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Böttcher B, Kienast SD, Leufken J, Eggers C, Sharma P, Leufken CM, Morgner B, Drexler HCA, Schulz D, Allert S, Jacobsen ID, Vylkova S, Leidel SA, Brunke S. A highly conserved tRNA modification contributes to C. albicans filamentation and virulence. Microbiol Spectr 2024; 12:e0425522. [PMID: 38587411 PMCID: PMC11064501 DOI: 10.1128/spectrum.04255-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/18/2024] [Indexed: 04/09/2024] Open
Abstract
tRNA modifications play important roles in maintaining translation accuracy in all domains of life. Disruptions in the tRNA modification machinery, especially of the anticodon stem loop, can be lethal for many bacteria and lead to a broad range of phenotypes in baker's yeast. Very little is known about the function of tRNA modifications in host-pathogen interactions, where rapidly changing environments and stresses require fast adaptations. We found that two closely related fungal pathogens of humans, the highly pathogenic Candida albicans and its much less pathogenic sister species, Candida dubliniensis, differ in the function of a tRNA-modifying enzyme. This enzyme, Hma1, exhibits species-specific effects on the ability of the two fungi to grow in the hypha morphology, which is central to their virulence potential. We show that Hma1 has tRNA-threonylcarbamoyladenosine dehydratase activity, and its deletion alters ribosome occupancy, especially at 37°C-the body temperature of the human host. A C. albicans HMA1 deletion mutant also shows defects in adhesion to and invasion into human epithelial cells and shows reduced virulence in a fungal infection model. This links tRNA modifications to host-induced filamentation and virulence of one of the most important fungal pathogens of humans.IMPORTANCEFungal infections are on the rise worldwide, and their global burden on human life and health is frequently underestimated. Among them, the human commensal and opportunistic pathogen, Candida albicans, is one of the major causative agents of severe infections. Its virulence is closely linked to its ability to change morphologies from yeasts to hyphae. Here, this ability is linked-to our knowledge for the first time-to modifications of tRNA and translational efficiency. One tRNA-modifying enzyme, Hma1, plays a specific role in C. albicans and its ability to invade the host. This adds a so-far unknown layer of regulation to the fungal virulence program and offers new potential therapeutic targets to fight fungal infections.
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Affiliation(s)
- Bettina Böttcher
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Sandra D. Kienast
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Research Group for Cellular RNA Biochemistry, Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Johannes Leufken
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Research Group for Cellular RNA Biochemistry, Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Cristian Eggers
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Research Group for Cellular RNA Biochemistry, Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Puneet Sharma
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Research Group for Cellular RNA Biochemistry, Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Christine M. Leufken
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Bianka Morgner
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Hannes C. A. Drexler
- Bioanalytical Mass Spectrometry Unit, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Daniela Schulz
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Stefanie Allert
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Ilse D. Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Slavena Vylkova
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
| | - Sebastian A. Leidel
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Research Group for Cellular RNA Biochemistry, Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knoell Institute, Jena, Germany
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Shirokikh NE, Jensen KB, Thakor N. Editorial: RNA machines. Front Genet 2023; 14:1290420. [PMID: 37829284 PMCID: PMC10565666 DOI: 10.3389/fgene.2023.1290420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 09/18/2023] [Indexed: 10/14/2023] Open
Affiliation(s)
- Nikolay E. Shirokikh
- The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Kirk Blomquist Jensen
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Nehal Thakor
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, Canada
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3
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Reyes CJF, Asano K. Between Order and Chaos: Understanding the Mechanism and Pathology of RAN Translation. Biol Pharm Bull 2023; 46:139-146. [PMID: 36724941 DOI: 10.1248/bpb.b22-00448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Repeat-associated non-AUG (RAN) translation is a pathogenic mechanism in which repetitive sequences are translated into aggregation-prone proteins from multiple reading frames, even without a canonical AUG start codon. Since its discovery in spinocerebellar ataxia type 8 (SCA8) and myotonic dystrophy type 1 (DM1), RAN translation is now known to occur in the context of 12 disease-linked repeat expansions. This review discusses recent advances in understanding the regulatory mechanisms controlling RAN translation and its contribution to the pathophysiology of repeat expansion diseases. We discuss the key findings in the context of Fragile X Tremor Ataxia Syndrome (FXTAS), a neurodegenerative disorder caused by a CGG repeat expansion in the 5' untranslated region of FMR1.
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Affiliation(s)
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University.,Laboratory of Translational Control Study, Graduate School of Integrated Sciences for Life, Hiroshima University.,Hiroshima Research Center for Healthy Aging, Hiroshima University
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4
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Nishisaka H, Tomohiro T, Fukao A, Funakami Y, Fujiwara T. Neuronal RNA-Binding Protein HuD Interacts with Translation Initiation Factor eIF3. Biol Pharm Bull 2023; 46:158-162. [PMID: 36724943 DOI: 10.1248/bpb.b22-00478] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Translation initiation is the rate-limiting step of protein synthesis and is the main target of translation regulation. RNA-binding proteins (RBPs) are key mediators of the spatiotemporal control of translation and are critical for cell proliferation, development, and differentiation. We have previously shown that HuD, one of the neuronal RBPs, enhances cap-dependent translation through the direct interaction with eukaryotic initiation factor 4A (eIF4A) and poly(A) tail using a HeLa-derived in vitro translation system. We have also found that translation stimulation of HuD is essential for HuD-induced neurite outgrowth in PC12 cells. However, it remains unclear how HuD is involved in the regulation of translation initiation. Here, we report that HuD binds to eukaryotic initiation factor 3 (eIF3) via the eIF3b subunit, which belongs to the functional core of mammalian eIF3. eIF3 plays an essential role in recruiting the 40S ribosomal subunit onto mRNA in translation initiation. We hypothesize that the interaction between HuD and eIF3 stabilizes the translation initiation complex and increases translation efficiency. We also showed that the linker region of HuD is required for the interaction with eIF3b. Moreover, we found that eIF3b-binding region of HuD is conserved in all Hu proteins (HuB, HuC, HuD, and HuR). These data might also help to explain how Hu proteins stimulate translation in a cap- and poly(A)-dependent way.
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5
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Singh CR, Tani N, Nakamura A, Asano K. Mass spectrometry analysis of affinity-purified cytoplasmic translation initiation complexes from human and fly cells. STAR Protoc 2022; 3:101739. [PMID: 36181679 PMCID: PMC9529597 DOI: 10.1016/j.xpro.2022.101739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/25/2022] [Accepted: 09/08/2022] [Indexed: 11/05/2022] Open
Abstract
eIF5-mimic protein (5MP) controls translation through binding to the ribosomal pre-initiation complex (PIC) and alters non-AUG translation rates for cancer oncogenes and repeat-expansions in neurodegenerative diseases. Here, we describe a semi-quantitative protocol for detecting 5MP-associated proteins in cultured human and fly cells. We detail one-step anti-FLAG affinity purification and whole-lane mass spectrometry analysis of samples resolved by SDS-PAGE. This protocol allows for quantitative evaluation of the effect of 5MP mutations on its molecular interactions, to elucidate translational control by 5MP. For complete details on the use and execution of this protocol, please refer to Singh et al. (2021).
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Affiliation(s)
- Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA; Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA; Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
| | - Naoki Tani
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan.
| | - Akira Nakamura
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan.
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA; Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan; Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
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6
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Singh CR, Jaiswal R, Escalante CR, Asano K. Label-free protocol to quantify protein affinity using isothermal titration calorimetry and bio-layer interferometry of a human eIF5-mimic protein. STAR Protoc 2022; 3:101615. [PMID: 36035794 PMCID: PMC9403556 DOI: 10.1016/j.xpro.2022.101615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
eIF5-mimic protein (5MP) controls translation through its interaction with eukaryotic translation initiation factor (eIF) 2 and eIF3 and alters non-AUG translation rates for oncogenes in cancer and repeat expansions in neurodegenerative disease. To precisely evaluate the effect of 5MP mutations on binding affinity against eIFs, here we describe two label-free protocols of affinity measurement for 5MP binding to eIF2 or eIF3 protein segments, termed isothermal titration calorimetry (ITC) and bio-layer interferometry (BLI), starting with how to purify proteins used. For complete details on the use and execution of this protocol, please refer to Singh et al. (2021). Label-free protocols to quantify protein affinity Isothermal titration calorimetry or ITC titrates heat released by ligand injection Bio-layer interferometry or BLI titrates sensogram responses by ligand binding Protocols for protein purification by nickel-affinity chromatography are included
Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
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7
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Fujita Y, Kameda T, Singh CR, Pepper W, Cecil A, Hilgers M, Thornton M, Asano I, Moravek C, Togashi Y, Saito H, Asano K. Translational recoding by chemical modification of non-AUG start codon ribonucleotide bases. SCIENCE ADVANCES 2022; 8:eabm8501. [PMID: 35394828 DOI: 10.1126/sciadv.abm8501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In contrast to prokaryotes wherein GUG and UUG are permissive start codons, initiation frequencies from non-AUG codons are generally low in eukaryotes, with CUG being considered as strongest. Here, we report that combined 5-cytosine methylation (5mC) and pseudouridylation (Ψ) of near-cognate non-AUG start codons convert GUG and UUG initiation strongly favored over CUG initiation in eukaryotic translation under a certain context. This prokaryotic-like preference is attributed to enhanced NUG initiation by Ψ in the second base and reduced CUG initiation by 5mC in the first base. Molecular dynamics simulation analysis of tRNAiMet anticodon base pairing to the modified codons demonstrates that Ψ universally raises the affinity of codon:anticodon pairing within the ribosomal preinitiation complex through partially mitigating discrimination against non-AUG codons imposed by eukaryotic initiation factor 1. We propose that translational control by chemical modifications of start codon bases can offer a new layer of proteome diversity regulation and therapeutic mRNA technology.
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Affiliation(s)
- Yoshihiko Fujita
- Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Takeru Kameda
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-0046, Japan
- RIKEN Center for Biosystems Dynamics Research (BDR), Wako, Saitama 351-0198, Japan
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Whitney Pepper
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ariana Cecil
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Madelyn Hilgers
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Izumi Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Carter Moravek
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Yuichi Togashi
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
- Research Center for the Mathematics on Chromatin Live Dynamics (RcMcD), Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan 739-8530
- RIKEN Center for Biosystems Dynamics Research (BDR), Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - Hirohide Saito
- Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
- Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
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8
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Wang J, Teng Y, Zhang R, Wu Y, Lou L, Zou Y, Li M, Xie ZR, Yan Y. Engineering a PAM-flexible SpdCas9 variant as a universal gene repressor. Nat Commun 2021; 12:6916. [PMID: 34824292 PMCID: PMC8617050 DOI: 10.1038/s41467-021-27290-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 11/11/2021] [Indexed: 11/08/2022] Open
Abstract
The RNA-guided CRISPR-associated Cas9 proteins have been widely applied in programmable genome recombination, base editing or gene regulation in both prokaryotes and eukaryotes. SpCas9 from Streptococcus pyogenes is the most extensively engineered Cas9 with robust and manifold functionalities. However, one inherent limitation of SpCas9 is its stringent 5'-NGG-3' PAM requirement that significantly restricts its DNA target range. Here, to repurpose SpCas9 as a universal gene repressor, we generate and screen variants of the deactivated SpCas9 (SpdCas9) with relaxed 5'-CAT-3' PAM compatibility that can bind to the start codon ATG of almost any gene. Stepwise structure-guided mutations of the PAM-interacting residues and auxiliary PAM-proximal residues of the SpdNG (5'-NG-3' PAM) create a PAM-flexible variant SpdNG-LWQT that preferentially accommodates 5'-NRN-3' PAMs. SpdNG-LWQT is demonstrated to be effective in gene repression with the advantage of customizable sgRNA design in both Escherichia coli and Saccharomyces cerevisiae. This work validates the feasibility of purposeful PAM expansion of Cas9 towards signature PAMs and establishes a universal SpdCas9-based gene repressor.
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Affiliation(s)
- Jian Wang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Yuxi Teng
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Ruihua Zhang
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Yifei Wu
- School of Electrical and Computer Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Lei Lou
- School of Electrical and Computer Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Yusong Zou
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Michelle Li
- North Oconee High School, Bogart, GA, 30622, USA
| | - Zhong-Ru Xie
- School of Electrical and Computer Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA
| | - Yajun Yan
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, 30602, USA.
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9
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Singh CR, Glineburg MR, Moore C, Tani N, Jaiswal R, Zou Y, Aube E, Gillaspie S, Thornton M, Cecil A, Hilgers M, Takasu A, Asano I, Asano M, Escalante CR, Nakamura A, Todd PK, Asano K. Human oncoprotein 5MP suppresses general and repeat-associated non-AUG translation via eIF3 by a common mechanism. Cell Rep 2021; 36:109376. [PMID: 34260931 PMCID: PMC8363759 DOI: 10.1016/j.celrep.2021.109376] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/11/2021] [Accepted: 06/17/2021] [Indexed: 11/15/2022] Open
Abstract
eIF5-mimic protein (5MP) is a translational regulatory protein that binds the small ribosomal subunit and modulates its activity. 5MP is proposed to reprogram non-AUG translation rates for oncogenes in cancer, but its role in controlling non-AUG initiated synthesis of deleterious repeat-peptide products, such as FMRpolyG observed in fragile-X-associated tremor ataxia syndrome (FXTAS), is unknown. Here, we show that 5MP can suppress both general and repeat-associated non-AUG (RAN) translation by a common mechanism in a manner dependent on its interaction with eIF3. Essentially, 5MP displaces eIF5 through the eIF3c subunit within the preinitiation complex (PIC), thereby increasing the accuracy of initiation. In Drosophila, 5MP/Kra represses neuronal toxicity and enhances the lifespan in an FXTAS disease model. These results implicate 5MP in protecting cells from unwanted byproducts of non-AUG translation in neurodegeneration.
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Affiliation(s)
- Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Chelsea Moore
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Naoki Tani
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
| | - Rahul Jaiswal
- Department of Physiology and Biophysics, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298, USA
| | - Ye Zou
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Eric Aube
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Sarah Gillaspie
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ariana Cecil
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Madelyn Hilgers
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Azuma Takasu
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Izumi Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Masayo Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Carlos R Escalante
- Department of Physiology and Biophysics, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298, USA
| | - Akira Nakamura
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Ann Arbor VA Medical Center, Ann Arbor, MI 48105, USA
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA; Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan; Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan.
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10
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Li G, Lu A, Chen A, Geng S, Xu Y, Chen X, Yang J. BZW2/5MP1 acts as a promising target in hepatocellular carcinoma. J Cancer 2021; 12:5125-5135. [PMID: 34335929 PMCID: PMC8317536 DOI: 10.7150/jca.53282] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 06/09/2021] [Indexed: 11/17/2022] Open
Abstract
Basic leucine zipper and W2 domain 2 (BZW2), also known as 5MP1, is a protein related to translation regulation. Evidence from previous studies indicates that BZW2 is involved in tumorigenesis in several cancers. However, little is known about the role of BZW2 in hepatocellular carcinoma (HCC). In this study, we first analyzed the gene expression profile of BZW2 in multiple HCC datasets. Next, we explored the biological effects of BZW2 in HCC cell lines. BZW2 was overexpressed in different HCC cohorts. Multivariate analysis confirmed that increased BZW2 expression is an independent prognostic indicator of shorter overall survival. BZW2 coexpressed genes were mainly enriched in the biological processes of ribonucleoprotein complex biogenesis, rRNA metabolism, translational initiation, and negative regulation of metabolic processes. BZW2 depletion reduced proliferation, clonality, and invasion and increased apoptosis in MHCC97-H cells. Furthermore, BZW2 overexpression or knockdown enhanced or impaired c-Myc expression, respectively. Overall, these findings identified BZW2 as a biomarker of HCC and provided novel insight that the effect of BZW2 on the translatome is a potential mechanism that promotes HCC progression via the c-Myc pathway.
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Affiliation(s)
- Guoxiong Li
- Department of Gastroenterology, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Anqian Lu
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Anna Chen
- Department of Gastroenterology, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China.,Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Shuang Geng
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Yu Xu
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Xin Chen
- Department of Gastroenterology, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Jin Yang
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
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11
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Kameda T, Asano K, Togashi Y. Free energy landscape of RNA binding dynamics in start codon recognition by eukaryotic ribosomal pre-initiation complex. PLoS Comput Biol 2021; 17:e1009068. [PMID: 34125830 PMCID: PMC8224888 DOI: 10.1371/journal.pcbi.1009068] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 06/24/2021] [Accepted: 05/12/2021] [Indexed: 12/25/2022] Open
Abstract
Specific interaction between the start codon, 5'-AUG-3', and the anticodon, 5'-CAU-3', ensures accurate initiation of translation. Recent studies show that several near-cognate start codons (e.g. GUG and CUG) can play a role in initiating translation in eukaryotes. However, the mechanism allowing initiation through mismatched base-pairs at the ribosomal decoding site is still unclear at an atomic level. In this work, we propose an extended simulation-based method to evaluate free energy profiles, through computing the distance between each base-pair of the triplet interactions involved in recognition of start codons in eukaryotic translation pre-initiation complex. Our method provides not only the free energy penalty for mismatched start codons relative to the AUG start codon, but also the preferred pathways of transitions between bound and unbound states, which has not been described by previous studies. To verify the method, the binding dynamics of cognate (AUG) and near-cognate start codons (CUG and GUG) were simulated. Evaluated free energy profiles agree with experimentally observed changes in initiation frequencies from respective codons. This work proposes for the first time how a G:U mismatch at the first position of codon (GUG)-anticodon base-pairs destabilizes the accommodation in the initiating eukaryotic ribosome and how initiation at a CUG codon is nearly as strong as, or sometimes stronger than, that at a GUG codon. Our method is expected to be applied to study the affinity changes for various mismatched base-pairs.
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Affiliation(s)
- Takeru Kameda
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
- RIKEN Center for Biosystems Dynamics Research (BDR), Wako, Saitama, Japan
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
- Hiroshima Research Center for Healthy Aging (HiHA), Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Yuichi Togashi
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
- Research Center for the Mathematics on Chromatin Live Dynamics (RcMcD), Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
- RIKEN Center for Biosystems Dynamics Research (BDR), Higashi-Hiroshima, Hiroshima, Japan
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12
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Asano K. Origin of translational control by eIF2α phosphorylation: insights from genome-wide translational profiling studies in fission yeast. Curr Genet 2021; 67:359-368. [PMID: 33420908 PMCID: PMC8140999 DOI: 10.1007/s00294-020-01149-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 12/09/2020] [Accepted: 12/14/2020] [Indexed: 01/14/2023]
Abstract
During amino acid limitation, the protein kinase Gcn2 phosphorylates the α subunit of eIF2, thereby regulating mRNA translation. In yeast Saccharomyces cerevisiae and mammals, eIF2α phosphorylation regulates translation of related transcription factors Gcn4 and Atf4 through upstream open reading frames (uORFs) to activate transcription genome wide. However, mammals encode three more eIF2α kinases activated by distinct stimuli. Did the translational control system involving eIF2α phosphorylation evolve from so simple (as found in yeast S. cerevisiae) to complex (as found in humans)? Recent genome-wide translational profiling studies of amino acid starvation response in the fission yeast Schizosaccharomyces pombe provide an unexpected answer to this question.
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Affiliation(s)
- Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS, 66506, USA.
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8530, Japan.
- Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8530, Japan.
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13
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de Breyne S, Vindry C, Guillin O, Condé L, Mure F, Gruffat H, Chavatte L, Ohlmann T. Translational control of coronaviruses. Nucleic Acids Res 2020; 48:12502-12522. [PMID: 33264393 PMCID: PMC7736815 DOI: 10.1093/nar/gkaa1116] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 12/14/2022] Open
Abstract
Coronaviruses represent a large family of enveloped RNA viruses that infect a large spectrum of animals. In humans, the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is responsible for the current COVID-19 pandemic and is genetically related to SARS-CoV and Middle East respiratory syndrome-related coronavirus (MERS-CoV), which caused outbreaks in 2002 and 2012, respectively. All viruses described to date entirely rely on the protein synthesis machinery of the host cells to produce proteins required for their replication and spread. As such, virus often need to control the cellular translational apparatus to avoid the first line of the cellular defense intended to limit the viral propagation. Thus, coronaviruses have developed remarkable strategies to hijack the host translational machinery in order to favor viral protein production. In this review, we will describe some of these strategies and will highlight the role of viral proteins and RNAs in this process.
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Affiliation(s)
- Sylvain de Breyne
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Caroline Vindry
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Olivia Guillin
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Lionel Condé
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Fabrice Mure
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Henri Gruffat
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Laurent Chavatte
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Théophile Ohlmann
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
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14
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Ma S, Dong Z, Cui Q, Liu JY, Zhang JT. eIF3i regulation of protein synthesis, cell proliferation, cell cycle progression, and tumorigenesis. Cancer Lett 2020; 500:11-20. [PMID: 33301799 DOI: 10.1016/j.canlet.2020.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/22/2020] [Accepted: 12/06/2020] [Indexed: 02/07/2023]
Abstract
eIF3i, a 36-kDa protein, is a putative subunit of the eIF3 complex important for translation initiation of mRNAs. It is a WD40 domain-containing protein with seven WD40 repeats that forms a β-propeller structure with an important function in pre-initiation complex formation and mRNA translation initiation. In addition to participating in the eIF3 complex formation for global translational control, eIF3i may bind to specific mRNAs and regulate their translation individually. Furthermore, eIF3i has been shown to bind to TGF-β type II receptor and participate in TGF-β signaling. It may also participate in and regulate other signaling pathways including Wnt/β-catenin pathway via translational regulation of COX-2 synthesis. These multiple canonical and noncanonical functions of eIF3i in translational control and in regulating signal transduction pathways may be responsible for its role in cell differentiation, cell cycle regulation, proliferation, and tumorigenesis. In this review, we will critically evaluate recent progresses and assess future prospects in studying eIF3i.
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Affiliation(s)
- Shijie Ma
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong, 510095, China.
| | - Zizheng Dong
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, 43614, USA
| | - Qingbin Cui
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, 43614, USA
| | - Jing-Yuan Liu
- Department of Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, OH, 43614, USA.
| | - Jian-Ting Zhang
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, 43614, USA.
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15
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Unusually efficient CUG initiation of an overlapping reading frame in POLG mRNA yields novel protein POLGARF. Proc Natl Acad Sci U S A 2020; 117:24936-24946. [PMID: 32958672 DOI: 10.1073/pnas.2001433117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
While near-cognate codons are frequently used for translation initiation in eukaryotes, their efficiencies are usually low (<10% compared to an AUG in optimal context). Here, we describe a rare case of highly efficient near-cognate initiation. A CUG triplet located in the 5' leader of POLG messenger RNA (mRNA) initiates almost as efficiently (∼60 to 70%) as an AUG in optimal context. This CUG directs translation of a conserved 260-triplet-long overlapping open reading frame (ORF), which we call POLGARF (POLG Alternative Reading Frame). Translation of a short upstream ORF 5' of this CUG governs the ratio between POLG (the catalytic subunit of mitochondrial DNA polymerase) and POLGARF synthesized from a single POLG mRNA. Functional investigation of POLGARF suggests a role in extracellular signaling. While unprocessed POLGARF localizes to the nucleoli together with its interacting partner C1QBP, serum stimulation results in rapid cleavage and secretion of a POLGARF C-terminal fragment. Phylogenetic analysis shows that POLGARF evolved ∼160 million y ago due to a mammalian-wide interspersed repeat (MIR) transposition into the 5' leader sequence of the mammalian POLG gene, which became fixed in placental mammals. This discovery of POLGARF unveils a previously undescribed mechanism of de novo protein-coding gene evolution.
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16
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Chikashige Y, Kato H, Thornton M, Pepper W, Hilgers M, Cecil A, Asano I, Yamada H, Mori C, Brunkow C, Moravek C, Urano T, Singh CR, Asano K. Gcn2 eIF2α kinase mediates combinatorial translational regulation through nucleotide motifs and uORFs in target mRNAs. Nucleic Acids Res 2020; 48:8977-8992. [PMID: 32710633 PMCID: PMC7498311 DOI: 10.1093/nar/gkaa608] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/06/2020] [Accepted: 07/24/2020] [Indexed: 12/14/2022] Open
Abstract
The protein kinase Gcn2 is a central transducer of nutritional stress signaling important for stress adaptation by normal cells and the survival of cancer cells. In response to nutrient deprivation, Gcn2 phosphorylates eIF2α, thereby repressing general translation while enhancing translation of specific mRNAs with upstream ORFs (uORFs) situated in their 5'-leader regions. Here we performed genome-wide measurements of mRNA translation during histidine starvation in fission yeast Schizosaccharomyces pombe. Polysome analyses were combined with microarray measurements to identify gene transcripts whose translation was up-regulated in response to the stress in a Gcn2-dependent manner. We determined that translation is reprogrammed to enhance RNA metabolism and chromatin regulation and repress ribosome synthesis. Interestingly, translation of intron-containing mRNAs was up-regulated. The products of the regulated genes include additional eIF2α kinase Hri2 amplifying the stress signaling and Gcn5 histone acetyl transferase and transcription factors, together altering genome-wide transcription. Unique dipeptide-coding uORFs and nucleotide motifs, such as '5'-UGA(C/G)GG-3', are found in 5' leader regions of regulated genes and shown to be responsible for translational control.
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Affiliation(s)
- Yuji Chikashige
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Hyogo 651-2492, Japan
| | - Hiroaki Kato
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Whitney Pepper
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Madelyn Hilgers
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ariana Cecil
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Izumi Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Haana Yamada
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
- Department of Advanced Transdisciplinary Sciences, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Chie Mori
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Hyogo 651-2492, Japan
| | - Cheyenne Brunkow
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Carter Moravek
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Takeshi Urano
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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17
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Horie F, Endo K, Ito K. Artificial Protein-Responsive Riboswitches Upregulate Non-AUG Translation Initiation in Yeast. ACS Synth Biol 2020; 9:1623-1631. [PMID: 32531157 DOI: 10.1021/acssynbio.0c00206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Artificial control of gene expression is one of the core technologies for engineering biological systems. Riboswitches are cis-acting elements on mRNA that regulate gene expression in a ligand-dependent manner often seen in prokaryotes, but rarely in eukaryotes. Because of the poor variety of such elements available in eukaryotic systems, the number of artificially engineered eukaryotic riboswitches, especially of the upregulation type, is still limited. Here, we developed a design principle for upregulation-type riboswitches that utilize non-AUG initiation induced by ribosomal stalling in a ligand-dependent manner in Saccharomyces cerevisiae. Our design principle simply required the proper positioning of a near-cognate start codon relative to the RNA aptamer. Intriguingly, the CUG codon was the most preferable for non-AUG ON switches in terms of output level and switch performance. This work establishes novel choices for artificial genetic control in eukaryotes with versatile potential for industrial and biomedical applications as well as basic research.
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Affiliation(s)
- Fumihiro Horie
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Kei Endo
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Koichi Ito
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
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18
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Faisal MB, Gechev TS, Mueller-Roeber B, Dijkwel PP. Putative alternative translation start site-encoding nucleotides of CPR5 regulate growth and resistance. BMC PLANT BIOLOGY 2020; 20:295. [PMID: 32600419 PMCID: PMC7322872 DOI: 10.1186/s12870-020-02485-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The Arabidopsis CONSTITUTIVE EXPRESSER of PATHOGENESIS-RELATED GENES 5 (CPR5) has recently been shown to play a role in gating as part of the nuclear pore complex (NPC). Mutations in CPR5 cause multiple defects, including aberrant trichomes, reduced ploidy levels, reduced growth and enhanced resistance to bacterial and fungal pathogens. The pleiotropic nature of cpr5 mutations implicates that the CPR5 protein affects multiple pathways. However, little is known about the structural features that allow CPR5 to affect the different pathways. RESULTS Our in silico studies suggest that in addition to three clusters of putative nuclear localization signals and four or five transmembrane domains, CPR5 contains two putative alternative translation start sites. To test the role of the methionine-encoding nucleotides implicated in those sites, metCPR5 cDNAs, in which the relevant nucleotides were changed to encode glutamine, were fused to the CPR5 native promoter and the constructs transformed to cpr5-2 plants to complement cpr5-compromised phenotypes. The control and metCPR5 constructs were able to complement all cpr5 phenotypes, although the extent of complementation depended on the specific complementing plant lines. Remarkably, plants transformed with metCPR5 constructs showed larger leaves and displayed reduced resistance when challenged to Pseudomonas syringae pv Pst DC3000, as compared to control plants. Thus, the methionine-encoding nucleotides regulate growth and resistance. We propose that structural features of the CPR5 N-terminus are implicated in selective gating of proteins involved in regulating the balance between growth and resistance. CONCLUSION Plants need to carefully balance the amount of resources used for growth and resistance. The Arabidopsis CPR5 protein regulates plant growth and immunity. Here we show that N-terminal features of CPR5 are involved in the regulation of the balance between growth and resistance. These findings may benefit efforts to improve plant yield, while maintaining optimal levels of disease resistance.
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Affiliation(s)
- Muhammad B Faisal
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Tsanko S Gechev
- Center of Plant Systems Biology and Biotechnology, 4000, Plovdiv, Bulgaria
| | - Bernd Mueller-Roeber
- Center of Plant Systems Biology and Biotechnology, 4000, Plovdiv, Bulgaria
- Department of Molecular Biology, Institute of Biochemistry and Biology, University of Potsdam, 14476, Potsdam, Germany
| | - Paul P Dijkwel
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
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19
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Manjunath H, Zhang H, Rehfeld F, Han J, Chang TC, Mendell JT. Suppression of Ribosomal Pausing by eIF5A Is Necessary to Maintain the Fidelity of Start Codon Selection. Cell Rep 2019; 29:3134-3146.e6. [PMID: 31801078 PMCID: PMC6917043 DOI: 10.1016/j.celrep.2019.10.129] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/19/2019] [Accepted: 10/30/2019] [Indexed: 12/12/2022] Open
Abstract
Sequences within 5' UTRs dictate the site and efficiency of translation initiation. In this study, an unbiased screen designed to interrogate the 5' UTR-mediated regulation of the growth-promoting gene MYC unexpectedly revealed the ribosomal pause relief factor eIF5A as a regulator of translation initiation codon selection. Depletion of eIF5A enhances upstream translation within 5' UTRs across yeast and human transcriptomes, including on the MYC transcript, where this results in increased production of an N-terminally extended protein. Furthermore, ribosome profiling experiments established that the function of eIF5A as a suppressor of ribosomal pausing at sites of suboptimal peptide bond formation is conserved in human cells. We present evidence that proximal ribosomal pausing on a transcript triggers enhanced use of upstream suboptimal or non-canonical initiation codons. Thus, we propose that eIF5A functions not only to maintain efficient translation elongation in eukaryotic cells but also to maintain the fidelity of translation initiation.
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Affiliation(s)
- Hema Manjunath
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - He Zhang
- Quantitative Biomedical Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8821, USA; Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390-8821, USA
| | - Frederick Rehfeld
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - Jaeil Han
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - Tsung-Cheng Chang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - Joshua T Mendell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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20
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Ye Y, Chen M, Kato K, Yao M. The pH-dependent conformational change of eukaryotic translation initiation factor 5: Insights into partner-binding manner. Biochem Biophys Res Commun 2019; 519:186-191. [PMID: 31492496 DOI: 10.1016/j.bbrc.2019.08.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 08/23/2019] [Indexed: 10/26/2022]
Abstract
In the process of eukaryotic translation, the formation of preinitiation complex 43S, which consists of a 40S subunit, the eIF2-GTP-Met-tRNAiMet ternary complex, eIF3, eIF1, eIF1A, and eIF5, is essential for translational quality control. Of those factors, eIF5 promotes the hydrolysis of eIF2-bound GTP to release eIF2-GDP in the complex for the recycling of eIF2. eIF5 appears to bind to the β subunit of eIF2 (eIF2β) via an interaction between aromatic/acidic residue-rich regions (AA-boxes) in the C-terminal domain of eIF5 (eIF5CTD) and three lysine clusters (K-boxes) in the N-terminal domain of eIF2β (eIF2βNTD). However, the details of this interaction are unclear, due to the lack of a structure for the eIF5-eIF2β complex, and the unavailability of an intact structure of eIF5, in which the AA-boxes are always disordered, with high flexibility. In this study, we solved two crystal structures of eIF5CTD from Candida albicans, which for the first time showed the AA-box2 of eIF5 presenting as an ordered helical structure. The structures exhibited different arrangements of AA-box2 under different pH values, which may reflect the dynamic nature of the interactions of eIF5CTD, and eIF2βNTD in the preinitiation complex.
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Affiliation(s)
- Yuxin Ye
- Faculty of Advanced Life Science, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo, 060-0810, Japan
| | - Meirong Chen
- Faculty of Advanced Life Science, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo, 060-0810, Japan; College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Koji Kato
- Faculty of Advanced Life Science, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo, 060-0810, Japan
| | - Min Yao
- Faculty of Advanced Life Science, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo, 060-0810, Japan.
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21
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Control of Translation at the Initiation Phase During Glucose Starvation in Yeast. Int J Mol Sci 2019; 20:ijms20164043. [PMID: 31430885 PMCID: PMC6720308 DOI: 10.3390/ijms20164043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/10/2019] [Accepted: 08/15/2019] [Indexed: 12/13/2022] Open
Abstract
Glucose is one of the most important sources of carbon across all life. Glucose starvation is a key stress relevant to all eukaryotic cells. Glucose starvation responses have important implications in diseases, such as diabetes and cancer. In yeast, glucose starvation causes rapid and dramatic effects on the synthesis of proteins (mRNA translation). Response to glucose deficiency targets the initiation phase of translation by different mechanisms and with diverse dynamics. Concomitantly, translationally repressed mRNAs and components of the protein synthesis machinery may enter a variety of cytoplasmic foci, which also form with variable kinetics and may store or degrade mRNA. Much progress has been made in understanding these processes in the last decade, including with the use of high-throughput/omics methods of RNA and RNA:protein detection. This review dissects the current knowledge of yeast reactions to glucose starvation systematized by the stage of translation initiation, with the focus on rapid responses. We provide parallels to mechanisms found in higher eukaryotes, such as metazoans, for the most critical responses, and point out major remaining gaps in knowledge and possible future directions of research on translational responses to glucose starvation.
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22
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Sato K, Masuda T, Hu Q, Tobo T, Gillaspie S, Niida A, Thornton M, Kuroda Y, Eguchi H, Nakagawa T, Asano K, Mimori K. Novel oncogene 5MP1 reprograms c-Myc translation initiation to drive malignant phenotypes in colorectal cancer. EBioMedicine 2019; 44:387-402. [PMID: 31175057 PMCID: PMC6606960 DOI: 10.1016/j.ebiom.2019.05.058] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/26/2019] [Accepted: 05/28/2019] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Translational reprogramming through controlled initiation from non-AUG start codons is considered a crucial driving force in tumorigenesis and tumor progression. However, its clinical impact and underlying mechanism are not fully understood. METHODS Using a bioinformatics approach, we identified translation initiation regulator 5MP1/BZW2 on chromosome 7p as a potential oncogenic driver gene in colorectal cancer (CRC), and explored the biological effect of 5MP1 in CRC in vitro or in vivo. Pathway analysis was performed to identify the downstream target of 5MP1, which was verified with transcriptomic and biochemical analyses. Finally, we assessed the clinical significance of 5MP1 expression in CRC patients. FINDINGS 5MP1 was ubiquitously amplified and overexpressed in CRC. 5MP1 promoted tumor growth and induced cell cycle progression of CRC. c-Myc was identified as its potential downstream effector. c-Myc has two in-frame start codons, AUG and CUG (non-AUG) located upstream of the AUG. 5MP1 expression increased the AUG-initiated c-Myc isoform relative to the CUG-initiated isoform. The AUG-initiated c-Myc isoform displayed higher protein stability and a stronger transactivation activity for oncogenic pathways than the CUG-initiated isoform, accounting for 5MP1-driven cell cycle progression and tumor growth. Clinically, high 5MP1 expression predicts poor survival of CRC patients. INTERPRETATION 5MP1 is a novel oncogene that reprograms c-Myc translation in CRC. 5MP1 could be a potential therapeutic target to overcome therapeutic resistance conferred by tumor heterogeneity of CRC. FUND: Japan Society for the Promotion of Science; Priority Issue on Post-K computer; National Institutes of Health; National Science Foundation; KSU Johnson Cancer Center.
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Affiliation(s)
- Kuniaki Sato
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan; Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Higashi-ku, Fukuoka, Fukuoka 860-8556, Japan
| | - Takaaki Masuda
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Qingjiang Hu
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Taro Tobo
- Department of Clinical Laboratory Medicine and Pathology, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Sarah Gillaspie
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Atsushi Niida
- Division of Health Medical Computational Science, Health Intelligence Center, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Yousuke Kuroda
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Hidetoshi Eguchi
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Takashi Nakagawa
- Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Higashi-ku, Fukuoka, Fukuoka 860-8556, Japan
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Koshi Mimori
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan.
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Antony A C, Ram AK, Dutta K, Alone PV. Ribosomal mutation in helix 32 of 18S rRNA alters fidelity of eukaryotic translation start site selection. FEBS Lett 2019; 593:852-867. [PMID: 30900251 DOI: 10.1002/1873-3468.13369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 03/14/2019] [Accepted: 03/18/2019] [Indexed: 11/09/2022]
Abstract
The 40S ribosome plays a critical role in start codon selection. To gain insights into the role of its 18S rRNA in start codon selection, a suppressor screen was performed that suppressed the preferential UUG start codon recognition (Suppressor of initiation codon: Sui- phenotype) associated with the eIF5G31R mutant. The C1209U mutation in helix h32 of 18S rRNA was found to suppress the Sui- and Gcn- (failure to derepress GCN4 expression) phenotype of the eIF5G31R mutant. The C1209U mutation suppressed Sui- and Gcd- (constitutive derepression of GCN4 expression) phenotype of eIF2βS264Y , eIF1K60E , and eIF1A-ΔC mutation. We propose that the C1209U mutation in 40S ribosomal may perturb the premature head rotation in 'Closed/PIN ' state and enhance the stringency of translation start site selection.
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Affiliation(s)
- Charles Antony A
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Anup Kumar Ram
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Kalloly Dutta
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
| | - Pankaj V Alone
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India.,Homi Bhabha National Institute (HBNI), Mumbai, India
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24
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Pierce BL, Tong L, Dean S, Argos M, Jasmine F, Rakibuz-Zaman M, Sarwar G, Islam MT, Shahriar H, Islam T, Rahman M, Yunus M, Lynch VJ, Oglesbee D, Graziano JH, Kibriya MG, Gamble MV, Ahsan H. A missense variant in FTCD is associated with arsenic metabolism and toxicity phenotypes in Bangladesh. PLoS Genet 2019; 15:e1007984. [PMID: 30893314 PMCID: PMC6443193 DOI: 10.1371/journal.pgen.1007984] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 04/01/2019] [Accepted: 01/23/2019] [Indexed: 12/02/2022] Open
Abstract
Inorganic arsenic (iAs) is a carcinogen, and exposure to iAs via food and water is a global public health problem. iAs-contaminated drinking water alone affects >100 million people worldwide, including ~50 million in Bangladesh. Once absorbed into the blood stream, most iAs is converted to mono-methylated (MMA) and then di-methylated (DMA) forms, facilitating excretion in urine. Arsenic metabolism efficiency varies among individuals, in part due to genetic variation near AS3MT (arsenite methyltransferase; 10q24.32). To identify additional arsenic metabolism loci, we measured protein-coding variants across the human exome for 1,660 Bangladeshi individuals participating in the Health Effects of Arsenic Longitudinal Study (HEALS). Among the 19,992 coding variants analyzed exome-wide, the minor allele (A) of rs61735836 (p.Val101Met) in exon 3 of FTCD (formiminotransferase cyclodeaminase) was associated with increased urinary iAs% (P = 8x10-13), increased MMA% (P = 2x10-16) and decreased DMA% (P = 6x10-23). Among 2,401 individuals with arsenic-induced skin lesions (an indicator of arsenic toxicity and cancer risk) and 2,472 controls, carrying the low-efficiency A allele (frequency = 7%) was associated with increased skin lesion risk (odds ratio = 1.35; P = 1x10-5). rs61735836 is in weak linkage disequilibrium with all nearby variants. The high-efficiency/major allele (G/Valine) is human-specific and eliminates a start codon at the first 5´-proximal Kozak sequence in FTCD, suggesting selection against an alternative translation start site. FTCD is critical for catabolism of histidine, a process that generates one-carbon units that can enter the one-carbon/folate cycle, which provides methyl groups for arsenic metabolism. In our study population, FTCD and AS3MT SNPs together explain ~10% of the variation in DMA% and support a causal effect of arsenic metabolism efficiency on arsenic toxicity (i.e., skin lesions). In summary, this work identifies a coding variant in FTCD associated with arsenic metabolism efficiency, providing new evidence supporting the established link between one-carbon/folate metabolism and arsenic toxicity.
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Affiliation(s)
- Brandon L. Pierce
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States of America
- Department of Human Genetics, The University of Chicago, Chicago, IL, United States of America
- Comprehensive Cancer Center, The University of Chicago, Chicago, IL United States of America
| | - Lin Tong
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States of America
| | - Samantha Dean
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States of America
| | - Maria Argos
- Division of Epidemiology and Biostatistics, University of Illinois at Chicago, Chicago, IL, United States of America
| | - Farzana Jasmine
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States of America
| | | | - Golam Sarwar
- UChicago Research Bangladesh, Mohakhali, Dhaka, Bangladesh
| | | | - Hasan Shahriar
- UChicago Research Bangladesh, Mohakhali, Dhaka, Bangladesh
| | - Tariqul Islam
- UChicago Research Bangladesh, Mohakhali, Dhaka, Bangladesh
| | - Mahfuzar Rahman
- UChicago Research Bangladesh, Mohakhali, Dhaka, Bangladesh
- Research and Evaluation Division, BRAC, Dhaka, Bangladesh
| | - Md. Yunus
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Vincent J. Lynch
- Department of Human Genetics, The University of Chicago, Chicago, IL, United States of America
| | - Devin Oglesbee
- Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, United States of America
| | - Joseph H. Graziano
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States of America
| | - Muhammad G. Kibriya
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States of America
| | - Mary V. Gamble
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States of America
| | - Habibul Ahsan
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States of America
- Department of Human Genetics, The University of Chicago, Chicago, IL, United States of America
- Comprehensive Cancer Center, The University of Chicago, Chicago, IL United States of America
- Department of Medicine, The University of Chicago, Chicago, IL, United States of America
- Institute for Population and Precision Health, The University of Chicago, Chicago, IL, United States of America
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25
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Abad-Navarro F, de la Morena-Barrio ME, Fernández-Breis JT, Corral J. Lost in translation: bioinformatic analysis of variations affecting the translation initiation codon in the human genome. Bioinformatics 2018; 34:3788-3794. [PMID: 29868922 DOI: 10.1093/bioinformatics/bty453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 05/30/2018] [Indexed: 11/12/2022] Open
Abstract
Motivation Translation is a key biological process controlled in eukaryotes by the initiation AUG codon. Variations affecting this codon may have pathological consequences by disturbing the correct initiation of translation. Unfortunately, there is no systematic study describing these variations in the human genome. Moreover, we aimed to develop new tools for in silico prediction of the pathogenicity of gene variations affecting AUG codons, because to date, these gene defects have been wrongly classified as missense. Results Whole-exome analysis revealed the mean of 12 gene variations per person affecting initiation codons, mostly with high (>0.01) minor allele frequency (MAF). Moreover, analysis of Ensembl data (December 2017) revealed 11 261 genetic variations affecting the initiation AUG codon of 7205 genes. Most of these variations (99.5%) have low or unknown MAF, probably reflecting deleterious consequences. Only 62 variations had high MAF. Genetic variations with high MAF had closer alternative AUG downstream codons than did those with low MAF. Besides, the high-MAF group better maintained both the signal peptide and reading frame. These differentiating elements could help to determine the pathogenicity of this kind of variation. Availability and implementation Data and scripts in Perl and R are freely available at https://github.com/fanavarro/hemodonacion. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Francisco Abad-Navarro
- Departamento de Informática y Sistemas, Universidad de Murcia, IMIB-Arrixaca, Murcia, Spain
| | - María Eugenia de la Morena-Barrio
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, Murcia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Spain
| | | | - Javier Corral
- Servicio de Hematología y Oncología Médica, Hospital Universitario Morales Meseguer, Centro Regional de Hemodonación, Universidad de Murcia, IMIB-Arrixaca, Murcia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Spain
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26
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Sheshukova EV, Komarova TV, Ershova NM, Bronstein AM, Dorokhov YL. The Expression of Matryoshka Gene Encoding a Homologue of Kunitz Peptidase Inhibitor Is Regulated Both at the Level of Transcription and Translation. BIOCHEMISTRY. BIOKHIMIIA 2018; 83:1255-1262. [PMID: 30472962 DOI: 10.1134/s0006297918100103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/05/2018] [Indexed: 11/23/2022]
Abstract
The gene for Kunitz peptidase inhibitor-like protein (KPILP) contains nested alternative open reading frame (aORF) that controls expression of the maternal mRNA. The content of NbKPILP mRNA in intact leaves of Nicotiana benthamiana plant is low but increases significantly upon extended dark exposure or when foreign nucleic acid is overexpressed in the cells. The NbKPILP gene promoter along with the expressed nested aORF are likely to play an important role in maintaining the levels of NbKPILP mRNA. To elucidate the role of NbKPILP promoter, we isolated a fragment of N. benthamiana chromosomal DNA upstream of the NbKPILP transcription start, sequenced it, and created constructs in which reporter E. coli uidA gene coding for β-D-glucuronidase (GUS) was placed under control of the NbKPILP promoter. By assessing the efficacy of uidA mRNA synthesis directed by the NbKPILP promoter and 35S promoter of the cauliflower mosaic virus in a transient expression system, we showed that the levels of GUS accumulation were comparable for both promoters. Prolonged incubation of the agroinjected plants in the darkness stimulated accumulation of the uidA mRNA directed by the NbKPILP promoter. Our experiments indicate that along with regulation at the transcriptional level, expression of NbKPILP mRNA can be affected by expression of the nested aORF controlled by the polypurine block (PPB) located upstream of its start codon, since introduction of mutations in the PPB resulted in significant accumulation of the NbKPILP mRNA. Nucleotide replacement in the aORF start codon led to the drastic increase in the amounts of NbKPILP mRNA and its protein product.
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Affiliation(s)
- E V Sheshukova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - T V Komarova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - N M Ershova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A M Bronstein
- Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - Y L Dorokhov
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia.
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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27
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Lin KY, Nag N, Pestova TV, Marintchev A. Human eIF5 and eIF1A Compete for Binding to eIF5B. Biochemistry 2018; 57:5910-5920. [PMID: 30211544 DOI: 10.1021/acs.biochem.8b00839] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Eukaryotic translation initiation is a multistep process requiring a number of eukaryotic translation initiation factors (eIFs). Two GTPases play key roles in the process. eIF2 brings the initiator Met-tRNAi to the preinitiation complex (PIC). Upon start codon selection and GTP hydrolysis promoted by the GTPase-activating protein (GAP) eIF5, eIF2-GDP is displaced from Met-tRNAi by eIF5B-GTP and is released in complex with eIF5. eIF5B promotes ribosomal subunit joining, with the help of eIF1A. Upon subunit joining, eIF5B hydrolyzes GTP and is released together with eIF1A. We found that human eIF5 interacts with eIF5B and may help recruit eIF5B to the PIC. An eIF5B-binding motif was identified at the C-terminus of eIF5, similar to that found in eIF1A. Indeed, eIF5 competes with eIF1A for binding and has an ∼100-fold higher affinity for eIF5B. Because eIF5 is the GAP of eIF2, the newly discovered interaction offers a possible mechanism for coordination between the two steps in translation initiation controlled by GTPases: start codon selection and ribosomal subunit joining. Our results indicate that in humans, eIF5B displacing eIF2 from Met-tRNAi upon subunit joining may be coupled to eIF1A displacing eIF5 from eIF5B, allowing the eIF5:eIF2-GDP complex to leave the ribosome.
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Affiliation(s)
- Kai Ying Lin
- Department of Physiology & Biophysics , Boston University School of Medicine , Boston , Massachusetts 02118 , United States
| | - Nabanita Nag
- Department of Physiology & Biophysics , Boston University School of Medicine , Boston , Massachusetts 02118 , United States
| | - Tatyana V Pestova
- Department of Cell Biology , State University of New York, Downstate Medical Center , Brooklyn , New York 11203 , United States
| | - Assen Marintchev
- Department of Physiology & Biophysics , Boston University School of Medicine , Boston , Massachusetts 02118 , United States
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28
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Biochemical and cellular consequences of the antithrombin p.Met1? mutation identified in a severe thrombophilic family. Oncotarget 2018; 9:33202-33214. [PMID: 30237862 PMCID: PMC6145704 DOI: 10.18632/oncotarget.26059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 07/31/2018] [Indexed: 11/25/2022] Open
Abstract
Nature is always the best inspiration for basic research. A family with severe thrombosis and antithrombin deficiency, the strongest anticoagulant, carried a new mutation affecting the translation-start codon of SERPINC1, the gene encoding antithrombin. Expression of this variant in a eukaryotic cell system produced three different antithrombins. Two downstream methionines were used as alternative initiation codons, generating highly expressed small aglycosylated antithrombins with cytoplasmic localization. Wild-type antithrombin was generated by the use of the mutated AUU as initiation codon. Actually, any codon except for the three stop codons might be used to initiate translation in this strong Kozak context. We show unexpected consequences of natural mutations affecting translation-start codons. Downstream alternative initiation AUG codons may be used when the start codon is mutated, generating smaller molecules with potential different cell localization, biochemical features and unexplored consequences. Additionally, our data further support the use of other codons apart from AUG for initiation of translation in eukaryotes.
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29
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The Interaction between the Ribosomal Stalk Proteins and Translation Initiation Factor 5B Promotes Translation Initiation. Mol Cell Biol 2018; 38:MCB.00067-18. [PMID: 29844065 DOI: 10.1128/mcb.00067-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/14/2018] [Indexed: 01/01/2023] Open
Abstract
Ribosomal stalk proteins recruit translation elongation GTPases to the factor-binding center of the ribosome. Initiation factor 5B (eIF5B in eukaryotes and aIF5B in archaea) is a universally conserved GTPase that promotes the joining of the large and small ribosomal subunits during translation initiation. Here we show that aIF5B binds to the C-terminal tail of the stalk protein. In the cocrystal structure, the interaction occurs between the hydrophobic amino acids of the stalk C-terminal tail and a small hydrophobic pocket on the surface of the GTP-binding domain (domain I) of aIF5B. A substitution mutation altering the hydrophobic pocket of yeast eIF5B resulted in a marked reduction in ribosome-dependent eIF5B GTPase activity in vitro In yeast cells, the eIF5B mutation affected growth and impaired GCN4 expression during amino acid starvation via a defect in start site selection for the first upstream open reading frame in GCN4 mRNA, as observed with the eIF5B deletion mutant. The deletion of two of the four stalk proteins diminished polyribosome levels (indicating defective translation initiation) and starvation-induced GCN4 expression, both of which were suppressible by eIF5B overexpression. Thus, the mutual interaction between a/eIF5B and the ribosomal stalk plays an important role in subunit joining during translation initiation in vivo.
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30
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Abrahams L, Hurst LD. Adenine Enrichment at the Fourth CDS Residue in Bacterial Genes Is Consistent with Error Proofing for +1 Frameshifts. Mol Biol Evol 2018; 34:3064-3080. [PMID: 28961919 PMCID: PMC5850271 DOI: 10.1093/molbev/msx223] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Beyond selection for optimal protein functioning, coding sequences (CDSs) are under selection at the RNA and DNA levels. Here, we identify a possible signature of “dual-coding,” namely extensive adenine (A) enrichment at bacterial CDS fourth sites. In 99.07% of studied bacterial genomes, fourth site A use is greater than expected given genomic A-starting codon use. Arguing for nucleotide level selection, A-starting serine and arginine second codons are heavily utilized when compared with their non-A starting synonyms. Several models have the ability to explain some of this trend. In part, A-enrichment likely reduces 5′ mRNA stability, promoting translation initiation. However T/U, which may also reduce stability, is avoided. Further, +1 frameshifts on the initiating ATG encode a stop codon (TGA) provided A is the fourth residue, acting either as a frameshift “catch and destroy” or a frameshift stop and adjust mechanism and hence implicated in translation initiation. Consistent with both, genomes lacking TGA stop codons exhibit weaker fourth site A-enrichment. Sequences lacking a Shine–Dalgarno sequence and those without upstream leader genes, that may be more error prone during initiation, have greater utilization of A, again suggesting a role in initiation. The frameshift correction model is consistent with the notion that many genomic features are error-mitigation factors and provides the first evidence for site-specific out of frame stop codon selection. We conjecture that the NTG universal start codon may have evolved as a consequence of TGA being a stop codon and the ability of NTGA to rapidly terminate or adjust a ribosome.
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Affiliation(s)
- Liam Abrahams
- Department of Biology and Biochemistry, The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
| | - Laurence D Hurst
- Department of Biology and Biochemistry, The Milner Centre for Evolution, University of Bath, Bath, United Kingdom
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31
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Andreev DE, Arnold M, Kiniry SJ, Loughran G, Michel AM, Rachinskii D, Baranov PV. TASEP modelling provides a parsimonious explanation for the ability of a single uORF to derepress translation during the integrated stress response. eLife 2018; 7:32563. [PMID: 29932418 PMCID: PMC6033536 DOI: 10.7554/elife.32563] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 06/21/2018] [Indexed: 12/13/2022] Open
Abstract
Translation initiation is the rate-limiting step of protein synthesis that is downregulated during the Integrated Stress Response (ISR). Previously, we demonstrated that most human mRNAs that are resistant to this inhibition possess translated upstream open reading frames (uORFs), and that in some cases a single uORF is sufficient for the resistance. Here we developed a computational model of Initiation Complexes Interference with Elongating Ribosomes (ICIER) to gain insight into the mechanism. We explored the relationship between the flux of scanning ribosomes upstream and downstream of a single uORF depending on uORF features. Paradoxically, our analysis predicts that reducing ribosome flux upstream of certain uORFs increases initiation downstream. The model supports the derepression of downstream translation as a general mechanism of uORF-mediated stress resistance. It predicts that stress resistance can be achieved with long slowly decoded uORFs that do not favor translation reinitiation and that start with initiators of low leakiness.
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Affiliation(s)
- Dmitry E Andreev
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Maxim Arnold
- Department of Mathematical Sciences, The University of Texas at Dallas, Richardson, United States
| | - Stephen J Kiniry
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Audrey M Michel
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Dmitrii Rachinskii
- Department of Mathematical Sciences, The University of Texas at Dallas, Richardson, United States
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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32
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Shirokikh NE, Preiss T. Translation initiation by cap-dependent ribosome recruitment: Recent insights and open questions. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1473. [PMID: 29624880 DOI: 10.1002/wrna.1473] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/02/2018] [Accepted: 02/14/2018] [Indexed: 12/14/2022]
Abstract
Gene expression universally relies on protein synthesis, where ribosomes recognize and decode the messenger RNA template by cycling through translation initiation, elongation, and termination phases. All aspects of translation have been studied for decades using the tools of biochemistry and molecular biology available at the time. Here, we focus on the mechanism of translation initiation in eukaryotes, which is remarkably more complex than prokaryotic initiation and is the target of multiple types of regulatory intervention. The "consensus" model, featuring cap-dependent ribosome entry and scanning of mRNA leader sequences, represents the predominantly utilized initiation pathway across eukaryotes, although several variations of the model and alternative initiation mechanisms are also known. Recent advances in structural biology techniques have enabled remarkable molecular-level insights into the functional states of eukaryotic ribosomes, including a range of ribosomal complexes with different combinations of translation initiation factors that are thought to represent bona fide intermediates of the initiation process. Similarly, high-throughput sequencing-based ribosome profiling or "footprinting" approaches have allowed much progress in understanding the elongation phase of translation, and variants of them are beginning to reveal the remaining mysteries of initiation, as well as aspects of translation termination and ribosomal recycling. A current view on the eukaryotic initiation mechanism is presented here with an emphasis on how recent structural and footprinting results underpin axioms of the consensus model. Along the way, we further outline some contested mechanistic issues and major open questions still to be addressed. This article is categorized under: Translation > Translation Mechanisms Translation > Translation Regulation RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Nikolay E Shirokikh
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
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33
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Shamimuzzaman M, Vodkin L. Ribosome profiling reveals changes in translational status of soybean transcripts during immature cotyledon development. PLoS One 2018; 13:e0194596. [PMID: 29570733 PMCID: PMC5865733 DOI: 10.1371/journal.pone.0194596] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 03/06/2018] [Indexed: 11/19/2022] Open
Abstract
To understand translational capacity on a genome-wide scale across three developmental stages of immature soybean seed cotyledons, ribosome profiling was performed in combination with RNA sequencing and cluster analysis. Transcripts representing 216 unique genes demonstrated a higher level of translational activity in at least one stage by exhibiting higher translational efficiencies (TEs) in which there were relatively more ribosome footprint sequence reads mapping to the transcript than were present in the control total RNA sample. The majority of these transcripts were more translationally active at the early stage of seed development and included 12 unique serine or cysteine proteases and 16 2S albumin and low molecular weight cysteine-rich proteins that may serve as substrates for turnover and mobilization early in seed development. It would appear that the serine proteases and 2S albumins play a vital role in the early stages. In contrast, our investigation of profiles of 19 genes encoding high abundance seed storage proteins, such as glycinins, beta-conglycinins, lectin, and Kunitz trypsin inhibitors, showed that they all had similar patterns in which the TE values started at low levels and increased approximately 2 to 6-fold during development. The highest levels of these seed protein transcripts were found at the mid-developmental stage, whereas the highest ribosome footprint levels of only up to 1.6 TE were found at the late developmental stage. These experimental findings suggest that the major seed storage protein coding genes are primarily regulated at the transcriptional level during normal soybean cotyledon development. Finally, our analyses also identified a total of 370 unique gene models that showed very low TE values including over 48 genes encoding ribosomal family proteins and 95 gene models that are related to energy and photosynthetic functions, many of which have homology to the chloroplast genome. Additionally, we showed that genes of the chloroplast were relatively translationally inactive during seed development.
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Affiliation(s)
- Md. Shamimuzzaman
- Department of Crop Sciences, University of Illinois, Urbana, Illinois, United States of America
| | - Lila Vodkin
- Department of Crop Sciences, University of Illinois, Urbana, Illinois, United States of America
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34
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Prieve MG, Harvie P, Monahan SD, Roy D, Li AG, Blevins TL, Paschal AE, Waldheim M, Bell EC, Galperin A, Ella-Menye JR, Houston ME. Targeted mRNA Therapy for Ornithine Transcarbamylase Deficiency. Mol Ther 2018; 26:801-813. [PMID: 29433939 PMCID: PMC5910669 DOI: 10.1016/j.ymthe.2017.12.024] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 12/21/2017] [Accepted: 12/28/2017] [Indexed: 11/18/2022] Open
Abstract
We describe a novel, two-nanoparticle mRNA delivery system and show that it is highly effective as a means of intracellular enzyme replacement therapy (i-ERT) using a murine model of ornithine transcarbamylase deficiency (OTCD). Our Hybrid mRNA Technology delivery system (HMT) comprises an inert lipid nanoparticle that protects the mRNA from nucleases in the blood as it distributes to the liver and a polymer micelle that targets hepatocytes and triggers endosomal release of mRNA. This results in high-level synthesis of the desired protein specifically in the liver. HMT delivery of human OTC mRNA normalizes plasma ammonia and urinary orotic acid levels, and leads to a prolonged survival benefit in the murine OTCD model. HMT represents a unique, non-viral mRNA delivery method that allows multi-dose, systemic administration for treatment of single-gene inherited metabolic diseases.
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Affiliation(s)
- Mary G Prieve
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA.
| | - Pierrot Harvie
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Sean D Monahan
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Debashish Roy
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Allen G Li
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Teri L Blevins
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Amber E Paschal
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Matt Waldheim
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Eric C Bell
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | - Anna Galperin
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
| | | | - Michael E Houston
- PhaseRx, Inc., 410 W. Harrison Street, Suite 300, Seattle, WA 98119, USA
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35
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The Regulation of Translation in Alphavirus-Infected Cells. Viruses 2018; 10:v10020070. [PMID: 29419763 PMCID: PMC5850377 DOI: 10.3390/v10020070] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/02/2018] [Accepted: 02/06/2018] [Indexed: 12/12/2022] Open
Abstract
Sindbis virus (SINV) contains an RNA genome of positive polarity with two open reading frames (ORFs). The first ORF is translated from the genomic RNA (gRNA), rendering the viral non-structural proteins, whereas the second ORF is translated from a subgenomic mRNA (sgRNA), which directs the synthesis of viral structural proteins. SINV infection strongly inhibits host cell translation through a variety of different mechanisms, including the phosphorylation of the eukaryotic initiation factor eIF2α and the redistribution of cellular proteins from the nucleus to the cytoplasm. A number of motifs have been identified in SINV sgRNA, including a hairpin downstream of the AUG initiation codon, which is involved in the translatability of the viral sgRNA when eIF2 is inactivated. Moreover, a 3′-UTR motif containing three stem-loop structures is involved in the enhancement of translation in insect cells, but not in mammalian cells. Accordingly, SINV sgRNA has evolved several structures to efficiently compete for the cellular translational machinery. Mechanistically, sgRNA translation involves scanning of the 5′-UTR following a non-canonical mode and without the requirement for several initiation factors. Indeed, sgRNA-directed polypeptide synthesis occurs even after eIF4G cleavage or inactivation of eIF4A by selective inhibitors. Remarkably, eIF2α phosphorylation does not hamper sgRNA translation during the late phase of SINV infection. SINV sgRNA thus constitutes a unique model of a capped viral mRNA that is efficiently translated in the absence of several canonical initiation factors. The present review will mainly focus in the non-canonical mechanism of translation of SINV sgRNA.
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36
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Zydowicz-Machtel P, Swiatkowska A, Popenda Ł, Gorska A, Ciesiołka J. Variants of the 5'-terminal region of p53 mRNA influence the ribosomal scanning and translation efficiency. Sci Rep 2018; 8:1533. [PMID: 29367734 PMCID: PMC5784139 DOI: 10.1038/s41598-018-20010-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 01/11/2018] [Indexed: 12/25/2022] Open
Abstract
The p53 protein is one of the major cell cycle regulators. The protein is expressed as at least twelve protein isoforms resulting from the use of alternative promoters, alternative splicing or downstream initiation codons. Importantly, there is growing evidence that translation initiation of p53 mRNA may be regulated by the structure and length of the naturally occurring variants of the 5′-terminal region of p53 mRNA transcripts. Here, several mRNA constructs were synthesized with variable length of the p53 5′-terminal regions and encoding luciferase reporter protein, and their translation was monitored continuously in situ in a rabbit reticulocyte lysate system. Moreover, four additional mRNA constructs were prepared. In two constructs, the structural context of AUG1 initiation codon was altered while in the other two constructs, characteristic hairpin motifs present in the p53 5′-terminal region were changed. Translation of the last two constructs was also performed in the presence of the cap analogue to test the function of the 5′-terminal region in cap-independent translation initiation. Superposition of several structural factors connected with the length of the 5′-terminal region, stable elements of the secondary structure, structural environment of the initiation codon and IRES elements greatly influenced the ribosomal scanning and translation efficiency.
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Affiliation(s)
- Paulina Zydowicz-Machtel
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Agata Swiatkowska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Łukasz Popenda
- NanoBioMedical Centre, Adam Mickiewicz University in Poznan, Umultowska 85, 61-614, Poznan, Poland
| | - Agnieszka Gorska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Jerzy Ciesiołka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
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37
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Tang L, Morris J, Wan J, Moore C, Fujita Y, Gillaspie S, Aube E, Nanda J, Marques M, Jangal M, Anderson A, Cox C, Hiraishi H, Dong L, Saito H, Singh CR, Witcher M, Topisirovic I, Qian SB, Asano K. Competition between translation initiation factor eIF5 and its mimic protein 5MP determines non-AUG initiation rate genome-wide. Nucleic Acids Res 2017; 45:11941-11953. [PMID: 28981728 PMCID: PMC5714202 DOI: 10.1093/nar/gkx808] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 08/31/2017] [Indexed: 12/27/2022] Open
Abstract
In the human genome, translation initiation from non-AUG codons plays an important role in various gene regulation programs. However, mechanisms regulating the non-AUG initiation rate remain poorly understood. Here, we show that the non-AUG initiation rate is nearly consistent under a fixed nucleotide context in various human and insect cells. Yet, it ranges from <1% to nearly 100% compared to AUG translation, depending on surrounding sequences, including Kozak, and possibly additional nucleotide contexts. Mechanistically, this range of non-AUG initiation is controlled in part, by the eIF5-mimic protein (5MP). 5MP represses non-AUG translation by competing with eIF5 for the Met-tRNAi-binding factor eIF2. Consistently, eIF5 increases, whereas 5MP decreases translation of NAT1/EIF4G2/DAP5, whose sole start codon is GUG. By modulating eIF5 and 5MP1 expression in combination with ribosome profiling we identified a handful of previously unknown non-AUG initiation sites, some of which serve as the exclusive start codons. If the initiation rate for these codons is low, then an AUG-initiated downstream ORF prevents the generation of shorter, AUG-initiated isoforms. We propose that the homeostasis of the non-AUG translatome is maintained through balanced expression of eIF5 and 5MP.
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Affiliation(s)
- Leiming Tang
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Jacob Morris
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ji Wan
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Chelsea Moore
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Yoshihiko Fujita
- Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Sarah Gillaspie
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Eric Aube
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Maud Marques
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Maika Jangal
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Abbey Anderson
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Christian Cox
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Hiroyuki Hiraishi
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Leiming Dong
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Hirohide Saito
- Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Michael Witcher
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Ivan Topisirovic
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Shu-Bing Qian
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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38
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Lalonde MML, Marcus JM. The complete mitochondrial genome of the long-horned caddisfly Triaenodes tardus (Insecta: Trichoptera: Leptoceridae). Mitochondrial DNA B Resour 2017; 2:765-767. [PMID: 33473974 PMCID: PMC7800763 DOI: 10.1080/23802359.2017.1398619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 10/26/2017] [Indexed: 10/25/2022] Open
Abstract
The long-horned caddisfly Triaenodes tardus Milne, 1934 (Leptoceridae), is a widespread herbivorous North American caddisfly found in both lentic and lotic habitats. Whole genome Illumina sequencing allowed the assembly of a complete circular mitogenome of 14,963 bp from T. tardus consisting of 73.4% AT nucleotides, 22 tRNAs, 13 protein-coding genes, two rRNAs and a control region in the ancestral insect gene order. Triaenodes tardus COX1 features an atypical TTG start codon as in some lepdioptera and prokaryotes. Phylogenetic reconstruction places T. tardus as sister to Sericostoma personatum (Sericostomatidae) within a monophyletic Order Trichoptera, which is consistent with previous phylogenetic hypotheses.
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Affiliation(s)
| | - Jeffrey M. Marcus
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
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39
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Selection on start codons in prokaryotes and potential compensatory nucleotide substitutions. Sci Rep 2017; 7:12422. [PMID: 28963504 PMCID: PMC5622118 DOI: 10.1038/s41598-017-12619-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/06/2017] [Indexed: 11/29/2022] Open
Abstract
Reconstruction of the evolution of start codons in 36 groups of closely related bacterial and archaeal genomes reveals purifying selection affecting AUG codons. The AUG starts are replaced by GUG and especially UUG significantly less frequently than expected under the neutral expectation derived from the frequencies of the respective nucleotide triplet substitutions in non-coding regions and in 4-fold degenerate sites. Thus, AUG is the optimal start codon that is actively maintained by purifying selection. However, purifying selection on start codons is significantly weaker than the selection on the same codons in coding sequences, although the switches between the codons result in conservative amino acid substitutions. The only exception is the AUG to UUG switch that is strongly selected against among start codons. Selection on start codons is most pronounced in evolutionarily conserved, highly expressed genes. Mutation of the start codon to a sub-optimal form (GUG or UUG) tends to be compensated by mutations in the Shine-Dalgarno sequence towards a stronger translation initiation signal. Together, all these findings indicate that in prokaryotes, translation start signals are subject to weak but significant selection for maximization of initiation rate and, consequently, protein production.
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40
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Hecht A, Glasgow J, Jaschke PR, Bawazer LA, Munson MS, Cochran JR, Endy D, Salit M. Measurements of translation initiation from all 64 codons in E. coli. Nucleic Acids Res 2017; 45:3615-3626. [PMID: 28334756 PMCID: PMC5397182 DOI: 10.1093/nar/gkx070] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 01/25/2017] [Indexed: 12/21/2022] Open
Abstract
Our understanding of translation underpins our capacity to engineer living systems. The canonical start codon (AUG) and a few near-cognates (GUG, UUG) are considered as the ‘start codons’ for translation initiation in Escherichia coli. Translation is typically not thought to initiate from the 61 remaining codons. Here, we quantified translation initiation of green fluorescent protein and nanoluciferase in E. coli from all 64 triplet codons and across a range of DNA copy number. We detected initiation of protein synthesis above measurement background for 47 codons. Translation from non-canonical start codons ranged from 0.007 to 3% relative to translation from AUG. Translation from 17 non-AUG codons exceeded the highest reported rates of non-cognate codon recognition. Translation initiation from non-canonical start codons may contribute to the synthesis of peptides in both natural and synthetic biological systems.
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Affiliation(s)
- Ariel Hecht
- Joint Initiative for Metrology in Biology, Stanford, CA 94305, USA.,Genome-scale Measurements Group, National Institute of Standards and Technology, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford, CA 94305, USA
| | - Jeff Glasgow
- Joint Initiative for Metrology in Biology, Stanford, CA 94305, USA.,Genome-scale Measurements Group, National Institute of Standards and Technology, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford, CA 94305, USA
| | - Paul R Jaschke
- Department of Bioengineering, Stanford, CA 94305, USA.,Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Lukmaan A Bawazer
- Joint Initiative for Metrology in Biology, Stanford, CA 94305, USA.,Genome-scale Measurements Group, National Institute of Standards and Technology, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford, CA 94305, USA
| | - Matthew S Munson
- Joint Initiative for Metrology in Biology, Stanford, CA 94305, USA.,Genome-scale Measurements Group, National Institute of Standards and Technology, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford, CA 94305, USA
| | - Jennifer R Cochran
- Joint Initiative for Metrology in Biology, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford, CA 94305, USA
| | - Drew Endy
- Joint Initiative for Metrology in Biology, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford, CA 94305, USA
| | - Marc Salit
- Joint Initiative for Metrology in Biology, Stanford, CA 94305, USA.,Genome-scale Measurements Group, National Institute of Standards and Technology, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford, CA 94305, USA
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41
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Efficient and Accurate Translation Initiation Directed by TISU Involves RPS3 and RPS10e Binding and Differential Eukaryotic Initiation Factor 1A Regulation. Mol Cell Biol 2017; 37:MCB.00150-17. [PMID: 28584194 DOI: 10.1128/mcb.00150-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/17/2017] [Indexed: 01/20/2023] Open
Abstract
Canonical translation initiation involves ribosomal scanning, but short 5' untranslated region (5'UTR) mRNAs are translated in a scanning-independent manner. The extent and mechanism of scanning-independent translation are not fully understood. Here we report that short 5'UTR mRNAs constitute a substantial fraction of the translatome. Short 5'UTR mRNAs are enriched with TISU (translation initiator of short 5'UTR), a 12-nucleotide element directing efficient scanning-independent translation. Comprehensive mutagenesis revealed that each AUG codon-flanking nucleotide of TISU contributes to translational strength, but only a few are important for accuracy. Using site-specific UV cross-linking of ribosomal complexes assembled on TISU mRNA, we demonstrate specific binding of TISU to ribosomal proteins at the E and A sites. We identified RPS3 as the major TISU binding protein in the 48S complex A site. Upon 80S complex formation, RPS3 interaction is weakened and switched to RPS10e (formerly called RPS10). We further demonstrate that TISU is particularly dependent on eukaryotic initiation factor 1A (eIF1A) which interacts with both RPS3 and RPS10e. Our findings suggest that the cap-recruited ribosome specifically binds the TISU nucleotides at the A and E sites in cooperation with eIF1A to promote scanning arrest.
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42
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Obayashi E, Luna RE, Nagata T, Martin-Marcos P, Hiraishi H, Singh CR, Erzberger JP, Zhang F, Arthanari H, Morris J, Pellarin R, Moore C, Harmon I, Papadopoulos E, Yoshida H, Nasr ML, Unzai S, Thompson B, Aube E, Hustak S, Stengel F, Dagraca E, Ananbandam A, Gao P, Urano T, Hinnebusch AG, Wagner G, Asano K. Molecular Landscape of the Ribosome Pre-initiation Complex during mRNA Scanning: Structural Role for eIF3c and Its Control by eIF5. Cell Rep 2017; 18:2651-2663. [PMID: 28297669 PMCID: PMC5382721 DOI: 10.1016/j.celrep.2017.02.052] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/07/2016] [Accepted: 02/16/2017] [Indexed: 10/20/2022] Open
Abstract
During eukaryotic translation initiation, eIF3 binds the solvent-accessible side of the 40S ribosome and recruits the gate-keeper protein eIF1 and eIF5 to the decoding center. This is largely mediated by the N-terminal domain (NTD) of eIF3c, which can be divided into three parts: 3c0, 3c1, and 3c2. The N-terminal part, 3c0, binds eIF5 strongly but only weakly to the ribosome-binding surface of eIF1, whereas 3c1 and 3c2 form a stoichiometric complex with eIF1. 3c1 contacts eIF1 through Arg-53 and Leu-96, while 3c2 faces 40S protein uS15/S13, to anchor eIF1 to the scanning pre-initiation complex (PIC). We propose that the 3c0:eIF1 interaction diminishes eIF1 binding to the 40S, whereas 3c0:eIF5 interaction stabilizes the scanning PIC by precluding this inhibitory interaction. Upon start codon recognition, interactions involving eIF5, and ultimately 3c0:eIF1 association, facilitate eIF1 release. Our results reveal intricate molecular interactions within the PIC, programmed for rapid scanning-arrest at the start codon.
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Affiliation(s)
- Eiji Obayashi
- Shimane University School of Medicine, Izumo, Shimane 690-8504, Japan
| | - Rafael E Luna
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Takashi Nagata
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Pilar Martin-Marcos
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hiroyuki Hiraishi
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Chingakham Ranjit Singh
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Jan Peter Erzberger
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Fan Zhang
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Jacob Morris
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Riccardo Pellarin
- California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Chelsea Moore
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ian Harmon
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Evangelos Papadopoulos
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Hisashi Yoshida
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama 230-0045, Japan; Drug Design Group, Kanagawa Academy of Science and Technology, Takatsu-ku, Kawasaki 213-0012, Japan
| | - Mahmoud L Nasr
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Satoru Unzai
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Brytteny Thompson
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Eric Aube
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Samantha Hustak
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Florian Stengel
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Eddie Dagraca
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Philip Gao
- COBRE-PSF, University of Kansas, Lawrence, KS 66047, USA
| | - Takeshi Urano
- Shimane University School of Medicine, Izumo, Shimane 690-8504, Japan
| | - Alan G Hinnebusch
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Katsura Asano
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
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43
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Cid E, Yamamoto M, Yamamoto F. Non-AUG start codons responsible for ABO weak blood group alleles on initiation mutant backgrounds. Sci Rep 2017; 7:41720. [PMID: 28139731 PMCID: PMC5282485 DOI: 10.1038/srep41720] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 12/29/2016] [Indexed: 11/09/2022] Open
Abstract
Histo-blood group ABO gene polymorphism is crucial in transfusion medicine. We studied the activity and subcellular distribution of ABO gene-encoded A glycosyltransferases with N-terminal truncation. We hypothesized that truncated enzymes starting at internal methionines drove the synthesis of oligosaccharide A antigen in those already described alleles that lack a proper translation initiation codon. Not only we tested the functionality of the mutant transferases by expressing them and assessing their capacity to drive the appearance of A antigen on the cell surface, but we also analyzed their subcellullar localization, which has not been described before. The results highlight the importance of the transmembrane domain because proteins deprived of it are not able to localize properly and deliver substantial amounts of antigen on the cell surface. Truncated proteins with their first amino acid well within the luminal domain are not properly localized and lose their enzymatic activity. Most importantly, we demonstrated that other codons than AUG might be used to start the protein synthesis rather than internal methionines in translation-initiation mutants, explaining the molecular mechanism by which transferases lacking a classical start codon are able to synthesize A/B antigens.
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Affiliation(s)
- Emili Cid
- Laboratory of Immunohematology and Glycobiology, Josep Carreras Leukaemia Research Institute (IJC), Campus Can Ruti, Badalona, Barcelona, Spain
| | - Miyako Yamamoto
- Laboratory of Immunohematology and Glycobiology, Josep Carreras Leukaemia Research Institute (IJC), Campus Can Ruti, Badalona, Barcelona, Spain
| | - Fumiichiro Yamamoto
- Laboratory of Immunohematology and Glycobiology, Josep Carreras Leukaemia Research Institute (IJC), Campus Can Ruti, Badalona, Barcelona, Spain
- Program of Predictive and Personalized Medicine of Cancer (PMPPC), Institut d’Investigació Germans Trias i Pujol (IGTP), Campus Can Ruti, Badalona, Barcelona, Spain
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44
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Pisareva VP, Pisarev AV. DHX29 and eIF3 cooperate in ribosomal scanning on structured mRNAs during translation initiation. RNA (NEW YORK, N.Y.) 2016; 22:1859-1870. [PMID: 27733651 PMCID: PMC5113206 DOI: 10.1261/rna.057851.116] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/12/2016] [Indexed: 06/06/2023]
Abstract
Eukaryotic translation initiation is a complex process involving many components. eIF3 is a scaffold for multiple initiation factors and plays multiple roles in initiation, and DHX29 helicase enhances the formation of the 48S initiation complex on structured mRNAs. Because DHX29 is not a processive helicase, the mechanism underlying its activity is unclear. Here, we show that DHX29 establishes many points of contact with eIF3. In particular, the unique N terminus of DHX29 associates with the RNA recognition motif of eIF3b and the C terminus of the eIF3a subunits of eIF3, and the disruption of either contact impairs DHX29 activity. In turn, DHX29 has weak points of contact with mRNA in the 48S initiation complex, and the pathway taken by mRNA remains unchanged. These results exclude the direct role for this protein in unwinding. Thus, DHX29 and eIF3 cooperate in scanning on structured mRNAs. Our findings support previous genetic data on the role of eIF3 during scanning.
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Affiliation(s)
- Vera P Pisareva
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York 11203, USA
| | - Andrey V Pisarev
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York 11203, USA
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45
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Kozel C, Thompson B, Hustak S, Moore C, Nakashima A, Singh CR, Reid M, Cox C, Papadopoulos E, Luna RE, Anderson A, Tagami H, Hiraishi H, Slone EA, Yoshino KI, Asano M, Gillaspie S, Nietfeld J, Perchellet JP, Rothenburg S, Masai H, Wagner G, Beeser A, Kikkawa U, Fleming SD, Asano K. Overexpression of eIF5 or its protein mimic 5MP perturbs eIF2 function and induces ATF4 translation through delayed re-initiation. Nucleic Acids Res 2016; 44:8704-8713. [PMID: 27325740 PMCID: PMC5062967 DOI: 10.1093/nar/gkw559] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/07/2016] [Accepted: 06/10/2016] [Indexed: 11/14/2022] Open
Abstract
ATF4 is a pro-oncogenic transcription factor whose translation is activated by eIF2 phosphorylation through delayed re-initiation involving two uORFs in the mRNA leader. However, in yeast, the effect of eIF2 phosphorylation can be mimicked by eIF5 overexpression, which turns eIF5 into translational inhibitor, thereby promoting translation of GCN4, the yeast ATF4 equivalent. Furthermore, regulatory protein termed eIF5-mimic protein (5MP) can bind eIF2 and inhibit general translation. Here, we show that 5MP1 overexpression in human cells leads to strong formation of 5MP1:eIF2 complex, nearly comparable to that of eIF5:eIF2 complex produced by eIF5 overexpression. Overexpression of eIF5, 5MP1 and 5MP2, the second human paralog, promotes ATF4 expression in certain types of human cells including fibrosarcoma. 5MP overexpression also induces ATF4 expression in Drosophila The knockdown of 5MP1 in fibrosarcoma attenuates ATF4 expression and its tumor formation on nude mice. Since 5MP2 is overproduced in salivary mucoepidermoid carcinoma, we propose that overexpression of eIF5 and 5MP induces translation of ATF4 and potentially other genes with uORFs in their mRNA leaders through delayed re-initiation, thereby enhancing the survival of normal and cancer cells under stress conditions.
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Affiliation(s)
- Caitlin Kozel
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
| | - Brytteny Thompson
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Samantha Hustak
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Chelsea Moore
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Akio Nakashima
- Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Chingakham Ranjit Singh
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Megan Reid
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Christian Cox
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Evangelos Papadopoulos
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Rafael E Luna
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Abbey Anderson
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Hideaki Tagami
- Graduate School of Natural Sciences, Nagoya City University, Nagoya 467-8501, Japan
| | - Hiroyuki Hiraishi
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Emily Archer Slone
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ken-Ichi Yoshino
- Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Masayo Asano
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Sarah Gillaspie
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Jerome Nietfeld
- College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
| | - Jean-Pierre Perchellet
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Stefan Rothenburg
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Hisao Masai
- Genome Dynamics Project, Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Alexander Beeser
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ushio Kikkawa
- Biosignal Research Center, Kobe University, Kobe 657-8501, Japan
| | - Sherry D Fleming
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Katsura Asano
- Molecular Cellular Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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46
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Li H, Hu C, Bai L, Li H, Li M, Zhao X, Czajkowsky DM, Shao Z. Ultra-deep sequencing of ribosome-associated poly-adenylated RNA in early Drosophila embryos reveals hundreds of conserved translated sORFs. DNA Res 2016; 23:571-580. [PMID: 27559081 PMCID: PMC5144680 DOI: 10.1093/dnares/dsw040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 07/11/2016] [Indexed: 11/23/2022] Open
Abstract
There is growing recognition that small open reading frames (sORFs) encoding peptides shorter than 100 amino acids are an important class of functional elements in the eukaryotic genome, with several already identified to play critical roles in growth, development, and disease. However, our understanding of their biological importance has been hindered owing to the significant technical challenges limiting their annotation. Here we combined ultra-deep sequencing of ribosome-associated poly-adenylated RNAs with rigorous conservation analysis to identify a comprehensive population of translated sORFs during early Drosophila embryogenesis. In total, we identify 399 sORFs, including those previously annotated but without evidence of translational capacity, those found within transcripts previously classified as non-coding, and those not previously known to be transcribed. Further, we find, for the first time, evidence for translation of many sORFs with different isoforms, suggesting their regulation is as complex as longer ORFs. Furthermore, many sORFs are found not associated with ribosomes in late-stage Drosophila S2 cells, suggesting that many of the translated sORFs may have stage-specific functions during embryogenesis. These results thus provide the first comprehensive annotation of the sORFs present during early Drosophila embryogenesis, a necessary basis for a detailed delineation of their function in embryogenesis and other biological processes.
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Affiliation(s)
- Hongmei Li
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chuansheng Hu
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ling Bai
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hua Li
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Mingfa Li
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaodong Zhao
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Daniel M Czajkowsky
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhifeng Shao
- Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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47
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Hellens RP, Brown CM, Chisnall MAW, Waterhouse PM, Macknight RC. The Emerging World of Small ORFs. TRENDS IN PLANT SCIENCE 2016; 21:317-328. [PMID: 26684391 DOI: 10.1016/j.tplants.2015.11.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/23/2015] [Accepted: 11/05/2015] [Indexed: 05/10/2023]
Abstract
Small open reading frames (sORFs) are an often overlooked feature of plant genomes. Initially found in plant viral RNAs and considered an interesting curiosity, an increasing number of these sORFs have been shown to encode functional peptides or play a regulatory role. The recent discovery that many of these sORFs initiate with start codons other than AUG, together with the identification of functional small peptides encoded in supposedly noncoding primary miRNA transcripts (pri-miRs), has drastically increased the number of potentially functional sORFs within the genome. Here we review how advances in technology, notably ribosome profiling (RP) assays, are complementing bioinformatics and proteogenomic methods to provide powerful ways to identify these elusive features of plant genomes, and highlight the regulatory roles sORFs can play.
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Affiliation(s)
- Roger P Hellens
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia
| | - Chris M Brown
- Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Matthew A W Chisnall
- Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Peter M Waterhouse
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia
| | - Richard C Macknight
- Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand; New Zealand Institute for Plant and Food Research Ltd.
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48
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Meleppattu S, Kamus-Elimeleh D, Zinoviev A, Cohen-Mor S, Orr I, Shapira M. The eIF3 complex of Leishmania-subunit composition and mode of recruitment to different cap-binding complexes. Nucleic Acids Res 2015; 43:6222-35. [PMID: 26092695 PMCID: PMC4513851 DOI: 10.1093/nar/gkv564] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 05/13/2015] [Accepted: 05/16/2015] [Indexed: 11/14/2022] Open
Abstract
Eukaryotic initiation factor 3 (eIF3) is a multi-protein complex and a key participant in the assembly of the translation initiation machinery. In mammals, eIF3 comprises 13 subunits, most of which are characterized by conserved structural domains. The trypanosomatid eIF3 subunits are poorly conserved. Here, we identify 12 subunits that comprise the Leishmania eIF3 complex (LeishIF3a-l) by combining bioinformatics with affinity purification and mass spectrometry analyses. These results highlight the strong association of LeishIF3 with LeishIF1, LeishIF2 and LeishIF5, suggesting the existence of a multi-factor complex. In trypanosomatids, the translation machinery is tightly regulated in the different life stages of these organisms as part of their adaptation and survival in changing environments. We, therefore, addressed the mechanism by which LeishIF3 is recruited to different mRNA cap-binding complexes. A direct interaction was observed in vitro between the fully assembled LeishIF3 complex and recombinant LeishIF4G3, the canonical scaffolding protein of the cap-binding complex in Leishmania promastigotes. We further highlight a novel interaction between the C-terminus of LeishIF3a and LeishIF4E1, the only cap-binding protein that efficiently binds the cap structure under heat shock conditions, anchoring a complex that is deficient of any MIF4G-based scaffolding subunit.
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Affiliation(s)
- Shimi Meleppattu
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Dikla Kamus-Elimeleh
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Alexandra Zinoviev
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Shahar Cohen-Mor
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Irit Orr
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Michal Shapira
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
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49
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Abstract
ATP-binding cassette 50 (ABC50; also known as ABCF1) binds to eukaryotic initiation factor 2 (eIF2) and is required for efficient translation initiation. An essential step of this process is accurate recognition and selection of the initiation codon. It is widely accepted that the presence and movement of eIF1, eIF1A and eIF5 are key factors in modulating the stringency of start-site selection, which normally requires an AUG codon in an appropriate sequence context. In the present study, we show that expression of ABC50 mutants, which cannot hydrolyse ATP, decreases general translation and relaxes the discrimination against the use of non-AUG codons at translation start sites. These mutants do not appear to alter the association of key initiation factors to 40S subunits. The stringency of start-site selection can be restored through overexpression of eIF1, consistent with the role of that factor in enhancing stringency. The present study indicates that interfering with the function of ABC50 influences the accuracy of initiation codon selection.
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50
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Browning KS, Bailey-Serres J. Mechanism of cytoplasmic mRNA translation. THE ARABIDOPSIS BOOK 2015; 13:e0176. [PMID: 26019692 PMCID: PMC4441251 DOI: 10.1199/tab.0176] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein synthesis is a fundamental process in gene expression that depends upon the abundance and accessibility of the mRNA transcript as well as the activity of many protein and RNA-protein complexes. Here we focus on the intricate mechanics of mRNA translation in the cytoplasm of higher plants. This chapter includes an inventory of the plant translational apparatus and a detailed review of the translational processes of initiation, elongation, and termination. The majority of mechanistic studies of cytoplasmic translation have been carried out in yeast and mammalian systems. The factors and mechanisms of translation are for the most part conserved across eukaryotes; however, some distinctions are known to exist in plants. A comprehensive understanding of the complex translational apparatus and its regulation in plants is warranted, as the modulation of protein production is critical to development, environmental plasticity and biomass yield in diverse ecosystems and agricultural settings.
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Affiliation(s)
- Karen S. Browning
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin TX 78712-0165
- Both authors contributed equally to this work
| | - Julia Bailey-Serres
- Department of Botany and Plant Sciences and Center for Plant Cell Biology, University of California, Riverside, CA, 92521 USA
- Both authors contributed equally to this work
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