Res Ther 2022; 13:351. [PMID: 35883200 DOI: 10.1186/s13287-022-03025-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/02/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Stem cell niche maintains stem cell population identity and is essential for the homeostasis of self-renewal and differentiation in Drosophila testes. However, the mechanisms of CySC lineage signals-mediated soma-germline communications in response to external stimuli are unclear. METHODS Pre-initiation complex functions were evaluated by UAS-Gal4-mediated cell effects. RNA sequencing was conducted in NC and eIF5 siRNA-treated cells. Genetic interaction analysis was used to indicate the relationships between eIF5 and eIF1A/eIF2γ in Drosophila testes. RESULTS Here, we demonstrated that in CySCs, translation initiation factor eIF5 mediates cyst cell differentiation and the non-autonomously affected germ cell differentiation process. CySCs lacking eIF5 displayed unbalanced cell proliferation and apoptosis, forming testicular germ cell tumors (TGCTs) during spermatogenesis. eIF5 transcriptional regulation network analysis identified multiple metabolic processes and several key factors that might be involved in germ cell differentiation and TGCT formation. Importantly, knockdown of eIF1A and eIF2γ, key components of pre-initiation complex, mimicked the phenotype of knocking down eIF5 in the stem cell niche of Drosophila testes. Genetic interaction analysis indicated that eIF5 was sufficient to rescue the phenotype of tumorlike structures induced by down-regulating eIF1A or eIF2γ in CySCs. CONCLUSIONS These findings demonstrated that CySC lineage eIF5, together with eIF1A or eIF2γ, mediates soma-germline communications for the stem cell niche homeostasis in Drosophila testes, providing new insights for the prevention of TGCTs.
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18
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Lokdarshi A, von Arnim AG. Review: Emerging roles of the signaling network of the protein kinase GCN2 in the plant stress response. Plant Sci 2022; 320:111280. [PMID: 35643606 PMCID: PMC9197246 DOI: 10.1016/j.plantsci.2022.111280] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/07/2022] [Accepted: 03/30/2022] [Indexed: 06/15/2023]
Abstract
The pan-eukaryotic protein kinase GCN2 (General Control Nonderepressible2) regulates the translation of mRNAs in response to external and metabolic conditions. Although GCN2 and its substrate, translation initiation factor 2 (eIF2) α, and several partner proteins are substantially conserved in plants, this kinase has assumed novel functions in plants, including in innate immunity and retrograde signaling between the chloroplast and cytosol. How exactly some of the biochemical paradigms of the GCN2 system have diverged in the green plant lineage is only partially resolved. Specifically, conflicting data underscore and cast doubt on whether GCN2 regulates amino acid biosynthesis; also whether phosphorylation of eIF2α can in fact repress global translation or activate mRNA specific translation via upstream open reading frames; and whether GCN2 is controlled in vivo by the level of uncharged tRNA. This review examines the status of research on the eIF2α kinase, GCN2, its function in the response to xenobiotics, pathogens, and abiotic stress conditions, and its rather tenuous role in the translational control of mRNAs.
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Affiliation(s)
- Ansul Lokdarshi
- Department of Biology, Valdosta State University, Valdosta, GA 31698, USA.
| | - Albrecht G von Arnim
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN 37996-1939, USA; UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996-1939, USA.
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19
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Das S. Analysis of domain organization and functional signatures of trypanosomatid keIF4Gs. Mol Cell Biochem 2022; 477:2415-2431. [PMID: 35585276 DOI: 10.1007/s11010-022-04464-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 05/02/2022] [Indexed: 11/25/2022]
Abstract
Translation initiation is the first step in three essential processes leading to protein synthesis. It is carried out by proteins called translation initiation factors and ribosomes on the mRNA. One of the critical translation initiation factors in eukaryotes is eIF4G which is a scaffold protein that helps assemble translation initiation complexes that carry out translation initiation which ultimately leads to polypeptide synthesis. Trypanosomatids are a large family of kinetoplastids, some of which are protozoan parasites that cause diseases in humans through transmission by vectors. While the protein translation mechanisms in eukaryotes and prokaryotes are well understood, the protein translation factors and mechanisms in trypanosomatids are poorly understood necessitating further studies. Unlike other eukaryotes, trypanosomatids contain five eIF4G orthologues with diversity in length and sequences. Here, I have used bioinformatics tools to look at trypanosomatid keIF4G orthologue sequences and report that there are similarities and considerable differences in their domains/motifs organization and signature amino acid sequences that are required for different functions as compared to human eIF4G. My analysis suggests that there is likely to be considerable diversity and complexity in trypanosomatid keIF4G functions as compared to other eukaryotes.
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Affiliation(s)
- Supratik Das
- Infection and Immunology, Translational Health Science and Technology Institute, Faridabad, Haryana, 121001, India.
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, PO Box #04, Faridabad, Haryana, 121001, India.
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20
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Paul EE, Lin KY, Gamble N, Tsai AWL, Swan SHK, Yang Y, Doran M, Marintchev A. Dynamic interaction network involving the conserved intrinsically disordered regions in human eIF5. Biophys Chem 2022; 281:106740. [PMID: 34923394 PMCID: PMC8741751 DOI: 10.1016/j.bpc.2021.106740] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 02/03/2023]
Abstract
Translation initiation in eukaryotes requires multiple eukaryotic translation initiation factors (eIFs) and involves continuous remodeling of the ribosomal preinitiation complex (PIC). The GTPase eIF2 brings the initiator Met-tRNAi to the PIC. Upon start codon selection and GTP hydrolysis, promoted by eIF5, eIF2-GDP is released in complex with eIF5. Here, we report that two intrinsically disordered regions (IDRs) in eIF5, the DWEAR motif and the C-terminal tail (CTT) dynamically contact the folded C-terminal domain (CTD) and compete with each other. The eIF5-CTD•CTT interaction favors eIF2β binding to eIF5-CTD, whereas the eIF5-CTD•DWEAR interaction favors eIF1A binding, which suggests how intramolecular contact rearrangement could play a role in PIC remodeling. We show that eIF5 phosphorylation by CK2, which is known to stimulate translation and cell proliferation, significantly increases the eIF5 affinity for eIF2. Our results also indicate that the eIF2β subunit has at least two, and likely three eIF5-binding sites.
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Affiliation(s)
- Eleanor Elise Paul
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Kay Ying Lin
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Nathan Gamble
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Amy Wei-Lun Tsai
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Simon H. K. Swan
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Yu Yang
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Matthew Doran
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Assen Marintchev
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
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21
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Garcia VE, Dial R, DeRisi JL. Functional characterization of 5' UTR cis-acting sequence elements that modulate translational efficiency in Plasmodium falciparum and humans. Malar J 2022; 21:15. [PMID: 34991611 DOI: 10.1186/s12936-021-04024-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 12/14/2021] [Indexed: 11/10/2022] Open
Abstract
Background The eukaryotic parasite Plasmodium falciparum causes millions of malarial infections annually while drug resistance to common anti-malarials is further confounding eradication efforts. Translation is an attractive therapeutic target that will benefit from a deeper mechanistic understanding. As the rate limiting step of translation, initiation is a primary driver of translational efficiency. It is a complex process regulated by both cis and trans acting factors, providing numerous potential targets. Relative to model organisms and humans, P. falciparum mRNAs feature unusual 5′ untranslated regions suggesting cis-acting sequence complexity in this parasite may act to tune levels of protein synthesis through their effects on translational efficiency. Methods Here, in vitro translation is deployed to compare the role of cis-acting regulatory sequences in P. falciparum and humans. Using parasite mRNAs with high or low translational efficiency, the presence, position, and termination status of upstream “AUG”s, in addition to the base composition of the 5′ untranslated regions, were characterized. Results The density of upstream “AUG”s differed significantly among the most and least efficiently translated genes in P. falciparum, as did the average “GC” content of the 5′ untranslated regions. Using exemplars from highly translated and poorly translated mRNAs, multiple putative upstream elements were interrogated for impact on translational efficiency. Upstream “AUG”s were found to repress translation to varying degrees, depending on their position and context, while combinations of upstream “AUG”s had non-additive effects. The base composition of the 5′ untranslated regions also impacted translation, but to a lesser degree. Surprisingly, the effects of cis-acting sequences were remarkably conserved between P. falciparum and humans. Conclusions While translational regulation is inherently complex, this work contributes toward a more comprehensive understanding of parasite and human translational regulation by examining the impact of discrete cis-acting features, acting alone or in context. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-04024-2.
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22
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Abstract
The emergence of ribosome profiling as a tool for measuring the translatome has provided researchers with valuable insights into the post-transcriptional regulation of gene expression. Despite the biological insights and technical improvements made since the technique was initially described by Ingolia et al. (Science 324(5924):218-223, 2009), ribosome profiling measurements and subsequent data analysis remain challenging. Here, we describe our lab's protocol for performing ribosome profiling in bacteria, yeast, and mammalian cells. This protocol has integrated elements from three published ribosome profiling methods. In addition, we describe a tool called RiboViz (Carja et al., BMC Bioinformatics 18:461, 2017) ( https://github.com/riboviz/riboviz ) for the analysis and visualization of ribosome profiling data. Given raw sequencing reads and transcriptome information (e.g., FASTA, GFF) for a species, RiboViz performs the necessary pre-processing and mapping of the raw sequencing reads. RiboViz also provides the user with various quality control visualizations.
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Affiliation(s)
- Alexander L Cope
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Human Genetics Institute of New Jersey, Piscataway, NJ, USA
| | - Sangeevan Vellappan
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Waksman Institute, Rutgers University, Piscataway, NJ, USA
| | - John S Favate
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Human Genetics Institute of New Jersey, Piscataway, NJ, USA
| | - Kyle S Skalenko
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Waksman Institute, Rutgers University, Piscataway, NJ, USA
| | - Srujana S Yadavalli
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Waksman Institute, Rutgers University, Piscataway, NJ, USA
| | - Premal Shah
- Department of Genetics, Rutgers University, Piscataway, NJ, USA.
- Human Genetics Institute of New Jersey, Piscataway, NJ, USA.
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23
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Jennings MD, Pavitt GD. Quantifying the Binding of Fluorescently Labeled Guanine Nucleotides and Initiator tRNA to Eukaryotic Translation Initiation Factor 2. Methods Mol Biol 2022; 2428:89-99. [PMID: 35171475 DOI: 10.1007/978-1-0716-1975-9_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The translation initiation factor eIF2 is critical for protein synthesis initiation, and its regulation is central to the integrated stress response (ISR). eIF2 is a G protein, and the activity is regulated by its GDP or GTP-binding status, such that only GTP-bound eIF2 has high affinity for initiator methionyl tRNA. In the ISR, regulatory signaling reduces the availability of eIF2-GTP and so downregulates protein synthesis initiation in cells. Fluorescence spectroscopy can be used as an analytical tool to study protein-ligand interactions in vitro. Here we describe methods to purify eIF2 and assays of its activity, employing analogs of GDP, GTP, and methionyl initiator tRNA ligands to accurately measure their binding affinities.
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Affiliation(s)
- Martin D Jennings
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
| | - Graham D Pavitt
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
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24
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Pietras P, Aulas A, Fay MM, Leśniczak-Staszak M, Sowiński M, Lyons SM, Szaflarski W, Ivanov P. Translation inhibition and suppression of stress granules formation by cisplatin. Biomed Pharmacother 2021; 145:112382. [PMID: 34864307 PMCID: PMC8782064 DOI: 10.1016/j.biopha.2021.112382] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/13/2021] [Accepted: 10/25/2021] [Indexed: 12/24/2022] Open
Abstract
Platinum-based antineoplastic drugs, such as cisplatin, are commonly used to induce tumor cell death. Cisplatin is believed to induce apoptosis as a result of cisplatin-DNA adducts that inhibit DNA and RNA synthesis. Although idea that DNA damage underlines anti-proliferative effects of cisplatin is dominant in cancer research, there is a poor correlation between the degree of the cell sensitivity to cisplatin and the extent of DNA platination. Here, we examined possible effects of cisplatin on post-transcriptional gene regulation that may contribute to cisplatin-mediated cytotoxicity. We show that cisplatin suppresses formation of stress granules (SGs), pro-survival RNA granules with multiple roles in cellular metabolism. Mechanistically, cisplatin inhibits cellular translation to promote disassembly of polysomes and aggregation of ribosomal subunits. As SGs are in equilibrium with polysomes, cisplatin-induced shift towards ribosomal aggregation suppresses SG formation. Our data uncover previously unknown effects of cisplatin on RNA metabolism.
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Affiliation(s)
- Paulina Pietras
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
| | - Anaïs Aulas
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Marta M Fay
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Marta Leśniczak-Staszak
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
| | - Mateusz Sowiński
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland
| | - Shawn M Lyons
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Witold Szaflarski
- Department of Histology and Embryology, Poznan University of Medical Sciences, Poznań, Poland; Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
| | - Pavel Ivanov
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
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25
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Liang R, Shen X, Wang F, Wang X, DesJarlais A, Syed A, Saba R, Tan Z, Yu F, Ji X, Shrestha S, Ren Y, Yang J, Park Y, Schwartz RJ, Soibam B, McConnell BK, Stewart MD, Kumar A, Liu Y. H19X-encoded miR-322(424)/miR-503 regulates muscle mass by targeting translation initiation factors. J Cachexia Sarcopenia Muscle 2021; 12:2174-2186. [PMID: 34704401 PMCID: PMC8718088 DOI: 10.1002/jcsm.12827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/02/2021] [Accepted: 09/11/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Skeletal muscle atrophy is a debilitating complication of many chronic diseases, disuse conditions, and ageing. Genome-wide gene expression analyses have identified that elevated levels of microRNAs encoded by the H19X locus are among the most significant changes in skeletal muscles in a wide scope of human cachectic conditions. We have previously reported that the H19X locus is important for the establishment of striated muscle fate during embryogenesis. However, the role of H19X-encoded microRNAs in regulating skeletal mass in adults is unknown. METHODS We have created a transgenic mouse strain in which ectopic expression of miR-322/miR-503 is driven by the skeletal muscle-specific muscle creatine kinase promoter. We also used an H19X mutant mouse strain in which transcription from the locus is interrupted by a gene trap. Animal phenotypes were analysed by standard histological methods. Underlying mechanisms were explored by using transcriptome profiling and validated in the two animal models and cultured myotubes. RESULTS Our results demonstrate that the levels of H19X microRNAs are inversely related to postnatal skeletal muscle growth. Targeted overexpression of miR-322/miR-503 impeded skeletal muscle growth. The weight of gastrocnemius muscles of transgenic mice was only 54.5% of the counterparts of wild-type littermates. By contrast, interruption of transcription from the H19X locus stimulates postnatal muscle growth by 14.4-14.9% and attenuates the loss of skeletal muscle mass in response to starvation by 12.8-21.0%. Impeded muscle growth was not caused by impaired IGF1/AKT/mTOR signalling or a hyperactive ubiquitin-proteasome system, instead accompanied by markedly dropped abundance of translation initiation factors in transgenic mice. miR-322/miR-503 directly targets eIF4E, eIF4G1, eIF4B, eIF2B5, and eIF3M. CONCLUSIONS Our study illustrates a novel pathway wherein H19X microRNAs regulate skeletal muscle growth and atrophy through regulating the abundance of translation initiation factors, thereby protein synthesis. The study highlights how translation initiation factors lie at the crux of multiple signalling pathways that control skeletal muscle mass.
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Affiliation(s)
- Rui Liang
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Xiaopeng Shen
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Fan Wang
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA.,Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Xin Wang
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA.,Department of Oncology, Shangluo Central Hospital, Shangluo, Shaanxi Province, China
| | - Alex DesJarlais
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Anam Syed
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Raymond Saba
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Zhi Tan
- Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Fang Yu
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA.,Department of Oncology, Shangluo Central Hospital, Shangluo, Shaanxi Province, China
| | - Xuan Ji
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Shreesti Shrestha
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Yinghong Ren
- Department of Oncology, Shangluo Central Hospital, Shangluo, Shaanxi Province, China
| | - Jin Yang
- Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yoonjung Park
- Department of Health and Human Performance, University of Houston, Houston, TX, USA
| | - Robert J Schwartz
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Benjamin Soibam
- Department of Computer Science and Engineering Technology, University of Houston-Downtown, Houston, TX, USA
| | - Bradley K McConnell
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, Houston, TX, USA
| | - M David Stewart
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Ashok Kumar
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, Houston, TX, USA
| | - Yu Liu
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
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26
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Castellano MM, Merchante C. Peculiarities of the regulation of translation initiation in plants. Curr Opin Plant Biol 2021; 63:102073. [PMID: 34186463 DOI: 10.1016/j.pbi.2021.102073] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/21/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
Protein synthesis is a fundamental process for life and, as such, plays a crucial role in the adaptation to energy, developmentaland environmental conditions. For these reasons, and despite the general conservation of the eukaryotic translational machinery, it is not surprising that organisms with different lifestyles have evolved distinct mechanisms of regulation to adapt translation initiation to their intrinsic growth and development. Plants have clear peculiarities compared with other eukaryotes that have also extended to translation control. This review describes the plant-specific mechanisms for regulation of translation initiation, with a focus on those that modulate the eIF4F complexes, central translational regulatory hubs in all eukaryotes, and highlights the latest discoveries on the signaling pathways that regulate their constituents and activity.
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Affiliation(s)
- M Mar Castellano
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA, CSIC), Campus Montegancedo UPM, Pozuelo de Alarcón, Madrid, 28223, Spain.
| | - Catharina Merchante
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Campus de Teatinos, Universidad de Málaga, Málaga, 29071, Spain.
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27
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Romagnoli A, D'Agostino M, Ardiccioni C, Maracci C, Motta S, La Teana A, Di Marino D. Control of the eIF4E activity: structural insights and pharmacological implications. Cell Mol Life Sci 2021; 78:6869-85. [PMID: 34541613 DOI: 10.1007/s00018-021-03938-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 08/28/2021] [Accepted: 09/08/2021] [Indexed: 12/17/2022]
Abstract
The central role of eukaryotic translation initiation factor 4E (eIF4E) in controlling mRNA translation has been clearly assessed in the last decades. eIF4E function is essential for numerous physiological processes, such as protein synthesis, cellular growth and differentiation; dysregulation of its activity has been linked to ageing, cancer onset and progression and neurodevelopmental disorders, such as autism spectrum disorder (ASD) and Fragile X Syndrome (FXS). The interaction between eIF4E and the eukaryotic initiation factor 4G (eIF4G) is crucial for the assembly of the translational machinery, the initial step of mRNA translation. A well-characterized group of proteins, named 4E-binding proteins (4E-BPs), inhibits the eIF4E–eIF4G interaction by competing for the same binding site on the eIF4E surface. 4E-BPs and eIF4G share a single canonical motif for the interaction with a conserved hydrophobic patch of eIF4E. However, a second non-canonical and not conserved binding motif was recently detected for eIF4G and several 4E-BPs. Here, we review the structural features of the interaction between eIF4E and its molecular partners eIF4G and 4E-BPs, focusing on the implications of the recent structural and biochemical evidence for the development of new therapeutic strategies. The design of novel eIF4E-targeting molecules that inhibit translation might provide new avenues for the treatment of several conditions.
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28
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Deutschmann-Olek KM, Yue WW, Bezerra GA, Skern T. Defining substrate selection by rhinoviral 2A proteinase through its crystal structure with the inhibitor zVAM.fmk. Virology 2021; 562:128-141. [PMID: 34315103 DOI: 10.1016/j.virol.2021.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 11/16/2022]
Abstract
Picornavirus family members cause disease in humans. Human rhinoviruses (RV), the main causative agents of the common cold, increase the severity of asthma and COPD; hence, effective agents against RVs are required. The 2A proteinase (2Apro), found in all enteroviruses, represents an attractive target; inactivating mutations in poliovirus 2Apro result in an extension of the VP1 protein preventing infectious virion assembly. Variations in sequence and substrate specificity on eIF4G isoforms between RV 2Apro of genetic groups A and B hinder 2Apro as drug targets. Here, we demonstrate that although RV-A2 and RV-B4 2Apro cleave the substrate GAB1 at different sites, the 2Apro from both groups cleave equally efficiently an artificial site containing P1 methionine. We determined the RV-A2 2Apro structure complexed with zVAM.fmk, containing P1 methionine. Analysis of this first 2Apro-inhibitor complex reveals a conserved hydrophobic P4 pocket among enteroviral 2Apro as a potential target for broad-spectrum anti-enteroviral inhibitors.
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Affiliation(s)
- Karin M Deutschmann-Olek
- Department of Medical Biochemistry, Max Perutz Labs, Vienna Biocenter, Medical University of Vienna, A-1030, Vienna, Austria
| | - Wyatt W Yue
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, United Kingdom
| | - Gustavo A Bezerra
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, United Kingdom
| | - Tim Skern
- Department of Medical Biochemistry, Max Perutz Labs, Vienna Biocenter, Medical University of Vienna, A-1030, Vienna, Austria.
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29
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Tjeldnes H, Labun K, Torres Cleuren Y, Chyżyńska K, Świrski M, Valen E. ORFik: a comprehensive R toolkit for the analysis of translation. BMC Bioinformatics 2021; 22:336. [PMID: 34147079 PMCID: PMC8214792 DOI: 10.1186/s12859-021-04254-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 06/09/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND With the rapid growth in the use of high-throughput methods for characterizing translation and the continued expansion of multi-omics, there is a need for back-end functions and streamlined tools for processing, analyzing, and characterizing data produced by these assays. RESULTS Here, we introduce ORFik, a user-friendly R/Bioconductor API and toolbox for studying translation and its regulation. It extends GenomicRanges from the genome to the transcriptome and implements a framework that integrates data from several sources. ORFik streamlines the steps to process, analyze, and visualize the different steps of translation with a particular focus on initiation and elongation. It accepts high-throughput sequencing data from ribosome profiling to quantify ribosome elongation or RCP-seq/TCP-seq to also quantify ribosome scanning. In addition, ORFik can use CAGE data to accurately determine 5'UTRs and RNA-seq for determining translation relative to RNA abundance. ORFik supports and calculates over 30 different translation-related features and metrics from the literature and can annotate translated regions such as proteins or upstream open reading frames (uORFs). As a use-case, we demonstrate using ORFik to rapidly annotate the dynamics of 5' UTRs across different tissues, detect their uORFs, and characterize their scanning and translation in the downstream protein-coding regions. CONCLUSION In summary, ORFik introduces hundreds of tested, documented and optimized methods. ORFik is designed to be easily customizable, enabling users to create complete workflows from raw data to publication-ready figures for several types of sequencing data. Finally, by improving speed and scope of many core Bioconductor functions, ORFik offers enhancement benefiting the entire Bioconductor environment. AVAILABILITY http://bioconductor.org/packages/ORFik .
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Affiliation(s)
- Håkon Tjeldnes
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Kornel Labun
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Yamila Torres Cleuren
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway.,Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Katarzyna Chyżyńska
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Michał Świrski
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Eivind Valen
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway. .,Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway.
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30
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Tharp JM, Walker JA, Söll D, Schepartz A. Initiating protein synthesis with noncanonical monomers in vitro and in vivo. Methods Enzymol 2021; 656:495-519. [PMID: 34325796 DOI: 10.1016/bs.mie.2021.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
With few exceptions, ribosomal protein synthesis begins with methionine (or its derivative N-formyl-methionine) across all domains of life. The role of methionine as the initiating amino acid is dictated by the unique structure of its cognate tRNA known as tRNAfMet. By mis-acylating tRNAfMet, we and others have shown that protein synthesis can be initiated with a variety of canonical and noncanonical amino acids both in vitro and in vivo. Furthermore, because the α-amine of the initiating amino acid is not required for peptide bond formation, translation can be initiated with a variety of structurally disparate carboxylic acids that bear little resemblance to traditional α-amino acids. Herein, we provide a detailed protocol to initiate in vitro protein synthesis with substituted benzoic acid and 1,3-dicarbonyl compounds. These moieties are introduced at the N-terminus of peptides by mis-acylated tRNAfMet, prepared by flexizyme-catalyzed tRNA acylation. In addition, we describe a protocol to initiate in vivo protein synthesis with aromatic noncanonical amino acids (ncAAs). This method relies on an engineered chimeric initiator tRNA that is acylated with ncAAs by an orthogonal aminoacyl-tRNA synthetase. Together, these systems are useful platforms for producing N-terminally modified proteins and for engineering the protein synthesis machinery of Escherichia coli to accept additional nonproteinogenic carboxylic acid monomers.
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31
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de Lima GB, de Lima Cavalcanti TYV, de Brito ANALM, de Assis LA, Andrade-Vieira RP, Freire ER, da Silva Assunção TR, de Souza Reis CR, Zanchin NIT, Guimarães BG, de-Melo-Neto OP. The translation initiation factor EIF4E5 from Leishmania: crystal structure and interacting partners. RNA Biol 2021; 18:2433-2449. [PMID: 33945405 DOI: 10.1080/15476286.2021.1918919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The mRNA cap-binding protein, eIF4E, mediates the recognition of the mRNA 5' end and, as part of the heterotrimeric eIF4F complex, facilitates the recruitment of the ribosomal subunits to initiate eukaryotic translation. Various regulatory events involving eIF4E and a second eIF4F subunit, eIF4G, are required for proper control of translation initiation. In pathogenic trypanosomatids, six eIF4Es and five eIF4Gs have been described, several forming different eIF4F-like complexes with yet unresolved roles. EIF4E5 is one of the least known of the trypanosomatid eIF4Es and has not been characterized in Leishmania species. Here, we used immunoprecipitation assays, combined with mass-spectrometry, to identify major EIF4E5 interacting proteins in L. infantum. A constitutively expressed, HA-tagged, EIF4E5 co-precipitated mainly with EIF4G1 and binding partners previously described in Trypanosoma brucei, EIF4G1-IP, RBP43 and the 14-3-3 proteins. In contrast, no clear co-precipitation with EIF4G2, also previously reported, was observed. EIF4E5 also co-precipitated with protein kinases, possibly associated with cell-cycle regulation, selected RNA binding proteins and histones. Phosphorylated residues were identified and mapped to the Leishmania-specific C-terminal end. Mutagenesis of the tryptophan residue (W53) postulated to mediate interactions with protein partners or of a neighbouring tryptophan conserved in Leishmania (W45) did not substantially impair the identified interactions. Finally, the crystal structure of Leishmania EIF4E5 evidences remarkable differences in the eIF4G interfacing region, when compared with human eIF4E-1 and with its Trypanosoma orthologue. Mapping of its C-terminal end near the cap-binding site also imply relevant differences in cap-binding function and/or regulation.
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Affiliation(s)
- Gustavo Barbosa de Lima
- Departamento de Microbiologia, Instituto Aggeu Magalhães, FIOCRUZ-PE, Av. Moraes Rego s/n, Recife-PE, Brazil
| | - Thaíse Yasmine Vasconcelos de Lima Cavalcanti
- Departamento de Microbiologia, Instituto Aggeu Magalhães, FIOCRUZ-PE, Av. Moraes Rego s/n, Recife-PE, Brazil.,Programa de Pós-Graduação em Genética, Universidade Federal de Pernambuco, Recife-PE, Brazil
| | - Adriana Neuman Albuquerque Lins Moura de Brito
- Departamento de Microbiologia, Instituto Aggeu Magalhães, FIOCRUZ-PE, Av. Moraes Rego s/n, Recife-PE, Brazil.,Programa de Pós-Graduação em Genética, Universidade Federal de Pernambuco, Recife-PE, Brazil
| | - Ludmilla Arruda de Assis
- Departamento de Microbiologia, Instituto Aggeu Magalhães, FIOCRUZ-PE, Av. Moraes Rego s/n, Recife-PE, Brazil
| | | | - Eden Ribeiro Freire
- Departamento de Microbiologia, Instituto Aggeu Magalhães, FIOCRUZ-PE, Av. Moraes Rego s/n, Recife-PE, Brazil.,Laboratório de Biologia Estrutural e Engenharia de Proteínas, Instituto Carlos Chagas, FIOCRUZ-PR, Curitiba-PR, Brazil
| | | | | | - Nilson Ivo Tonin Zanchin
- Laboratório de Biologia Estrutural e Engenharia de Proteínas, Instituto Carlos Chagas, FIOCRUZ-PR, Curitiba-PR, Brazil
| | - Beatriz Gomes Guimarães
- Laboratório de Biologia Estrutural e Engenharia de Proteínas, Instituto Carlos Chagas, FIOCRUZ-PR, Curitiba-PR, Brazil
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32
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Gao NL, He Z, Zhu Q, Jiang P, Hu S, Chen WH. Selection for Cheaper Amino Acids Drives Nucleotide Usage at the Start of Translation in Eukaryotic Genes. Genomics Proteomics Bioinformatics 2021; 19:949-957. [PMID: 33741525 PMCID: PMC9403032 DOI: 10.1016/j.gpb.2021.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 05/30/2019] [Accepted: 08/18/2019] [Indexed: 12/04/2022]
Abstract
Coding regions have complex interactions among multiple selective forces, which are manifested as biases in nucleotide composition. Previous studies have revealed a decreasing GC gradient from the 5′-end to 3′-end of coding regions in various organisms. We confirmed that this gradient is universal in eukaryotic genes, but the decrease only starts from the ∼ 25th codon. This trend is mostly found in nonsynonymous (ns) sites at which the GC gradient is universal across the eukaryotic genome. Increased GC contents at ns sites result in cheaper amino acids, indicating a universal selection for energy efficiency toward the N-termini of encoded proteins. Within a genome, the decreasing GC gradient is intensified from lowly to highly expressed genes (more and more protein products), further supporting this hypothesis. This reveals a conserved selective constraint for cheaper amino acids at the translation start that drives the increased GC contents at ns sites. Elevated GC contents can facilitate transcription but result in a more stable local secondary structure around the start codon and subsequently impede translation initiation. Conversely, the GC gradients at four-fold and two-fold synonymous sites vary across species. They could decrease or increase, suggesting different constraints acting at the GC contents of different codon sites in different species. This study reveals that the overall GC contents at the translation start are consequences of complex interactions among several major biological processes that shape the nucleotide sequences, especially efficient energy usage.
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Affiliation(s)
- Na L Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular-imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Institute for Computer Science and Cluster of Excellence on Plant Sciences, Heinrich Heine University, Duesseldorf 40225, Germany
| | - Zilong He
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Interdisciplinary Innovation Institute of Medicine and Engineering, Beihang University, Beijing 100191, China
| | - Qianhui Zhu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Puzi Jiang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular-imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Songnian Hu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Wei-Hua Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular-imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
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33
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Müller C, Obermann W, Karl N, Wendel HG, Taroncher-Oldenburg G, Pleschka S, Hartmann RK, Grünweller A, Ziebuhr J. The rocaglate CR-31-B (-) inhibits SARS-CoV-2 replication at non-cytotoxic, low nanomolar concentrations in vitro and ex vivo. Antiviral Res 2021; 186:105012. [PMID: 33422611 DOI: 10.1016/j.antiviral.2021.105012] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 12/17/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of COVID-19, a severe respiratory disease with varying clinical presentations and outcomes, and responsible for a major pandemic that started in early 2020. With no vaccines or effective antiviral treatments available, the quest for novel therapeutic solutions remains an urgent priority. Rocaglates, a class of plant-derived cyclopenta[b]benzofurans, exhibit broad-spectrum antiviral activity against multiple RNA viruses including coronaviruses. Specifically, rocaglates inhibit eukaryotic initiation factor 4A (eIF4A)-dependent mRNA translation initiation, resulting in strongly reduced viral RNA translation. Here, we assessed the antiviral activity of the synthetic rocaglate CR-31-B (-) against SARS-CoV-2 using both in vitro and ex vivo cell culture models. In Vero E6 cells, CR-31-B (-) inhibited SARS-CoV-2 replication with an EC50 of ~1.8 nM. In primary human airway epithelial cells, CR-31-B (-) reduced viral titers to undetectable levels at a concentration of 100 nM. Reduced virus reproduction was accompanied by substantially reduced viral protein accumulation and replication/transcription complex formation. The data reveal a potent anti-SARS-CoV-2 activity by CR-31-B (-), corroborating previous results obtained for other coronaviruses and supporting the idea that rocaglates may be used in first-line antiviral intervention strategies against novel and emerging RNA virus outbreaks.
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34
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Abstract
The knowledge of translation start sites is crucial for annotation of genes in bacterial genomes. However, systematic mapping of start codons in bacterial genes has mainly relied on predictions based on protein conservation and mRNA sequence features which, although useful, are not always accurate. We recently found that the pleuromutilin antibiotic retapamulin (RET) is a specific inhibitor of translation initiation that traps ribosomes specifically at start codons, and we used it in combination with ribosome profiling to map start codons in the Escherichia coli genome. This genome-wide strategy, that was named Ribo-RET, not only verifies the position of start codons in already annotated genes but also enables identification of previously unannotated open reading frames and reveals the presence of internal start sites within genes. Here, we provide a detailed Ribo-RET protocol for E. coli. Ribo-RET can be adapted for mapping the start codons of the protein-coding sequences in a variety of bacterial species.
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Affiliation(s)
- Sezen Meydan
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Dorota Klepacki
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA.
| | - Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA.
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35
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Thelen MP, Wirth B, Kye MJ. Mitochondrial defects in the respiratory complex I contribute to impaired translational initiation via ROS and energy homeostasis in SMA motor neurons. Acta Neuropathol Commun 2020; 8:223. [PMID: 33353564 PMCID: PMC7754598 DOI: 10.1186/s40478-020-01101-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 12/22/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by loss of lower motor neurons, which leads to proximal muscle weakness and atrophy. SMA is caused by reduced survival motor neuron (SMN) protein levels due to biallelic deletions or mutations in the SMN1 gene. When SMN levels fall under a certain threshold, a plethora of cellular pathways are disturbed, including RNA processing, protein synthesis, metabolic defects, and mitochondrial function. Dysfunctional mitochondria can harm cells by decreased ATP production and increased oxidative stress due to elevated cellular levels of reactive oxygen species (ROS). Since neurons mainly produce energy via mitochondrial oxidative phosphorylation, restoring metabolic/oxidative homeostasis might rescue SMA pathology. Here, we report, based on proteome analysis, that SMA motor neurons show disturbed energy homeostasis due to dysfunction of mitochondrial complex I. This results in a lower basal ATP concentration and higher ROS production that causes an increase of protein carbonylation and impaired protein synthesis in SMA motor neurons. Counteracting these cellular impairments with pyruvate reduces elevated ROS levels, increases ATP and SMN protein levels in SMA motor neurons. Furthermore, we found that pyruvate-mediated SMN protein synthesis is mTOR-dependent. Most importantly, we showed that ROS regulates protein synthesis at the translational initiation step, which is impaired in SMA. As many neuropathies share pathological phenotypes such as dysfunctional mitochondria, excessive ROS, and impaired protein synthesis, our findings suggest new molecular interactions among these pathways. Additionally, counteracting these impairments by reducing ROS and increasing ATP might be beneficial for motor neuron survival in SMA patients.
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Das S. Taking a re-look at cap-binding signatures of the mRNA cap-binding protein eIF4E orthologues in trypanosomatids. Mol Cell Biochem 2020; 476:1037-1049. [PMID: 33169189 DOI: 10.1007/s11010-020-03970-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 10/31/2020] [Indexed: 01/04/2023]
Abstract
Protein translation leading to polypeptide synthesis involves three distinct events, namely, initiation, elongation, and termination. Translation initiation is a multi-step process that is carried out by ribosomes on the mRNA with the assistance of a large number of proteins called translation initiation factors. Trypanosomatids are kinetoplastidas (flagellated protozoans), some of which cause acute disease syndromes in humans. Vector-borne transmission of protozoan parasites like Leishmania and Trypanosoma causes diseases that affect a large section of the world population and lead to significant morbidity and mortality. The mechanisms of translation initiation in higher eukaryotes are relatively well understood. However, structural and functional conservation of initiation factors in trypanosomatids are only beginning to be understood. Studies carried out so far suggests that at least in Leishmania and Trypanosoma eIF4E function may not be restricted to canonical translation initiation and some of the homologues may have alternate/non-canonical functions. Nonetheless, all of them bind the cap analogs, albeit with different efficiencies, indicating that this property may play an important role in the functionality of eIF4Es. Here, I give a brief background of trypanosomatid eIF4Es and revisit the cap-binding signatures of eIF4E orthologues in trypanosomatids, whose genome sequences are available, in detail, in comparison to human eIF4E1 and Trypanosoma cruzi eIF4E5, with an expanded list of members of this group in light of newer findings. The group 1 and 2 eIF4Es may use either a variation of heIF4E1 or T. cruzi eIF4E5 cap-4-binding signatures, while eIF4E5 and eIF4E6 use distinct amino acid contacts.
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Affiliation(s)
- Supratik Das
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, PO Box #04, Faridabad, Haryana, 121001, India.
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Higdon AL, Brar GA. Rules are made to be broken: a "simple" model organism reveals the complexity of gene regulation. Curr Genet 2020; 67:49-56. [PMID: 33130938 DOI: 10.1007/s00294-020-01121-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/14/2020] [Accepted: 10/19/2020] [Indexed: 11/27/2022]
Abstract
Global methods for assaying translation have greatly improved our understanding of the protein-coding capacity of the genome. In particular, it is now possible to perform genome-wide and condition-specific identification of translation initiation sites through modified ribosome profiling methods that selectively capture initiating ribosomes. Here we discuss our recent study applying such an approach to meiotic and mitotic timepoints in the simple eukaryote, budding yeast, as an example of the surprising diversity of protein products-many of which are non-canonical-that can be revealed by such methods. We also highlight several key challenges in studying non-canonical protein isoforms that have precluded their prior systematic discovery. A growing body of work supports expanded use of empirical protein-coding region identification, which can help relieve some of the limitations and biases inherent to traditional genome annotation approaches. Our study also argues for the adoption of less static views of gene identity and a broader framework for considering the translational capacity of the genome.
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Affiliation(s)
- Andrea L Higdon
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA
- Center for Computational Biology, University of California, Berkeley, CA, 94720, USA
| | - Gloria A Brar
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA.
- Center for Computational Biology, University of California, Berkeley, CA, 94720, USA.
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An S, Kwon OS, Yu J, Jang SK. A cyclin-dependent kinase, CDK11/p58, represses cap-dependent translation during mitosis. Cell Mol Life Sci 2020; 77:4693-4708. [PMID: 32030451 PMCID: PMC7599166 DOI: 10.1007/s00018-019-03436-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 12/11/2019] [Accepted: 12/23/2019] [Indexed: 01/08/2023]
Abstract
During mitosis, translation of most mRNAs is strongly repressed; none of the several explanatory hypotheses suggested can fully explain the molecular basis of this phenomenon. Here we report that cyclin-dependent CDK11/p58-a serine/threonine kinase abundantly expressed during M phase-represses overall translation by phosphorylating a subunit (eIF3F) of the translation factor eIF3 complex that is essential for translation initiation of most mRNAs. Ectopic expression of CDK11/p58 strongly repressed cap-dependent translation, and knockdown of CDK11/p58 nullified the translational repression during M phase. We identified the phosphorylation sites in eIF3F responsible for M phase-specific translational repression by CDK11/p58. Alanine substitutions of CDK11/p58 target sites in eIF3F nullified its effects on cell cycle-dependent translational regulation. The mechanism of translational regulation by the M phase-specific kinase, CDK11/p58, has deep evolutionary roots considering the conservation of CDK11 and its target sites on eIF3F from C. elegans to humans.
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Affiliation(s)
- Sihyeon An
- PBC, Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Cheongam-ro 77, Nam-gu, Pohang-si, Gyeongsangbuk-do, 37673, Republic of Korea
| | - Oh Sung Kwon
- PBC, Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Cheongam-ro 77, Nam-gu, Pohang-si, Gyeongsangbuk-do, 37673, Republic of Korea
| | - Jinbae Yu
- PBC, Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Cheongam-ro 77, Nam-gu, Pohang-si, Gyeongsangbuk-do, 37673, Republic of Korea
| | - Sung Key Jang
- PBC, Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Cheongam-ro 77, Nam-gu, Pohang-si, Gyeongsangbuk-do, 37673, Republic of Korea.
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Wang Y, Gai Y, Li Y, Li C, Li Z, Wang X. SARS-CoV-2 has the advantage of competing the iMet-tRNAs with human hosts to allow efficient translation. Mol Genet Genomics 2020; 296:113-118. [PMID: 33040198 PMCID: PMC7547557 DOI: 10.1007/s00438-020-01731-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 09/29/2020] [Indexed: 11/25/2022]
Abstract
To better understand the interaction between SARS-CoV-2 and human host and find potential ways to block the pandemic, one of the unresolved questions is that how the virus economically utilizes the resources of the hosts. Particularly, the tRNA pool has been adapted to the host genes. If the virus intends to translate its own RNA, then it has to compete with the abundant host mRNAs for the tRNA molecules. Translation initiation is the rate-limiting step during protein synthesis. The tRNAs carrying the initiation Methionine (iMet) recognize the start codon termed initiation ATG (iATG). Other normal Met-carrying tRNAs recognize the internal ATGs. The tAI of virus genes is significantly lower than the tAI of human genes. This disadvantage in translation elongation of viral RNAs must be compensated by more efficient initiation rates. In the human genome, the abundance of iMet–tRNAs to Met–tRNAs is five times higher than the iATG to ATG ratio. However, when SARS-CoV-2 infects human cells, the iMet has an 8.5-time enrichment to iATG. We collected 58 virus species and found that the enrichment of iMet is higher in all viruses compared to human. Our study indicates that the genome sequences of viruses like SARS-CoV-2 have the advantage of competing for the iMet–tRNAs with host mRNAs. The capture of iMet–tRNAs allows the fast translation initiation and the reproduction of virus itself, which compensates the lower tAI of viral genes. This might explain why the virus could rapidly translate its own RNA and reproduce itself from the sea of host mRNAs. Meanwhile, our study reminds the researchers not to ignore the mutations related to ATGs.
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Affiliation(s)
- Yan Wang
- Department of Respiration, Qingdao Central Hospital, Qingdao, China
| | - Yanhong Gai
- Department of Respiration, Qingdao Central Hospital, Qingdao, China
| | - Yuefan Li
- Department of Respiration, Qingdao Central Hospital, Qingdao, China
| | - Chunxiao Li
- Department of Respiration, Qingdao Central Hospital, Qingdao, China
| | - Ziliang Li
- Department of Respiration, Qingdao Central Hospital, Qingdao, China
| | - Xuekun Wang
- Department of Respiration, Qingdao Central Hospital, Qingdao, China.
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Belfetmi A, Léger-Abraham M. 1H, 13C, and 15N backbone chemical shift assignments of m 7GTP cap-bound Leishmania initiation factor 4E-1. Biomol NMR Assign 2020; 14:259-263. [PMID: 32519295 PMCID: PMC7462832 DOI: 10.1007/s12104-020-09958-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Most of the translational control of gene expression in higher eukaryotes occurs during the initiation step of protein synthesis. While this process is well characterized in mammalian cells, it is less defined in parasites, including the ones that cause human Leishmaniasis. The Leishmania cap-binding isoform 1 (LeishIF4E-1) is the only isoform that binds the specific trypanosomatids-specific hypermethylated 5' cap, called cap-4, in the human stage of the parasite life cycle. We report here the extensive NMR resonance assignment of LeishIF4E-1 bound to a cap analog, m7GTP. The chemical shift data constitute a prerequisite to understanding specific translation initiation mechanisms used in Leishmania parasites and to developing antiparasitic drugs targeting their translation initiation factors.
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Affiliation(s)
- Anissa Belfetmi
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Mélissa Léger-Abraham
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
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Yuan H, Li N, Li P, Bai X, Sun P, Bao H, Gong X, Ma X, Cao Y, Li K, Fu Y, Zhang J, Li D, Chen Y, Zhang J, Lu Z, Liu Z. Modification of the second translation initiation site restricts the replication of foot-and-mouth disease virus in PK-15 cells. Appl Microbiol Biotechnol 2020; 104:8455-66. [PMID: 32820373 DOI: 10.1007/s00253-020-10810-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/23/2020] [Accepted: 08/02/2020] [Indexed: 11/22/2022]
Abstract
Abstract The translation initiation of foot-and-mouth disease virus (FMDV) occurs at two alternative initiation sites (Lab AUG and Lb AUG). Usually, the Lb AUG is more favorably used to initiate protein synthesis than the Lab AUG. To explore the effect of Lb AUG on FMDV replication and obtain FMDV with restricted replication, this initiation codon was mutated to a variety of non-AUG codons (UGG, AUC, CUG, and AAA). Fortunately, the modifications did not prevent viral viability but influenced replication characteristics of some FMDV mutants in a cell-specific manner, as was shown by the similar replication in BHK-21 cells and delayed growth kinetics in PK-15 cells. This attenuated phenotype of FMDV mutants in PK-15 cells was found to be correlated with reduced abilities to cleave eIF4GI and suppress interference (IFN) expression. As leader (L) protein was reported to be responsible for eIF4GI cleavage and inhibition of IFN expression, the in vivo L protein synthesis was examined during the infection of FMDV mutants. Our results showed that not only the total yield of L proteins was severely influenced but also the individual yield of L protein was seen to be affected, which implied that both the relative usage of the two initiation sites and overall translation efficiency were changed by Lb AUG modifications. In addition, the in vitro translation activity was also negatively regulated by Lb AUG mutations. Collectively, these findings suggested that the restricted replications of Lb AUG-modified FMDVs were related to the delayed eIF4GI cleavage and decreased ability to block IFN expression but were mainly determined by the inefficient translation initiation. FMDVs precisely with modifications of Lb AUG initiation codon may represent safer seed viruses for vaccine production. Key points • The polyprotein translation of FMDV initiates at two alternative initiation sites (Lab AUG and Lb AUG). In order to explore the effect of Lb AUG on FMDV replication and obtain FMDV with restricted replication, the Lb initiation AUG was mutated to a variety of non-AUG codons (UGG, AUC, CUG, and AAA), and four FMDV mutants with Lb AUG modification were generated. • We found that partial FMDV mutants grew almost as well as WT virus in BHK-21 cells, a typical cell line used for FMD vaccine production, but displayed impaired replication in IFN-competent PK-15 cells. • The attenuation of mutant FMDVs in PK-15 cells was found to be correlated with delayed eIF4GI cleavage and decreased ability to block IFN expression. • We proved that the attenuated phenotype of Lb AUG-modified FMDVs was mainly determined by the inefficient translation initiation, as demonstrated by the decrease of total yield of L proteins and individual production of L protein. • We successfully generated genetically engineered FMDV with attenuated phenotype. The approach of precise engineering of FMDV with the modification of initiation codon provides a safe platform to produce inactivated antigen vaccines.
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Díaz-López I, Toribio R, Ventoso I. Mapping mRNA-18S rRNA Contacts Within Translation Initation Complexby Means of Reverse Transcriptase Termination Sites and RNAseq. Bio Protoc 2020; 10:e3713. [PMID: 33659377 DOI: 10.21769/bioprotoc.3713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 06/10/2020] [Accepted: 07/14/2020] [Indexed: 11/02/2022] Open
Abstract
The nucleotides involved in RNA-RNA interaction can be tagged by chemical- or UV-induced crosslinking, and further identified by classical or modern high throughput techniques. The contacts of mRNA with 18S rRNA that occur along the mRNA channel of 40S subunit have been mapped by site-specific UV crosslinking followed by reverse transcriptase termination sites (RTTS) using radioactive or fluorescent oligonucleotides. However, the sensitivity of this technique is restricted to the detection of those fragments that resulted from the most frequent crosslinkings. Here, we combined RTTS with RNAseq to map the mRNA-18S rRNA contacts with a much deeper resolution. Although aimed to detect the interaction of mRNA with the ES6S region of 18S rRNA, this technique can also be applied to map the interaction of mRNA with other non-coding RNA molecules (e.g., snRNAs, microRNAs and lncRNAs) during transcription, splicing or RNA-mediated postranscriptional regulation.
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Affiliation(s)
- Irene Díaz-López
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - René Toribio
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Iván Ventoso
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) and Departamento de Biología Molecular, Universidad Autónoma de Madrid (UAM), Madrid, Spain
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Volkenborn K, Kuschmierz L, Benz N, Lenz P, Knapp A, Jaeger KE. The length of ribosomal binding site spacer sequence controls the production yield for intracellular and secreted proteins by Bacillus subtilis. Microb Cell Fact 2020; 19:154. [PMID: 32727460 PMCID: PMC7392706 DOI: 10.1186/s12934-020-01404-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/13/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Bacillus subtilis is widely used for the industrial production of recombinant proteins, mainly due to its high secretion capacity, but higher production yields can be achieved only if bottlenecks are removed. To this end, a crucial process is translation initiation which takes place at the ribosome binding site enclosing the Shine Dalgarno sequence, the start codon of the target gene and a short spacer sequence in between. Here, we have studied the effects of varying spacer sequence lengths in vivo on the production yield of different intra- and extracellular proteins. RESULTS The shuttle vector pBSMul1 containing the strong constitutive promoter PHpaII and the optimal Shine Dalgarno sequence TAAGGAGG was used as a template to construct a series of vectors with spacer lengths varying from 4 to 12 adenosines. For the intracellular proteins GFPmut3 and β-glucuronidase, an increase of spacer lengths from 4 to 7-9 nucleotides resulted in a gradual increase of product yields up to 27-fold reaching a plateau for even longer spacers. The production of secreted proteins was tested with cutinase Cut and swollenin EXLX1 which were N-terminally fused to one of the Sec-dependent signal peptides SPPel, SPEpr or SPBsn. Again, longer spacer sequences resulted in up to tenfold increased yields of extracellular proteins. Fusions with signal peptides SPPel or SPBsn revealed the highest production yields with spacers of 7-10nt length. Remarkably, fusions with SPEpr resulted in a twofold lower production yield with 6 or 7nt spacers reaching a maximum with 10-12nt spacers. This pattern was observed for both secreted proteins fused to SPEpr indicating a dominant role also of the nucleotide sequence encoding the respective signal peptide for translation initiation. This conclusion was corroborated by RT qPCR revealing only slightly different amounts of transcript. Also, the effect of a putative alternative translation initiation site could be ruled out. CONCLUSION Our results confirm the importance of the 5' end sequence of a target gene for translation initiation. Optimizing production yields thus may require screenings for optimal spacer sequence lengths. In case of secreted proteins, the 5' sequence encoding the signal peptide for Sec-depended secretion should also be considered.
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Affiliation(s)
- Kristina Volkenborn
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Laura Kuschmierz
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Environmental Microbiology and Biotechnology-Molecular Enzyme Technology and Biochemistry, University Duisburg-Essen, 45141, Essen, Germany
| | - Nuka Benz
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Patrick Lenz
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Andreas Knapp
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany. .,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany.
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany
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Younkin AD, Gregory ST, O'Connor M. Alterations in the ribosomal protein bL12 of E. coli affecting the initiation, elongation and termination of protein synthesis. Biochimie 2020; 175:173-180. [PMID: 32569619 DOI: 10.1016/j.biochi.2020.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 11/27/2022]
Abstract
In bacteria, ribosomal protein bL12 forms the prominent stalk structure on the ribosome and binds to multiple, distinct translational GTPase factors during the sequential steps of translation. Using a genetic selection in E. coli for altered readthrough of UGA stop codons, we have isolated seven different mutations affecting the C-terminal domain of the protein that forms the interaction surface with translation factors. Analysis of these altered proteins, along with four additional alterations previously shown to affect IF2-ribosome interactions, indicates that multiple steps of translation are affected, consistent with bL12's interaction with multiple factors. Surprisingly, deletion of the release factor GTPase, RF3, has relatively little effect on bL12-promoted stop codon readthrough, suggesting that other steps in termination are also influenced by bL12.
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Affiliation(s)
- Adam D Younkin
- School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Steven T Gregory
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, 02881, USA
| | - Michael O'Connor
- School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, USA.
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Barrera A, Olguín V, Vera-Otarola J, López-Lastra M. Cap-independent translation initiation of the unspliced RNA of retroviruses. Biochim Biophys Acta Gene Regul Mech 2020; 1863:194583. [PMID: 32450258 DOI: 10.1016/j.bbagrm.2020.194583] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022]
Abstract
Retroviruses are a unique family of RNA viruses that utilize a virally encoded reverse transcriptase (RT) to replicate their genomic RNA (gRNA) through a proviral DNA intermediate. The provirus is permanently integrated into the host cell chromosome and is expressed by the host cell transcription, RNA processing, and translation machinery. Retroviral messenger RNAs (mRNAs) entirely resemble a cellular mRNA as they have a 5'cap structure, 5'untranslated region (UTR), an open reading frame (ORF), 3'UTR, and a 3'poly(A) tail. The primary transcription product interacts with the cellular RNA processing machinery and is spliced, exported to the cytoplasm, and translated. However, a proportion of the pre-mRNA subverts typical RNA processing giving rise to the full-length RNA. In the cytoplasm, the full-length retroviral RNA fulfills a dual role acting as mRNA and as the gRNA. Simple retroviruses generate two pools of full-length RNA, one for each purpose. However, complex retroviruses have a single pool of full-length RNA, which is destined for translation or encapsidation. As for eukaryotic mRNAs, translational control of retroviral protein synthesis is mostly exerted at the step of initiation. Interestingly, some retroviral mRNAs, both simple and complex, use a dual mechanism to initiate protein synthesis, a cap-dependent initiation mechanism, or via internal initiation using an internal ribosome entry site (IRES). In this review, we describe and discuss data regarding the molecular mechanism driving the canonical cap-dependent and IRES-mediated translation initiation for retroviral mRNA, focusing the discussion mainly on the most studied retroviral mRNA, the HIV-1 mRNA.
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Affiliation(s)
- Aldo Barrera
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Valeria Olguín
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Jorge Vera-Otarola
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Marcelo López-Lastra
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile.
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Mirzadeh K, Shilling PJ, Elfageih R, Cumming AJ, Cui HL, Rennig M, Nørholm MHH, Daley DO. Increased production of periplasmic proteins in Escherichia coli by directed evolution of the translation initiation region. Microb Cell Fact 2020; 19:85. [PMID: 32264894 PMCID: PMC7137448 DOI: 10.1186/s12934-020-01339-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 03/23/2020] [Indexed: 12/11/2022] Open
Abstract
Background Recombinant proteins are often engineered with an N-terminal signal peptide, which facilitates their secretion to the oxidising environment of the periplasm (gram-negative bacteria) or the culture supernatant (gram-positive bacteria). A commonly encountered problem is that the signal peptide influences the synthesis and secretion of the recombinant protein in an unpredictable manner. A molecular understanding of this phenomenon is highly sought after, as it could lead to improved methods for producing recombinant proteins in bacterial cell factories. Results Herein we demonstrate that signal peptides contribute to an unpredictable translation initiation region. A directed evolution approach that selects a new translation initiation region, whilst leaving the amino acid sequence of the signal peptide unchanged, can increase production levels of secreted recombinant proteins. The approach can increase production of single chain antibody fragments, hormones and other recombinant proteins in the periplasm of E. coli. Conclusions The study demonstrates that signal peptide performance is coupled to the efficiency of the translation initiation region.
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Affiliation(s)
- Kiavash Mirzadeh
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.,CloneOpt AB, Stockholm, Sweden
| | - Patrick J Shilling
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Rageia Elfageih
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Alister J Cumming
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Huanhuan L Cui
- Department of Medicine (Solna), Division of Microbial Pathogenesis, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Maja Rennig
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Morten H H Nørholm
- CloneOpt AB, Stockholm, Sweden.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Daniel O Daley
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden. .,CloneOpt AB, Stockholm, Sweden.
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Lomakin IB, De S, Wang J, Borkar AN, Steitz TA. Crystal structure of the C-terminal domain of DENR. Comput Struct Biotechnol J 2020; 18:696-704. [PMID: 32257053 PMCID: PMC7114459 DOI: 10.1016/j.csbj.2020.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 02/04/2023] Open
Abstract
The density regulated protein (DENR) forms a stable heterodimer with malignant T-cell-amplified sequence 1 (MCT-1). DENR-MCT-1 heterodimer then participates in regulation of non-canonical translation initiation and ribosomal recycling. The N-terminal domain of DENR interacts with MCT-1 and carries a classical tetrahedral zinc ion-binding site, which is crucial for the dimerization. DENR-MCT-1 binds the small (40S) ribosomal subunit through interactions between MCT-1 and helix h24 of the 18S rRNA, and through interactions between the C-terminal domain of DENR and helix h44 of the 18S rRNA. This later interaction occurs in the vicinity of the P site that is also the binding site for canonical translation initiation factor eIF1, which plays the key role in initiation codon selection and scanning. Sequence homology modeling and a low-resolution crystal structure of the DENR-MCT-1 complex with the human 40S subunit suggests that the C-terminal domain of DENR and eIF1 adopt a similar fold. Here we present the crystal structure of the C-terminal domain of DENR determined at 1.74 Å resolution, which confirms its resemblance to eIF1 and advances our understanding of the mechanism by which DENR-MCT-1 regulates non-canonical translation initiation and ribosomal recycling.
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Affiliation(s)
- Ivan B. Lomakin
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
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Rol-Moreno J, Kuhn L, Marzi S, Simonetti A. Grad-cryo-EM: Tool to Isolate Translation Initiation Complexes from Rabbit Reticulocyte Lysate Suitable for Structural Studies. Methods Mol Biol 2020; 2113:329-39. [PMID: 32006323 DOI: 10.1007/978-1-0716-0278-2_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Since its development, single-particle cryogenic electron microscopy (cryo-EM) has played a central role in the study at medium resolution of both bacterial and eukaryotic ribosomal complexes. With the advent of the direct electron detectors and new processing software which allow obtaining structures at atomic resolution, formerly obtained only by X-ray crystallography, cryo-EM has become the method of choice for the structural analysis of the translation machinery. In most of the cases, the ribosomal complexes at different stages of the translation process are assembled in vitro from purified components, which limit the analysis to previously well-characterized complexes with known factors composition. The initiation phase of the protein synthesis is a very dynamic process during which several proteins interact with the translation apparatus leading to the formation of a chronological series of initiation complexes (ICs). Here we describe a method to isolate ICs assembled on natural in vitro transcribed mRNA directly from rabbit reticulocyte lysate (RRL) by sucrose density gradient centrifugation . The Grad-cryo-EM approach allows investigating structures and composition of intermediate ribosomal complexes prepared in near-native condition by cryo-EM and mass spectrometry analyses. This is a powerful approach, which could be used to study translation initiation of any mRNAs, including IRES containing ones, and which could be adapted to different cell extracts.
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Abstract
Abstract CSDE1 (cold shock domain containing E1) plays a key role in translational reprogramming, which determines the fate of a number of RNAs during biological processes. Interestingly, the role of CSDE1 is bidirectional. It not only promotes and represses the translation of RNAs but also increases and decreases the abundance of RNAs. However, the mechanisms underlying this phenomenon are still unknown. In this review, we propose a “protein-RNA connector” model to explain this bidirectional role and depict its three versions: sequential connection, mutual connection and facilitating connection. As described in this molecular model, CSDE1 binds to RNAs and cooperates with other protein regulators. CSDE1 connects with different RNAs and their regulators for different purposes. The triple complex of CSDE1, a regulator and an RNA reprograms translation in different directions for each transcript. Meanwhile, a number of recent studies have found important roles for CSDE1 in human diseases. This model will help us to understand the role of CSDE1 in translational reprogramming and human diseases. Video Abstract
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Affiliation(s)
- Ao-Xiang Guo
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, 410078, People's Republic of China.,Institute of Clinical Pharmacology, Central South University; Hunan Key Laboratory of Pharmacogenetics, Changsha, 410078, People's Republic of China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, 110 Xiangya Road, Changsha, 410078, People's Republic of China.,National Clinical Research Center for Geriatric Disorders, 87 Xiangya Road, Changsha, 410008, Hunan, People's Republic of China
| | - Jia-Jia Cui
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, 410078, People's Republic of China.,Institute of Clinical Pharmacology, Central South University; Hunan Key Laboratory of Pharmacogenetics, Changsha, 410078, People's Republic of China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, 110 Xiangya Road, Changsha, 410078, People's Republic of China.,National Clinical Research Center for Geriatric Disorders, 87 Xiangya Road, Changsha, 410008, Hunan, People's Republic of China
| | - Lei-Yun Wang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, 410078, People's Republic of China.,Institute of Clinical Pharmacology, Central South University; Hunan Key Laboratory of Pharmacogenetics, Changsha, 410078, People's Republic of China.,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, 110 Xiangya Road, Changsha, 410078, People's Republic of China.,National Clinical Research Center for Geriatric Disorders, 87 Xiangya Road, Changsha, 410008, Hunan, People's Republic of China
| | - Ji-Ye Yin
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, 410078, People's Republic of China. .,Institute of Clinical Pharmacology, Central South University; Hunan Key Laboratory of Pharmacogenetics, Changsha, 410078, People's Republic of China. .,Engineering Research Center of Applied Technology of Pharmacogenomics, Ministry of Education, 110 Xiangya Road, Changsha, 410078, People's Republic of China. .,National Clinical Research Center for Geriatric Disorders, 87 Xiangya Road, Changsha, 410008, Hunan, People's Republic of China. .,Hunan Provincial Gynecological Cancer Diagnosis and Treatment Engineering Research Center, Changsha, 410078, People's Republic of China. .,Hunan Key Laboratory of Precise Diagnosis and Treatment of Gastrointestinal Tumor, Changsha, 410078, People's Republic of China.
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50
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Piecyk K, Lukaszewicz M, Kamel K, Janowska M, Pietrow P, Kmiecik S, Jankowska-Anyszka M. Isoxazole-containing 5' mRNA cap analogues as inhibitors of the translation initiation process. Bioorg Chem 2020; 96:103583. [PMID: 31972465 DOI: 10.1016/j.bioorg.2020.103583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 12/16/2019] [Accepted: 01/11/2020] [Indexed: 12/11/2022]
Abstract
Herein we describe a synthesis of new isoxazole-containing 5' mRNA cap analogues via a cycloaddition reaction. The obtained analogues show a capability to inhibit cap-dependent translation in vitro and are characterized by a new binding mode in which an isoxazolic ring, instead of guanine, is involved in the stacking effect. Our study provides valuable information toward designing new compounds that can be potentially used as anticancer therapeutics.
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