1
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Liu H, Tan S, Chen Y, Chen X, Liu X, Li Z, Wang N, Han S, Wu Z, Ma J, Shi K, Wang W, Sha Z. Regulatory mechanism of miR-722 on C5aR1 and its functions against bacterial inflammation in half-smooth tongue sole (Cynoglossus semilaevis). Int J Biol Macromol 2023; 252:126445. [PMID: 37611685 DOI: 10.1016/j.ijbiomac.2023.126445] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/25/2023]
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs involved in various biological processes, including immunity. Previously, we investigated the miRNAs of half-smooth tongue sole (Cynoglossus semilaevis) and found that miR-722 (designated Cse-miR-722) was significantly differentially expressed after infection with Vibrio anguillarum, reflecting its importance in immune response. Our preliminary bioinformatic analysis suggested that Cse-miR-722 could target C5aR1 (designated CsC5aR1), which was known to play crucial roles in complement activation and inflammatory response, as a receptor of C5a. However, the underlying mechanisms of their interactions and specific functions in inflammatory and immune response are still enigmas. In this study, we successfully cloned the precursor sequence of Cse-miR-722 (94 bp) and the full length of CsC5aR1 (1541 bp, protein molecular weight 39 kDa). The target gene of Cse-miR-722 was verified as CsC5aR1 by a dual luciferase reporter assay, and Cse-miR-722 was confirmed to regulate CsC5aR1 at the protein level using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The expression of CsC5aR1 and Cse-miR-722 in liver cells and four immune tissues of half-smooth tongue sole changed significantly after LPS stimulation and infection with V. anguillarum. To explore the functional role of Cse-miR-722 in half-smooth tongue sole, we performed both in vitro and in vivo experiments. Cse-miR-722 was observed to affect phagocytosis and respiratory burst activity of macrophages by regulating CsC5aR1 in half-smooth tongue sole. Furthermore, we found that Cse-miR-722 regulated the expression of CsC5aR1, CsC5a, and the inflammatory factors CsIL1-β, CsIL6, CsIL8, and CsTNF-α both in vitro and in vivo. In addition, Cse-miR-722 reduced mortality and pathological damage. This study clarified the regulatory mechanism of Cse-miR-722 on CsC5aR1 and provided insight into the regulatory roles of Cse-miR-722 in immune responses, laying a theoretical foundation for the feasibility of using miR-722 to prevent and control bacterial diseases in teleost.
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Affiliation(s)
- Hongning Liu
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Suxu Tan
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Yadong Chen
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Xuejie Chen
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Xinbao Liu
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Zhujun Li
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Ningning Wang
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China; College of Basic Medicine, Qingdao University, Qingdao 266071, China
| | - Sen Han
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Zhendong Wu
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Jie Ma
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Kunpeng Shi
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Wenwen Wang
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China
| | - Zhenxia Sha
- Institute of Aquatic Biotechnology, College of Life Sciences, Qingdao University, Qingdao 266071, China.
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2
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Hernández G, Vazquez-Pianzola P. eIF4E as a molecular wildcard in metazoans RNA metabolism. Biol Rev Camb Philos Soc 2023; 98:2284-2306. [PMID: 37553111 DOI: 10.1111/brv.13005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 07/01/2023] [Accepted: 07/25/2023] [Indexed: 08/10/2023]
Abstract
The evolutionary origin of eukaryotes spurred the transition from prokaryotic-like translation to a more sophisticated, eukaryotic translation. During this process, successive gene duplication of a single, primordial eIF4E gene encoding the mRNA cap-binding protein eukaryotic translation initiation factor 4E (eIF4E) gave rise to a plethora of paralog genes across eukaryotes that underwent further functional diversification in RNA metabolism. The ability to take different roles is due to eIF4E promiscuity in binding many partner proteins, rendering eIF4E a highly versatile and multifunctional player that functions as a molecular wildcard. Thus, in metazoans, eIF4E paralogs are involved in various processes, including messenger RNA (mRNA) processing, export, translation, storage, and decay. Moreover, some paralogs display differential expression in tissues and developmental stages and show variable biochemical properties. In this review, we discuss recent advances shedding light on the functional diversification of eIF4E in metazoans. We emphasise humans and two phylogenetically distant species which have become paradigms for studies on development, namely the fruit fly Drosophila melanogaster and the roundworm Caenorhabditis elegans.
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Affiliation(s)
- Greco Hernández
- mRNA and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), 22 San Fernando Ave., Tlalpan, Mexico City, 14080, Mexico
| | - Paula Vazquez-Pianzola
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, Berne, 3012, Switzerland
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3
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Naeli P, Zhang X, Snell PH, Chatterjee S, Kamran M, Ladak RJ, Orr N, Duchaine T, Sonenberg N, Jafarnejad SM. The SARS-CoV-2 protein NSP2 enhances microRNA-mediated translational repression. J Cell Sci 2023; 136:jcs261286. [PMID: 37732428 PMCID: PMC10617620 DOI: 10.1242/jcs.261286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/08/2023] [Indexed: 09/22/2023] Open
Abstract
Viruses use microRNAs (miRNAs) to impair the host antiviral response and facilitate viral infection by expressing their own miRNAs or co-opting cellular miRNAs. miRNAs inhibit translation initiation of their target mRNAs by recruiting the GIGYF2-4EHP (or EIF4E2) translation repressor complex to the mRNA 5'-cap structure. We recently reported that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-encoded non-structural protein 2 (NSP2) interacts with GIGYF2. This interaction is critical for blocking translation of the Ifnb1 mRNA that encodes the cytokine interferon β, and thereby impairs the host antiviral response. However, it is not known whether NSP2 also affects miRNA-mediated silencing. Here, we demonstrate the pervasive augmentation of miRNA-mediated translational repression of cellular mRNAs by NSP2. We show that NSP2 interacts with argonaute 2 (AGO2), the core component of the miRNA-induced silencing complex (miRISC), via GIGYF2 and enhances the translational repression mediated by natural miRNA-binding sites in the 3' untranslated region of cellular mRNAs. Our data reveal an additional layer of the complex mechanism by which SARS-CoV-2 and likely other coronaviruses manipulate the host gene expression program by co-opting the host miRNA-mediated silencing machinery.
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Affiliation(s)
- Parisa Naeli
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, BT9 7AE, UK
| | - Xu Zhang
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, H3A 1A3, Canada
| | - Patric Harris Snell
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, BT9 7AE, UK
| | - Susanta Chatterjee
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, BT9 7AE, UK
| | - Muhammad Kamran
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, BT9 7AE, UK
| | - Reese Jalal Ladak
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, H3A 1A3, Canada
| | - Nick Orr
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, BT9 7AE, UK
| | - Thomas Duchaine
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, H3A 1A3, Canada
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, H3A 1A3, Canada
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, BT9 7AE, UK
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4
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Badr D, Fouad MA, Hussein M, Salem S, Zekri A, Shouman S. Rebound increase in microRNA levels at the end of 5-FU-based therapy in colorectal cancer patients. Sci Rep 2023; 13:14237. [PMID: 37648713 PMCID: PMC10469181 DOI: 10.1038/s41598-023-41030-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 08/21/2023] [Indexed: 09/01/2023] Open
Abstract
Treatment with 5-fluorouracil (5-FU) based therapy is still used for colorectal cancer (CRC). Epigenetics has become a focus of study in cancer because of its reversibility besides its known regulatory functions. In this study, we will monitor the change in microRNAs (miRNAs) levels with 5-FU-based therapy at baseline and after 3 and 6 months of treatment to be correlated with their prognostic potential. The expression levels of 5 miRNAs, namely miRNA223-3p, miRNA20a-5p, miRNA17-5p, miRNA19a-3p, and miRNA7-5p, were measured in the peripheral blood of 77 CRC patients, along with the expression of 3 proteins PTEN, ERK, and EGFR. At baseline, CRC patients had significantly higher levels of circulating miRNAs than healthy controls. This level was reduced after 3 months of 5-FU-based therapy, then increased after 6 months significantly in responder patients compared to non-responders. MiRNA19a-3p showed that significant pattern of change in the subgroups of patients with high ERK, EGFR, and PTEN protein levels, and its 6 months level after 5-FU-based therapy showed significance for the hazard of increased risk of disease recurrence and progression.
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Affiliation(s)
- Doaa Badr
- Pharmacology and Experimental Oncology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Mariam A Fouad
- Cancer Signaling and Microenvironment Program, Fox Chase Cancer Center. 333 Cottman Avenue, Philadelphia, PA, 19111, USA.
| | - Marwa Hussein
- Medical Oncology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Salem Salem
- Medical Oncology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Abdelrahman Zekri
- Virology and Immunology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Samia Shouman
- Pharmacology and Experimental Oncology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
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5
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Wiebe S, Huang Z, Ladak RJ, Skalecka A, Cagnetta R, Lacaille JC, Aguilar-Valles A, Sonenberg N. Cell-type-specific translational control of spatial working memory by the cap-binding protein 4EHP. Mol Brain 2023; 16:9. [PMID: 36650535 PMCID: PMC9847188 DOI: 10.1186/s13041-023-00995-2] [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: 09/30/2022] [Accepted: 01/01/2023] [Indexed: 01/19/2023] Open
Abstract
The consolidation of learned information into long-lasting memories requires the strengthening of synaptic connections through de novo protein synthesis. Translation initiation factors play a cardinal role in gating the production of new proteins thereby regulating memory formation. Both positive and negative regulators of translation play a critical role in learning and memory consolidation. The eukaryotic initiation factor 4E (eIF4E) homologous protein (4EHP, encoded by the gene Eif4e2) is a pivotal negative regulator of translation but its role in learning and memory is unknown. To address this gap in knowledge, we generated excitatory (glutamatergic: CaMKIIα-positive) and inhibitory (GABAergic: GAD65-positive) conditional knockout mice for 4EHP, which were analyzed in various behavioral memory tasks. Knockout of 4EHP in Camk2a-expressing neurons (4EHP-cKOexc) did not impact long-term memory in either contextual fear conditioning or Morris water maze tasks. Similarly, long-term contextual fear memory was not altered in Gad2-directed 4EHP knockout mice (4EHP-cKOinh). However, when subjected to a short-term T-maze working memory task, both mouse models exhibited impaired cognition. We therefore tested the hypothesis that de novo protein synthesis plays a direct role in working memory. We discovered that phosphorylation of ribosomal protein S6, a measure of mTORC1 activity, is dramatically reduced in the CA1 hippocampus of 4EHP-cKOexc mice. Consistently, genetic reduction of mTORC1 activity in either excitatory or inhibitory neurons was sufficient to impair working memory. Taken together, these findings indicate that translational control by 4EHP and mTORC1 in both excitatory and inhibitory neurons are necessary for working memory.
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Affiliation(s)
- Shane Wiebe
- grid.14709.3b0000 0004 1936 8649Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 Canada ,Goodman Cancer Institute, 1160 Pine Avenue West, Room 614, Montreal, QC H3A 1A3 Canada
| | - Ziying Huang
- grid.14709.3b0000 0004 1936 8649Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 Canada ,Goodman Cancer Institute, 1160 Pine Avenue West, Room 614, Montreal, QC H3A 1A3 Canada
| | - Reese Jalal Ladak
- grid.14709.3b0000 0004 1936 8649Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 Canada ,Goodman Cancer Institute, 1160 Pine Avenue West, Room 614, Montreal, QC H3A 1A3 Canada
| | - Agnieszka Skalecka
- grid.14709.3b0000 0004 1936 8649Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 Canada ,Goodman Cancer Institute, 1160 Pine Avenue West, Room 614, Montreal, QC H3A 1A3 Canada
| | - Roberta Cagnetta
- grid.14709.3b0000 0004 1936 8649Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 Canada ,Goodman Cancer Institute, 1160 Pine Avenue West, Room 614, Montreal, QC H3A 1A3 Canada
| | - Jean-Claude Lacaille
- grid.14848.310000 0001 2292 3357Department of Neuroscience and CIRCA, University of Montreal, Succ. Downtown, P. O. Box 6128, Montreal, QC H3C 3J7 Canada
| | - Argel Aguilar-Valles
- grid.34428.390000 0004 1936 893XDepartment of Neuroscience, Carleton University, Health Sciences Building, 1125 Colonel By Drive, Ottawa, ON K1S 5B6 Canada
| | - Nahum Sonenberg
- grid.14709.3b0000 0004 1936 8649Department of Biochemistry, McGill University, McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 Canada ,Goodman Cancer Institute, 1160 Pine Avenue West, Room 614, Montreal, QC H3A 1A3 Canada
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6
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Christie M, Igreja C. eIF4E-homologous protein (4EHP): a multifarious cap-binding protein. FEBS J 2023; 290:266-285. [PMID: 34758096 DOI: 10.1111/febs.16275] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/29/2021] [Accepted: 11/09/2021] [Indexed: 02/05/2023]
Abstract
The cap-binding protein 4EHP/eIF4E2 has been a recent object of interest in the field of post-transcriptional gene regulation and translational control. From ribosome-associated quality control, to RNA decay and microRNA-mediated gene silencing, this member of the eIF4E protein family regulates gene expression through numerous pathways. Low in abundance but ubiquitously expressed, 4EHP interacts with different binding partners to form multiple protein complexes that regulate translation in a variety of biological contexts. Documented functions of 4EHP primarily relate to its role as a translational repressor, but recent findings indicate that it might also participate in the activation of translation in specific settings. In this review, we discuss the known functions, properties and mechanisms that involve 4EHP in the control of gene expression. We also discuss our current understanding of how 4EHP processes are regulated in eukaryotic cells, and the diseases implicated with dysregulation of 4EHP-mediated translational control.
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Affiliation(s)
- Mary Christie
- School of Life and Environmental Sciences, The University of Sydney, NSW, Australia
| | - Cátia Igreja
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
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7
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SARS-CoV-2 impairs interferon production via NSP2-induced repression of mRNA translation. Proc Natl Acad Sci U S A 2022; 119:e2204539119. [PMID: 35878012 PMCID: PMC9371684 DOI: 10.1073/pnas.2204539119] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A robust antiviral innate immune response is indispensable for combating infections. However, an exacerbated response can result in pathological inflammation and tissue damage. mRNA translational control mechanisms play a crucial role in maintaining the appropriate magnitude and duration of the immune response. We show that the GIGYF2/4EHP translational repressor complex represses translation of Ifnb1 mRNA, which encodes type I interferon β (IFN-β). We also demonstrate that the NSP2 protein encoded by SARS-CoV-2 virus further impedes translation of Ifnb1 mRNA through coopting the GIGYF2/4EHP complex, leading to evasion of a cellular innate immune response. The knowledge of the mechanism of action of NSP2-mediated IFN-β suppression provides valuable information for development of treatments for infections of SARS-CoV-2 and other coronaviruses. Viruses evade the innate immune response by suppressing the production or activity of cytokines such as type I interferons (IFNs). Here we report the discovery of a mechanism by which the SARS-CoV-2 virus coopts an intrinsic cellular machinery to suppress the production of the key immunostimulatory cytokine IFN-β. We reveal that the SARS-CoV-2 encoded nonstructural protein 2 (NSP2) directly interacts with the cellular GIGYF2 protein. This interaction enhances the binding of GIGYF2 to the mRNA cap-binding protein 4EHP, thereby repressing the translation of the Ifnb1 mRNA. Depletion of GIGYF2 or 4EHP significantly enhances IFN-β production, which inhibits SARS-CoV-2 replication. Our findings reveal a target for rescuing the antiviral innate immune response to SARS-CoV-2 and other RNA viruses.
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8
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Zou L, Moch C, Graille M, Chapat C. The SARS-CoV-2 protein NSP2 impairs the silencing capacity of the human 4EHP-GIGYF2 complex. iScience 2022; 25:104646. [PMID: 35756894 PMCID: PMC9213009 DOI: 10.1016/j.isci.2022.104646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/12/2022] [Accepted: 06/15/2022] [Indexed: 01/20/2023] Open
Abstract
There is an urgent need for a molecular understanding of how SARS-CoV-2 influences the machineries of the host cell. Herein, we focused our attention on the capacity of the SARS-CoV-2 protein NSP2 to bind the human 4EHP-GIGYF2 complex, a key factor involved in microRNA-mediated silencing of gene expression. Using in vitro interaction assays, our data demonstrate that NSP2 physically associates with both 4EHP and a central segment in GIGYF2 in the cytoplasm. We also provide functional evidence showing that NSP2 impairs the function of GIGYF2 in mediating translation repression using reporter-based assays. Collectively, these data reveal the potential impact of NSP2 on the post-transcriptional silencing of gene expression in human cells, pointing out 4EHP-GIGYF2 targeting as a possible strategy of SARS-CoV-2 to take over the silencing machinery and to suppress host defenses.
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Affiliation(s)
- Limei Zou
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
| | - Clara Moch
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
| | - Marc Graille
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
| | - Clément Chapat
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
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9
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Nguyen MA, Hoang HD, Rasheed A, Duchez AC, Wyatt H, Lynn Cottee M, Graber TE, Susser L, Robichaud S, Berber İ, Geoffrion M, Ouimet M, Kazan H, Maegdefessel L, Mulvihill EE, Alain T, Rayner KJ. miR-223 Exerts Translational Control of Proatherogenic Genes in Macrophages. Circ Res 2022; 131:42-58. [PMID: 35611698 PMCID: PMC9213086 DOI: 10.1161/circresaha.121.319120] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
A significant burden of atherosclerotic disease is driven by inflammation. Recently, microRNAs (miRNAs) have emerged as important factors driving and protecting from atherosclerosis. miR-223 regulates cholesterol metabolism and inflammation via targeting both cholesterol biosynthesis pathway and NFkB signaling pathways; however, its role in atherosclerosis has not been investigated. We hypothesize that miR-223 globally regulates core inflammatory pathways in macrophages in response to inflammatory and atherogenic stimuli thus limiting the progression of atherosclerosis.
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Affiliation(s)
- My-Anh Nguyen
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Huy-Dung Hoang
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada (H.-D.H., T.E.G., T.A.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Adil Rasheed
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Anne-Claire Duchez
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.)
| | - Hailey Wyatt
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Mary Lynn Cottee
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.)
| | - Tyson E Graber
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada (H.-D.H., T.E.G., T.A.)
| | - Leah Susser
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Sabrina Robichaud
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - İbrahim Berber
- Electrical and Computer Engineering Graduate Program, Antalya Bilim University, Turkey (I.B.)
| | - Michele Geoffrion
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.)
| | - Mireille Ouimet
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Hilal Kazan
- Department of Computer Engineering, Antalya Bilim University, Turkey (H.K.)
| | - Lars Maegdefessel
- Department of Vascular and Endovascular Surgery, Technical University Munich, Germany (L.M.).,Department of Medicine, Karolinska Institute, Stockholm, Sweden (L.M.)
| | - Erin E Mulvihill
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Tommy Alain
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada (H.-D.H., T.E.G., T.A.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
| | - Katey J Rayner
- University of Ottawa Heart Institute, Canada (M.-A.N., A.R., A.-C.D., H.W., M.L.C., L.S., S.R., M.G., M.O., E.E.M., K.J.R.).,Centre for Infection, Immunity & Inflammation, Faculty of Medicine, University of Ottawa, Canada (K.J.R.).,Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Canada (M.-A.N., H.-D.H., A.R., M.L.C., L.S., S.R., M.O., E.E.M., T.A., K.J.R.)
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10
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Naeli P, Winter T, Hackett AP, Alboushi L, Jafarnejad SM. The intricate balance between microRNA-induced mRNA decay and translational repression. FEBS J 2022; 290:2508-2524. [PMID: 35247033 DOI: 10.1111/febs.16422] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 02/08/2022] [Accepted: 03/03/2022] [Indexed: 12/23/2022]
Abstract
Post-transcriptional regulation of messenger RNAs (mRNAs) (i.e., mechanisms that control translation, stability and localization) is a critical focal point in spatiotemporal regulation of gene expression in response to changes in environmental conditions. The human genome encodes ~ 2000 microRNAs (miRNAs), each of which could control the expression of hundreds of protein-coding mRNAs by inducing translational repression and/or promoting mRNA decay. While mRNA degradation is a terminal event, translational repression is reversible and can be employed for rapid response to internal or external cues. Recent years have seen significant progress in our understanding of how miRNAs induce degradation or translational repression of the target mRNAs. Here, we review the recent findings that illustrate the cellular machinery that contributes to miRNA-induced silencing, with a focus on the factors that could influence translational repression vs. decay.
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Affiliation(s)
- Parisa Naeli
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, UK
| | - Timothy Winter
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, UK
| | - Angela P Hackett
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, UK
| | - Lilas Alboushi
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, UK
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11
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Méndez-Solís O, Bendjennat M, Naipauer J, Theodoridis PR, Ho JJD, Verdun RE, Hare JM, Cesarman E, Lee S, Mesri EA. Kaposi's sarcoma herpesvirus activates the hypoxia response to usurp HIF2α-dependent translation initiation for replication and oncogenesis. Cell Rep 2021; 37:110144. [PMID: 34965440 PMCID: PMC9121799 DOI: 10.1016/j.celrep.2021.110144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/19/2021] [Accepted: 11/29/2021] [Indexed: 12/19/2022] Open
Abstract
Kaposi's sarcoma herpesvirus (KSHV) is an angiogenesis-inducing oncovirus whose ability to usurp the oxygen-sensing machinery is central to its oncogenicity. By upregulating the hypoxia-inducible factors (HIFs), KSHV reprograms infected cells to a hypoxia-like state, triggering angiogenesis. Here we identify a link between KSHV replicative biology and oncogenicity by showing that KSHV's ability to regulate HIF2α levels and localization to the endoplasmic reticulum (ER) in normoxia enables translation of viral lytic mRNAs through the HIF2α-regulated eIF4E2 translation-initiation complex. This mechanism of translation in infected cells is critical for lytic protein synthesis and contributes to KSHV-induced PDGFRA activation and VEGF secretion. Thus, KSHV regulation of the oxygen-sensing machinery allows virally infected cells to initiate translation via the mTOR-dependent eIF4E1 or the HIF2α-dependent, mTOR-independent, eIF4E2. This "translation initiation plasticity" (TRIP) is an oncoviral strategy used to optimize viral protein expression that links molecular strategies of viral replication to angiogenicity and oncogenesis.
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Affiliation(s)
- Omayra Méndez-Solís
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Mourad Bendjennat
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Julian Naipauer
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Phaedra R Theodoridis
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - J J David Ho
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ramiro E Verdun
- Cancer Epigenetics Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Joshua M Hare
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ethel Cesarman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Stephen Lee
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Enrique A Mesri
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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12
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Iwakawa HO, Tomari Y. Life of RISC: Formation, action, and degradation of RNA-induced silencing complex. Mol Cell 2021; 82:30-43. [PMID: 34942118 DOI: 10.1016/j.molcel.2021.11.026] [Citation(s) in RCA: 124] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 01/12/2023]
Abstract
Small RNAs regulate a wide variety of biological processes by repressing the expression of target genes at the transcriptional and post-transcriptional levels. To achieve these functions, small RNAs form RNA-induced silencing complex (RISC) together with a member of the Argonaute (AGO) protein family. RISC is directed by its bound small RNA to target complementary RNAs and represses their expression through mRNA cleavage, degradation, and/or translational repression. Many different factors fine-tune RISC activity and stability-from guide-target RNA complementarity to the recruitment of other protein partners to post-translational modifications of RISC itself. Here, we review recent progress in understanding RISC formation, action, and degradation, and discuss new, intriguing questions in the field.
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Affiliation(s)
- Hiro-Oki Iwakawa
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.
| | - Yukihide Tomari
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.
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13
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Zinshteyn B, Sinha NK, Enam SU, Koleske B, Green R. Translational repression of NMD targets by GIGYF2 and EIF4E2. PLoS Genet 2021; 17:e1009813. [PMID: 34665823 PMCID: PMC8555832 DOI: 10.1371/journal.pgen.1009813] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 10/29/2021] [Accepted: 09/08/2021] [Indexed: 12/26/2022] Open
Abstract
Translation of messenger RNAs (mRNAs) with premature termination codons produces truncated proteins with potentially deleterious effects. This is prevented by nonsense-mediated mRNA decay (NMD) of these mRNAs. NMD is triggered by ribosomes terminating upstream of a splice site marked by an exon-junction complex (EJC), but also acts on many mRNAs lacking a splice junction after their termination codon. We developed a genome-wide CRISPR flow cytometry screen to identify regulators of mRNAs with premature termination codons in K562 cells. This screen recovered essentially all core NMD factors and suggested a role for EJC factors in degradation of PTCs without downstream splicing. Among the strongest hits were the translational repressors GIGYF2 and EIF4E2. GIGYF2 and EIF4E2 mediate translational repression but not mRNA decay of a subset of NMD targets and interact with NMD factors genetically and physically. Our results suggest a model wherein recognition of a stop codon as premature can lead to its translational repression through GIGYF2 and EIF4E2.
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Affiliation(s)
- Boris Zinshteyn
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Niladri K. Sinha
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Syed Usman Enam
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Benjamin Koleske
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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14
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Transcriptional and epigenetic regulation of temporal patterning in neural progenitors. Dev Biol 2021; 481:116-128. [PMID: 34666024 DOI: 10.1016/j.ydbio.2021.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/05/2021] [Accepted: 10/12/2021] [Indexed: 12/15/2022]
Abstract
During development, neural progenitors undergo temporal patterning as they age to sequentially generate differently fated progeny. Temporal patterning of neural progenitors is relatively well-studied in Drosophila. Temporal cascades of transcription factors or opposing temporal gradients of RNA-binding proteins are expressed in neural progenitors as they age to control the fates of the progeny. The temporal progression is mostly driven by intrinsic mechanisms including cross-regulations between temporal genes, but environmental cues also play important roles in certain transitions. Vertebrate neural progenitors demonstrate greater plasticity in response to extrinsic cues. Recent studies suggest that vertebrate neural progenitors are also temporally patterned by a combination of transcriptional and post-transcriptional mechanisms in response to extracellular signaling to regulate neural fate specification. In this review, we summarize recent advances in the study of temporal patterning of neural progenitors in Drosophila and vertebrates. We also discuss the involvement of epigenetic mechanisms, specifically the Polycomb group complexes and ATP-dependent chromatin remodeling complexes, in the temporal patterning of neural progenitors.
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15
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Mayya VK, Flamand MN, Lambert AM, Jafarnejad SM, Wohlschlegel JA, Sonenberg N, Duchaine TF. microRNA-mediated translation repression through GYF-1 and IFE-4 in C. elegans development. Nucleic Acids Res 2021; 49:4803-4815. [PMID: 33758928 PMCID: PMC8136787 DOI: 10.1093/nar/gkab162] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/24/2021] [Accepted: 03/17/2021] [Indexed: 12/11/2022] Open
Abstract
microRNA (miRNA)-mediated gene silencing is enacted through the recruitment of effector proteins that direct translational repression or degradation of mRNA targets, but the relative importance of their activities for animal development remains unknown. Our concerted proteomic surveys identified the uncharacterized GYF-domain encoding protein GYF-1 and its direct interaction with IFE-4, the ortholog of the mammalian translation repressor 4EHP, as key miRNA effector proteins in Caenorhabditis elegans. Recruitment of GYF-1 protein to mRNA reporters in vitro or in vivo leads to potent translation repression without affecting the poly(A) tail or impinging on mRNA stability. Loss of gyf-1 is synthetic lethal with hypomorphic alleles of embryonic miR-35-42 and larval (L4) let-7 miRNAs, which is phenocopied through engineered mutations in gyf-1 that abolish interaction with IFE-4. GYF-1/4EHP function is cascade-specific, as loss of gyf-1 had no noticeable impact on the functions of other miRNAs, including lin-4 and lsy-6. Overall, our findings reveal the first direct effector of miRNA-mediated translational repression in C. elegans and its physiological importance for the function of several, but likely not all miRNAs.
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Affiliation(s)
- Vinay K Mayya
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Mathieu N Flamand
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Alice M Lambert
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University of Belfast, Belfast BT9 7AE UK
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Nahum Sonenberg
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Thomas F Duchaine
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
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16
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Alboushi L, Hackett AP, Naeli P, Bakhti M, Jafarnejad SM. Multifaceted control of mRNA translation machinery in cancer. Cell Signal 2021; 84:110037. [PMID: 33975011 DOI: 10.1016/j.cellsig.2021.110037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 05/06/2021] [Indexed: 12/15/2022]
Abstract
The mRNA translation machinery is tightly regulated through several, at times overlapping, mechanisms that modulate its efficiency and accuracy. Due to their fast rate of growth and metabolism, cancer cells require an excessive amount of mRNA translation and protein synthesis. However, unfavorable conditions, such as hypoxia, amino acid starvation, and oxidative stress, which are abundant in cancer, as well as many anti-cancer treatments inhibit mRNA translation. Cancer cells adapt to the various internal and environmental stresses by employing specialised transcript-specific translation to survive and gain a proliferative advantage. We will highlight the major signaling pathways and mechanisms of translation that regulate the global or mRNA-specific translation in response to the intra- or extra-cellular signals and stresses that are key components in the process of tumourigenesis.
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Affiliation(s)
- Lilas Alboushi
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Angela P Hackett
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Parisa Naeli
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
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17
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microRNA-induced translational control of antiviral immunity by the cap-binding protein 4EHP. Mol Cell 2021; 81:1187-1199.e5. [PMID: 33581076 DOI: 10.1016/j.molcel.2021.01.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 12/14/2022]
Abstract
Type I interferons (IFNs) are critical cytokines in the host defense against invading pathogens. Sustained production of IFNs, however, is detrimental to the host, as it provokes autoimmune diseases. Thus, the expression of IFNs is tightly controlled. We report that the mRNA 5' cap-binding protein 4EHP plays a key role in regulating type I IFN concomitant with controlling virus replication, both in vitro and in vivo. Mechanistically, 4EHP suppresses IFN-β production by effecting the miR-34a-induced translational silencing of Ifnb1 mRNA. miR-34a is upregulated by both RNA virus infection and IFN-β induction, prompting a negative feedback regulatory mechanism that represses IFN-β expression via 4EHP. These findings demonstrate the direct involvement of 4EHP in virus-induced host response, underscoring a critical translational silencing mechanism mediated by 4EHP and miR-34a to impede sustained IFN production. This study highlights an intrinsic regulatory function for miRNA and the translation machinery in maintaining host homeostasis.
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18
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The eIF4E homolog 4EHP (eIF4E2) regulates hippocampal long-term depression and impacts social behavior. Mol Autism 2020; 11:92. [PMID: 33225984 PMCID: PMC7682028 DOI: 10.1186/s13229-020-00394-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/23/2020] [Indexed: 12/27/2022] Open
Abstract
Background The regulation of protein synthesis is a critical step in gene expression, and its dysfunction is implicated in autism spectrum disorder (ASD). The eIF4E homologous protein (4EHP, also termed eIF4E2) binds to the mRNA 5′ cap to repress translation. The stability of 4EHP is maintained through physical interaction with GRB10 interacting GYF protein 2 (GIGYF2). Gene-disruptive mutations in GIGYF2 are linked to ASD, but causality is lacking. We hypothesized that GIGYF2 mutations cause ASD by disrupting 4EHP function. Methods Since homozygous deletion of either gene is lethal, we generated a cell-type-specific knockout model where Eif4e2 (the gene encoding 4EHP) is deleted in excitatory neurons of the forebrain (4EHP-eKO). In this model, we investigated ASD-associated synaptic plasticity dysfunction, ASD-like behaviors, and global translational control. We also utilized mice lacking one copy of Gigyf2, Eif4e2 or co-deletion of one copy of each gene to further investigate ASD-like behaviors. Results 4EHP is expressed in excitatory neurons and synaptosomes, and its amount increases during development. 4EHP-eKO mice display exaggerated mGluR-LTD, a phenotype frequently observed in mouse models of ASD. Consistent with synaptic plasticity dysfunction, the mice displayed social behavior impairments without being confounded by deficits in olfaction, anxiety, locomotion, or motor ability. Repetitive behaviors and vocal communication were not affected by loss of 4EHP in excitatory neurons. Heterozygous deletion of either Gigyf2, Eif4e2, or both genes in mice did not result in ASD-like behaviors (i.e. decreases in social behavior or increases in marble burying). Interestingly, exaggerated mGluR-LTD and impaired social behaviors were not attributed to changes in hippocampal global protein synthesis, which suggests that 4EHP and GIGYF2 regulate the translation of specific mRNAs to mediate these effects. Limitations This study did not identify which genes are translationally regulated by 4EHP and GIGYF2. Identification of mistranslated genes in 4EHP-eKO mice might provide a mechanistic explanation for the observed impairment in social behavior and exaggerated LTD. Future experiments employing affinity purification of translating ribosomes and mRNA sequencing in 4EHP-eKO mice will address this relevant issue. Conclusions Together these results demonstrate an important role of 4EHP in regulating hippocampal plasticity and ASD-associated social behaviors, consistent with the link between mutations in GIGYF2 and ASD.
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19
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The Regulatory Properties of the Ccr4-Not Complex. Cells 2020; 9:cells9112379. [PMID: 33138308 PMCID: PMC7692201 DOI: 10.3390/cells9112379] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
The mammalian Ccr4–Not complex, carbon catabolite repression 4 (Ccr4)-negative on TATA-less (Not), is a large, highly conserved, multifunctional assembly of proteins that acts at different cellular levels to regulate gene expression. In the nucleus, it is involved in the regulation of the cell cycle, chromatin modification, activation and inhibition of transcription initiation, control of transcription elongation, RNA export, nuclear RNA surveillance, and DNA damage repair. In the cytoplasm, the Ccr4–Not complex plays a central role in mRNA decay and affects protein quality control. Most of our original knowledge of the Ccr4–Not complex is derived, primarily, from studies in yeast. More recent studies have shown that the mammalian complex has a comparable structure and similar properties. In this review, we summarize the evidence for the multiple roles of both the yeast and mammalian Ccr4–Not complexes, highlighting their similarities.
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20
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Hoang HD, Graber TE, Jia JJ, Vaidya N, Gilchrist VH, Xiang X, Li W, Cowan KN, Gkogkas CG, Jaramillo M, Jafarnejad SM, Alain T. Induction of an Alternative mRNA 5' Leader Enhances Translation of the Ciliopathy Gene Inpp5e and Resistance to Oncolytic Virus Infection. Cell Rep 2020; 29:4010-4023.e5. [PMID: 31851930 DOI: 10.1016/j.celrep.2019.11.072] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 10/16/2019] [Accepted: 11/15/2019] [Indexed: 01/10/2023] Open
Abstract
Residual cell-intrinsic innate immunity in cancer cells hampers infection with oncolytic viruses. Translational control of mRNA is an important feature of innate immunity, yet the identity of translationally regulated mRNAs functioning in host defense remains ill-defined. We report the translatomes of resistant murine "4T1" breast cancer cells infected with three of the most clinically advanced oncolytic viruses: herpes simplex virus 1, reovirus, and vaccinia virus. Common among all three infections are translationally de-repressed mRNAs, including Inpp5e, encoding an inositol 5-phosphatase that modifies lipid second messenger signaling. We find that viral infection induces the expression of an Inpp5e mRNA variant that lacks repressive upstream open reading frames (uORFs) within its 5' leader and is efficiently translated. Furthermore, we show that INPP5E contributes to antiviral immunity by altering virus attachment. These findings uncover a role for translational control through alternative 5' leader expression and assign an antiviral function to the ciliopathy gene Inpp5e.
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Affiliation(s)
- Huy-Dung Hoang
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada; Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Tyson E Graber
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada; Department of Biochemistry and Goodman Cancer Center, McGill University, Montreal, QC H3A 1A3, Canada
| | - Jian-Jun Jia
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
| | - Nasana Vaidya
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
| | - Victoria H Gilchrist
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada; Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Xiao Xiang
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Wencheng Li
- Department of Biochemistry and Molecular Biology, Rutgers New Jersey Medical School, Newark, NJ 07101, USA
| | - Kyle N Cowan
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Department of Surgery, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Christos G Gkogkas
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Maritza Jaramillo
- INRS Institut Armand-Frappier Research Centre, Laval, QC H7V 1B7, Canada
| | - Seyed Mehdi Jafarnejad
- Centre for Cancer Research and Cell Biology, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast BT9 7AE, UK
| | - Tommy Alain
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada; Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
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21
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Liu J, Hu HB, Liu YM, Li FX, Zhang LP, Liao ZM. LncRNA HOTTIP promotes the proliferation and invasion of ovarian cancer cells by activating the MEK/ERK pathway. Mol Med Rep 2020; 22:3667-3676. [PMID: 33000231 PMCID: PMC7533522 DOI: 10.3892/mmr.2020.11452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 06/22/2020] [Indexed: 12/27/2022] Open
Abstract
Recent studies have revealed that long non-coding RNAs (lncRNAs) serve important roles in carcinogenesis and that this type of gene may be used as biomarkers in cancer. A high level of lncRNA HOXA distal transcript antisense RNA (HOTTIP) is associated with unfavorable prognosis for patients with ovarian cancer (OC), but the mechanism of HOTTIP involved in OC development remains to be elucidated. The present study aimed to investigate the mechanism of HOTTIP in metastasis-associated OC cell behaviors. HOTTIP levels in ovarian cells were quantified by reverse transcription-quantitative PCR, cell proliferation was analyzed by colony formation assay, and apoptosis was assessed by flow cytometry. Cell migratory and invasive abilities were evaluated by wound healing and Transwell assays, respectively. The expression levels of mitogen-activated protein kinase kinase (MEK)/ERK pathway-associated proteins were detected by western blotting. The results demonstrated that knockdown of HOTTIP in OC cells significantly reduced the phosphorylation levels of MEK and ERK, inhibited the proliferation and invasion of OC cells and promoted their apoptosis. Furthermore, the effects of HOTTIP on cell migration and invasion were partly associated with the epithelial-mesenchymal transition (EMT) process. Proliferation, invasion and EMT of OC cells were enhanced following overexpression of HOTTIP; however, these effects were reversed by the MEK/ERK pathway inhibitor U0126. In conclusion, HOTTIP was demonstrated to promote the proliferation, migration and invasion of OC cells by activating the MEK/ERK pathway. Therefore, HOTTIP may serve as a potential therapeutic target for OC.
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Affiliation(s)
- Jian Liu
- Department of Gynaecology, Yuebei People's Hospital, Shaoguan, Guangdong 512026, P.R. China
| | - Hong-Bo Hu
- Department of Gynaecology, Yuebei People's Hospital, Shaoguan, Guangdong 512026, P.R. China
| | - Yan-Ming Liu
- Department of Clinical Laboratory, Yuebei People's Hospital, Shaoguan, Guangdong 512026, P.R. China
| | - Fan-Xiang Li
- Department of Gynaecology, Yuebei People's Hospital, Shaoguan, Guangdong 512026, P.R. China
| | - Liu-Ping Zhang
- Department of Gynaecology, Yuebei People's Hospital, Shaoguan, Guangdong 512026, P.R. China
| | - Zong-Min Liao
- Department of Gynaecology, Yuebei People's Hospital, Shaoguan, Guangdong 512026, P.R. China
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22
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Yan YB. Diverse functions of deadenylases in DNA damage response and genomic integrity. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1621. [PMID: 32790161 DOI: 10.1002/wrna.1621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 12/18/2022]
Abstract
DNA damage response (DDR) is a coordinated network of diverse cellular processes including the detection, signaling, and repair of DNA lesions, the adjustment of metabolic network and cell fate determination. To deal with the unavoidable DNA damage caused by either endogenous or exogenous stresses, the cells need to reshape the gene expression profile to allow efficient transcription and translation of DDR-responsive messenger RNAs (mRNAs) and to repress the nonessential mRNAs. A predominant method to adjust RNA fate is achieved by modulating the 3'-end oligo(A) or poly(A) length via the opposing actions of polyadenylation and deadenylation. Poly(A)-specific ribonuclease (PARN) and the carbon catabolite repressor 4 (CCR4)-Not complex, the major executors of deadenylation, are indispensable to DDR and genomic integrity in eukaryotic cells. PARN modulates cell cycle progression by regulating the stabilities of mRNAs and microRNA (miRNAs) involved in the p53 pathway and contributes to genomic stability by affecting the biogenesis of noncoding RNAs including miRNAs and telomeric RNA. The CCR4-Not complex is involved in diverse pathways of DDR including transcriptional regulation, signaling pathways, mRNA stabilities, translation regulation, and protein degradation. The RNA targets of deadenylases are tuned by the DDR signaling pathways, while in turn the deadenylases can regulate the levels of DNA damage-responsive proteins. The mutual feedback between deadenylases and the DDR signaling pathways allows the cells to precisely control DDR by dynamically adjusting the levels of sensors and effectors of the DDR signaling pathways. Here, the diverse functions of deadenylases in DDR are summarized and the underlying mechanisms are proposed according to recent findings. This article is categorized under: RNA Processing > 3' End Processing RNA in Disease and Development > RNA in Disease RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms.
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Affiliation(s)
- Yong-Bin Yan
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, China
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23
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Wang C, Zhu J, Zhang Z, Chen H, Ji M, Chen C, Hu Y, Yu Y, Xia R, Shen J, Gong X, Wang SL. Rno-miR-224-5p contributes to 2,2',4,4'-tetrabromodiphenyl ether-induced low triiodothyronine in rats by targeting deiodinases. CHEMOSPHERE 2020; 246:125774. [PMID: 31901531 DOI: 10.1016/j.chemosphere.2019.125774] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/24/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
Hypothyroidism is commonly associated with substantial adverse impacts on human health, and polybrominated diphenyl ether (PBDE), a kind of classic thyroid hormone disruptor, was speculated to be a potential environmental factor, but its effect on thyroxine metabolism has received little attention. In the present study, we investigated the role and mechanism of rno-miR-224-5p in deiodinase-mediated thyroxine metabolism in rats treated with 2,2',4,4'-tetrabromodiphenyl ether (BDE47), a predominant PBDE congener in humans. BDE47 decreased plasma triiodothyronine (T3) and thyroxine (T4) and increased reverse T3 (rT3) in the rats, and the expression of type 1 deiodinase (DIO1) and type 3 deiodinase (DIO3) increased in both the rats and H4-II-E cells. Rno-miR-224-5p was predicted to target dio1 instead of dio3, according to the TargetScan, miRmap.org and microRNA.org databases. Experiments showed that the rno-miR-224-5p level was decreased by BDE47 in a dose-dependent manner and confirmed that rno-miR-224-5p downregulated both DIO1 and DIO3 in the H4-II-E cells and in the rats, as determined using mimics and an inhibitor of rno-miR-224-5p. Furthermore, DIO1 was observed to be a direct functional target of rno-miR-224-5p, whereas DIO3 was indirectly regulated by rno-miR-224-5p via the phosphorylation of the MAPK/ERK (but not p38 or JNK) pathway. Reportedly, DIO1 and DIO3 act principally as inner-ring deiodinases and are responsible for the conversion of T4 to rT3, but not to T3, and the final clearance of thyroxine (mainly in the form of T2). Our results demonstrated that BDE47 induced low levels of T3 conversion through DIO1 and DIO3, which were regulated by rno-miR-224-5p. The findings suggest a novel additional mechanism of PBDE-induced thyroxine metabolism disorder that differs from that of PBDEs as environmental thyroid disruptors.
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Affiliation(s)
- Chao Wang
- State Key Lab of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China; Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Jiansheng Zhu
- State Key Lab of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China; Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Zhan Zhang
- Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Hang Chen
- Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Minghui Ji
- Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Chao Chen
- Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Yuhuan Hu
- State Key Lab of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China; Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Yongquan Yu
- State Key Lab of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China; Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Rong Xia
- Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Jiemiao Shen
- Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Xing Gong
- State Key Lab of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China; Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China
| | - Shou-Lin Wang
- State Key Lab of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China; Key Lab of Modern Toxicology of Ministry of Education, Center for Global Health, School of Public Health, Nanjing Medical University, 101 Longmian Avenue, Nanjing, 211166, PR China.
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24
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Räsch F, Weber R, Izaurralde E, Igreja C. 4E-T-bound mRNAs are stored in a silenced and deadenylated form. Genes Dev 2020; 34:847-860. [PMID: 32354837 PMCID: PMC7263148 DOI: 10.1101/gad.336073.119] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 04/02/2020] [Indexed: 12/20/2022]
Abstract
Human 4E-T is an eIF4E-binding protein (4E-BP) present in processing (P)-bodies that represses translation and regulates decay of mRNAs destabilized by AU-rich elements and microRNAs (miRNAs). However, the underlying regulatory mechanisms are still unclear. Here, we show that upon mRNA binding 4E-T represses translation and promotes deadenylation via the recruitment of the CCR4-NOT deadenylase complex. The interaction with CCR4-NOT is mediated by previously uncharacterized sites in the middle region of 4E-T. Importantly, mRNA decapping and decay are inhibited by 4E-T and the deadenylated target is stored in a repressed form. Inhibition of mRNA decapping requires the interaction of 4E-T with the cap-binding proteins eIF4E/4EHP. We further show that regulation of decapping by 4E-T participates in mRNA repression by the miRNA effector protein TNRC6B and that 4E-T overexpression interferes with tristetraprolin (TTP)- and NOT1-mediated mRNA decay. Thus, we postulate that 4E-T modulates 5'-to-3' decay by swapping the fate of a deadenylated mRNA from complete degradation to storage. Our results provide insight into the mechanism of mRNA storage that controls localized translation and mRNA stability in P-bodies.
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Affiliation(s)
- Felix Räsch
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Ramona Weber
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
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25
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Otsuka H, Fukao A, Tomohiro T, Adachi S, Suzuki T, Takahashi A, Funakami Y, Natsume T, Yamamoto T, Duncan KE, Fujiwara T. ARE-binding protein ZFP36L1 interacts with CNOT1 to directly repress translation via a deadenylation-independent mechanism. Biochimie 2020; 174:49-56. [PMID: 32311426 DOI: 10.1016/j.biochi.2020.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 10/24/2022]
Abstract
Eukaryotic gene expression can be spatiotemporally tuned at the post-transcriptional level by cis-regulatory elements in mRNA sequences. An important example is the AU-rich element (ARE), which induces mRNA destabilization in a variety of biological contexts in mammals and can also mediate translational control. Regulation is mediated by trans-acting factors that recognize the ARE, such as Tristetraprolin (TTP) and BRF1/ZFP36L1. Although both proteins can destabilize their target mRNAs through the recruitment of the CCR4-NOT deadenylation complex, TTP also directly regulates translation. Whether ZFP36L1 can directly repress translation remains unknown. Here, we used an in vitro translation system derived from mammalian cell lines to address this key mechanistic issue in ARE regulation by ZFP36L1. Functional assays with mutant proteins reveal that ZFP36L1 can repress translation via AU-Rich elements independent of deadenylation. ZFP36L1-mediated translation repression requires interaction between ZFP36L1 and CNOT1, suggesting that it might use a repression mechanism similar to either TPP or miRISC. However, several lines of evidence suggest that the similarity ends there. Unlike, TTP, it does not efficiently interact with either 4E-HP or GIGYF2, suggesting it does not repress translation by recruiting these proteins to the mRNA cap. Moreover, ZFP36L1 could not repress ECMV-IRES driven translation and was resistant to pharmacological eIF4A inhibitor silvestrol, suggesting fundamental differences with miRISC repression via eIF4A. Collectively, our results reveal that ZFP36L1 represses translation directly and suggest that it does so via a novel mechanism distinct from other translational regulators that interact with the CCR4-NOT deadenylase complex.
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Affiliation(s)
- Hiroshi Otsuka
- Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Japan
| | | | - Takumi Tomohiro
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Shungo Adachi
- Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan
| | - Toru Suzuki
- Laboratory for Immunogenetics, Center for Integrative Medical Sciences, RIKEN, 1-7-22, Suehiro-cho, Yokohama, Japan
| | - Akinori Takahashi
- Cell Signal Unit, Okinawa Institute of Science and Technology, Onna-son, Kunigami-gun, Okinawa, Japan
| | | | - Toru Natsume
- Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan
| | - Tadashi Yamamoto
- Laboratory for Immunogenetics, Center for Integrative Medical Sciences, RIKEN, 1-7-22, Suehiro-cho, Yokohama, Japan; Cell Signal Unit, Okinawa Institute of Science and Technology, Onna-son, Kunigami-gun, Okinawa, Japan
| | - Kent E Duncan
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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26
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Ma R, Ma L, Weng W, Wang Y, Liu H, Guo R, Gao Y, Tu J, Xu TL, Cheng J, Zhu MX, Zhou A, Li Y. DUSP6 SUMOylation protects cells from oxidative damage via direct regulation of Drp1 dephosphorylation. SCIENCE ADVANCES 2020; 6:eaaz0361. [PMID: 32232156 PMCID: PMC7096176 DOI: 10.1126/sciadv.aaz0361] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/06/2020] [Indexed: 05/05/2023]
Abstract
Imbalanced mitochondrial fission/fusion, a major cause of apoptotic cell death, often results from dysregulation of Drp1 phosphorylation of two serines, S616 and S637. Whereas kinases for Drp1-S616 phosphorylation are well-described, phosphatase(s) for its dephosphorylation remains unclear. Here, we show that dual-specificity phosphatase 6 (DUSP6) dephosphorylates Drp1-S616 independently of its known substrates ERK1/2. DUSP6 keeps Drp1-S616 phosphorylation levels low under normal conditions. The stability and catalytic function of DUSP6 are maintained through conjugation of small ubiquitin-like modifier-1 (SUMO1) and SUMO2/3 at lysine-234 (K234), which is disrupted during oxidation through transcriptional up-regulation of SUMO-deconjugating enzyme, SENP1, causing DUSP6 degradation by ubiquitin-proteasome. deSUMOylation underlies DUSP6 degradation, Drp1-S616 hyperphosphorylation, mitochondrial fragmentation, and apoptosis induced by H2O2 in cultured cells or brain ischemia/reperfusion in mice. Overexpression of DUSP6, but not the SUMOylation-deficient DUSP6K234R mutant, protected cells from apoptosis. Thus, DUSP6 exerts a cytoprotective role by directly dephosphorylating Drp1-S616, which is disrupted by deSUMOylation under oxidation.
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Affiliation(s)
- Ruining Ma
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Lina Ma
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Weiji Weng
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yingping Wang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huiqing Liu
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Rongjun Guo
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yingwei Gao
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jun Tu
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Tian-Le Xu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jinke Cheng
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Michael X. Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Aiwu Zhou
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Corresponding author. (Y.L.); (A.Z.)
| | - Yong Li
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Corresponding author. (Y.L.); (A.Z.)
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27
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Ruscica V, Bawankar P, Peter D, Helms S, Igreja C, Izaurralde E. Direct role for the Drosophila GIGYF protein in 4EHP-mediated mRNA repression. Nucleic Acids Res 2020; 47:7035-7048. [PMID: 31114929 PMCID: PMC6648886 DOI: 10.1093/nar/gkz429] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 05/02/2019] [Accepted: 05/08/2019] [Indexed: 02/07/2023] Open
Abstract
The eIF4E-homologous protein (4EHP) is a translational repressor that competes with eIF4E for binding to the 5'-cap structure of specific mRNAs, to which it is recruited by protein factors such as the GRB10-interacting GYF (glycine-tyrosine-phenylalanine domain) proteins (GIGYF). Several experimental evidences suggest that GIGYF proteins are not merely facilitating 4EHP recruitment to transcripts but are actually required for the repressor activity of the complex. However, the underlying molecular mechanism is unknown. Here, we investigated the role of the uncharacterized Drosophila melanogaster (Dm) GIGYF protein in post-transcriptional mRNA regulation. We show that, when in complex with 4EHP, Dm GIGYF not only elicits translational repression but also promotes target mRNA decay via the recruitment of additional effector proteins. We identified the RNA helicase Me31B/DDX6, the decapping activator HPat and the CCR4-NOT deadenylase complex as binding partners of GIGYF proteins. Recruitment of Me31B and HPat via discrete binding motifs conserved among metazoan GIGYF proteins is required for downregulation of mRNA expression by the 4EHP-GIGYF complex. Our findings are consistent with a model in which GIGYF proteins additionally recruit decapping and deadenylation complexes to 4EHP-containing RNPs to induce translational repression and degradation of mRNA targets.
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Affiliation(s)
- Vincenzo Ruscica
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Praveen Bawankar
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany.,Institute of Molecular Biology gGmbH, Ackermannweg 4, 55128 Mainz, Germany
| | - Daniel Peter
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany.,European Molecular Biology Laboratory, 71 avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Sigrun Helms
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
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28
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Communication Is Key: 5'-3' Interactions that Regulate mRNA Translation and Turnover. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:149-164. [PMID: 31811634 DOI: 10.1007/978-3-030-31434-7_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Most eukaryotic mRNAs maintain a 5' cap structure and 3' poly(A) tail, cis-acting elements that are often separated by thousands of nucleotides. Nevertheless, multiple paradigms exist where mRNA 5' and 3' termini interact with each other in order to regulate mRNA translation and turnover. mRNAs recruit translation initiation factors to their termini, which in turn physically interact with each other. This physical bridging of the mRNA termini is known as the "closed loop" model, with years of genetic and biochemical evidence supporting the functional synergy between the 5' cap and 3' poly(A) tail to enhance mRNA translation initiation. However, a number of examples exist of "non-canonical" 5'-3' communication for cellular and viral RNAs that lack 5' cap structures and/or poly(A) tails. Moreover, in several contexts, mRNA 5'-3' communication can function to repress translation. Overall, we detail how various mRNA 5'-3' interactions play important roles in posttranscriptional regulation, wherein depending on the protein factors involved can result in translational stimulation or repression.
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29
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Adaptive Responses as Mechanisms of Resistance to BRAF Inhibitors in Melanoma. Cancers (Basel) 2019; 11:cancers11081176. [PMID: 31416288 PMCID: PMC6721815 DOI: 10.3390/cancers11081176] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 12/14/2022] Open
Abstract
: The introduction of v-raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors in melanoma patients with BRAF (V600E) mutations has demonstrated significant clinical benefits. However, rarely do tumours regress completely. Frequently, the reason for this is that therapies targeting specific oncogenic mutations induce a number of intrinsic compensatory mechanisms, also known as adaptive responses or feedback loops, that enhance the pro-survival and pro-proliferative capacity of a proportion of the original tumour population, thereby resulting in tumour progression. In this review we will summarize the known adaptive responses that limit BRAF mutant therapy and discuss potential novel combinatorial therapies to overcome resistance.
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30
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Proud CG. Phosphorylation and Signal Transduction Pathways in Translational Control. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033050. [PMID: 29959191 DOI: 10.1101/cshperspect.a033050] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein synthesis, including the translation of specific messenger RNAs (mRNAs), is regulated by extracellular stimuli such as hormones and by the levels of certain nutrients within cells. This control involves several well-understood signaling pathways and protein kinases, which regulate the phosphorylation of proteins that control the translational machinery. These pathways include the mechanistic target of rapamycin complex 1 (mTORC1), its downstream effectors, and the mitogen-activated protein (MAP) kinase (extracellular ligand-regulated kinase [ERK]) signaling pathway. This review describes the regulatory mechanisms that control translation initiation and elongation factors, in particular the effects of phosphorylation on their interactions or activities. It also discusses current knowledge concerning the impact of these control systems on the translation of specific mRNAs or subsets of mRNAs, both in physiological processes and in diseases such as cancer.
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Affiliation(s)
- Christopher G Proud
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide SA5000, Australia; and School of Biological Sciences, University of Adelaide, Adelaide SA5000, Australia
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31
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Terrao M, Marucha KK, Mugo E, Droll D, Minia I, Egler F, Braun J, Clayton C. The suppressive cap-binding complex factor 4EIP is required for normal differentiation. Nucleic Acids Res 2019; 46:8993-9010. [PMID: 30124912 PMCID: PMC6158607 DOI: 10.1093/nar/gky733] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/01/2018] [Indexed: 12/27/2022] Open
Abstract
Trypanosoma brucei live in mammals as bloodstream forms and in the Tsetse midgut as procyclic forms. Differentiation from one form to the other proceeds via a growth-arrested stumpy form with low messenger RNA (mRNA) content and translation. The parasites have six eIF4Es and five eIF4Gs. EIF4E1 pairs with the mRNA-binding protein 4EIP but not with any EIF4G. EIF4E1 and 4EIP each inhibit expression when tethered to a reporter mRNA, but while tethered EIF4E1 suppresses only when 4EIP is present, suppression by tethered 4EIP does not require the interaction with EIF4E1. In growing bloodstream forms, 4EIP is preferentially associated with unstable mRNAs. Bloodstream- or procyclic-form trypanosomes lacking 4EIP have only a marginal growth disadvantage. Bloodstream forms without 4EIP are, however, defective in translation suppression during stumpy-form differentiation and cannot subsequently convert to growing procyclic forms. Intriguingly, the differentiation defect can be complemented by a truncated 4EIP that does not interact with EIF4E1. In contrast, bloodstream forms lacking EIF4E1 have a growth defect, stumpy formation seems normal, but they appear unable to grow as procyclic forms. We suggest that 4EIP and EIF4E1 fine-tune mRNA levels in growing cells, and that 4EIP contributes to translation suppression during differentiation to the stumpy form.
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Affiliation(s)
- Monica Terrao
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Kevin K Marucha
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Elisha Mugo
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Dorothea Droll
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Igor Minia
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Franziska Egler
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Johanna Braun
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Christine Clayton
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
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32
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Duchaine TF, Fabian MR. Mechanistic Insights into MicroRNA-Mediated Gene Silencing. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032771. [PMID: 29959194 DOI: 10.1101/cshperspect.a032771] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
MicroRNAs (miRNAs) posttranscriptionally regulate gene expression by repressing protein synthesis and exert a broad influence over development, physiology, adaptation, and disease. Over the past two decades, great strides have been made toward elucidating how miRNAs go about shutting down messenger RNA (mRNA) translation and promoting mRNA decay.
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Affiliation(s)
- Thomas F Duchaine
- Department of Biochemistry & Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Marc R Fabian
- Department of Oncology, McGill University, Montreal, Quebec H3G 1Y6, Canada.,Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
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Hassanzadeh G, Naing T, Graber T, Jafarnejad SM, Stojdl DF, Alain T, Holcik M. Characterizing Cellular Responses During Oncolytic Maraba Virus Infection. Int J Mol Sci 2019; 20:ijms20030580. [PMID: 30700020 PMCID: PMC6387032 DOI: 10.3390/ijms20030580] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 02/07/2023] Open
Abstract
The rising demand for powerful oncolytic virotherapy agents has led to the identification of Maraba virus, one of the most potent oncolytic viruses from Rhabdoviridae family which displays high selectivity for killing malignant cells and low cytotoxicity in normal cells. Although the virus is readied to be used for clinical trials, the interactions between the virus and the host cells is still unclear. Using a newly developed interferon-sensitive mutant Maraba virus (MG1), we have identified two key regulators of global translation (4E-BP1 and eIF2α) as being involved in the regulation of protein synthesis in the infected cells. Despite the translational arrest upon viral stress, we showed an up-regulation of anti-apoptotic Bcl-xL protein that provides a survival benefit for the host cell, yet facilitates effective viral propagation. Given the fact that eIF5B canonically regulates 60S ribosome subunit end joining and is able to replace the role of eIF2 in delivering initiator tRNA to the 40S ribosome subunit upon the phosphorylation of eIF2α we have tested whether eIF5B mediates the translation of target mRNAs during MG1 infection. Our results show that the inhibition of eIF5B significantly down-regulates the level of Bcl-xL steady-state mRNA, thus indirectly attenuates viral propagation.
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Affiliation(s)
- Golnoush Hassanzadeh
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada.
| | - Thet Naing
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada.
- Department of Health Sciences, Carleton University, Ottawa, ON K1S 5B6, Canada.
| | - Tyson Graber
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada.
| | - Seyed Mehdi Jafarnejad
- Centre for Cancer Research and Cell Biology (CCRCB), Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, UK.
| | - David F Stojdl
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada.
| | - Tommy Alain
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada.
| | - Martin Holcik
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada.
- Department of Health Sciences, Carleton University, Ottawa, ON K1S 5B6, Canada.
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Mayya VK, Duchaine TF. Ciphers and Executioners: How 3'-Untranslated Regions Determine the Fate of Messenger RNAs. Front Genet 2019; 10:6. [PMID: 30740123 PMCID: PMC6357968 DOI: 10.3389/fgene.2019.00006] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/07/2019] [Indexed: 12/29/2022] Open
Abstract
The sequences and structures of 3'-untranslated regions (3'UTRs) of messenger RNAs govern their stability, localization, and expression. 3'UTR regulatory elements are recognized by a wide variety of trans-acting factors that include microRNAs (miRNAs), their associated machinery, and RNA-binding proteins (RBPs). In turn, these factors instigate common mechanistic strategies to execute the regulatory programs encoded by 3'UTRs. Here, we review classes of factors that recognize 3'UTR regulatory elements and the effector machineries they guide toward mRNAs to dictate their expression and fate. We outline illustrative examples of competitive, cooperative, and coordinated interplay such as mRNA localization and localized translation. We further review the recent advances in the study of mRNP granules and phase transition, and their possible significance for the functions of 3'UTRs. Finally, we highlight some of the most recent strategies aimed at deciphering the complexity of the regulatory codes of 3'UTRs, and identify some of the important remaining challenges.
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Affiliation(s)
| | - Thomas F. Duchaine
- Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, QC, Canada
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Battling for Ribosomes: Translational Control at the Forefront of the Antiviral Response. J Mol Biol 2018; 430:1965-1992. [PMID: 29746850 DOI: 10.1016/j.jmb.2018.04.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/24/2018] [Accepted: 04/27/2018] [Indexed: 01/05/2023]
Abstract
In the early stages of infection, gaining control of the cellular protein synthesis machinery including its ribosomes is the ultimate combat objective for a virus. To successfully replicate, viruses unequivocally need to usurp and redeploy this machinery for translation of their own mRNA. In response, the host triggers global shutdown of translation while paradoxically allowing swift synthesis of antiviral proteins as a strategy to limit collateral damage. This fundamental conflict at the level of translational control defines the outcome of infection. As part of this special issue on molecular mechanisms of early virus-host cell interactions, we review the current state of knowledge regarding translational control during viral infection with specific emphasis on protein kinase RNA-activated and mammalian target of rapamycin-mediated mechanisms. We also describe recent technological advances that will allow unprecedented insight into how viruses and host cells battle for ribosomes.
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