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Boyer JA, Sharma M, Dorso MA, Mai N, Amor C, Reiter JM, Kannan R, Gadal S, Xu J, Miele M, Li Z, Chen X, Chang Q, Pareja F, Worland S, Warner D, Sperry S, Chiang GG, Thompson PA, Yang G, Ouerfelli O, de Stanchina E, Wendel HG, Rosen EY, Chandarlapaty S, Rosen N. eIF4A controls translation of estrogen receptor alpha and is a therapeutic target in advanced breast cancer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593195. [PMID: 38766126 PMCID: PMC11100762 DOI: 10.1101/2024.05.08.593195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The majority of human breast cancers are dependent on hormone-stimulated estrogen receptor alpha (ER) and are sensitive to its inhibition. Treatment resistance arises in most advanced cancers due to genetic alterations that promote ligand independent activation of ER itself or ER target genes. Whereas re-targeting of the ER ligand binding domain (LBD) with newer ER antagonists can work in some cases, these drugs are largely ineffective in many genetic backgrounds including ER fusions that lose the LBD or in cancers that hyperactivate ER targets. By identifying the mechanism of ER translation, we herein present an alternative strategy to target ER and difficult to treat ER variants. We find that ER translation is cap-independent and mTOR inhibitor insensitive, but dependent on 5' UTR elements and sensitive to pharmacologic inhibition of the translation initiation factor eIF4A, an mRNA helicase. EIF4A inhibition rapidly reduces expression of ER and short-lived targets of ER such as cyclin D1 and other components of the cyclin D-CDK complex in breast cancer cells. These effects translate into suppression of growth of a variety of ligand-independent breast cancer models including those driven by ER fusion proteins that lack the ligand binding site. The efficacy of eIF4A inhibition is enhanced when it is combined with fulvestrant-an ER degrader. Concomitant inhibition of ER synthesis and induction of its degradation causes synergistic and durable inhibition of ER expression and tumor growth. The clinical importance of these findings is confirmed by results of an early clinical trial (NCT04092673) of the selective eIF4A inhibitor zotatifin in patients with estrogen receptor positive metastatic breast cancer. Multiple clinical responses have been observed on combination therapy including durable regressions. These data suggest that eIF4A inhibition could be a useful new strategy for treating advanced ER+ breast cancer.
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Affiliation(s)
- Jacob A. Boyer
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
- Ludwig Institute for Cancer Research, Princeton University, Princeton, NJ, USA
| | - Malvika Sharma
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Madeline A. Dorso
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nicholas Mai
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Corina Amor
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
- Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jason M. Reiter
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Ram Kannan
- Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sunyana Gadal
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Jianing Xu
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Matthew Miele
- Microchemistry and Proteomics Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Zhuoning Li
- Microchemistry and Proteomics Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Xiaoping Chen
- Antitumor Assessment Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY 11065, USA
| | - Qing Chang
- Antitumor Assessment Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY 11065, USA
| | - Fresia Pareja
- Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Stephan Worland
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Douglas Warner
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Sam Sperry
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Gary G. Chiang
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Peggy A. Thompson
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Guangli Yang
- The Organic Synthesis Core Facility, MSK, New York, NY, USA
| | | | - Elisa de Stanchina
- Antitumor Assessment Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY 11065, USA
| | - Hans-Guido Wendel
- Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ezra Y. Rosen
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sarat Chandarlapaty
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Neal Rosen
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
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NMR Analysis Suggests Synergy between the RRM2 and the Carboxy-Terminal Segment of Human La Protein in the Recognition and Interaction with HCV IRES. Int J Mol Sci 2023; 24:ijms24032572. [PMID: 36768895 PMCID: PMC9916714 DOI: 10.3390/ijms24032572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/18/2023] [Accepted: 01/18/2023] [Indexed: 01/31/2023] Open
Abstract
The La protein (lupus antigen) is a ubiquitous RNA-binding protein found in all human cells. It is mainly localized in the nucleus, associates with all RNA polymerase III (Pol III) transcripts, as the first factor they interact with, and modulates subsequent processing events. Export of La to the cytoplasm has been reported to stimulate the decoding of specific cellular and viral mRNAs through IRES-dependent (Internal ribosome entry site) binding and translation. Using NMR (Nuclear Magnetic Resonance) spectroscopy, we provide atomic-level-resolution structural insights on the dynamical properties of human La (hLa) protein in solution. Moreover, using a combination of NMR spectroscopy and isothermal titration calorimetry (ITC), we provide evidence about the role and ligand specificity of the C-terminal domain of the La protein (RRM2 and C-terminal region) that could mediate the recognition of HCV-IRES.
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Angulo J, Cáceres CJ, Contreras N, Fernández-García L, Chamond N, Ameur M, Sargueil B, López-Lastra M. Polypyrimidine-Tract-Binding Protein Isoforms Differentially Regulate the Hepatitis C Virus Internal Ribosome Entry Site. Viruses 2022; 15:8. [PMID: 36680049 PMCID: PMC9864772 DOI: 10.3390/v15010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/03/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Translation initiation of the hepatitis C virus (HCV) mRNA depends on an internal ribosome entry site (IRES) that encompasses most of the 5'UTR and includes nucleotides of the core coding region. This study shows that the polypyrimidine-tract-binding protein (PTB), an RNA-binding protein with four RNA recognition motifs (RRMs), binds to the HCV 5'UTR, stimulating its IRES activity. There are three isoforms of PTB: PTB1, PTB2, and PTB4. Our results show that PTB1 and PTB4, but not PTB2, stimulate HCV IRES activity in HuH-7 and HEK293T cells. In HuH-7 cells, PTB1 promotes HCV IRES-mediated initiation more strongly than PTB4. Mutations in PTB1, PTB4, RRM1/RRM2, or RRM3/RRM4, which disrupt the RRM's ability to bind RNA, abrogated the protein's capacity to stimulate HCV IRES activity in HuH-7 cells. In HEK293T cells, PTB1 and PTB4 stimulate HCV IRES activity to similar levels. In HEK293T cells, mutations in RRM1/RRM2 did not impact PTB1's ability to promote HCV IRES activity; and mutations in PTB1 RRM3/RRM4 domains reduced, but did not abolish, the protein's capacity to stimulate HCV IRES activity. In HEK293T cells, mutations in PTB4 RRM1/RRM2 abrogated the protein's ability to promote HCV IRES activity, and mutations in RRM3/RRM4 have no impact on PTB4 ability to enhance HCV IRES activity. Therefore, PTB1 and PTB4 differentially stimulate the IRES activity in a cell type-specific manner. We conclude that PTB1 and PTB4, but not PTB2, act as IRES transacting factors of the HCV IRES.
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Affiliation(s)
- Jenniffer Angulo
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- Facultad de Odontología, Universidad Finis Terrae, Santiago 7501015, Chile
| | - C. Joaquín Cáceres
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Nataly Contreras
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
- Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Santiago 7500975, Chile
| | - Leandro Fernández-García
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Nathalie Chamond
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8038, Laboratoire CiTCoM, Université Paris Cité, 75006 Paris, France
| | - Melissa Ameur
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8038, Laboratoire CiTCoM, Université Paris Cité, 75006 Paris, France
| | - Bruno Sargueil
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8038, Laboratoire CiTCoM, Université Paris Cité, 75006 Paris, France
| | - Marcelo López-Lastra
- Laboratorio de Virología Molecular, Centro de Investigaciones Médicas, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
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Guo H, Cui Y, Huang L, Ge L, Xu X, Xue D, Tang M, Zheng J, Yi Y, Chen L. The RNA binding protein OsLa influences grain and anther development in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:1397-1414. [PMID: 35322500 DOI: 10.1111/tpj.15746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/15/2022] [Accepted: 03/20/2022] [Indexed: 06/14/2023]
Abstract
La proteins are found widely in eukaryotes and play a variety of vital roles. AtLa1 has been identified as an La protein that is necessary for embryogenesis in Arabidopsis; however, the existence and biological functions of La proteins in rice (Oryza sativa L.) remain unclear. In this study, we identified and characterized two La proteins in rice that are homologous to AtLa1 and named them OsLa1 and OsLa2. Both the OsLa1 and OsLa2 genes encode RNA-binding proteins with an La domain and two RNA-binding domains. Mutant OsLa1 reduced grain length and pollen fertility, whereas OsLa1 overexpression caused the opposite phenotypes. Further experiments indicated that OsLa1 modulates grain size by influencing cell expansion. Interestingly, mutant OsLa2 resulted in thin grains with decreased weight and a low seed-setting rate. We also found that OsLa1 interacted with OsLa2 and that both OsLa1 and OsLa2 interacted with OseIF6.1, a eukaryotic translation initiation factor involved in ribosome biogenesis. In addition, OsLa1 was able to bind to OseIF6.1 mRNA to modulate its expression. Complete OseIF6.1 knockout caused lethality and OseIF6.1/oseif6.1 heterozygous plants displayed low fertility and low seed setting. Together, our results enrich our knowledge of the role of La proteins in rice growth and development, as well as the relationship between La and eIF6 in rice.
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Affiliation(s)
- Hongming Guo
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
| | - Yuchao Cui
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
| | - Linjuan Huang
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
| | - Li Ge
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
| | - Xiaorong Xu
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
- Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, School of Life Science, Guizhou Normal University, Guiyang, China
| | - Danyang Xue
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
| | - Ming Tang
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
- Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, School of Life Science, Guizhou Normal University, Guiyang, China
| | - Jingsheng Zheng
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
| | - Yin Yi
- Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, School of Life Science, Guizhou Normal University, Guiyang, China
| | - Liang Chen
- Xiamen Key Laboratory for Plant Genetics, School of Life Sciences, Xiamen University, Xiamen, China
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RNA-Binding Proteins as Regulators of Internal Initiation of Viral mRNA Translation. Viruses 2022; 14:v14020188. [PMID: 35215780 PMCID: PMC8879377 DOI: 10.3390/v14020188] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/03/2022] [Accepted: 01/14/2022] [Indexed: 12/17/2022] Open
Abstract
Viruses are obligate intracellular parasites that depend on the host’s protein synthesis machinery for translating their mRNAs. The viral mRNA (vRNA) competes with the host mRNA to recruit the translational machinery, including ribosomes, tRNAs, and the limited eukaryotic translation initiation factor (eIFs) pool. Many viruses utilize non-canonical strategies such as targeting host eIFs and RNA elements known as internal ribosome entry sites (IRESs) to reprogram cellular gene expression, ensuring preferential translation of vRNAs. In this review, we discuss vRNA IRES-mediated translation initiation, highlighting the role of RNA-binding proteins (RBPs), other than the canonical translation initiation factors, in regulating their activity.
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Berndt N, Bippes CC, Michalk I, Bartsch T, Arndt C, Puentes-Cala E, Soto JA, Loureiro LR, Kegler A, Bachmann D, Gross JK, Gross T, Kurien BT, Scofield RH, Farris AD, James JA, Bergmann R, Schmitz M, Feldmann A, Bachmann MP. And Yet It Moves: Oxidation of the Nuclear Autoantigen La/SS-B Is the Driving Force for Nucleo-Cytoplasmic Shuttling. Int J Mol Sci 2021; 22:9699. [PMID: 34575862 PMCID: PMC8470643 DOI: 10.3390/ijms22189699] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 01/10/2023] Open
Abstract
Decades ago, we and many other groups showed a nucleo-cytoplasmic translocation of La protein in cultured cells. This shuttling of La protein was seen after UV irradiation, virus infections, hydrogen peroxide exposure and the Fenton reaction based on iron or copper ions. All of these conditions are somehow related to oxidative stress. Unfortunately, these harsh conditions could also cause an artificial release of La protein. Even until today, the shuttling and the cytoplasmic function of La/SS-B is controversially discussed. Moreover, the driving mechanism for the shuttling of La protein remains unclear. Recently, we showed that La protein undergoes redox-dependent conformational changes. Moreover, we developed anti-La monoclonal antibodies (anti-La mAbs), which are specific for either the reduced form of La protein or the oxidized form. Using these tools, here we show that redox-dependent conformational changes are the driving force for the shuttling of La protein. Moreover, we show that translocation of La protein to the cytoplasm can be triggered in a ligand/receptor-dependent manner under physiological conditions. We show that ligands of toll-like receptors lead to a redox-dependent shuttling of La protein. The shuttling of La protein depends on the redox status of the respective cell type. Endothelial cells are usually resistant to the shuttling of La protein, while dendritic cells are highly sensitive. However, the deprivation of intracellular reducing agents in endothelial cells makes endothelial cells sensitive to a redox-dependent shuttling of La protein.
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Affiliation(s)
- Nicole Berndt
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
| | - Claudia C. Bippes
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technische Universität Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
| | - Irene Michalk
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technische Universität Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
| | - Tabea Bartsch
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
| | - Claudia Arndt
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
| | - Edinson Puentes-Cala
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
- Corporación para la Investigación de la Corrosión (CIC), Piedecuesta 681011, Colombia
| | - Javier Andrés Soto
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
- Instituto de Investigación Masira, Facultad de Ciencias Médicas y de la Salud, Universidad de Santander, Cúcuta 540001, Colombia
| | - Liliana R. Loureiro
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
| | - Alexandra Kegler
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
| | - Dominik Bachmann
- Tumor Immunology, University Cancer Center (UCC), University Hospital Carl Gustav Carus Technische Universität Dresden, 01307 Dresden, Germany;
| | - Joanne K. Gross
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Tim Gross
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Biji T. Kurien
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - R. Hal Scofield
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - A. Darise Farris
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Judith A. James
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Ralf Bergmann
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
- Department of Biophysics and Radiobiology, Semmelweis University, 1094 Budapest, Hungary
| | - Marc Schmitz
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technische Universität Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
- National Center for Tumor Diseases (NCT), 03128 Dresden, Germany
| | - Anja Feldmann
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
| | - Michael P. Bachmann
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (T.B.); (C.A.); (E.P.-C.); (J.A.S.); (L.R.L.); (A.K.); (R.B.); (A.F.)
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technische Universität Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
- National Center for Tumor Diseases (NCT), 03128 Dresden, Germany
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N6-methyladenosine modification of HCV RNA genome regulates cap-independent IRES-mediated translation via YTHDC2 recognition. Proc Natl Acad Sci U S A 2021; 118:2022024118. [PMID: 33649237 DOI: 10.1073/pnas.2022024118] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatitis C virus (HCV) infections are associated with the risk of progression to fibrosis, cirrhosis, and hepatocellular carcinoma. The HCV RNA genome is translated by an internal ribosome entry site (IRES)-dependent mechanism. The structure and function of the HCV IRES have been investigated by both biological and biophysical criteria. Recently, the role of N6-methyladenosine (m6A) in cellular RNA and viral transcripts has been intensely investigated. The HCV RNA genome is m6A-methylated, and this modification regulates the viral life cycle. In this study, we investigated the role of m6A modification of the HCV genome in the IRES-dependent translation function by mutating m6A consensus motifs (DRACH) within the IRES element in stem-loop III and IV regions and studied their effect on translation initiation. There are several DRACH motifs within the IRES element. Of these, the DRACH motif at nucleotide (nt) 329-333, located about 7 nt upstream of initiator AUG (iAUG) codon, regulates IRES-mediated translation initiation. Mutational analysis showed that m6A methylation of the adenosine at nt 331 is essential for the IRES-dependent translation. m6A reader protein YTHDC2, containing the RNA helicase domain, recognizes m6A-methylated adenosine at nt 331 and, in concert with the cellular La antigen, supports HCV IRES-dependent translation. The RNA helicase dead YTHDC2 (E332Q) mutant failed to stimulate HCV translation initiation. This report highlights the functional roles of m6A modification and YTHDC2 in the HCV IRES-dependent translation initiation, thus offering alternative therapeutic avenues to interfere with the infectious process.
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8
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Berndt N, Bippes CC, Michalk I, Bachmann D, Bachmann J, Puentes-Cala E, Bartsch T, Loureiro LR, Kegler A, Bergmann R, Gross JK, Gross T, Kurien BT, Scofield RH, Farris AD, James JA, Schmitz M, Fahmy K, Feldmann A, Arndt C, Bachmann MP. Two Be or Not Two Be: The Nuclear Autoantigen La/SS-B Is Able to Form Dimers and Oligomers in a Redox Dependent Manner. Int J Mol Sci 2021; 22:3377. [PMID: 33806091 PMCID: PMC8036718 DOI: 10.3390/ijms22073377] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/17/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
According to the literature, the autoantigen La is involved in Cap-independent translation. It was proposed that one prerequisite for this function is the formation of a protein dimer. However, structural analyses argue against La protein dimers. Noteworthy to mention, these structural analyses were performed under reducing conditions. Here we describe that La protein can undergo redox-dependent structural changes. The oxidized form of La protein can form dimers, oligomers and even polymers stabilized by disulfide bridges. The primary sequence of La protein contains three cysteine residues. Only after mutation of all three cysteine residues to alanine La protein becomes insensitive to oxidation, indicating that all three cysteines are involved in redox-dependent structural changes. Biophysical analyses of the secondary structure of La protein support the redox-dependent conformational changes. Moreover, we identified monoclonal anti-La antibodies (anti-La mAbs) that react with either the reduced or oxidized form of La protein. Differential reactivities to the reduced and oxidized form of La protein were also found in anti-La sera of autoimmune patients.
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Affiliation(s)
- Nicole Berndt
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
| | - Claudia C. Bippes
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technical University Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
| | - Irene Michalk
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technical University Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
| | - Dominik Bachmann
- University Cancer Center (UCC), Tumor Immunology, University Hospital Carl Gustav Carus Dresden, Technical University Dresden, 01307 Dresden, Germany; (D.B.); (J.B.)
| | - Jennifer Bachmann
- University Cancer Center (UCC), Tumor Immunology, University Hospital Carl Gustav Carus Dresden, Technical University Dresden, 01307 Dresden, Germany; (D.B.); (J.B.)
| | - Edinson Puentes-Cala
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
- Corporación para la Investigación de la Corrosión (CIC), Piedecuesta 681011, Colombia
| | - Tabea Bartsch
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
| | - Liliana R. Loureiro
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
| | - Alexandra Kegler
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
| | - Ralf Bergmann
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
- Department of Biophysics and Radiobiology, Semmelweis University, 1094 Budapest, Hungary
| | - Joanne K. Gross
- The Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation and University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Tim Gross
- The Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation and University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Biji T. Kurien
- The Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation and University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - R. Hal Scofield
- The Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation and University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - A. Darise Farris
- The Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation and University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Judith A. James
- The Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation and University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.K.G.); (T.G.); (B.T.K.); (R.H.S.); (A.D.F.); (J.A.J.)
| | - Marc Schmitz
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technical University Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
- National Center for Tumor Diseases (NCT), 01307 Dresden, Germany
| | - Karim Fahmy
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany;
| | - Anja Feldmann
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
| | - Claudia Arndt
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
| | - Michael P. Bachmann
- Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany; (N.B.); (E.P.-C.); (T.B.); (L.R.L.); (A.K.); (R.B.); (A.F.); (C.A.)
- Institute of Immunology, Medical Faculty Carl Gustav Carus Dresden, Technical University Dresden, 01307 Dresden, Germany; (C.C.B.); (I.M.); (M.S.)
- University Cancer Center (UCC), Tumor Immunology, University Hospital Carl Gustav Carus Dresden, Technical University Dresden, 01307 Dresden, Germany; (D.B.); (J.B.)
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9
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Al-Ashtal HA, Rubottom CM, Leeper TC, Berman AJ. The LARP1 La-Module recognizes both ends of TOP mRNAs. RNA Biol 2021; 18:248-258. [PMID: 31601159 PMCID: PMC7927982 DOI: 10.1080/15476286.2019.1669404] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/22/2019] [Accepted: 09/12/2019] [Indexed: 12/11/2022] Open
Abstract
La-Related Protein 1 (LARP1) is an RNA-binding protein that regulates the stability and translation of mRNAs encoding the translation machinery, including ribosomal proteins and translation factors. These mRNAs are characterized by a 5'-terminal oligopyrimidine (TOP) motif that coordinates their temporal and stoichiometric expression. While LARP1 represses TOP mRNA translation via the C-terminal DM15 region, the role of the N-terminal La-Module in the recognition and translational regulation of TOP mRNAs remains elusive. Herein we show that the LARP1 La-Module also binds TOP motifs, although in a cap-independent manner. We also demonstrate that it recognizes poly(A) RNA. Further, our data reveal that the LARP1 La-Module can simultaneously engage TOP motifs and poly(A) RNA. These results evoke an intriguing molecular mechanism whereby LARP1 could regulate translation and stabilization of TOP transcripts.
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Affiliation(s)
- Hiba A. Al-Ashtal
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Courtney M. Rubottom
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Thomas C. Leeper
- Department of Chemistry & Biochemistry, Kennesaw State University, Kennesaw, GA, USA
| | - Andrea J. Berman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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10
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Basu R, Eichhorn CD, Cheng R, Peterson RD, Feigon J. Structure of S. pombe telomerase protein Pof8 C-terminal domain is an xRRM conserved among LARP7 proteins. RNA Biol 2020; 18:1181-1192. [PMID: 33131423 DOI: 10.1080/15476286.2020.1836891] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
La-related proteins 7 (LARP7) are a class of RNA chaperones that bind the 3' ends of RNA and are constitutively associated with their specific target RNAs. In metazoa, Larp7 binds to the long non-coding 7SK RNA as a core component of the 7SK RNP, a major regulator of eukaryotic transcription. In the ciliate Tetrahymena the LARP7 protein p65 is a component of telomerase, an essential ribonucleoprotein complex that maintains the telomeric DNA at eukaryotic chromosome ends. p65 is important for the ordered assembly of telomerase RNA (TER) with telomerase reverse transcriptase. Unexpectedly, Schizosaccharomyces pombe Pof8 was recently identified as a LARP7 protein and a core component of fission yeast telomerase essential for biogenesis. LARP7 proteins have a conserved N-terminal La motif and RRM1 (La module) and C-terminal RRM2 with specific RNA substrate recognition attributed to RRM2, first structurally characterized in p65 as an atypical RRM named xRRM. Here we present the X-ray crystal structure and NMR studies of S. pombe Pof8 RRM2. Sequence and structure comparison of Pof8 RRM2 to p65 and human Larp7 xRRMs reveals conserved features for RNA binding with the main variability in the length of the non-canonical helix α3. This study shows that Pof8 has conserved xRRM features, providing insight into TER recognition and the defining characteristics of the xRRM.
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Affiliation(s)
- Ritwika Basu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Catherine D Eichhorn
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Ryan Cheng
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Robert D Peterson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
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11
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Bouhaddou M, Memon D, Meyer B, White KM, Rezelj VV, Correa Marrero M, Polacco BJ, Melnyk JE, Ulferts S, Kaake RM, Batra J, Richards AL, Stevenson E, Gordon DE, Rojc A, Obernier K, Fabius JM, Soucheray M, Miorin L, Moreno E, Koh C, Tran QD, Hardy A, Robinot R, Vallet T, Nilsson-Payant BE, Hernandez-Armenta C, Dunham A, Weigang S, Knerr J, Modak M, Quintero D, Zhou Y, Dugourd A, Valdeolivas A, Patil T, Li Q, Hüttenhain R, Cakir M, Muralidharan M, Kim M, Jang G, Tutuncuoglu B, Hiatt J, Guo JZ, Xu J, Bouhaddou S, Mathy CJP, Gaulton A, Manners EJ, Félix E, Shi Y, Goff M, Lim JK, McBride T, O'Neal MC, Cai Y, Chang JCJ, Broadhurst DJ, Klippsten S, De Wit E, Leach AR, Kortemme T, Shoichet B, Ott M, Saez-Rodriguez J, tenOever BR, Mullins RD, Fischer ER, Kochs G, Grosse R, García-Sastre A, Vignuzzi M, Johnson JR, Shokat KM, Swaney DL, Beltrao P, Krogan NJ. The Global Phosphorylation Landscape of SARS-CoV-2 Infection. Cell 2020; 182:685-712.e19. [PMID: 32645325 PMCID: PMC7321036 DOI: 10.1016/j.cell.2020.06.034] [Citation(s) in RCA: 684] [Impact Index Per Article: 171.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/09/2020] [Accepted: 06/23/2020] [Indexed: 02/07/2023]
Abstract
The causative agent of the coronavirus disease 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected millions and killed hundreds of thousands of people worldwide, highlighting an urgent need to develop antiviral therapies. Here we present a quantitative mass spectrometry-based phosphoproteomics survey of SARS-CoV-2 infection in Vero E6 cells, revealing dramatic rewiring of phosphorylation on host and viral proteins. SARS-CoV-2 infection promoted casein kinase II (CK2) and p38 MAPK activation, production of diverse cytokines, and shutdown of mitotic kinases, resulting in cell cycle arrest. Infection also stimulated a marked induction of CK2-containing filopodial protrusions possessing budding viral particles. Eighty-seven drugs and compounds were identified by mapping global phosphorylation profiles to dysregulated kinases and pathways. We found pharmacologic inhibition of the p38, CK2, CDK, AXL, and PIKFYVE kinases to possess antiviral efficacy, representing potential COVID-19 therapies.
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Affiliation(s)
- Mehdi Bouhaddou
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Danish Memon
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Bjoern Meyer
- Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Kris M White
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Veronica V Rezelj
- Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Miguel Correa Marrero
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Benjamin J Polacco
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - James E Melnyk
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute
| | - Svenja Ulferts
- Institute for Clinical and Experimental Pharmacology and Toxicology, University of Freiburg, Freiburg 79104, Germany
| | - Robyn M Kaake
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jyoti Batra
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alicia L Richards
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Erica Stevenson
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - David E Gordon
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ajda Rojc
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kirsten Obernier
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jacqueline M Fabius
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Margaret Soucheray
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Lisa Miorin
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Elena Moreno
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Cassandra Koh
- Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Quang Dinh Tran
- Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Alexandra Hardy
- Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Rémy Robinot
- Virus & Immunity Unit, Department of Virology, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France; Vaccine Research Institute, 94000 Creteil, France
| | - Thomas Vallet
- Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France
| | | | - Claudia Hernandez-Armenta
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Alistair Dunham
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Sebastian Weigang
- Institute of Virology, Medical Center - University of Freiburg, Freiburg 79104, Germany
| | - Julian Knerr
- Institute for Clinical and Experimental Pharmacology and Toxicology, University of Freiburg, Freiburg 79104, Germany
| | - Maya Modak
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Diego Quintero
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuan Zhou
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Aurelien Dugourd
- Institute for Computational Biomedicine, Bioquant, Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Alberto Valdeolivas
- Institute for Computational Biomedicine, Bioquant, Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Trupti Patil
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Qiongyu Li
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ruth Hüttenhain
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Merve Cakir
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Monita Muralidharan
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Minkyu Kim
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Gwendolyn Jang
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Beril Tutuncuoglu
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Joseph Hiatt
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jeffrey Z Guo
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jiewei Xu
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sophia Bouhaddou
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA
| | - Christopher J P Mathy
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; Department of Bioengineering & Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Anna Gaulton
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Emma J Manners
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Eloy Félix
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Ying Shi
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute
| | - Marisa Goff
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jean K Lim
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | | | | | | | | | | | - Emmie De Wit
- NIH/NIAID/Rocky Mountain Laboratories, Hamilton, MT 59840, USA
| | - Andrew R Leach
- European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Tanja Kortemme
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; Department of Bioengineering & Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Brian Shoichet
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA
| | - Melanie Ott
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
| | - Julio Saez-Rodriguez
- Institute for Computational Biomedicine, Bioquant, Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Heidelberg 69120, Germany
| | - Benjamin R tenOever
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - R Dyche Mullins
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute
| | | | - Georg Kochs
- Institute of Virology, Medical Center - University of Freiburg, Freiburg 79104, Germany; Faculty of Medicine, University of Freiburg, Freiburg 79008, Germany
| | - Robert Grosse
- Institute for Clinical and Experimental Pharmacology and Toxicology, University of Freiburg, Freiburg 79104, Germany; Faculty of Medicine, University of Freiburg, Freiburg 79008, Germany; Centre for Integrative Biological Signalling Studies (CIBSS), Freiburg 79104, Germany.
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| | - Marco Vignuzzi
- Viral Populations and Pathogenesis Unit, CNRS UMR 3569, Institut Pasteur, 75724 Paris, Cedex 15, France.
| | - Jeffery R Johnson
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Kevan M Shokat
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute.
| | - Danielle L Swaney
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Pedro Beltrao
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; European Molecular Biology Laboratory (EMBL), European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.
| | - Nevan J Krogan
- QBI COVID-19 Research Group (QCRG), San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, San Francisco, CA 94158, USA; J. David Gladstone Institutes, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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12
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Abstract
RNA-binding proteins are important regulators of RNA metabolism and are of critical importance in all steps of the gene expression cascade. The role of aberrantly expressed RBPs in human disease is an exciting research field and the potential application of RBPs as a therapeutic target or a diagnostic marker represents a fast-growing area of research.Aberrant overexpression of the human RNA-binding protein La has been found in various cancer entities including lung, cervical, head and neck, and chronic myelogenous leukaemia. Cancer-associated La protein supports tumour-promoting processes such as proliferation, mobility, invasiveness and tumour growth. Moreover, the La protein maintains the survival of cancer cells by supporting an anti-apoptotic state that may cause resistance to chemotherapeutic therapy.The human La protein represents a multifunctional post-translationally modified RNA-binding protein with RNA chaperone activity that promotes processing of non-coding precursor RNAs but also stimulates the translation of selective messenger RNAs encoding tumour-promoting and anti-apoptotic factors. In our model, La facilitates the expression of those factors and helps cancer cells to cope with cellular stress. In contrast to oncogenes, able to initiate tumorigenesis, we postulate that the aberrantly elevated expression of the human La protein contributes to the non-oncogenic addiction of cancer cells. In this review, we summarize the current understanding about the implications of the RNA-binding protein La in cancer progression and therapeutic resistance. The concept of exploiting the RBP La as a cancer drug target will be discussed.
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Affiliation(s)
- Gunhild Sommer
- Department for Pediatric Hematology, Oncology and Stem Cell Transplantation, University Hospital Regensburg, Regensburg, Germany
| | - Tilman Heise
- Department for Pediatric Hematology, Oncology and Stem Cell Transplantation, University Hospital Regensburg, Regensburg, Germany
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13
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Barrera A, Olguín V, Vera-Otarola J, López-Lastra M. Cap-independent translation initiation of the unspliced RNA of retroviruses. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194583. [PMID: 32450258 DOI: 10.1016/j.bbagrm.2020.194583] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022]
Abstract
Retroviruses are a unique family of RNA viruses that utilize a virally encoded reverse transcriptase (RT) to replicate their genomic RNA (gRNA) through a proviral DNA intermediate. The provirus is permanently integrated into the host cell chromosome and is expressed by the host cell transcription, RNA processing, and translation machinery. Retroviral messenger RNAs (mRNAs) entirely resemble a cellular mRNA as they have a 5'cap structure, 5'untranslated region (UTR), an open reading frame (ORF), 3'UTR, and a 3'poly(A) tail. The primary transcription product interacts with the cellular RNA processing machinery and is spliced, exported to the cytoplasm, and translated. However, a proportion of the pre-mRNA subverts typical RNA processing giving rise to the full-length RNA. In the cytoplasm, the full-length retroviral RNA fulfills a dual role acting as mRNA and as the gRNA. Simple retroviruses generate two pools of full-length RNA, one for each purpose. However, complex retroviruses have a single pool of full-length RNA, which is destined for translation or encapsidation. As for eukaryotic mRNAs, translational control of retroviral protein synthesis is mostly exerted at the step of initiation. Interestingly, some retroviral mRNAs, both simple and complex, use a dual mechanism to initiate protein synthesis, a cap-dependent initiation mechanism, or via internal initiation using an internal ribosome entry site (IRES). In this review, we describe and discuss data regarding the molecular mechanism driving the canonical cap-dependent and IRES-mediated translation initiation for retroviral mRNA, focusing the discussion mainly on the most studied retroviral mRNA, the HIV-1 mRNA.
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Affiliation(s)
- Aldo Barrera
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Valeria Olguín
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Jorge Vera-Otarola
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Marcelo López-Lastra
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile.
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14
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Hepatitis C Virus Translation Regulation. Int J Mol Sci 2020; 21:ijms21072328. [PMID: 32230899 PMCID: PMC7178104 DOI: 10.3390/ijms21072328] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/18/2020] [Accepted: 03/25/2020] [Indexed: 12/12/2022] Open
Abstract
Translation of the hepatitis C virus (HCV) RNA genome is regulated by the internal ribosome entry site (IRES), located in the 5’-untranslated region (5′UTR) and part of the core protein coding sequence, and by the 3′UTR. The 5′UTR has some highly conserved structural regions, while others can assume different conformations. The IRES can bind to the ribosomal 40S subunit with high affinity without any other factors. Nevertheless, IRES activity is modulated by additional cis sequences in the viral genome, including the 3′UTR and the cis-acting replication element (CRE). Canonical translation initiation factors (eIFs) are involved in HCV translation initiation, including eIF3, eIF2, eIF1A, eIF5, and eIF5B. Alternatively, under stress conditions and limited eIF2-Met-tRNAiMet availability, alternative initiation factors such as eIF2D, eIF2A, and eIF5B can substitute for eIF2 to allow HCV translation even when cellular mRNA translation is downregulated. In addition, several IRES trans-acting factors (ITAFs) modulate IRES activity by building large networks of RNA-protein and protein–protein interactions, also connecting 5′- and 3′-ends of the viral RNA. Moreover, some ITAFs can act as RNA chaperones that help to position the viral AUG start codon in the ribosomal 40S subunit entry channel. Finally, the liver-specific microRNA-122 (miR-122) stimulates HCV IRES-dependent translation, most likely by stabilizing a certain structure of the IRES that is required for initiation.
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15
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Vinayak J, Marrella SA, Hussain RH, Rozenfeld L, Solomon K, Bayfield MA. Human La binds mRNAs through contacts to the poly(A) tail. Nucleic Acids Res 2019; 46:4228-4240. [PMID: 29447394 PMCID: PMC5934636 DOI: 10.1093/nar/gky090] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/31/2018] [Indexed: 12/31/2022] Open
Abstract
In addition to a role in the processing of nascent RNA polymerase III transcripts, La proteins are also associated with promoting cap-independent translation from the internal ribosome entry sites of numerous cellular and viral coding RNAs. La binding to RNA polymerase III transcripts via their common UUU-3’OH motif is well characterized, but the mechanism of La binding to coding RNAs is poorly understood. Using electromobility shift assays and cross-linking immunoprecipitation, we show that in addition to a sequence specific UUU-3’OH binding mode, human La exhibits a sequence specific and length dependent poly(A) binding mode. We demonstrate that this poly(A) binding mode uses the canonical nucleic acid interaction winged helix face of the eponymous La motif, previously shown to be vacant during uridylate binding. We also show that cytoplasmic, but not nuclear La, engages poly(A) RNA in human cells, that La entry into polysomes utilizes the poly(A) binding mode, and that La promotion of translation from the cyclin D1 internal ribosome entry site occurs in competition with cytoplasmic poly(A) binding protein (PABP). Our data are consistent with human La functioning in translation through contacts to the poly(A) tail.
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Affiliation(s)
- Jyotsna Vinayak
- Department of Biology, York University, 4700 Keele St., Life Science Building #327E, Toronto, ON M3J 1P3, Canada
| | - Stefano A Marrella
- Department of Biology, York University, 4700 Keele St., Life Science Building #327E, Toronto, ON M3J 1P3, Canada
| | - Rawaa H Hussain
- Department of Biology, York University, 4700 Keele St., Life Science Building #327E, Toronto, ON M3J 1P3, Canada
| | - Leonid Rozenfeld
- Department of Biology, York University, 4700 Keele St., Life Science Building #327E, Toronto, ON M3J 1P3, Canada
| | - Karine Solomon
- Department of Biology, York University, 4700 Keele St., Life Science Building #327E, Toronto, ON M3J 1P3, Canada
| | - Mark A Bayfield
- Department of Biology, York University, 4700 Keele St., Life Science Building #327E, Toronto, ON M3J 1P3, Canada
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16
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Chandra N, Biswas S, Rout J, Basu G, Tripathy U. Stability of β-turn in LaR2C-N7 peptide for its translation-inhibitory activity against hepatitis C viral infection: A molecular dynamics study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 211:26-33. [PMID: 30502581 DOI: 10.1016/j.saa.2018.11.056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 11/03/2018] [Accepted: 11/20/2018] [Indexed: 06/09/2023]
Abstract
Hepatitis C virus (HCV) requires an essential host factor, human La protein, for its translation and replication activity. Earlier, it was demonstrated that a 24-mer synthetic peptide (LaR2C) encompassing residues 112 to 184 of the natural human La protein interacts with the HCV internal ribosome entry site (IRES) and inhibits translation. Interestingly, a shorter version of the same LaR2C peptide, LaR2C-N7, containing residues 174 to 180 (KYKETDL), with a unique β-turn secondary structure, is sufficient to inhibit IRES mediated translation of HCV. Hence, it is imperative to understand the role of each amino acid of this heptapeptide towards β-turn formation which will then help in designing potential drugs against HCV infection. Here, we use Nanoscale Molecular Dynamics (NAMD) simulation to investigate the factors modulating its β-turn formation and stability. Using 100 ns simulation paradigms, we find that the peptide populated the type 1 β-turn conformation in its free form in solution. However, simulation of the single-site mutants of the heptapeptide revealed that none of the 7 mutants retained the β-turn conformation with sufficient stability. We observed that the β-turn was stabilized mainly by the side chain interaction, salt-bridge and weak hydrogen bonds between K3 and D6 residues. Y2, K1 and K3 sites upon mutation heavily destabilized the β-turn when compared to alteration at the E4 and T5 sites which would then drastically reduce its HCV RNA IRES binding capabilities. Taken together, our results provide a basis for designing peptidomimetics as potential anti-HCV drug candidates.
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Affiliation(s)
- Navin Chandra
- University Department of Physics, Vinoba Bhave University, Hazaribag 825301, Jharkhand, India.
| | - Shrutidhara Biswas
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati 781039, Assam, India
| | - Janmejaya Rout
- Department of Applied Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, Jharkhand, India
| | - Gautam Basu
- Department of Biophysics, Centenary Campus, Bose Institute, Kolkata 700054, West Bengal, India
| | - Umakanta Tripathy
- Department of Applied Physics, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, Jharkhand, India.
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17
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Sharma G, Raheja H, Das S. Hepatitis C virus: Enslavement of host factors. IUBMB Life 2018; 70:41-49. [PMID: 29281185 DOI: 10.1002/iub.1702] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 11/20/2017] [Accepted: 11/28/2017] [Indexed: 12/11/2022]
Abstract
Hepatitis C virus (HCV) has infected over 170 million people world-wide. This infection causes severe liver damage that can progress to hepatocellular carcinoma leading to death of the infected patients. Development of a cell culture model system for the study of HCV infection in the recent past has helped the researchers world-wide to understand the biology of this virus. Studies over the past decade have revealed the tricks played by the virus to sustain itself, for as long as 40 years, in the host setup without being eliminated by the immune system. Today we understand that the host organelles and different cellular proteins are affected during HCV infection. This cytoplasmic virus has all the cellular organelles at its disposal to successfully replicate, from ribosomes and intracellular membranous structures to the nucleus. It modulates these organelles at both the structural and the functional levels. The vast knowledge about the viral genome and viral proteins has also helped in the development of drugs against the virus. Despite the achieved success rate to cure the infected patients, we struggle to eliminate the cases of recurrence and the non-responders. Such cases might emerge owing to the property of the viral genome to accumulate mutations during its succeeding replication cycles which favours its survival. The current situation calls an urgent need for alternate therapeutic strategies to counter this major problem of human health. © 2017 IUBMB Life, 70(1):41-49, 2018.
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Affiliation(s)
- Geetika Sharma
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, Karnataka, India
| | - Harsha Raheja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, Karnataka, India
| | - Saumitra Das
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, Karnataka, India
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18
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RNA binding protein 24 regulates the translation and replication of hepatitis C virus. Protein Cell 2018; 9:930-944. [PMID: 29380205 PMCID: PMC6208484 DOI: 10.1007/s13238-018-0507-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/10/2017] [Indexed: 12/12/2022] Open
Abstract
The secondary structures of hepatitis C virus (HCV) RNA and the cellular proteins that bind to them are important for modulating both translation and RNA replication. However, the sets of RNA-binding proteins involved in the regulation of HCV translation, replication and encapsidation remain unknown. Here, we identified RNA binding motif protein 24 (RBM24) as a host factor participated in HCV translation and replication. Knockdown of RBM24 reduced HCV propagation in Huh7.5.1 cells. An enhanced translation and delayed RNA synthesis during the early phase of infection was observed in RBM24 silencing cells. However, both overexpression of RBM24 and recombinant human RBM24 protein suppressed HCV IRES-mediated translation. Further analysis revealed that the assembly of the 80S ribosome on the HCV IRES was interrupted by RBM24 protein through binding to the 5'-UTR. RBM24 could also interact with HCV Core and enhance the interaction of Core and 5'-UTR, which suppresses the expression of HCV. Moreover, RBM24 enhanced the interaction between the 5'- and 3'-UTRs in the HCV genome, which probably explained its requirement in HCV genome replication. Therefore, RBM24 is a novel host factor involved in HCV replication and may function at the switch from translation to replication.
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19
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The La protein counteracts cisplatin-induced cell death by stimulating protein synthesis of anti-apoptotic factor Bcl2. Oncotarget 2018; 7:29664-76. [PMID: 27105491 PMCID: PMC5045424 DOI: 10.18632/oncotarget.8819] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/28/2016] [Indexed: 02/06/2023] Open
Abstract
Up-regulation of anti-apoptotic factors is a critical mechanism of cancer cell resistance and often counteracts the success of chemotherapeutic treatment. Herein, we identified the cancer-associated RNA-binding protein La as novel factor contributing to cisplatin resistance. Our data demonstrate that depletion of the RNA-binding protein La in head and neck squamous cell carcinoma cells (HNSCC) increases the sensitivity toward cisplatin-induced cell death paralleled by reduced expression of the anti-apoptotic factor Bcl2. Furthermore, it is shown that transient expression of Bcl2 in La-depleted cells protects against cisplatin-induced cell death. By dissecting the underlying mechanism we report herein, that the La protein is required for Bcl2 protein synthesis in cisplatin-treated cells. The RNA chaperone La binds in close proximity to the authentic translation start site and unwinds a secondary structure embedding the authentic AUG. Altogether, our data support a novel model, whereby cancer-associated La protein contributes to cisplatin resistance by stimulating the translation of anti-apoptotic factor Bcl2 in HNSCC cells.
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20
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Glab-Ampai K, Chulanetra M, Malik AA, Juntadech T, Thanongsaksrikul J, Srimanote P, Thueng-In K, Sookrung N, Tongtawe P, Chaicumpa W. Human single chain-transbodies that bound to domain-I of non-structural protein 5A (NS5A) of hepatitis C virus. Sci Rep 2017; 7:15042. [PMID: 29118372 PMCID: PMC5678119 DOI: 10.1038/s41598-017-14886-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/18/2017] [Indexed: 12/15/2022] Open
Abstract
A safe and broadly effective direct acting anti-hepatitis C virus (HCV) agent that can withstand the viral mutation is needed. In this study, human single chain antibody variable fragments (HuscFvs) to conserved non-structural protein-5A (NS5A) of HCV were produced by phage display technology. Recombinant NS5A was used as bait for fishing-out the protein bound-phages from the HuscFv-phage display library. NS5A-bound HuscFvs produced by five phage transfected-E. coli clones were linked molecularly to nonaarginine (R9) for making them cell penetrable (become transbodies). The human monoclonal transbodies inhibited HCV replication in the HCVcc infected human hepatic cells and also rescued the cellular antiviral immune response from the viral suppression. Computerized simulation verified by immunoassays indicated that the transbodies used several residues in their multiple complementarity determining regions (CDRs) to form contact interface with many residues of the NS5A domain-I which is important for HCV replication complex formation and RNA binding as well as for interacting with several host proteins for viral immune evasion and regulation of cellular physiology. The human monoclonal transbodies have high potential for testing further as a new ramification of direct acting anti-HCV agent, either alone or in combination with their cognates that target other HCV proteins.
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Affiliation(s)
- Kittirat Glab-Ampai
- Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Monrat Chulanetra
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Aijaz Ahmad Malik
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Thanate Juntadech
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Jeeraphong Thanongsaksrikul
- Graduate Program in Biomedical Science, Faculty of Allied Health Sciences, Thammasat University, Rangsit Campus, Pathum-thani province, 12120, Thailand
| | - Potjanee Srimanote
- Graduate Program in Biomedical Science, Faculty of Allied Health Sciences, Thammasat University, Rangsit Campus, Pathum-thani province, 12120, Thailand
| | - Kanyarat Thueng-In
- School of Pathology, Institute of Medicine, Suranaree University of Technology, Nakhon-ratchaseema province, Thailand
| | - Nitat Sookrung
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Pongsri Tongtawe
- Graduate Program in Biomedical Science, Faculty of Allied Health Sciences, Thammasat University, Rangsit Campus, Pathum-thani province, 12120, Thailand
| | - Wanpen Chaicumpa
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
- Graduate Program in Biomedical Science, Faculty of Allied Health Sciences, Thammasat University, Rangsit Campus, Pathum-thani province, 12120, Thailand.
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21
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Maraia RJ, Mattijssen S, Cruz-Gallardo I, Conte MR. The La and related RNA-binding proteins (LARPs): structures, functions, and evolving perspectives. WILEY INTERDISCIPLINARY REVIEWS. RNA 2017; 8:10.1002/wrna.1430. [PMID: 28782243 PMCID: PMC5647580 DOI: 10.1002/wrna.1430] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 01/02/2023]
Abstract
La was first identified as a polypeptide component of ribonucleic protein complexes targeted by antibodies in autoimmune patients and is now known to be a eukaryote cell-ubiquitous protein. Structure and function studies have shown that La binds to a common terminal motif, UUU-3'-OH, of nascent RNA polymerase III (RNAP III) transcripts and protects them from exonucleolytic decay. For precursor-tRNAs, the most diverse and abundant of these transcripts, La also functions as an RNA chaperone that helps to prevent their misfolding. Related to this, we review evidence that suggests that La and its link to RNAP III were significant in the great expansions of the tRNAomes that occurred in eukaryotes. Four families of La-related proteins (LARPs) emerged during eukaryotic evolution with specialized functions. We provide an overview of the high-resolution structural biology of La and LARPs. LARP7 family members most closely resemble La but function with a single RNAP III nuclear transcript, 7SK, or telomerase RNA. A cytoplasmic isoform of La protein as well as LARPs 6, 4, and 1 function in mRNA metabolism and translation in distinct but similar ways, sometimes with the poly(A)-binding protein, and in some cases by direct binding to poly(A)-RNA. New structures of LARP domains, some complexed with RNA, provide novel insights into the functional versatility of these proteins. We also consider LARPs in relation to ancestral La protein and potential retention of links to specific RNA-related pathways. One such link may be tRNA surveillance and codon usage by LARP-associated mRNAs. WIREs RNA 2017, 8:e1430. doi: 10.1002/wrna.1430 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Richard J. Maraia
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
- Commissioned Corps, U.S. Public Health Service, Rockville, MD USA
| | - Sandy Mattijssen
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Isabel Cruz-Gallardo
- Randall Division of Cell and Molecular Biophysics, King's College London, Guy's Campus, London, UK
| | - Maria R. Conte
- Randall Division of Cell and Molecular Biophysics, King's College London, Guy's Campus, London, UK
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22
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Blewett NH, Iben JR, Gaidamakov S, Maraia RJ. La Deletion from Mouse Brain Alters Pre-tRNA Metabolism and Accumulation of Pre-5.8S rRNA, with Neuron Death and Reactive Astrocytosis. Mol Cell Biol 2017; 37:e00588-16. [PMID: 28223366 PMCID: PMC5477551 DOI: 10.1128/mcb.00588-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/01/2016] [Accepted: 02/06/2017] [Indexed: 12/20/2022] Open
Abstract
Human La antigen (Sjögren's syndrome antigen B [SSB]) is an abundant multifunctional RNA-binding protein. In the nucleoplasm, La binds to and protects from 3' exonucleases, the ends of precursor tRNAs, and other transcripts synthesized by RNA polymerase III and facilitates their maturation, while a nucleolar isoform has been implicated in rRNA biogenesis by multiple independent lines of evidence. We showed previously that conditional La knockout (La cKO) from mouse cortex neurons results in defective tRNA processing, although the pathway(s) involved in neuronal loss thereafter was unknown. Here, we demonstrate that La is stably associated with a spliced pre-tRNA intermediate. Microscopic evidence of aberrant nuclear accumulation of 5.8S rRNA in La cKO is supported by a 10-fold increase in a pre-5.8S rRNA intermediate. To identify pathways involved in subsequent neurodegeneration and loss of brain mass in the cKO cortex, we employed mRNA sequencing (mRNA-Seq), immunohistochemistry, and other approaches. This revealed robust enrichment of immune and astrocyte reactivity in La cKO cortex. Immunohistochemistry, including temporal analyses, demonstrated neurodegeneration, followed by astrocyte invasion associated with immune response and decreasing cKO cortex size over time. Thus, deletion of La from postmitotic neurons results in defective pre-tRNA and pre-rRNA processing and progressive neurodegeneration with loss of cortical brain mass.
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Affiliation(s)
- Nathan H Blewett
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA
| | - James R Iben
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA
| | - Sergei Gaidamakov
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland, USA
| | - Richard J Maraia
- Commissioned Corps, U.S. Public Health Service, Rockville, Maryland, USA
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Regulation Mechanisms of Viral IRES-Driven Translation. Trends Microbiol 2017; 25:546-561. [PMID: 28242053 DOI: 10.1016/j.tim.2017.01.010] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 01/10/2017] [Accepted: 01/30/2017] [Indexed: 02/06/2023]
Abstract
Internal ribosome entry sites (IRESs) can be found in the mRNA of many viruses as well as in cellular genes involved in the stress response, cell cycle, and apoptosis. IRES-mediated translation can occur when dominant cap-dependent translation is inhibited, and viruses can take advantage of this to subvert host translation machinery. In this review, we focus on the four major types of IRES identified in RNA viruses, and outline their distinct structural properties and requirements of translational factors. We further discuss auxiliary host factors known as IRES trans-acting factors (ITAFs), which are involved in the modulation of optimal IRES activity. Currently known strategies employed by viruses to harness ITAFs and regulate IRES activity are also highlighted.
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Brown KA, Sharifi S, Hussain R, Donaldson L, Bayfield MA, Wilson DJ. Distinct Dynamic Modes Enable the Engagement of Dissimilar Ligands in a Promiscuous Atypical RNA Recognition Motif. Biochemistry 2016; 55:7141-7150. [PMID: 27959512 DOI: 10.1021/acs.biochem.6b00995] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conformational dynamics play a critical role in ligand binding, often conferring divergent activities and specificities even in species with highly similar ground-state structures. Here, we employ time-resolved electrospray ionization hydrogen-deuterium exchange (TRESI-HDX) to characterize the changes in dynamics that accompany oligonucleotide binding in the atypical RNA recognition motif (RRM2) in the C-terminal domain (CTD) of human La protein. Using this approach, which is uniquely capable of probing changes in the structure and dynamics of weakly ordered regions of proteins, we reveal that binding of RRM2 to a model 23-mer single-stranded RNA and binding of RRM2 to structured IRES domain IV of the hepatitis C viral (HCV) RNA are driven by fundamentally different dynamic processes. In particular, binding of the single-stranded RNA induces helical "unwinding" in a region of the CTD previously hypothesized to play an important role in La and La-related protein-associated RNA remodeling, while the same region becomes less dynamic upon engagement with the double-stranded HCV RNA. Binding of double-stranded RNA also involves less penetration into the RRM2 binding pocket and more engagement with the unstructured C-terminus of the La CTD. The complementarity between TRESI-HDX and Δδ nuclear magnetic resonance measurements for ligand binding analysis is also explored.
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Affiliation(s)
- Kerene A Brown
- Department of Chemistry, York University , Toronto, ON M3J 1P3, Canada
- Centre for Research in Mass Spectrometry, York University , Toronto, ON M3J 1P3, Canada
| | - Samel Sharifi
- Department of Biology, York University , Toronto, ON M3J 1P3, Canada
| | - Rawaa Hussain
- Department of Biology, York University , Toronto, ON M3J 1P3, Canada
| | - Logan Donaldson
- Department of Biology, York University , Toronto, ON M3J 1P3, Canada
| | - Mark A Bayfield
- Department of Biology, York University , Toronto, ON M3J 1P3, Canada
- Centre for Research in Biomolecular Interactions, York University , Toronto, ON M3J 1P3, Canada
| | - Derek J Wilson
- Department of Chemistry, York University , Toronto, ON M3J 1P3, Canada
- Centre for Research in Mass Spectrometry, York University , Toronto, ON M3J 1P3, Canada
- Centre for Research in Biomolecular Interactions, York University , Toronto, ON M3J 1P3, Canada
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25
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De Lorenzo G, Drikic M, Papa G, Eichwald C, Burrone OR, Arnoldi F. An Inhibitory Motif on the 5'UTR of Several Rotavirus Genome Segments Affects Protein Expression and Reverse Genetics Strategies. PLoS One 2016; 11:e0166719. [PMID: 27846320 PMCID: PMC5112996 DOI: 10.1371/journal.pone.0166719] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 11/02/2016] [Indexed: 12/18/2022] Open
Abstract
Rotavirus genome consists of eleven segments of dsRNA, each encoding one single protein. Viral mRNAs contain an open reading frame (ORF) flanked by relatively short untranslated regions (UTRs), whose role in the viral cycle remains elusive. Here we investigated the role of 5'UTRs in T7 polymerase-driven cDNAs expression in uninfected cells. The 5'UTRs of eight genome segments (gs3, gs5-6, gs7-11) of the simian SA11 strain showed a strong inhibitory effect on the expression of viral proteins. Decreased protein expression was due to both compromised transcription and translation and was independent of the ORF and the 3'UTR sequences. Analysis of several mutants of the 21-nucleotide long 5'UTR of gs 11 defined an inhibitory motif (IM) represented by its primary sequence rather than its secondary structure. IM was mapped to the 5' terminal 6-nucleotide long pyrimidine-rich tract 5'-GGY(U/A)UY-3'. The 5' terminal position within the mRNA was shown to be essentially required, as inhibitory activity was lost when IM was moved to an internal position. We identified two mutations (insertion of a G upstream the 5'UTR and the U to A mutation of the fifth nucleotide of IM) that render IM non-functional and increase the transcription and translation rate to levels that could considerably improve the efficiency of virus helper-free reverse genetics strategies.
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Affiliation(s)
- Giuditta De Lorenzo
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Marija Drikic
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Guido Papa
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | | | - Oscar R. Burrone
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
- * E-mail: (FA); (OB)
| | - Francesca Arnoldi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
- * E-mail: (FA); (OB)
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26
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Schwerk J, Jarret AP, Joslyn RC, Savan R. Landscape of post-transcriptional gene regulation during hepatitis C virus infection. Curr Opin Virol 2015; 12:75-84. [PMID: 25890065 DOI: 10.1016/j.coviro.2015.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 02/11/2015] [Indexed: 12/11/2022]
Abstract
Post-transcriptional regulation of gene expression plays a pivotal role in various gene regulatory networks including, but not limited to metabolism, embryogenesis and immune responses. Different mechanisms of post-transcriptional regulation, which can act individually, synergistically, or even in an antagonistic manner have been described. Hepatitis C virus (HCV) is notorious for subverting host immune responses and indeed exploits several components of the host's post-transcriptional regulatory machinery for its own benefit. At the same time, HCV replication is post-transcriptionally targeted by host cell components to blunt viral propagation. This review discusses the interplay of post-transcriptional mechanisms that affect host immune responses in the setting of HCV infection and highlights the sophisticated mechanisms both host and virus have evolved in the race for superiority.
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Affiliation(s)
- Johannes Schwerk
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Abigail P Jarret
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Rochelle C Joslyn
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Ram Savan
- Department of Immunology, University of Washington, Seattle, WA 98109, USA.
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27
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Kuehnert J, Sommer G, Zierk AW, Fedarovich A, Brock A, Fedarovich D, Heise T. Novel RNA chaperone domain of RNA-binding protein La is regulated by AKT phosphorylation. Nucleic Acids Res 2015; 43:581-94. [PMID: 25520193 PMCID: PMC4288197 DOI: 10.1093/nar/gku1309] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 12/02/2014] [Accepted: 12/04/2014] [Indexed: 01/13/2023] Open
Abstract
The cellular function of the cancer-associated RNA-binding protein La has been linked to translation of viral and cellular mRNAs. Recently, we have shown that the human La protein stimulates IRES-mediated translation of the cooperative oncogene CCND1 in cervical cancer cells. However, there is little known about the underlying molecular mechanism by which La stimulates CCND1 IRES-mediated translation, and we propose that its RNA chaperone activity is required. Herein, we show that La binds close to the CCND1 start codon and demonstrate that La's RNA chaperone activity can change the folding of its binding site. We map the RNA chaperone domain (RCD) within the C-terminal region of La in close proximity to a novel AKT phosphorylation site (T389). Phosphorylation at T389 by AKT-1 strongly impairs its RNA chaperone activity. Furthermore, we demonstrate that the RCD as well as T389 is required to stimulate CCND1 IRES-mediated translation in cells. In summary, we provide a model whereby a novel interplay between RNA-binding, RNA chaperoning and AKT phosphorylation of La protein regulates CCND1 IRES-mediated translation.
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Affiliation(s)
- Julia Kuehnert
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Gunhild Sommer
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Avery W Zierk
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Alena Fedarovich
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Alexander Brock
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Dzmitry Fedarovich
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Tilman Heise
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
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28
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Xu B, Zhang J, Strom J, Lee S, Chen QM. Myocardial ischemic reperfusion induces de novo Nrf2 protein translation. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1638-47. [PMID: 24915518 DOI: 10.1016/j.bbadis.2014.06.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/31/2014] [Accepted: 06/02/2014] [Indexed: 12/15/2022]
Abstract
Nrf2 is a bZIP transcription factor regulating the expression of antioxidant and detoxification genes. We have found that Nrf2 knockout mice have an increased infarction size in response to regional ischemic reperfusion and have a reduced degree of cardiac protection by means of ischemic preconditioning. With cycles of brief ischemia and reperfusion (5'I/5'R) that induce cardiac protection in wild type mice, an elevated Nrf2 protein was observed without prior increases of Nrf2 mRNA. When an mRNA species is being translated into a protein, it is occupied by multiple ribosomes. The level of ribosome-associated Nrf2 mRNA increased following cycles of 5'I/5'R, supporting de novo Nrf2 protein translation. A dicistronic reporter assay indicated a role of the 5' untranslated region (5' UTR) of Nrf2 mRNA in oxidative stress induced Nrf2 protein translation in isolated cardiomyocytes. Western blot analyses after isolation of proteins binding to biotinylated Nrf2 5' UTR from the myocardium or cultured cardiomyocytes demonstrated that cycles of 5'I/5'R or oxidants caused an increased association of La protein with Nrf2 5' UTR. Ribonucleoprotein complex immunoprecipitation assays confirmed such association indeed occurring in vivo. Knocking down La using siRNA was able to prevent Nrf2 protein elevation by oxidants in cultured cardiomyocytes and by cycles of 5'I/5'R in the myocardium. Our data point out a novel mechanism of cardiac protection by de novo Nrf2 protein translation involving interaction of La protein with 5' UTR of Nrf2 mRNA in cardiomyocytes.
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Affiliation(s)
- Beibei Xu
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 N. Campbell Ave, Tucson, AZ 85724, USA
| | - Jack Zhang
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 N. Campbell Ave, Tucson, AZ 85724, USA
| | - Joshua Strom
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 N. Campbell Ave, Tucson, AZ 85724, USA
| | - Sang Lee
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 N. Campbell Ave, Tucson, AZ 85724, USA
| | - Qin M Chen
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 N. Campbell Ave, Tucson, AZ 85724, USA.
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29
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Ke PY, Chen SSL. Autophagy in hepatitis C virus-host interactions: potential roles and therapeutic targets for liver-associated diseases. World J Gastroenterol 2014; 20:5773-93. [PMID: 24914338 PMCID: PMC4024787 DOI: 10.3748/wjg.v20.i19.5773] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 01/14/2014] [Accepted: 03/04/2014] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a lysosome-associated, degradative process that catabolizes cytosolic components to recycle nutrients for further use and maintain cell homeostasis. Hepatitis C virus (HCV) is a major cause of chronic hepatitis, which often leads to end-stage liver-associated diseases and is a significant burden on worldwide public health. Emerging lines of evidence indicate that autophagy plays an important role in promoting the HCV life cycle in host cells. Moreover, the diverse impacts of autophagy on a variety of signaling pathways in HCV-infected cells suggest that the autophagic process is required for balancing HCV-host cell interactions and involved in the pathogenesis of HCV-related liver diseases. However, the detailed molecular mechanism underlying how HCV activates autophagy to benefit viral growth is still enigmatic. Additionally, how the autophagic response contributes to disease progression in HCV-infected cells remains largely unknown. Hence, in this review, we overview the interplay between autophagy and the HCV life cycle and propose possible mechanisms by which autophagy may promote the pathogenesis of HCV-associated chronic liver diseases. Moreover, we outline the related studies on how autophagy interplays with HCV replication and discuss the possible implications of autophagy and viral replication in the progression of HCV-induced liver diseases, e.g., steatosis and hepatocellular carcinoma. Finally, we explore the potential therapeutics that target autophagy to cure HCV infection and its related liver diseases.
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30
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Apostolidi M, Vourtsis DJ, Chasapis CT, Stathopoulos C, Bentrop D, Spyroulias GA. ¹H, ¹⁵N, ¹³C assignment and secondary structure determination of two domains of La protein from D. discoideum. BIOMOLECULAR NMR ASSIGNMENTS 2014; 8:47-51. [PMID: 23239108 DOI: 10.1007/s12104-012-9450-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 12/04/2012] [Indexed: 06/01/2023]
Abstract
Biosynthesis of RNA polymerase III transcripts requires binding of the La protein at their 3' end. La is an abundant nuclear RNA-binding protein which protects the nascent transcripts from 3' exonuclease degradation. Here, we report the high yield expression and preliminary structural analysis through NMR spectroscopy of two recombinant RNA binding domains (La motif and NRRM) from the La protein of Dictyostelium discoideum. Both recombinant protein constructs were well-folded and allowed for an almost complete sequence-specific assignment of the (15)N and (13)C labeled domains and their secondary structure prediction using PECAN online tool.
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Affiliation(s)
- Maria Apostolidi
- Department of Biochemistry, School of Medicine, University of Patras, 26504, Patras, Greece
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31
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Specific sequence of a Beta turn in human la protein may contribute to species specificity of hepatitis C virus. J Virol 2014; 88:4319-27. [PMID: 24478427 DOI: 10.1128/jvi.00049-14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
UNLABELLED Human La protein is known to be an essential host factor for translation and replication of hepatitis C virus (HCV) RNA. Previously, we have demonstrated that residues responsible for interaction of human La protein with the HCV internal ribosomal entry site (IRES) around the initiator AUG within stem-loop IV form a β-turn in the RNA recognition motif (RRM) structure. In this study, sequence alignment and mutagenesis suggest that the HCV RNA-interacting β-turn is conserved only in humans and chimpanzees, the species primarily known to be infected by HCV. A 7-mer peptide corresponding to the HCV RNA-interacting region of human La inhibits HCV translation, whereas another peptide corresponding to the mouse La sequence was unable to do so. Furthermore, IRES-mediated translation was found to be significantly high in the presence of recombinant human La protein in vitro in rabbit reticulocyte lysate. We observed enhanced replication with HCV subgenomic and full-length replicons upon overexpression of either human La protein or a chimeric mouse La protein harboring a human La β-turn sequence in mouse cells. Taken together, our results raise the possibility of creating an immunocompetent HCV mouse model using human-specific cell entry factors and a humanized form of La protein. IMPORTANCE Hepatitis C virus is known to infect only humans and chimpanzees under natural conditions. This has prevented the development of a small-animal model, which is important for development of new antiviral drugs. Although a number of human-specific proteins are responsible for this species selectivity and some of these proteins--mostly entry factors--have been identified, full multiplication of the virus in mouse cells is still not possible. In this study, we show that a turn in the human La protein that is responsible for the interaction with the viral RNA is highly specific for the human sequence. Replacement of the corresponding mouse sequence with the human sequence allows the mouse La to behave like its human counterpart and support viral growth in the mouse cell efficiently. This observation, in combination with previously identified cell entry factors, should open up the possibility of creating a mouse model of hepatitis C.
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Hussain RH, Zawawi M, Bayfield MA. Conservation of RNA chaperone activity of the human La-related proteins 4, 6 and 7. Nucleic Acids Res 2013; 41:8715-25. [PMID: 23887937 PMCID: PMC3794603 DOI: 10.1093/nar/gkt649] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/28/2013] [Accepted: 07/03/2013] [Indexed: 12/22/2022] Open
Abstract
The La module is a conserved tandem arrangement of a La motif and RNA recognition motif whose function has been best characterized in genuine La proteins. The best-characterized substrates of La proteins are pre-tRNAs, and previous work using tRNA mediated suppression in Schizosaccharomyces pombe has demonstrated that yeast and human La enhance the maturation of these using two distinguishable activities: UUU-3'OH-dependent trailer binding/protection and a UUU-3'OH independent activity related to RNA chaperone function. The La module has also been identified in several conserved families of La-related proteins (LARPs) that engage other RNAs, but their mode of RNA binding and function(s) are not well understood. We demonstrate that the La modules of the human LARPs 4, 6 and 7 are also active in tRNA-mediated suppression, even in the absence of stable UUU-3'OH trailer protection. Rather, the capacity of these to enhance pre-tRNA maturation is associated with RNA chaperone function, which we demonstrate to be a conserved activity for each hLARP in vitro. Our work reveals insight into the mechanisms by which La module containing proteins discriminate RNA targets and demonstrates that RNA chaperone activity is a conserved function across representative members of the La motif-containing superfamily.
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Affiliation(s)
| | | | - Mark A. Bayfield
- Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada
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Macarthur KL, Smolic R, Smolic MV, Wu CH, Wu GY. Update on the Development of Anti-Viral Agents Against Hepatitis C. J Clin Transl Hepatol 2013; 1:9-21. [PMID: 26357602 PMCID: PMC4521270 DOI: 10.14218/jcth.2013.007xx] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/14/2013] [Accepted: 05/14/2013] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) infects nearly 170 million people worldwide and causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The search for a drug regimen that maximizes efficacy and minimizes side effects is quickly evolving. This review will discuss a wide range of drug targets currently in all phases of development for the treatment of HCV. Direct data from agents in phase III/IV clinical trials will be presented, along with reported side-effect profiles. The mechanism of action of all treatments and resistance issues are highlighted. Special attention is given to available trial data supporting interferon-free treatment regimens. HCV has become an increasingly important public health concern, and it is important for physicians to stay up to date on the rapidly growing novel therapeutic options.
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Affiliation(s)
| | | | | | - Catherine H. Wu
- Department of Medicine, Division of Gastroenterology-Hepatology, University of Connecticut Health Center, Farmington, CT, USA
| | - George Y. Wu
- Department of Medicine, Division of Gastroenterology-Hepatology, University of Connecticut Health Center, Farmington, CT, USA
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Human La protein interaction with GCAC near the initiator AUG enhances hepatitis C Virus RNA replication by promoting linkage between 5' and 3' untranslated regions. J Virol 2013; 87:6713-26. [PMID: 23552417 DOI: 10.1128/jvi.00525-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Human La protein has been implicated in facilitating the internal initiation of translation as well as replication of hepatitis C virus (HCV) RNA. Previously, we demonstrated that La interacts with the HCV internal ribosome entry site (IRES) around the GCAC motif near the initiator AUG within stem-loop IV by its RNA recognition motif (RRM) (residues 112 to 184) and influences HCV translation. In this study, we have deciphered the role of this interaction in HCV replication in a hepatocellular carcinoma cell culture system. We incorporated mutation of the GCAC motif in an HCV monocistronic subgenomic replicon and a pJFH1 construct which altered the binding of La and checked HCV RNA replication by reverse transcriptase PCR (RT-PCR). The mutation drastically affected HCV replication. Furthermore, to address whether the decrease in replication is a consequence of translation inhibition or not, we incorporated the same mutation into a bicistronic replicon and observed a substantial decrease in HCV RNA levels. Interestingly, La overexpression rescued this inhibition of replication. More importantly, we observed that the mutation reduced the association between La and NS5B. The effect of the GCAC mutation on the translation-to-replication switch, which is regulated by the interplay between NS3 and La, was further investigated. Additionally, our analyses of point mutations in the GCAC motif revealed distinct roles of each nucleotide in HCV replication and translation. Finally, we showed that a specific interaction of the GCAC motif with human La protein is crucial for linking 5' and 3' ends of the HCV genome. Taken together, our results demonstrate the mechanism of regulation of HCV replication by interaction of the cis-acting element GCAC within the HCV IRES with human La protein.
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35
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Manna AK, Kumar A, Ray U, Das S, Basu G, Roy S. A cyclic peptide mimic of an RNA recognition motif of human La protein is a potent inhibitor of hepatitis C virus. Antiviral Res 2013; 97:223-6. [PMID: 23291201 DOI: 10.1016/j.antiviral.2012.12.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 12/25/2012] [Accepted: 12/26/2012] [Indexed: 10/27/2022]
Abstract
Due to limited available therapeutic options, developing new lead compounds against hepatitis C virus is an urgent need. Human La protein stimulates hepatitis C virus translation through interaction with the hepatitis C viral RNA. A cyclic peptide mimicking the β-turn of the human La protein that interacts with the viral RNA was synthesized. It inhibits hepatitis C viral RNA translation significantly better than the corresponding linear peptide at longer post-treatment times. The cyclic peptide also inhibited replication as measured by replicon RNA levels using real time RT-PCR. The cyclic peptide emerges as a promising lead compound against hepatitis C.
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Affiliation(s)
- Asit Kumar Manna
- Division of Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
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36
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37
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Shetty S, Stefanovic S, Mihailescu MR. Hepatitis C virus RNA: molecular switches mediated by long-range RNA-RNA interactions? Nucleic Acids Res 2012; 41:2526-40. [PMID: 23275555 PMCID: PMC3575821 DOI: 10.1093/nar/gks1318] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Multiple conserved structural cis-acting regulatory elements have been recognized both in the coding and untranslated regions (UTRs) of the hepatitis C virus (HCV) genome. For example, the cis-element 5BSL3.2 in the HCV-coding region has been predicted to use both its apical and internal loops to interact with the X RNA in the 3'-UTR, with the IIId domain in the 5'-UTR and with the Alt sequence in the coding region. Additionally, the X RNA region uses a palindromic sequence that overlaps the sequence required for the interaction with 5BSL3.2, to dimerize with another HCV genome. The ability of the 5BSL3.2 and X RNA regions to engage in multi-interactions suggests the existence of one or more molecular RNA switches which may regulate different steps of the HCV life cycle. In this study, we used biophysical methods to characterize the essential interactions of these HCV cis-elements at the molecular level. Our results indicate that X RNA interacts with 5BSL3.2 and another X RNA molecule by adopting two different conformations and that 5BSL3.2 engages simultaneously in kissing interactions using its apical and internal loops. Based on these results, we propose a mode of action for possible molecular switches involving the HCV RNA.
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Affiliation(s)
- Sumangala Shetty
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282, USA
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Chatel-Chaix L, Germain MA, Götte M, Lamarre D. Direct-acting and host-targeting HCV inhibitors: current and future directions. Curr Opin Virol 2012; 2:588-98. [PMID: 22959589 DOI: 10.1016/j.coviro.2012.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 08/07/2012] [Indexed: 02/07/2023]
Abstract
The inclusion of NS3 protease inhibitors to the interferon-containing standard of care improved sustained viral response rates in hepatitis C virus (HCV) infected patients. However, there is still an unmet medical need as this drug regimen is poorly tolerated and lacks efficacy, especially in difficult-to-treat patients. Intense drug discovery and development efforts have focused on direct-acting antivirals (DAA) that target NS3 protease, NS5B polymerase and the NS5A protein. DAA combinations are currently assessed in clinical trials. Alternative antivirals have emerged that target host machineries co-opted by HCV. Finally, continuous and better understanding of HCV biology allows speculating on the value of novel classes of DAA required in future personalized all-oral interferon-free combination therapy and for supporting global disease eradication.
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Affiliation(s)
- Laurent Chatel-Chaix
- Institut de Recherche en Immunologie et en Cancérologie (IRIC), Montréal, Québec H3T 1J4, Canada
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39
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Liu HM, Aizaki H, Machida K, Ou JHJ, Lai MMC. Hepatitis C virus translation preferentially depends on active RNA replication. PLoS One 2012; 7:e43600. [PMID: 22937067 PMCID: PMC3427374 DOI: 10.1371/journal.pone.0043600] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 07/26/2012] [Indexed: 12/19/2022] Open
Abstract
Hepatitis C virus (HCV) RNA initiates its replication on a detergent-resistant membrane structure derived from the endoplasmic reticulum (ER) in the HCV replicon cells. By performing a pulse-chase study of BrU-labeled HCV RNA, we found that the newly-synthesized HCV RNA traveled along the anterograde-membrane traffic and moved away from the ER. Presumably, the RNA moved to the site of translation or virion assembly in the later steps of viral life cycle. In this study, we further addressed how HCV RNA translation was regulated by HCV RNA trafficking. When the movement of HCV RNA from the site of RNA synthesis to the Golgi complex was blocked by nocodazole, an inhibitor of ER-Golgi transport, HCV protein translation was surprisingly enhanced, suggesting that the translation of viral proteins occurred near the site of RNA synthesis. We also found that the translation of HCV proteins was dependent on active RNA synthesis: inhibition of viral RNA synthesis by an NS5B inhibitor resulted in decreased HCV viral protein synthesis even when the total amount of intracellular HCV RNA remained unchanged. Furthermore, the translation activity of the replication-defective HCV replicons or viral RNA with an NS5B mutation was greatly reduced as compared to that of the corresponding wildtype RNA. By performing live cell labeling of newly synthesized HCV RNA and proteins, we further showed that the newly synthesized HCV proteins colocalized with the newly synthesized viral RNA, suggesting that HCV RNA replication and protein translation take place at or near the same site. Our findings together indicate that the translation of HCV RNA is coupled to RNA replication and that the both processes may occur at the same subcellular membrane compartments, which we term the replicasome.
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Affiliation(s)
- Helene Minyi Liu
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America.
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40
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Inhibition of the interaction between NS3 protease and HCV IRES with a small peptide: a novel therapeutic strategy. Mol Ther 2012; 21:57-67. [PMID: 22910295 DOI: 10.1038/mt.2012.151] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Recently, we have demonstrated that the protease domain of NS3 alone can bind specifically to hepatitis C virus (HCV) internal ribosome entry site (IRES) near the initiator AUG, dislodges human La protein and inhibits translation in favor of viral RNA replication. Here, by using a computational approach, the contact points of the protease on the HCV IRES were putatively mapped. A 30-mer NS3 peptide was designed from the predicted RNA-binding region that retained RNA-binding ability and also inhibited IRES-mediated translation. This peptide was truncated to 15 mer and this also demonstrated ability to inhibit HCV RNA-directed translation as well as replication. More importantly, its activity was tested in an in vivo mouse model by encapsulating the peptide in Sendai virus virosomes followed by intravenous delivery. The study demonstrates for the first time that the HCV NS3-IRES RNA interaction can be selectively inhibited using a small peptide and reports a strategy to deliver the peptide into the liver.
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41
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Naeeni AR, Conte MR, Bayfield MA. RNA chaperone activity of human La protein is mediated by variant RNA recognition motif. J Biol Chem 2012; 287:5472-82. [PMID: 22203678 PMCID: PMC3285324 DOI: 10.1074/jbc.m111.276071] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 12/23/2011] [Indexed: 02/05/2023] Open
Abstract
La proteins are conserved factors in eukaryotes that bind and protect the 3' trailers of pre-tRNAs from exonuclease digestion via sequence-specific recognition of UUU-3'OH. La has also been hypothesized to assist pre-tRNAs in attaining their native fold through RNA chaperone activity. In addition to binding polymerase III transcripts, human La has also been shown to enhance the translation of several internal ribosome entry sites and upstream ORF-containing mRNA targets, also potentially through RNA chaperone activity. Using in vitro FRET-based assays, we show that human and Schizosaccharomyces pombe La proteins harbor RNA chaperone activity by enhancing RNA strand annealing and strand dissociation. We use various RNA substrates and La mutants to show that UUU-3'OH-dependent La-RNA binding is not required for this function, and we map RNA chaperone activity to its RRM1 motif including a noncanonical α3-helix. We validate the importance of this α3-helix by appending it to the RRM of the unrelated U1A protein and show that this fusion protein acquires significant strand annealing activity. Finally, we show that residues required for La-mediated RNA chaperone activity in vitro are required for La-dependent rescue of tRNA-mediated suppression via a mutated suppressor tRNA in vivo. This work delineates the structural elements required for La-mediated RNA chaperone activity and provides a basis for understanding how La can enhance the folding of its various RNA targets.
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Affiliation(s)
- Amir R. Naeeni
- From the Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada and
| | - Maria R. Conte
- the Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, United Kingdom
| | - Mark A. Bayfield
- From the Department of Biology, York University, Toronto, Ontario M3J 1P3, Canada and
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42
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Martino L, Pennell S, Kelly G, Bui TTT, Kotik-Kogan O, Smerdon SJ, Drake AF, Curry S, Conte MR. Analysis of the interaction with the hepatitis C virus mRNA reveals an alternative mode of RNA recognition by the human La protein. Nucleic Acids Res 2012; 40:1381-94. [PMID: 22009680 PMCID: PMC3273827 DOI: 10.1093/nar/gkr890] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 09/29/2011] [Accepted: 10/01/2011] [Indexed: 12/31/2022] Open
Abstract
Human La protein is an essential factor in the biology of both coding and non-coding RNAs. In the nucleus, La binds primarily to 3' oligoU containing RNAs, while in the cytoplasm La interacts with an array of different mRNAs lacking a 3' UUU(OH) trailer. An example of the latter is the binding of La to the IRES domain IV of the hepatitis C virus (HCV) RNA, which is associated with viral translation stimulation. By systematic biophysical investigations, we have found that La binds to domain IV using an RNA recognition that is quite distinct from its mode of binding to RNAs with a 3' UUU(OH) trailer: although the La motif and first RNA recognition motif (RRM1) are sufficient for high-affinity binding to 3' oligoU, recognition of HCV domain IV requires the La motif and RRM1 to work in concert with the atypical RRM2 which has not previously been shown to have a significant role in RNA binding. This new mode of binding does not appear sequence specific, but recognizes structural features of the RNA, in particular a double-stranded stem flanked by single-stranded extensions. These findings pave the way for a better understanding of the role of La in viral translation initiation.
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Affiliation(s)
- Luigi Martino
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Simon Pennell
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Geoff Kelly
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Tam T. T. Bui
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Olga Kotik-Kogan
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Stephen J. Smerdon
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Alex F. Drake
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Stephen Curry
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
| | - Maria R. Conte
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, Division of Molecular Structure, MRC Biomedical NMR Centre, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, Pharmaceutical Science Division, King's College London, The Wolfson Wing, Guy's Campus, London SE1 1UL and Department of Life Sciences, Division of Cell and Molecular Biology, Imperial College, London SW7 2AZ, UK
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43
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Abstract
Hepatitis C viral protein translation occurs in a cap-independent manner through the use of an internal ribosomal entry site (IRES) present within the viral 5'-untranslated region. The IRES is composed of highly conserved structural domains that directly recruit the 40S ribosomal subunit to the viral genomic RNA. This frees the virus from relying on a large number of translation initiation factors that are required for cap-dependent translation, conferring a selective advantage to the virus especially in times when the availability of such factors is low. Although the mechanism of translation initiation on the Hepatitis C virus (HCV) IRES is well established, modulation of the HCV IRES activity by both cellular and viral factors is not well understood. As the IRES is essential in the HCV life cycle and as such remains well conserved in an otherwise highly heterogenic virus, the process of HCV protein translation represents an attractive target in the development of novel antivirals. This review will focus on the mechanisms of HCV protein translation and how this process is postulated to be modulated by cis-acting viral factors, as well as trans-acting viral and cellular factors. Numerous therapeutic approaches investigated in targeting HCV protein translation for the development of novel antivirals will also be discussed.
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Affiliation(s)
- Brett Hoffman
- Vaccine and Infectious Disease Organization/International Vaccine Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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44
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Requirement of rRNA methylation for 80S ribosome assembly on a cohort of cellular internal ribosome entry sites. Mol Cell Biol 2011; 31:4482-99. [PMID: 21930789 DOI: 10.1128/mcb.05804-11] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Protein syntheses mediated by cellular and viral internal ribosome entry sites (IRESs) are believed to have many features in common. Distinct mechanisms for ribosome recruitment and preinitiation complex assembly between the two processes have not been identified thus far. Here we show that the methylation status of rRNA differentially influenced the mechanism of 80S complex formation on IRES elements from the cellular sodium-coupled neutral amino acid transporter 2 (SNAT2) versus the hepatitis C virus mRNA. Translation initiation involves the assembly of the 48S preinitiation complex, followed by joining of the 60S ribosomal subunit and formation of the 80S complex. Abrogation of rRNA methylation did not affect the 48S complex but resulted in impairment of 80S complex assembly on the cellular, but not the viral, IRESs tested. Impairment of 80S complex assembly on the amino acid transporter SNAT2 IRES was rescued by purified 60S subunits containing fully methylated rRNA. We found that rRNA methylation did not affect the activity of any of the viral IRESs tested but affected the activity of numerous cellular IRESs. This work reveals a novel mechanism operating on a cohort of cellular IRESs that involves rRNA methylation for proper 80S complex assembly and efficient translation initiation.
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45
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Abstract
The nucleotide sequence diversity present among hepatitis C virus (HCV) isolates allows rapid adjustment to exterior forces including host immunity and drug therapy. This viral response reflects a combination of a high rate of replication together with an error-prone RNA-dependent RNA polymerase, providing for the selection and proliferation of the viruses with the highest fitness. We examined HCV subtype 1a whole-genome sequences to identify positions contributing to genotypic and phenotypic diversity. Phylogenetic tree reconstructions showed two distinct clades existing within the 1a subtype with each clade having a star-like tree topology and lacking definite correlation between time or place of isolation and phylogeny. Identification of significant phylogenetically informative sites at the nucleotide level revealed positions not only contributing to clade differentiation, but which are located at or proximal to codons associated with resistance to protease inhibitors (NS3 Q41) or polymerase inhibitors (NS5B S368). Synonymous/nonsynonymous substitution mutation analyses revealed that the majority of nucleotide mutations yielded synonymous amino acids, indicating the presence of purifying selection pressure across the polyprotein with pockets of positive selection also being detected. Despite evidence for divergence at several loci, certain 1a characteristics were preserved including the length of the alternative reading frame/F protein (ARF/F) gene, and a subtype 1a-specific phosphorylation site in NS5A (S349). Our analysis suggests that there may be strain-specific differences in the development of antiviral resistance to viruses infecting patients who are dependent on the genetic variation separating these two clades.
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Affiliation(s)
- B E Pickett
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
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46
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Park SM, Paek KY, Hong KY, Jang CJ, Cho S, Park JH, Kim JH, Jan E, Jang SK. Translation-competent 48S complex formation on HCV IRES requires the RNA-binding protein NSAP1. Nucleic Acids Res 2011; 39:7791-802. [PMID: 21715376 PMCID: PMC3177222 DOI: 10.1093/nar/gkr509] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Translation of many cellular and viral mRNAs is directed by internal ribosomal entry sites (IRESs). Several proteins that enhance IRES activity through interactions with IRES elements have been discovered. However, the molecular basis for the IRES-activating function of the IRES-binding proteins remains unknown. Here, we report that NS1-associated protein 1 (NSAP1), which augments several cellular and viral IRES activities, enhances hepatitis C viral (HCV) IRES function by facilitating the formation of translation-competent 48S ribosome-mRNA complex. NSAP1, which is associated with the solvent side of the 40S ribosomal subunit, enhances 80S complex formation through correct positioning of HCV mRNA on the 40S ribosomal subunit. NSAP1 seems to accomplish this positioning function by directly binding to both a specific site in the mRNA downstream of the initiation codon and a 40S ribosomal protein (or proteins).
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Affiliation(s)
- Sung Mi Park
- Department of Life Science, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea
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47
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Interplay between NS3 protease and human La protein regulates translation-replication switch of Hepatitis C virus. Sci Rep 2011; 1:1. [PMID: 22355520 PMCID: PMC3210691 DOI: 10.1038/srep00001] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 03/01/2011] [Indexed: 02/02/2023] Open
Abstract
HCV NS3 protein plays a central role in viral polyprotein processing and RNA replication. We demonstrate that the NS3 protease (NS3pro) domain alone can specifically bind to HCV-IRES RNA, predominantly in the SLIV region. The cleavage activity of the NS3 protease domain is reduced upon HCV-RNA binding. More importantly, NS3pro binding to the SLIV hinders the interaction of La protein, a cellular IRES-trans acting factor required for HCV IRES-mediated translation, resulting in inhibition of HCV-IRES activity. Although overexpression of both NS3pro as well as the full length NS3 protein decreased the level of HCV IRES mediated translation, replication of HCV replicon RNA was enhanced significantly. These observations suggest that the NS3pro binding to HCV IRES reduces translation in favor of RNA replication. The competition between the host factor (La) and the viral protein (NS3) for binding to HCV IRES might regulate the molecular switch from translation to replication of HCV.
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48
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Mittal S, Mir RA, Chauhan SS. Post-transcriptional regulation of human cathepsin L expression. Biol Chem 2011; 392:405-13. [PMID: 21395501 DOI: 10.1515/bc.2011.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The expression of cathepsin L, a lysosomal protease, is known to be elevated in cancer and other pathologies. Multiple splice variants of human cathepsin L with variable 5'UTRs exist, which encode for the same protein. Previously we have observed that variant hCATL A (bearing the longest 5'UTR) was translated in vitro with significantly lower efficiency than variant hCATL AIII (bearing the shortest 5'UTR). Contrary to these findings, results of the present study reveal that in cancer cells, hCATL A mRNA exhibits higher translatability in spite of having lower stability than AIII. This is the first report demonstrating a highly contrasting trend in translation efficiencies of hCATL variants in rabbit reticulocytes and live cells. Expression from chimeric mRNAs containing 5'UTRs of A or AIII upstream to luciferase reporter cDNA established the A UTR to be the sole determinant for this effect. Transient transfections of bicistronic plasmids and mRNAs confirmed the presence of a functional Internal Ribosome Entry Site in this UTR. Our data suggest that differential stability and translation initiation modes mediated by the 5'UTRs of human cathepsin L variants are involved in regulating its expression.
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Affiliation(s)
- Shivani Mittal
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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49
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Malys N, McCarthy JEG. Translation initiation: variations in the mechanism can be anticipated. Cell Mol Life Sci 2011; 68:991-1003. [PMID: 21076851 PMCID: PMC11115079 DOI: 10.1007/s00018-010-0588-z] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 10/25/2010] [Accepted: 10/28/2010] [Indexed: 01/05/2023]
Abstract
Translation initiation is a critical step in protein synthesis. Previously, two major mechanisms of initiation were considered as essential: prokaryotic, based on SD interaction; and eukaryotic, requiring cap structure and ribosomal scanning. Although discovered decades ago, cap-independent translation has recently been acknowledged as a widely spread mechanism in viruses, which may take place in some cellular mRNA translations. Moreover, it has become evident that translation can be initiated on the leaderless mRNA in all three domains of life. New findings demonstrate that other distinguishable types of initiation exist, including SD-independent in Bacteria and Archaea, and various modifications of 5' end-dependent and internal initiation mechanisms in Eukarya. Since translation initiation has developed through the loss, acquisition, and modification of functional elements, all of which have been elevated by competition with viral translation in a large number of organisms of different complexity, more variation in initiation mechanisms can be anticipated.
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Affiliation(s)
- Naglis Malys
- Manchester Centre for Integrative Systems Biology, Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, UK.
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50
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Sommer G, Dittmann J, Kuehnert J, Reumann K, Schwartz PE, Will H, Coulter BL, Smith MT, Heise T. The RNA-binding protein La contributes to cell proliferation and CCND1 expression. Oncogene 2011; 30:434-44. [PMID: 20856207 DOI: 10.1038/onc.2010.425] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 07/22/2010] [Accepted: 08/10/2010] [Indexed: 11/08/2022]
Abstract
The La protein is an essential RNA-binding protein implicated in different aspects of RNA metabolism. Herein, we report that small interfering (siRNA)-mediated La depletion reduces cell proliferation of different cell lines concomitant with a reduction in cyclin D1 (CCND1) protein. To exclude off-target effects we demonstrate that exogenous La expression in La-depleted cells restores cell proliferation and CCND1 protein levels. In contrast, proliferation of immortalized CCND1 knockout cells is not affected by La depletion, supporting a functional coherence between La, CCND1 and proliferation. Furthermore, we document by reversible in vivo crosslinking and ribonucleoprotein (RNP) immunoprecipitation an association of the La protein with CCND1 messengerRNA and that CCND1 internal ribosome entry site (IRES)-dependent translation is modulated by La protein level within the cell. In addition, we show elevated La protein expression in cervical cancer tissue and its correlation with aberrant CCND1 protein levels in cervical tumor tissue lysates. In conclusion, this study establishes a role of La in cell proliferation and CCND1 expression and demonstrates for the first time an overexpression of the RNA-binding protein La in solid tumors.
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Affiliation(s)
- G Sommer
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
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