1
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Blazie SM, Fortunati D, Zhao Y, Jin Y. C. elegans LIN-66 mediates EIF-3/eIF3-dependent protein translation via a cold-shock domain. Life Sci Alliance 2024; 7:e202402673. [PMID: 38886018 PMCID: PMC11184513 DOI: 10.26508/lsa.202402673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 06/20/2024] Open
Abstract
Protein translation initiation is a conserved process involving many proteins acting in concert. The 13 subunit eukaryotic initiation factor 3 (eIF3) complex is essential for assembly of the pre-initiation complex that scans mRNA and positions ribosome at the initiation codon. We previously reported that a gain-of-function (gf) mutation affecting the G subunit of the Caenorhabditis elegans eIF3 complex, eif-3.g(gf), selectively modulates protein translation in the ventral cord cholinergic motor neurons. Here, through unbiased genetic suppressor screening, we identified that the gene lin-66 mediates eif-3.g(gf)-dependent protein translation in motor neurons. LIN-66 is composed largely of low-complexity amino acid sequences with unknown functional domains. We combined bioinformatics analysis with in vivo functional dissection and identified a cold-shock domain in LIN-66 critical for its function. In cholinergic motor neurons, LIN-66 shows a close association with EIF-3.G in the cytoplasm. The low-complexity amino acid sequences of LIN-66 modulate its subcellular pattern. As cold-shock domains function broadly in RNA regulation, we propose that LIN-66 mediates stimulus-dependent protein translation by facilitating the interaction of mRNAs with EIF-3.G.
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Affiliation(s)
- Stephen M Blazie
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Daniel Fortunati
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Yan Zhao
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Yishi Jin
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA, USA
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2
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Mahé M, Rios-Fuller T, Katsara O, Schneider RJ. Non-canonical mRNA translation initiation in cell stress and cancer. NAR Cancer 2024; 6:zcae026. [PMID: 38828390 PMCID: PMC11140632 DOI: 10.1093/narcan/zcae026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/08/2024] [Accepted: 05/29/2024] [Indexed: 06/05/2024] Open
Abstract
The now well described canonical mRNA translation initiation mechanism of m7G 'cap' recognition by cap-binding protein eIF4E and assembly of the canonical pre-initiation complex consisting of scaffolding protein eIF4G and RNA helicase eIF4A has historically been thought to describe all cellular mRNA translation. However, the past decade has seen the discovery of alternative mechanisms to canonical eIF4E mediated mRNA translation initiation. Studies have shown that non-canonical alternate mechanisms of cellular mRNA translation initiation, whether cap-dependent or independent, serve to provide selective translation of mRNAs under cell physiological and pathological stress conditions. These conditions typically involve the global downregulation of canonical eIF4E1/cap-mediated mRNA translation, and selective translational reprogramming of the cell proteome, as occurs in tumor development and malignant progression. Cancer cells must be able to maintain physiological plasticity to acquire a migratory phenotype, invade tissues, metastasize, survive and adapt to severe microenvironmental stress conditions that involve inhibition of canonical mRNA translation initiation. In this review we describe the emerging, important role of non-canonical, alternate mechanisms of mRNA translation initiation in cancer, particularly in adaptation to stresses and the phenotypic cell fate changes involved in malignant progression and metastasis. These alternate translation initiation mechanisms provide new targets for oncology therapeutics development.
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Affiliation(s)
- Mélanie Mahé
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Tiffany Rios-Fuller
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Olga Katsara
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Robert J Schneider
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
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3
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Ide NA, Gentry RC, Rudbach MA, Yoo K, Velez PK, Comunale VM, Hartwick EW, Kinz-Thompson CD, Gonzalez RL, Aitken CE. A dynamic compositional equilibrium governs mRNA recognition by eIF3. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.581977. [PMID: 38712078 PMCID: PMC11071631 DOI: 10.1101/2024.04.25.581977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Eukaryotic translation initiation factor (eIF) 3 is a multi-subunit protein complex that binds both ribosomes and messenger RNAs (mRNAs) in order to drive a diverse set of mechanistic steps during translation. Despite its importance, a unifying framework explaining how eIF3 performs these numerous activities is lacking. Using single-molecule light scattering microscopy, we demonstrate that Saccharomyces cerevisiae eIF3 is an equilibrium mixture of the full complex, subcomplexes, and subunits. By extending our microscopy approach to an in vitro reconstituted eIF3 and complementing it with biochemical assays, we define the subspecies comprising this equilibrium and show that, rather than being driven by the full complex, mRNA binding by eIF3 is instead driven by the eIF3a subunit within eIF3a-containing subcomplexes. Our findings provide a mechanistic model for the role of eIF3 in the mRNA recruitment step of translation initiation and establish a mechanistic framework for explaining and investigating the other activities of eIF3.
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4
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González-Sánchez AM, Castellanos-Silva EA, Díaz-Figueroa G, Cate JHD. JUN mRNA translation regulation is mediated by multiple 5' UTR and start codon features. PLoS One 2024; 19:e0299779. [PMID: 38483896 PMCID: PMC10939236 DOI: 10.1371/journal.pone.0299779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/14/2024] [Indexed: 03/17/2024] Open
Abstract
Regulation of mRNA translation by eukaryotic initiation factors (eIFs) is crucial for cell survival. In humans, eIF3 stimulates translation of the JUN mRNA which encodes the transcription factor JUN, an oncogenic transcription factor involved in cell cycle progression, apoptosis, and cell proliferation. Previous studies revealed that eIF3 activates translation of the JUN mRNA by interacting with a stem loop in the 5' untranslated region (5' UTR) and with the 5' -7-methylguanosine cap structure. In addition to its interaction site with eIF3, the JUN 5' UTR is nearly one kilobase in length, and has a high degree of secondary structure, high GC content, and an upstream start codon (uAUG). This motivated us to explore the complexity of JUN mRNA translation regulation in human cells. Here we find that JUN translation is regulated in a sequence and structure-dependent manner in regions adjacent to the eIF3-interacting site in the JUN 5' UTR. Furthermore, we identify contributions of an additional initiation factor, eIF4A, in JUN regulation. We show that enhancing the interaction of eIF4A with JUN by using the compound Rocaglamide A (RocA) represses JUN translation. We also find that both the upstream AUG (uAUG) and the main AUG (mAUG) contribute to JUN translation and that they are conserved throughout vertebrates. Our results reveal additional layers of regulation for JUN translation and show the potential of JUN as a model transcript for understanding multiple interacting modes of translation regulation.
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Affiliation(s)
- Angélica M. González-Sánchez
- Comparative Biochemistry Graduate Program, University of California, Berkeley, Berkeley, CA, United States of America
| | - Eimy A. Castellanos-Silva
- Department of Biochemistry and Molecular Biology, University of California, Davis, Davis, CA, United States of America
| | - Gabriela Díaz-Figueroa
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States of America
| | - Jamie H. D. Cate
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States of America
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5
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Li C, Li B, Wang H, Qu L, Liu H, Weng C, Han J, Li Y. Role of N6-methyladenosine methylation in glioma: recent insights and future directions. Cell Mol Biol Lett 2023; 28:103. [PMID: 38072944 PMCID: PMC10712162 DOI: 10.1186/s11658-023-00514-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
Glioma is the most pervasive intracranial tumor in the central nervous system (CNS), with glioblastoma (GBM) being the most malignant type having a highly heterogeneous cancer cell population. There is a significantly high mortality rate in GBM patients. Molecular biomarkers related to GBM malignancy may have prognostic values in predicting survival outcomes and therapeutic responses, especially in patients with high-grade gliomas. In particular, N6-methyladenine (m6A) mRNA modification is the most abundant form of post-transcriptional RNA modification in mammals and is involved in regulating mRNA translation and degradation. Cumulative findings indicate that m6A methylation plays a crucial part in neurogenesis and glioma pathogenesis. In this review, we summarize recent advances regarding the functional significance of m6A modification and its regulatory factors in glioma occurrence and progression. Significant advancement of m6A methylation-associated regulators as potential therapeutic targets is also discussed.
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Affiliation(s)
- Chunlin Li
- Department of Neurology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250014, Shandong, China
| | - Bowen Li
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, 250000, Shandong, China
| | - Hui Wang
- Department of Acupuncture, Zaozhuang Traditional Chinese Medicine Hospital, Zaozhuang, 277000, Shandong, China
| | - Linglong Qu
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, 250000, Shandong, China
| | - Hui Liu
- First School of Clinical Medicine, Shandong University of Traditional Chinese Medicine, Jinan, 250000, Shandong, China
| | - Chao Weng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Jinming Han
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China.
| | - Yuan Li
- Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China.
- Suzhou Research Institute of Shandong University, Suzhou 215123, China.
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6
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González-Sánchez AM, Castellanos-Silva EA, Díaz-Figueroa G, Cate JHD. JUN mRNA Translation Regulation is Mediated by Multiple 5' UTR and Start Codon Features. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567602. [PMID: 38014201 PMCID: PMC10680820 DOI: 10.1101/2023.11.17.567602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Regulation of mRNA translation by eukaryotic initiation factors (eIFs) is crucial for cell survival. In humans, eIF3 stimulates translation of the JUN mRNA which encodes the transcription factor JUN, an oncogenic transcription factor involved in cell cycle progression, apoptosis, and cell proliferation. Previous studies revealed that eIF3 activates translation of the JUN mRNA by interacting with a stem loop in the 5' untranslated region (5' UTR) and with the 5'-7-methylguanosine cap structure. In addition to its interaction site with eIF3, the JUN 5' UTR is nearly one kilobase in length, and has a high degree of secondary structure, high GC content, and an upstream start codon (uAUG). This motivated us to explore the complexity of JUN mRNA translation regulation in human cells. Here we find that JUN translation is regulated in a sequence and structure-dependent manner in regions adjacent to the eIF3-interacting site in the JUN 5' UTR. Furthermore, we identify contributions of an additional initiation factor, eIF4A, in JUN regulation. We show that enhancing the interaction of eIF4A with JUN by using the compound Rocaglamide A (RocA) represses JUN translation. We also find that both the upstream AUG (uAUG) and the main AUG (mAUG) contribute to JUN translation and that they are conserved throughout vertebrates. Our results reveal additional layers of regulation for JUN translation and show the potential of JUN as a model transcript for understanding multiple interacting modes of translation regulation.
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Affiliation(s)
| | - Eimy A Castellanos-Silva
- University of California, Davis, Department of Biochemistry and Molecular Biology, Davis, CA, USA
| | - Gabriela Díaz-Figueroa
- University of California, Berkeley, Department of Molecular and Cell Biology, Berkeley, CA, USA
| | - Jamie H D Cate
- University of California, Berkeley, Department of Molecular and Cell Biology, Berkeley, CA, USA
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7
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Shin S, Han MJ, Jedrychowski MP, Zhang Z, Shokat KM, Plas DR, Dephoure N, Yoon SO. mTOR inhibition reprograms cellular proteostasis by regulating eIF3D-mediated selective mRNA translation and promotes cell phenotype switching. Cell Rep 2023; 42:112868. [PMID: 37494188 PMCID: PMC10528759 DOI: 10.1016/j.celrep.2023.112868] [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: 12/05/2022] [Revised: 05/31/2023] [Accepted: 07/11/2023] [Indexed: 07/28/2023] Open
Abstract
Cells maintain and dynamically change their proteomes according to the environment and their needs. Mechanistic target of rapamycin (mTOR) is a key regulator of proteostasis, homeostasis of the proteome. Thus, dysregulation of mTOR leads to changes in proteostasis and the consequent progression of diseases, including cancer. Based on the physiological and clinical importance of mTOR signaling, we investigated mTOR feedback signaling, proteostasis, and cell fate. Here, we reveal that mTOR targeting inhibits eIF4E-mediated cap-dependent translation, but feedback signaling activates a translation initiation factor, eukaryotic translation initiation factor 3D (eIF3D), to sustain alternative non-canonical translation mechanisms. Importantly, eIF3D-mediated protein synthesis enables cell phenotype switching from proliferative to more migratory. eIF3D cooperates with mRNA-binding proteins such as heterogeneous nuclear ribonucleoprotein F (hnRNPF), heterogeneous nuclear ribonucleoprotein K (hnRNPK), and Sjogren syndrome antigen B (SSB) to support selective mRNA translation following mTOR inhibition, which upregulates and activates proteins involved in insulin receptor (INSR)/insulin-like growth factor 1 receptor (IGF1R)/insulin receptor substrate (IRS) and interleukin 6 signal transducer (IL-6ST)/Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling. Our study highlights the mechanisms by which cells establish the dynamic change of proteostasis and the resulting phenotype switch.
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Affiliation(s)
- Sejeong Shin
- Department of Physiology and Biophysics, University of Illinois College of Medicine at Chicago, Chicago, IL 60612, USA
| | - Min-Joon Han
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | | - Ziyang Zhang
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA
| | - David R Plas
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Noah Dephoure
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10021, USA
| | - Sang-Oh Yoon
- Department of Physiology and Biophysics, University of Illinois College of Medicine at Chicago, Chicago, IL 60612, USA.
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8
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Sherlock ME, Baquero Galvis L, Vicens Q, Kieft JS, Jagannathan S. Principles, mechanisms, and biological implications of translation termination-reinitiation. RNA (NEW YORK, N.Y.) 2023; 29:865-884. [PMID: 37024263 PMCID: PMC10275272 DOI: 10.1261/rna.079375.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/28/2023] [Indexed: 06/11/2023]
Abstract
The gene expression pathway from DNA sequence to functional protein is not as straightforward as simple depictions of the central dogma might suggest. Each step is highly regulated, with complex and only partially understood molecular mechanisms at play. Translation is one step where the "one gene-one protein" paradigm breaks down, as often a single mature eukaryotic mRNA leads to more than one protein product. One way this occurs is through translation reinitiation, in which a ribosome starts making protein from one initiation site, translates until it terminates at a stop codon, but then escapes normal recycling steps and subsequently reinitiates at a different downstream site. This process is now recognized as both important and widespread, but we are only beginning to understand the interplay of factors involved in termination, recycling, and initiation that cause reinitiation events. There appear to be several ways to subvert recycling to achieve productive reinitiation, different types of stresses or signals that trigger this process, and the mechanism may depend in part on where the event occurs in the body of an mRNA. This perspective reviews the unique characteristics and mechanisms of reinitiation events, highlights the similarities and differences between three major scenarios of reinitiation, and raises outstanding questions that are promising avenues for future research.
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Affiliation(s)
- Madeline E Sherlock
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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9
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Bose P, Baron N, Pullaiahgari D, Ben-Zvi A, Shapira M. LeishIF3d is a non-canonical cap-binding protein in Leishmania. Front Mol Biosci 2023; 10:1191934. [PMID: 37325473 PMCID: PMC10266417 DOI: 10.3389/fmolb.2023.1191934] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/15/2023] [Indexed: 06/17/2023] Open
Abstract
Translation of most cellular mRNAs in eukaryotes proceeds through a cap-dependent pathway, whereby the cap-binding complex, eIF4F, anchors the pre-initiation complex at the 5' end of mRNAs driving translation initiation. The genome of Leishmania encodes a large repertoire of cap-binding complexes that fulfill a variety of functions possibly involved in survival along the life cycle. However, most of these complexes function in the promastigote life form that resides in the sand fly vector and decrease their activity in amastigotes, the mammalian life form. Here we examined the possibility that LeishIF3d drives translation in Leishmania using alternative pathways. We describe a non-canonical cap-binding activity of LeishIF3d and examine its potential role in driving translation. LeishIF3d is required for translation, as reducing its expression by a hemizygous deletion reduces the translation activity of the LeishIF3d(+/-) mutant cells. Proteomic analysis of the mutant cells highlights the reduced expression of flagellar and cytoskeletal proteins, as reflected in the morphological changes observed in the mutant cells. Targeted mutations in two predicted alpha helices diminish the cap-binding activity of LeishIF3d. Overall, LeishIF3d could serve as a driving force for alternative translation pathways, although it does not seem to offer an alternative pathway for translation in amastigotes.
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Affiliation(s)
- Priyanka Bose
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Nofar Baron
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | | | - Anat Ben-Zvi
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Michal Shapira
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
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10
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Anisimova AS, Kolyupanova NM, Makarova NE, Egorov AA, Kulakovskiy IV, Dmitriev SE. Human Tissues Exhibit Diverse Composition of Translation Machinery. Int J Mol Sci 2023; 24:ijms24098361. [PMID: 37176068 PMCID: PMC10179197 DOI: 10.3390/ijms24098361] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 04/26/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
While protein synthesis is vital for the majority of cell types of the human body, diversely differentiated cells require specific translation regulation. This suggests the specialization of translation machinery across tissues and organs. Using transcriptomic data from GTEx, FANTOM, and Gene Atlas, we systematically explored the abundance of transcripts encoding translation factors and aminoacyl-tRNA synthetases (ARSases) in human tissues. We revised a few known and identified several novel translation-related genes exhibiting strict tissue-specific expression. The proteins they encode include eEF1A1, eEF1A2, PABPC1L, PABPC3, eIF1B, eIF4E1B, eIF4ENIF1, and eIF5AL1. Furthermore, our analysis revealed a pervasive tissue-specific relative abundance of translation machinery components (e.g., PABP and eRF3 paralogs, eIF2B and eIF3 subunits, eIF5MPs, and some ARSases), suggesting presumptive variance in the composition of translation initiation, elongation, and termination complexes. These conclusions were largely confirmed by the analysis of proteomic data. Finally, we paid attention to sexual dimorphism in the repertoire of translation factors encoded in sex chromosomes (eIF1A, eIF2γ, and DDX3), and identified the testis and brain as organs with the most diverged expression of translation-associated genes.
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Affiliation(s)
- Aleksandra S Anisimova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Natalia M Kolyupanova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Nadezhda E Makarova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Artyom A Egorov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Ivan V Kulakovskiy
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 117971 Moscow, Russia
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia
- Laboratory of Regulatory Genomics, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008 Kazan, Russia
| | - Sergey E Dmitriev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
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11
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Ma S, Liu JY, Zhang JT. eIF3d: A driver of noncanonical cap-dependent translation of specific mRNAs and a trigger of biological/pathological processes. J Biol Chem 2023; 299:104658. [PMID: 36997088 PMCID: PMC10165153 DOI: 10.1016/j.jbc.2023.104658] [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: 09/01/2022] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/31/2023] Open
Abstract
Eukaryotic initiation factor 3d (eIF3d), a known RNA-binding subunit of the eIF3 complex, is a 66 to 68-kDa protein with an RNA-binding motif and a cap-binding domain. Compared with other eIF3 subunits, eIF3d is relatively understudied. However, recent progress in studying eIF3d has revealed a number of intriguing findings on its role in maintaining eIF3 complex integrity, global protein synthesis, and in biological and pathological processes. It has also been reported that eIF3d has noncanonical functions in regulating translation of a subset of mRNAs by binding to 5'-UTRs or interacting with other proteins independent of the eIF3 complex and additional functions in regulating protein stability. The noncanonical regulation of mRNA translation or protein stability may contribute to the role of eIF3d in biological processes such as metabolic stress adaptation and in disease onset and progression including severe acute respiratory syndrome coronavirus 2 infection, tumorigenesis, and acquired immune deficiency syndrome. In this review, we critically evaluate the recent studies on these aspects of eIF3d and assess prospects in understanding the function of eIF3d in regulating protein synthesis and in biological and pathological processes.
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Affiliation(s)
- Shijie Ma
- Department of Cell and Cancer Biology, The University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Jing-Yuan Liu
- Department of Medicine, The University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Jian-Ting Zhang
- Department of Cell and Cancer Biology, The University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA.
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12
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Wang Z, Zhong Z, Jiang Z, Chen Z, Chen Y, Xu Y. A novel prognostic 7-methylguanosine signature reflects immune microenvironment and alternative splicing in glioma based on multi-omics analysis. Front Cell Dev Biol 2022; 10:902394. [PMID: 36036011 PMCID: PMC9399734 DOI: 10.3389/fcell.2022.902394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/15/2022] [Indexed: 02/05/2023] Open
Abstract
Glioma is the most common type of central nervous system tumor with increasing incidence. 7-methylguanosine (m7G) is one of the diverse RNA modifications that is known to regulate RNA metabolism and its dysregulation was associated with various cancers. However, the expression pattern of m7G regulators and their roles in regulating tumor immune microenvironments (TIMEs) as well as alternative splicing events (ASEs) in glioma has not been reported. In this study, we showed that m7G regulators displayed a close correlation with each other and most of them were differentially expressed between normal and glioma tissues. Two m7G signatures were then constructed to predict the overall survival of both GBM and LGG patients with moderate predictive performance. The risk score calculated from the regression coefficient and expression level of signature genes was proved to be an independent prognostic factor for patients with LGG, thus, a nomogram was established on the risk score and other independent clinical parameters to predict the survival probability of LGG patients. We also investigated the correlation of m7G signatures with TIMEs in terms of immune scores, expression levels of HLA and immune checkpoint genes, immune cell composition, and immune-related functions. While exploring the correlation between signature genes and the ASEs in glioma, we found that EIF4E1B was a key regulator and might play dual roles depending on glioma grade. By incorporating spatial transcriptomic data, we found a cluster of cells featured by high expression of PTN exhibited the highest m7G score and may communicate with adjacent cancer cells via SPP1 and PTN signaling pathways. In conclusion, our work brought novel insights into the roles of m7G modification in TIMEs and ASEs in glioma, suggesting that evaluation of m7G in glioma could predict prognosis. Moreover, our data suggested that blocking SPP1 and PTN pathways might be a strategy for combating glioma.
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Affiliation(s)
- Zihan Wang
- Department of Neurosurgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- Shantou University Medical College, Shantou, China
| | - Zhiwei Zhong
- Department of Neurosurgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- Shantou University Medical College, Shantou, China
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Zehua Jiang
- Shantou University Medical College, Shantou, China
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - Zepeng Chen
- Department of Neurosurgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- Shantou University Medical College, Shantou, China
| | - Yuequn Chen
- Department of Neurosurgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
- Shantou University Medical College, Shantou, China
| | - Yimin Xu
- Department of Neurosurgery, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
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13
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Baud A, Derbis M, Tutak K, Sobczak K. Partners in crime: Proteins implicated in
RNA
repeat expansion diseases. WIRES RNA 2022; 13:e1709. [PMID: 35229468 PMCID: PMC9539487 DOI: 10.1002/wrna.1709] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Anna Baud
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Magdalena Derbis
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Katarzyna Tutak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Krzysztof Sobczak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
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14
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An eIF3d-dependent switch regulates HCMV replication by remodeling the infected cell translation landscape to mimic chronic ER stress. Cell Rep 2022; 39:110767. [PMID: 35508137 PMCID: PMC9127984 DOI: 10.1016/j.celrep.2022.110767] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 02/07/2022] [Accepted: 04/11/2022] [Indexed: 11/20/2022] Open
Abstract
Regulated loading of eIF3-bound 40S ribosomes on capped mRNA is generally dependent upon the translation initiation factor eIF4E; however, mRNA translation often proceeds during physiological stress, such as virus infection, when eIF4E availability and activity are limiting. It remains poorly understood how translation of virus and host mRNAs are regulated during infection stress. While initially sensitive to mTOR inhibition, which limits eIF4E-dependent translation, we show that protein synthesis in human cytomegalovirus (HCMV)-infected cells unexpectedly becomes progressively reliant upon eIF3d. Targeting eIF3d selectively inhibits HCMV replication, reduces polyribosome abundance, and interferes with expression of essential virus genes and a host gene expression signature indicative of chronic ER stress that fosters HCMV reproduction. This reveals a strategy whereby cellular eIF3d-dependent protein production is hijacked to exploit virus-induced ER stress. Moreover, it establishes how switching between eIF4E and eIF3d-responsive cap-dependent translation can differentially tune virus and host gene expression in infected cells. Instead of eIF4E-regulated ribosome loading, Thompson et al. show capped mRNA translation in HCMV-infected cells becomes reliant upon eIF3d. Depleting eIF3d inhibits HCMV replication, reduces polyribosomes, and restricts virus late gene and host chronic ER stress-induced gene expression. Thus, switching to eIF3d-responsive translation tunes gene expression to support virus replication.
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15
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Chen C, Zhang X, Wang Y, Chen X, Chen W, Dan S, She S, Hu W, Dai J, Hu J, Cao Q, Liu Q, Huang Y, Qin B, Kang B, Wang YJ. Translational and post-translational control of human naïve versus primed pluripotency. iScience 2022; 25:103645. [PMID: 35005567 PMCID: PMC8718978 DOI: 10.1016/j.isci.2021.103645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 10/22/2021] [Accepted: 12/10/2021] [Indexed: 01/05/2023] Open
Abstract
Deciphering the regulatory network for human naive and primed pluripotency is of fundamental theoretical and applicable significance. Here, by combining quantitative proteomics, phosphoproteomics, and acetylproteomics analyses, we revealed RNA processing and translation as the most differentially regulated processes between naive and primed human embryonic stem cells (hESCs). Although glycolytic primed hESCs rely predominantly on the eukaryotic initiation factor 4E (eIF4E)-mediated cap-dependent pathway for protein translation, naive hESCs with reduced mammalian target of rapamycin complex (mTORC1) activity are more tolerant to eIF4E inhibition, and their bivalent metabolism allows for translating selective mRNAs via both eIF4E-dependent and eIF4E-independent/eIF4A2-dependent pathways to form a more compact naive proteome. Globally up-regulated proteostasis and down-regulated post-translational modifications help to further refine the naive proteome that is compatible with the more rapid cycling of naive hESCs, where CDK1 plays an indispensable coordinative role. These findings may assist in better understanding the unrestricted lineage potential of naive hESCs and in further optimizing conditions for future clinical applications RNA processing and translation are most different between naive and primed hESCs Glycolytic primed hESCs mainly rely on eIF4E-dependent translation Bivalent metabolism in naive hESCs promotes eIF4E-independent translation CDK1 is required for naive pluripotency partially by activating E-cadherin signaling
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Affiliation(s)
- Cheng Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China.,Shaoxing People's Hospital, Shaoxing Hospital, Zhejiang University School of Medicine, Shaoxing, Zhejiang 312000, China
| | - Xiaobing Zhang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Yisha Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Xinyu Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Wenjie Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Songsong Dan
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Shiqi She
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China.,Zhejiang Museum of Natural History, Hangzhou, Zhejiang 310014, China
| | - Weiwei Hu
- Shanghai Bioprofile Technology Co., Ltd., Shanghai 200241, China
| | - Jie Dai
- Shanghai Bioprofile Technology Co., Ltd., Shanghai 200241, China
| | - Jianwen Hu
- Shanghai Bioprofile Technology Co., Ltd., Shanghai 200241, China
| | - Qingyi Cao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Qianyu Liu
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yinghua Huang
- Laboratory of Metabolism and Cell Fate, Center for Cell Lineage and Development, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Baoming Qin
- Laboratory of Metabolism and Cell Fate, Center for Cell Lineage and Development, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Bo Kang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Ying-Jie Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China.,Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China
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16
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Yuan S, Balaji S, Lomakin IB, Xiong Y. Coronavirus Nsp1: Immune Response Suppression and Protein Expression Inhibition. Front Microbiol 2021; 12:752214. [PMID: 34659188 PMCID: PMC8512706 DOI: 10.3389/fmicb.2021.752214] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/24/2021] [Indexed: 12/30/2022] Open
Abstract
Coronaviruses have brought severe challenges to public health all over the world in the past 20years. SARS-CoV-2, the causative agent of the COVID-19 pandemic that has led to millions of deaths, belongs to the genus beta-coronavirus. Alpha- and beta-coronaviruses encode a unique protein, nonstructural protein 1 (Nsp1) that both suppresses host immune responses and reduces global gene expression levels in the host cells. As a key pathogenicity factor of coronaviruses, Nsp1 redirects the host translation machinery to increase synthesis of viral proteins. Through multiple mechanisms, coronaviruses impede host protein expression through Nsp1, while escaping inhibition to allow the translation of viral RNA. In this review, we discuss current data about suppression of the immune responses and inhibition of protein synthesis induced by coronavirus Nsp1, as well as the prospect of live-attenuated vaccine development with virulence-attenuated viruses with mutations in Nsp1.
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Affiliation(s)
- Shuai Yuan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Shravani Balaji
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Ivan B Lomakin
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, United States
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
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17
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Blazie SM, Takayanagi-Kiya S, McCulloch KA, Jin Y. Eukaryotic initiation factor EIF-3.G augments mRNA translation efficiency to regulate neuronal activity. eLife 2021; 10:68336. [PMID: 34323215 PMCID: PMC8354637 DOI: 10.7554/elife.68336] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/28/2021] [Indexed: 11/18/2022] Open
Abstract
The translation initiation complex eIF3 imparts specialized functions to regulate protein expression. However, understanding of eIF3 activities in neurons remains limited despite widespread dysregulation of eIF3 subunits in neurological disorders. Here, we report a selective role of the C. elegans RNA-binding subunit EIF-3.G in shaping the neuronal protein landscape. We identify a missense mutation in the conserved Zinc-Finger (ZF) of EIF-3.G that acts in a gain-of-function manner to dampen neuronal hyperexcitation. Using neuron-type-specific seCLIP, we systematically mapped EIF-3.G-mRNA interactions and identified EIF-3.G occupancy on GC-rich 5′UTRs of a select set of mRNAs enriched in activity-dependent functions. We demonstrate that the ZF mutation in EIF-3.G alters translation in a 5′UTR-dependent manner. Our study reveals an in vivo mechanism for eIF3 in governing neuronal protein levels to control neuronal activity states and offers insights into how eIF3 dysregulation contributes to neurological disorders.
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Affiliation(s)
- Stephen M Blazie
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, United States
| | - Seika Takayanagi-Kiya
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, United States
| | - Katherine A McCulloch
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, United States
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, United States
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18
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Lee Y, Kim J, Kim MS, Kwon Y, Shin S, Yi H, Kim H, Chang MJ, Chang CB, Kang SB, Kim VN, Kim JH, Kim JS, Elledge SJ, Kang C. Coordinate regulation of the senescent state by selective autophagy. Dev Cell 2021; 56:1512-1525.e7. [PMID: 33915088 DOI: 10.1016/j.devcel.2021.04.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 02/05/2021] [Accepted: 04/05/2021] [Indexed: 01/10/2023]
Abstract
Cellular senescence is a complex stress response implicated in aging. Autophagy can suppress senescence but is counterintuitively necessary for full senescence. Although its anti-senescence role is well described, to what extent autophagy contributes to senescence establishment and the underlying mechanisms is poorly understood. Here, we show that selective autophagy of multiple regulatory components coordinates the homeostatic state of senescence. We combined a proteomic analysis of autophagy components with protein stability profiling, identifying autophagy substrate proteins involved in several senescence-related processes. Selective autophagy of KEAP1 promoted redox homeostasis during senescence. Furthermore, selective autophagy limited translational machinery components to ameliorate senescence-associated proteotoxic stress. Lastly, selective autophagy of TNIP1 enhanced senescence-associated inflammation. These selective autophagy networks appear to operate in vivo senescence during human osteoarthritis. Our data highlight a caretaker role of autophagy in the stress support network of senescence through regulated protein stability and unravel the intertwined relationship between two important age-related processes.
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Affiliation(s)
- Yeonghyeon Lee
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Jaejin Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Mi-Sung Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Yoojin Kwon
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Sanghee Shin
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea; Center for RNA Research, Institute of Basic Science, Seoul 08826, South Korea
| | - Hyerim Yi
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea; Center for RNA Research, Institute of Basic Science, Seoul 08826, South Korea
| | - Hyeonkyeong Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea; Center for RNA Research, Institute of Basic Science, Seoul 08826, South Korea
| | - Moon Jong Chang
- Department of Orthopedic Surgery, Seoul National University College of Medicine, Boramae Hospital, Seoul 07061, South Korea
| | - Chong Bum Chang
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam 13620, South Korea
| | - Seung-Baik Kang
- Department of Orthopedic Surgery, Seoul National University College of Medicine, Boramae Hospital, Seoul 07061, South Korea
| | - V Narry Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea; Center for RNA Research, Institute of Basic Science, Seoul 08826, South Korea
| | - Jin-Hong Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea; Center for RNA Research, Institute of Basic Science, Seoul 08826, South Korea
| | - Jong-Seo Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea; Center for RNA Research, Institute of Basic Science, Seoul 08826, South Korea
| | - Stephen J Elledge
- Department of Genetics, Harvard Medical School and Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Boston, MA 02115, USA
| | - Chanhee Kang
- School of Biological Sciences, Seoul National University, Seoul 08826, South Korea.
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19
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Morris C, Durand S, Jalinot P. Decreased expression of the translation factor eIF3e induces senescence in breast cancer cells via suppression of PARP1 and activation of mTORC1. Oncotarget 2021; 12:649-664. [PMID: 33868586 PMCID: PMC8021025 DOI: 10.18632/oncotarget.27923] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 03/08/2021] [Indexed: 12/28/2022] Open
Abstract
Altered expression of the translation factor eIF3e is associated with breast cancer occurrence. We have previously shown that eIF3e deficiency leads to an impaired DNA damage response with a marked decrease in DNA repair by homologous recombination. Here, we explored the possibility to exploit this DNA repair defect in targeted cancer therapy using PARP inhibitors. Surprisingly, eIF3e-deficient breast cancer cells are resistant to these drugs, in contrast to BRCA1-deficient cells. Studying this, we found that eIF3e-depleted cells synthesize lowered amounts of PARP1 protein, due to a weakened translation of the corresponding mRNA, associated with a strong decrease in cellular poly(ADP-ribosyl)ation. Additionally, we discovered that the mTORC1 signaling pathway is aberrantly activated in response to eIF3e suppression. Together, these PARP1 and mTORC1 dysfunctions upon eIF3e depletion are causally linked to induction of cellular senescence associated with a pro-inflammatory secretory phenotype. This study provides mechanistic insights into how eIF3e protects against breast cancer, with potential novel cancer therapeutic opportunities. While PARP inhibitors appear as inappropriate drugs for eIF3e-deficient breast tumors, our findings suggest that such cancers may benefit from senolytic drugs or mTORC1 inhibitors.
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Affiliation(s)
- Christelle Morris
- University Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5239, INSERM U1210, LBMC, Lyon, France
| | - Sébastien Durand
- University Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5239, INSERM U1210, LBMC, Lyon, France.,University Lyon, Cancer Research Center of Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS UMR 5286, Centre Léon Bérard, Cancer Cell Plasticity Department, Equipe 'Transcriptome Diversity in Stem Cells', Lyon, France
| | - Pierre Jalinot
- University Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5239, INSERM U1210, LBMC, Lyon, France
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20
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Vo DK, Engler A, Stoimenovski D, Hartig R, Kaehne T, Kalinski T, Naumann M, Haybaeck J, Nass N. Interactome Mapping of eIF3A in a Colon Cancer and an Immortalized Embryonic Cell Line Using Proximity-Dependent Biotin Identification. Cancers (Basel) 2021; 13:cancers13061293. [PMID: 33799492 PMCID: PMC7999522 DOI: 10.3390/cancers13061293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 12/12/2022] Open
Abstract
Translation initiation comprises complex interactions of eukaryotic initiation factor (eIF) subunits and the structural elements of the mRNAs. Translation initiation is a key process for building the cell's proteome. It not only determines the total amount of protein synthesized but also controls the translation efficiency for individual transcripts, which is important for cancer or ageing. Thus, understanding protein interactions during translation initiation is one key that contributes to understanding how the eIF subunit composition influences translation or other pathways not yet attributed to eIFs. We applied the BioID technique to two rapidly dividing cell lines (the immortalized embryonic cell line HEK-293T and the colon carcinoma cell line HCT-166) in order to identify interacting proteins of eIF3A, a core subunit of the eukaryotic initiation factor 3 complex. We identified a total of 84 interacting proteins, with very few proteins being specific to one cell line. When protein biosynthesis was blocked by thapsigargin-induced endoplasmic reticulum (ER) stress, the interacting proteins were considerably smaller in number. In terms of gene ontology, although eIF3A interactors are mainly part of the translation machinery, protein folding and RNA binding were also found. Cells suffering from ER-stress show a few remaining interactors which are mainly ribosomal proteins or involved in RNA-binding.
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Affiliation(s)
- Diep-Khanh Vo
- Department of Pathology, Medical Faculty, Otto-von-Guericke University Magdeburg, D-39120 Magdeburg, Germany; (D.-K.V.); (D.S.); (T.K.); (J.H.)
| | - Alexander Engler
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, D-39120 Magdeburg, Germany; (A.E.); (T.K.); (M.N.)
| | - Darko Stoimenovski
- Department of Pathology, Medical Faculty, Otto-von-Guericke University Magdeburg, D-39120 Magdeburg, Germany; (D.-K.V.); (D.S.); (T.K.); (J.H.)
| | - Roland Hartig
- Institute of Molecular and Clinical Immunology, Otto von Guericke University Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany;
| | - Thilo Kaehne
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, D-39120 Magdeburg, Germany; (A.E.); (T.K.); (M.N.)
| | - Thomas Kalinski
- Department of Pathology, Medical Faculty, Otto-von-Guericke University Magdeburg, D-39120 Magdeburg, Germany; (D.-K.V.); (D.S.); (T.K.); (J.H.)
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, D-39120 Magdeburg, Germany; (A.E.); (T.K.); (M.N.)
| | - Johannes Haybaeck
- Department of Pathology, Medical Faculty, Otto-von-Guericke University Magdeburg, D-39120 Magdeburg, Germany; (D.-K.V.); (D.S.); (T.K.); (J.H.)
- Department of Pathology, Neuropathology, and Molecular Pathology, Medical University of Innsbruck, A-6020 Innsbruck, Austria
- Department of Pathology, Diagnostic & Research Center for Molecular BioMedicine, Institute of Pathology, Medical University of Graz, A-8010 Graz, Austria
- Center for Biomarker Research in Medicine, A-8010 Graz, Austria
| | - Norbert Nass
- Department of Pathology, Medical Faculty, Otto-von-Guericke University Magdeburg, D-39120 Magdeburg, Germany; (D.-K.V.); (D.S.); (T.K.); (J.H.)
- Correspondence:
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21
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Liu X, Xiang D, Xu C, Chai R. EIF3m promotes the malignant phenotype of lung adenocarcinoma by the up-regulation of oncogene CAPRIN1. Am J Cancer Res 2021; 11:979-996. [PMID: 33791168 PMCID: PMC7994172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/29/2020] [Indexed: 06/12/2023] Open
Abstract
EIF3m is the latest identified subunit of the eukaryotic translation initiation factor 3 (eIF3), however, its function in malignant tumor is rarely reported. In the current work, we observed that EIF3m was aberrant over-expressed in lung adenocarcinoma (LADC) tissues and cell lines, and the increased EIF3m level was closely related to the poor clinical outcomes of the LADC patients. The gain- and loss-of-function assays demonstrated the proto-oncogenetic potential of EIF3m in vitro and in vivo. EIF3m induced-malignant phenotype was partly mediated by the up-regulation of CAPRIN1. The biochemical analysis showed that EIF3m could bind to the 5'UTR of CAPRIN1 and positively modulate its expression at the post-transcription level. Furthermore, we identified the interaction between EIF3m and the deubiquitinase UCHL5, which stabilized and promoted the accumulation of EIF3m in LADC cells. In summary, our findings extended the knowledge about the EIF3m function and highlight the roles of the UCHL5/EIF3m/CAPRIN1 axis during the progression of LADC.
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Affiliation(s)
- Xinwei Liu
- Department of Orthopaedics, The General Hospital of Northern Theater CommandShenyang 110016, People’s Republic of China
- Laboratory of Respiratory and Critical Care Medicine, The General Hospital of Northern Theater CommandShenyang 110016, People’s Republic of China
| | - Dulei Xiang
- Laboratory of Respiratory and Critical Care Medicine, The General Hospital of Northern Theater CommandShenyang 110016, People’s Republic of China
- Graduate Schools, Jinzhou Medical UniversityJinzhou 121001, People’s Republic of China
| | - Chong Xu
- Graduate Schools, Jinzhou Medical UniversityJinzhou 121001, People’s Republic of China
- Department of Respiratory Medicine, The General Hospital of Northern Theater CommandShenyang 110016, People’s Republic of China
| | - Ruonan Chai
- Department of Respiratory Medicine, The General Hospital of Northern Theater CommandShenyang 110016, People’s Republic of China
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22
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Jin Y, Manabe T. Visualized heterooligomeric subunit structures of 817 human cellular proteins by correlating native protein 2D maps with protein interaction databases. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1163:122509. [PMID: 33418243 DOI: 10.1016/j.jchromb.2020.122509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 11/17/2022]
Abstract
Previously, we have reported on the reconstruction of 4323 native protein 2D maps of human bronchial smooth muscle cells (HBSMC) by combining nondenaturing 2DE, grid gel-cutting, and quantitative LC-MS/MS. In this work, we report on the visualization of the heterooligomeric subunit structures of HBSMC proteins by correlating the native protein 2D maps with the information in protein interaction databases. Image analysis of the 2D maps was employed as the first approach. Each of the native protein 2D maps of 2327 proteins, which had three or more detected squares in the native protein 2D maps, was compared with the 2D maps of the remaining 2326 proteins scoring the degree of overlap in an area around the quantity peak and the protein partner which showed the best score was decided. The protein pairs were examined on their reported interactions referring to protein interaction databases. In order to consider the cases where a protein has multiple functions and the heterooligomeric subunit structures might not be detected from the image analysis, prior database search was employed as the second approach. Each of the 1689 HBSMC proteins, which had five or more detected squares in the native protein 2D maps, was examined on its interactor proteins described in the databases, then the native 2D map was compared with the maps of the interactor proteins to find the overlap which reasonably supported the interaction. Summarizing these examinations, 215 heterooligomeric subunit structures of 817 human cellular proteins could be visualized on the native protein 2D maps.
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Affiliation(s)
- Ya Jin
- Institute of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong 510006, China.
| | - Takashi Manabe
- Faculty of Science, Ehime University, 2-5 Bunkyo-cho, Matsuyama City 790-0825, Japan.
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23
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Hayek H, Gross L, Janvier A, Schaeffer L, Martin F, Eriani G, Allmang C. eIF3 interacts with histone H4 messenger RNA to regulate its translation. J Biol Chem 2021; 296:100578. [PMID: 33766559 PMCID: PMC8102920 DOI: 10.1016/j.jbc.2021.100578] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/15/2021] [Accepted: 03/21/2021] [Indexed: 11/23/2022] Open
Abstract
In eukaryotes, various alternative translation initiation mechanisms have been unveiled for the translation of specific mRNAs. Some do not conform to the conventional scanning-initiation model. Translation initiation of histone H4 mRNA combines both canonical (cap-dependent) and viral initiation strategies (no-scanning, internal recruitment of initiation factors). Specific H4 mRNA structures tether the translation machinery directly onto the initiation codon and allow massive production of histone H4 during the S phase of the cell cycle. The human eukaryotic translation initiation factor 3 (eIF3), composed of 13 subunits (a-m), was shown to selectively recruit and control the expression of several cellular mRNAs. Whether eIF3 mediates H4 mRNA translation remains to be elucidated. Here, we report that eIF3 binds to a stem-loop structure (eIF3-BS) located in the coding region of H4 mRNA. Combining cross-linking and ribonucleoprotein immunoprecipitation experiments in vivo and in vitro, we also found that eIF3 binds to H1, H2A, H2B, and H3 histone mRNAs. We identified direct contacts between eIF3c, d, e, g subunits, and histone mRNAs but observed distinct interaction patterns to each histone mRNA. Our results show that eIF3 depletion in vivo reduces histone mRNA binding and modulates histone neosynthesis, suggesting that synthesis of histones is sensitive to the levels of eIF3. Thus, we provide evidence that eIF3 acts as a regulator of histone translation.
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Affiliation(s)
- Hassan Hayek
- Architecture et Réactivité de l'ARN, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Lauriane Gross
- Architecture et Réactivité de l'ARN, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Aurélie Janvier
- Architecture et Réactivité de l'ARN, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Laure Schaeffer
- Architecture et Réactivité de l'ARN, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Franck Martin
- Architecture et Réactivité de l'ARN, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Gilbert Eriani
- Architecture et Réactivité de l'ARN, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France.
| | - Christine Allmang
- Architecture et Réactivité de l'ARN, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France.
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24
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Yuan S, Peng L, Park JJ, Hu Y, Devarkar SC, Dong MB, Shen Q, Wu S, Chen S, Lomakin IB, Xiong Y. Nonstructural Protein 1 of SARS-CoV-2 Is a Potent Pathogenicity Factor Redirecting Host Protein Synthesis Machinery toward Viral RNA. Mol Cell 2020. [PMID: 33188728 DOI: 10.1101/2020.08.09.243451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The causative virus of the COVID-19 pandemic, SARS-CoV-2, uses its nonstructural protein 1 (Nsp1) to suppress cellular, but not viral, protein synthesis through yet unknown mechanisms. We show here that among all viral proteins, Nsp1 has the largest impact on host viability in the cells of human lung origin. Differential expression analysis of mRNA-seq data revealed that Nsp1 broadly alters the cellular transcriptome. Our cryo-EM structure of the Nsp1-40S ribosome complex shows that Nsp1 inhibits translation by plugging the mRNA entry channel of the 40S. We also determined the structure of the 48S preinitiation complex formed by Nsp1, 40S, and the cricket paralysis virus internal ribosome entry site (IRES) RNA, which shows that it is nonfunctional because of the incorrect position of the mRNA 3' region. Our results elucidate the mechanism of host translation inhibition by SARS-CoV-2 and advance understanding of the impacts from a major pathogenicity factor of SARS-CoV-2.
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MESH Headings
- Animals
- COVID-19/genetics
- COVID-19/metabolism
- COVID-19/pathology
- Chlorocebus aethiops
- Cryoelectron Microscopy
- Humans
- Protein Biosynthesis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Ribosome Subunits, Small, Eukaryotic/ultrastructure
- Ribosome Subunits, Small, Eukaryotic/virology
- SARS-CoV-2/genetics
- SARS-CoV-2/metabolism
- SARS-CoV-2/pathogenicity
- SARS-CoV-2/ultrastructure
- Vero Cells
- Viral Nonstructural Proteins/genetics
- Viral Nonstructural Proteins/metabolism
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Affiliation(s)
- Shuai Yuan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Lei Peng
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Jonathan J Park
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Yingxia Hu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Swapnil C Devarkar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Matthew B Dong
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Qi Shen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Shenping Wu
- Department of Pharmacology, Yale University, West Haven, CT 06516, USA
| | - Sidi Chen
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA.
| | - Ivan B Lomakin
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA.
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25
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Kratzat H, Mackens-Kiani T, Ameismeier M, Potocnjak M, Cheng J, Dacheux E, Namane A, Berninghausen O, Herzog F, Fromont-Racine M, Becker T, Beckmann R. A structural inventory of native ribosomal ABCE1-43S pre-initiation complexes. EMBO J 2020; 40:e105179. [PMID: 33289941 PMCID: PMC7780240 DOI: 10.15252/embj.2020105179] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 09/21/2020] [Accepted: 09/29/2020] [Indexed: 11/24/2022] Open
Abstract
In eukaryotic translation, termination and ribosome recycling phases are linked to subsequent initiation of a new round of translation by persistence of several factors at ribosomal sub‐complexes. These comprise/include the large eIF3 complex, eIF3j (Hcr1 in yeast) and the ATP‐binding cassette protein ABCE1 (Rli1 in yeast). The ATPase is mainly active as a recycling factor, but it can remain bound to the dissociated 40S subunit until formation of the next 43S pre‐initiation complexes. However, its functional role and native architectural context remains largely enigmatic. Here, we present an architectural inventory of native yeast and human ABCE1‐containing pre‐initiation complexes by cryo‐EM. We found that ABCE1 was mostly associated with early 43S, but also with later 48S phases of initiation. It adopted a novel hybrid conformation of its nucleotide‐binding domains, while interacting with the N‐terminus of eIF3j. Further, eIF3j occupied the mRNA entry channel via its ultimate C‐terminus providing a structural explanation for its antagonistic role with respect to mRNA binding. Overall, the native human samples provide a near‐complete molecular picture of the architecture and sophisticated interaction network of the 43S‐bound eIF3 complex and the eIF2 ternary complex containing the initiator tRNA.
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Affiliation(s)
- Hanna Kratzat
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Timur Mackens-Kiani
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Michael Ameismeier
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Mia Potocnjak
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Jingdong Cheng
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Estelle Dacheux
- Génétique des Interactions Macromoléculaires, UMR3525 CNRS, Institut Pasteur, Paris, France
| | - Abdelkader Namane
- Génétique des Interactions Macromoléculaires, UMR3525 CNRS, Institut Pasteur, Paris, France
| | - Otto Berninghausen
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Franz Herzog
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | | | - Thomas Becker
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Roland Beckmann
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
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26
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Systematic Investigation of mRNA N 6-Methyladenosine Machinery in Primary Prostate Cancer. DISEASE MARKERS 2020; 2020:8833438. [PMID: 33273988 PMCID: PMC7676945 DOI: 10.1155/2020/8833438] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/27/2020] [Accepted: 10/20/2020] [Indexed: 12/21/2022]
Abstract
Background Appreciable findings have pointed out pivotal roles of N6-methyladenosine (m6A) machinery in cancer onset and progression. However, limited efforts have been directed towards relevant research in the prostate cancer area. Methods A PubMed search was conducted to acquire components of the mRNA m6A machinery. Multiomics integration was performed to systematically investigate the mRNA m6A machinery in primary prostate cancer. Furthermore, RNA interference assays of two prognostic m6A readers EIF3D and HNRNPA2B1 were conducted to explore m6A dependence of their functions in prostate cancer cell proliferation and migration. Results A total of 41 mRNA m6A regulators have been identified to date. A small degree of copy number aberrations and an extremely low frequency of somatic mutations were observed in the regulators across prostate tumors. Enrichment of CpG sites and extensive changes of DNA methylation in the m6A machinery were also found. Impact of copy number variation on m6A regulator expression was stronger than that of DNA methylation disturbance. Furthermore, our study identified a set of m6A regulators related to clinical features and/or survival which were largely m6A-binding proteins. The translation initiation factor subunit EIF3D and the splicing factor HNRNPA2B1 can be independent prognostic factors which may contribute to retardation and promotion of cancer progression, respectively, through affecting cancer-related processes such as cell cycle. Moreover, in vitro assays demonstrated that m6A impacted the EIF3D and HNRNPA2B1 roles in proliferation and migration of prostate cancer cells. Conclusions Our report systematically described molecular features of the mRNA m6A machinery and their potential roles in primary prostate cancer. Knowledge gained from this work may pave the way for further studies on the m6A system in prostate cancer.
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27
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Yuan S, Peng L, Park JJ, Hu Y, Devarkar SC, Dong MB, Shen Q, Wu S, Chen S, Lomakin IB, Xiong Y. Nonstructural Protein 1 of SARS-CoV-2 Is a Potent Pathogenicity Factor Redirecting Host Protein Synthesis Machinery toward Viral RNA. Mol Cell 2020; 80:1055-1066.e6. [PMID: 33188728 PMCID: PMC7833686 DOI: 10.1016/j.molcel.2020.10.034] [Citation(s) in RCA: 124] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/05/2020] [Accepted: 10/22/2020] [Indexed: 12/22/2022]
Abstract
The causative virus of the COVID-19 pandemic, SARS-CoV-2, uses its nonstructural protein 1 (Nsp1) to suppress cellular, but not viral, protein synthesis through yet unknown mechanisms. We show here that among all viral proteins, Nsp1 has the largest impact on host viability in the cells of human lung origin. Differential expression analysis of mRNA-seq data revealed that Nsp1 broadly alters the cellular transcriptome. Our cryo-EM structure of the Nsp1-40S ribosome complex shows that Nsp1 inhibits translation by plugging the mRNA entry channel of the 40S. We also determined the structure of the 48S preinitiation complex formed by Nsp1, 40S, and the cricket paralysis virus internal ribosome entry site (IRES) RNA, which shows that it is nonfunctional because of the incorrect position of the mRNA 3′ region. Our results elucidate the mechanism of host translation inhibition by SARS-CoV-2 and advance understanding of the impacts from a major pathogenicity factor of SARS-CoV-2.
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MESH Headings
- Animals
- COVID-19/genetics
- COVID-19/metabolism
- COVID-19/pathology
- Chlorocebus aethiops
- Cryoelectron Microscopy
- Humans
- Protein Biosynthesis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Ribosome Subunits, Small, Eukaryotic/ultrastructure
- Ribosome Subunits, Small, Eukaryotic/virology
- SARS-CoV-2/genetics
- SARS-CoV-2/metabolism
- SARS-CoV-2/pathogenicity
- SARS-CoV-2/ultrastructure
- Vero Cells
- Viral Nonstructural Proteins/genetics
- Viral Nonstructural Proteins/metabolism
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Affiliation(s)
- Shuai Yuan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Lei Peng
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Jonathan J Park
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Yingxia Hu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Swapnil C Devarkar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Matthew B Dong
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Qi Shen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Shenping Wu
- Department of Pharmacology, Yale University, West Haven, CT 06516, USA
| | - Sidi Chen
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA.
| | - Ivan B Lomakin
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA.
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28
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Translational control in the naked mole-rat as a model highly resistant to cancer. Biochim Biophys Acta Rev Cancer 2020; 1875:188455. [PMID: 33148499 DOI: 10.1016/j.bbcan.2020.188455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/23/2020] [Accepted: 10/15/2020] [Indexed: 12/24/2022]
Abstract
Dysregulation of mRNA translation is involved in the onset and progression of different types of cancer. To gain insight into novel genetic strategies to avoid this malady, we reviewed the available genomic, transcriptomic, and proteomic data about the translational machinery from the naked-mole rat (NMR) Heterocephalus glaber, a new model of study that exhibits high resistance to cancer. The principal features that might confer cancer resistance are 28S rRNA fragmentation, RPL26 and eIF4G overexpression, global downregulation of mTOR pathway, specific amino acid residues in RAPTOR (P908) and RICTOR (V1695), and the absence of 4E-BP3. These features are not only associated with cancer but also might couple longevity and adaptation to hypoxia. We propose that the regulation of translation is among the strategies endowing NMR cancer resistance.
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29
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Wagner S, Herrmannová A, Hronová V, Gunišová S, Sen ND, Hannan RD, Hinnebusch AG, Shirokikh NE, Preiss T, Valášek LS. Selective Translation Complex Profiling Reveals Staged Initiation and Co-translational Assembly of Initiation Factor Complexes. Mol Cell 2020; 79:546-560.e7. [PMID: 32589964 PMCID: PMC7447980 DOI: 10.1016/j.molcel.2020.06.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 04/10/2020] [Accepted: 05/18/2020] [Indexed: 11/25/2022]
Abstract
Translational control targeting the initiation phase is central to the regulation of gene expression. Understanding all of its aspects requires substantial technological advancements. Here we modified yeast translation complex profile sequencing (TCP-seq), related to ribosome profiling, and adapted it for mammalian cells. Human TCP-seq, capable of capturing footprints of 40S subunits (40Ss) in addition to 80S ribosomes (80Ss), revealed that mammalian and yeast 40Ss distribute similarly across 5'TRs, indicating considerable evolutionary conservation. We further developed yeast and human selective TCP-seq (Sel-TCP-seq), enabling selection of 40Ss and 80Ss associated with immuno-targeted factors. Sel-TCP-seq demonstrated that eIF2 and eIF3 travel along 5' UTRs with scanning 40Ss to successively dissociate upon AUG recognition; notably, a proportion of eIF3 lingers on during the initial elongation cycles. Highlighting Sel-TCP-seq versatility, we also identified four initiating 48S conformational intermediates, provided novel insights into ATF4 and GCN4 mRNA translational control, and demonstrated co-translational assembly of initiation factor complexes.
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Affiliation(s)
- Susan Wagner
- EMBL-Australia Collaborating Group, Department of Genome Sciences, John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia; Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic.
| | - Anna Herrmannová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Vladislava Hronová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Stanislava Gunišová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic
| | - Neelam D Sen
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ross D Hannan
- Australian Cancer Research Foundation Department of Cancer Biology and Therapeutics, John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Alan G Hinnebusch
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nikolay E Shirokikh
- EMBL-Australia Collaborating Group, Department of Genome Sciences, John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, John Curtin School of Medical Research, Australian National University, Canberra, ACT 2601, Australia; Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, Czech Republic.
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30
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Wolf DA, Lin Y, Duan H, Cheng Y. eIF-Three to Tango: emerging functions of translation initiation factor eIF3 in protein synthesis and disease. J Mol Cell Biol 2020; 12:403-409. [PMID: 32279082 PMCID: PMC7333474 DOI: 10.1093/jmcb/mjaa018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/20/2020] [Accepted: 02/17/2020] [Indexed: 12/12/2022] Open
Abstract
Studies over the past three years have substantially expanded the involvements of eukaryotic initiation factor 3 (eIF3) in messenger RNA (mRNA) translation. It now appears that this multi-subunit complex is involved in every possible form of mRNA translation, controlling every step of protein synthesis from initiation to elongation, termination, and quality control in positive as well as negative fashion. Through the study of eIF3, we are beginning to appreciate protein synthesis as a highly integrated process coordinating protein production with protein folding, subcellular targeting, and degradation. At the same time, eIF3 subunits appear to have specific functions that probably vary between different tissues and individual cells. Considering the broad functions of eIF3 in protein homeostasis, it comes as little surprise that eIF3 is increasingly implicated in major human diseases and first attempts at therapeutically targeting eIF3 have been undertaken. Much remains to be learned, however, about subunit- and tissue-specific functions of eIF3 in protein synthesis and disease and their regulation by environmental conditions and post-translational modifications.
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Affiliation(s)
- Dieter A Wolf
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research & Innovation Center for Cell Stress Signaling, Xiamen University, Xiamen 361102, China
| | - Yingying Lin
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research & Innovation Center for Cell Stress Signaling, Xiamen University, Xiamen 361102, China
| | - Haoran Duan
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research & Innovation Center for Cell Stress Signaling, Xiamen University, Xiamen 361102, China
| | - Yabin Cheng
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research & Innovation Center for Cell Stress Signaling, Xiamen University, Xiamen 361102, China
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31
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Maekawa M, Higashiyama S. KCTD10 Biology: An Adaptor for the Ubiquitin E3 Complex Meets Multiple Substrates: Emerging Divergent Roles of the cullin-3/KCTD10 E3 Ubiquitin Ligase Complex in Various Cell Lines. Bioessays 2020; 42:e1900256. [PMID: 32484264 DOI: 10.1002/bies.201900256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 04/08/2020] [Indexed: 12/18/2022]
Abstract
Protein ubiquitination constitutes a post-translational modification mediated by ubiquitin ligases whereby ubiquitinated substrates are degraded through the proteasomal or lysosomal pathways, or acquire novel molecular functions according to their "ubiquitin codes." Dysfunction of the ubiquitination process in cells causes various diseases such as cancers along with neurodegenerative, auto-immune/inflammatory, and metabolic diseases. KCTD10 functions as a substrate recognition receptor for cullin-3 (CUL3), a scaffold protein in RING-type ubiquitin ligase complexes. Recently, studies by ourselves and others have identified new substrates that are ubiquitinated by the CUL3/KCTD10 ubiquitin ligase complex. Moreover, the type of polyubiquitination (e.g., K27-, K48-, or K63-chain) of various substrates (e.g., RhoB, CEP97, EIF3D, and TRIF) mediated by KCTD10 underlies its divergent roles in endothelial barrier formation, primary cilium formation, plasma membrane dynamics, cell proliferation, and immune response. Here, the physiological functions of KCTD10 are summarized and potential mechanisms are proposed.
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Affiliation(s)
- Masashi Maekawa
- Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime, 791-0295, Japan.,Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
| | - Shigeki Higashiyama
- Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime, 791-0295, Japan.,Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan
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32
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Survey of SNPs Associated with Total Number Born and Total Number Born Alive in Pig. Genes (Basel) 2020; 11:genes11050491. [PMID: 32365801 PMCID: PMC7291110 DOI: 10.3390/genes11050491] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 12/26/2022] Open
Abstract
Reproductive productivity depend on a complex set of characteristics. The number of piglets at birth (Total number born, Litter size, TNB) and the number of alive piglets at birth (Total number born alive, NBA) are the main indicators of the reproductive productivity of sows in pig breeding. Great hopes are pinned on GWAS (Genome-Wide Association Studies) to solve the problems associated with studying the genetic architecture of reproductive traits of pigs. This paper provides an overview of international studies on SNP (Single nucleotide polymorphism) associated with TNB and NBA in pigs presented in PigQTLdb as "Genome map association". Currently on the base of Genome map association results 306 SNPs associated with TNB (218 SNPs) and NBA (88 SNPs) have been identified and presented in the Pig QTLdb database. The results are based on research of pigs such as Large White, Yorkshire, Landrace, Berkshire, Duroc and Erhualian. The presented review shows that most SNPs found in chromosome areas where candidate genes or QTLs (Quantitative trait locus) have been identified. Further research in the given direction will allow to obtain new data that will become an impulse for creating breakthrough breeding technologies and increase the production efficiency in pig farming.
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33
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Han W, Zhang C, Shi CT, Gao XJ, Zhou MH, Shao QX, Shen XJ, Wu CJ, Cao F, Hu YW, Yuan JL, Ding HZ, Wang QH, Wang HN. Roles of eIF3m in the tumorigenesis of triple negative breast cancer. Cancer Cell Int 2020; 20:141. [PMID: 32368187 PMCID: PMC7191806 DOI: 10.1186/s12935-020-01220-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/17/2020] [Indexed: 12/24/2022] Open
Abstract
Background Without targets, triple negative breast cancer (TNBC) has the worst prognosis in all subtypes of breast cancer (BC). Recently, eukaryotic translation initiation factor 3 m (eIF3m) has been declared to be involved in the malignant progression of various neoplasms. The aim of this study is to explore biological functions of eIF3m in TNBC. Methods Multiple databases, including Oncomine, KM-plotter and so on, were performed to analyze prognosis and function of eIF3m in TNBC. After transfection of eIF3m-shRNA lentivirus, CCK-8, colony formation assay, cell cycle analysis, wound healing assay, transwell assays, mitochondrial membrane potential assay and cell apoptosis analysis were performed to explore the roles of eIF3m in TNBC cell bio-behaviors. In addition, western blotting was conducted to analyze the potential molecular mechanisms of eIF3m. Results In multiple databases, up-regulated eIF3m had lower overall survival, relapse-free survival and post progression survival in BC. EIF3m expression in TNBC was obviously higher than in non-TNBC or normal breast tissues. Its expression in TNBC was positively related to differentiation, lymph node invasion and distant metastasis. After knockdown of eIF3m, cell proliferation, migration, invasion and levels of mitochondrial membrane potential of MDA-MB-231 and MDA-MB-436 were all significantly suppressed, while apoptosis rates of them were obviously increased. In addition, eIF3m could regulate cell-cycle, epithelial–mesenchymal transition and apoptosis-related proteins. Combined with public databases and RT-qPCR, 14 genes were identified to be modulated by eIF3m in the development of TNBC. Conclusions eIF3m is an unfavorable indicator of TNBC, and plays a vital role in the process of TNBC tumorigenesis.
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Affiliation(s)
- Wei Han
- 1Department of General Surgery, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Cong Zhang
- Department of Pharmacy, Kunshan Hospital of Traditional Chinese Medicine, Kunshan Jiangsu, 215300 People's Republic of China
| | - Chun-Tao Shi
- Department of General Surgery, Wuxi Xishan People's Hospital, Kunshan Wuxi Jiangsu, 214000 People's Republic of China
| | - Xiao-Jiao Gao
- 4Department of Pathology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Ming-Hui Zhou
- 5Centralab, Kunshan First People's Hospital Affiliated to Jiangsu University, Jiangsu, 215300 Kunshan People's Republic of China
| | - Qi-Xiang Shao
- 6Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang Jiangsu, 212013 People's Republic of China
| | - Xiao-Jun Shen
- 1Department of General Surgery, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Cheng-Jiang Wu
- 7Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou Jiangsu, 215000 People's Republic of China
| | - Fang Cao
- 1Department of General Surgery, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Yong-Wei Hu
- 1Department of General Surgery, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Jian-Liang Yuan
- 1Department of General Surgery, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Hou-Zhong Ding
- 1Department of General Surgery, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Qing-Hua Wang
- 1Department of General Surgery, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan Jiangsu, 215300 People's Republic of China
| | - Hao-Nan Wang
- Oncology Department, Wuxi Fifth People's Hospital, Wuxi Jiangsu, 214000 People's Republic of China
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Hepatitis C Virus Translation Regulation. Int J Mol Sci 2020; 21:ijms21072328. [PMID: 32230899 PMCID: PMC7178104 DOI: 10.3390/ijms21072328] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/18/2020] [Accepted: 03/25/2020] [Indexed: 12/12/2022] Open
Abstract
Translation of the hepatitis C virus (HCV) RNA genome is regulated by the internal ribosome entry site (IRES), located in the 5’-untranslated region (5′UTR) and part of the core protein coding sequence, and by the 3′UTR. The 5′UTR has some highly conserved structural regions, while others can assume different conformations. The IRES can bind to the ribosomal 40S subunit with high affinity without any other factors. Nevertheless, IRES activity is modulated by additional cis sequences in the viral genome, including the 3′UTR and the cis-acting replication element (CRE). Canonical translation initiation factors (eIFs) are involved in HCV translation initiation, including eIF3, eIF2, eIF1A, eIF5, and eIF5B. Alternatively, under stress conditions and limited eIF2-Met-tRNAiMet availability, alternative initiation factors such as eIF2D, eIF2A, and eIF5B can substitute for eIF2 to allow HCV translation even when cellular mRNA translation is downregulated. In addition, several IRES trans-acting factors (ITAFs) modulate IRES activity by building large networks of RNA-protein and protein–protein interactions, also connecting 5′- and 3′-ends of the viral RNA. Moreover, some ITAFs can act as RNA chaperones that help to position the viral AUG start codon in the ribosomal 40S subunit entry channel. Finally, the liver-specific microRNA-122 (miR-122) stimulates HCV IRES-dependent translation, most likely by stabilizing a certain structure of the IRES that is required for initiation.
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35
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Komar AA, Merrick WC. A Retrospective on eIF2A-and Not the Alpha Subunit of eIF2. Int J Mol Sci 2020; 21:E2054. [PMID: 32192132 PMCID: PMC7139343 DOI: 10.3390/ijms21062054] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/29/2020] [Accepted: 03/13/2020] [Indexed: 12/31/2022] Open
Abstract
Initiation of protein synthesis in eukaryotes is a complex process requiring more than 12 different initiation factors, comprising over 30 polypeptide chains. The functions of many of these factors have been established in great detail; however, the precise role of some of them and their mechanism of action is still not well understood. Eukaryotic initiation factor 2A (eIF2A) is a single chain 65 kDa protein that was initially believed to serve as the functional homologue of prokaryotic IF2, since eIF2A and IF2 catalyze biochemically similar reactions, i.e., they stimulate initiator Met-tRNAi binding to the small ribosomal subunit. However, subsequent identification of a heterotrimeric 126 kDa factor, eIF2 (α,β,γ) showed that this factor, and not eIF2A, was primarily responsible for the binding of Met-tRNAi to 40S subunit in eukaryotes. It was found however, that eIF2A can promote recruitment of Met-tRNAi to 40S/mRNA complexes under conditions of inhibition of eIF2 activity (eIF2α-phosphorylation), or its absence. eIF2A does not function in major steps in the initiation process, but is suggested to act at some minor/alternative initiation events such as re-initiation, internal initiation, or non-AUG initiation, important for translational control of specific mRNAs. This review summarizes our current understanding of the eIF2A structure and function.
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Affiliation(s)
- Anton A. Komar
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA;
| | - William C. Merrick
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA;
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36
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Herrmannová A, Prilepskaja T, Wagner S, Šikrová D, Zeman J, Poncová K, Valášek LS. Adapted formaldehyde gradient cross-linking protocol implicates human eIF3d and eIF3c, k and l subunits in the 43S and 48S pre-initiation complex assembly, respectively. Nucleic Acids Res 2020; 48:1969-1984. [PMID: 31863585 PMCID: PMC7039009 DOI: 10.1093/nar/gkz1185] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/04/2019] [Accepted: 12/09/2019] [Indexed: 12/18/2022] Open
Abstract
One of the key roles of the 12-subunit eukaryotic translation initiation factor 3 (eIF3) is to promote the formation of the 43S and 48S pre-initiation complexes (PICs). However, particular contributions of its individual subunits to these two critical initiation reactions remained obscure. Here, we adapted formaldehyde gradient cross-linking protocol to translation studies and investigated the efficiency of the 43S and 48S PIC assembly in knockdowns of individual subunits of human eIF3 known to produce various partial subcomplexes. We revealed that eIF3d constitutes an important intermolecular bridge between eIF3 and the 40S subunit as its elimination from the eIF3 holocomplex severely compromised the 43S PIC assembly. Similarly, subunits eIF3a, c and e were found to represent an important binding force driving eIF3 binding to the 40S subunit. In addition, we demonstrated that eIF3c, and eIF3k and l subunits alter the efficiency of mRNA recruitment to 43S PICs in an opposite manner. Whereas the eIF3c knockdown reduces it, downregulation of eIF3k or eIF3l increases mRNA recruitment, suggesting that the latter subunits possess a regulatory potential. Altogether this study provides new insights into the role of human eIF3 in the initial assembly steps of the translational machinery.
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Affiliation(s)
- Anna Herrmannová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Terezie Prilepskaja
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Susan Wagner
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Darina Šikrová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Jakub Zeman
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Kristýna Poncová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Videnska 1083, 142 20, the Czech Republic
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37
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Bhardwaj U, Powell P, Goss DJ. Eukaryotic initiation factor (eIF) 3 mediates Barley Yellow Dwarf Viral mRNA 3'-5' UTR interactions and 40S ribosomal subunit binding to facilitate cap-independent translation. Nucleic Acids Res 2020; 47:6225-6235. [PMID: 31114905 PMCID: PMC6614841 DOI: 10.1093/nar/gkz448] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/06/2019] [Accepted: 05/09/2019] [Indexed: 12/30/2022] Open
Abstract
Barley Yellow Dwarf Virus (BYDV) is a positive strand RNA virus that lacks the canonical 5′ 7-methylguanosine cap and a 3′ poly-A tail. Instead, BYDV utilizes a cruciform cap independent translation element (CITE) in its 3′UTR RNA (BYDV-like CITE or BTE) that binds eukaryotic translation initiation factor (eIF) 4F and recruits 40S ribosomal subunits in the presence of active helicase factors (eIF4A, eIF4B, eIF4F and ATP). A long-range, 5-nucleotide, base-pairing kissing loop interaction between the 3′BTE and a 5′UTR stem-loop is necessary for translation to initiate. The 40S–eIF complex does not bind to the BYDV 5′UTR, suggesting the involvement of additional factors. We identified eIF3 as a component of the 3′BTE recruited complex using affinity-tagged 3′BTE RNA pull-down assays. Fluorescence anisotropy binding and gel shift assays showed that the 3′BTE and 5′UTR RNAs can simultaneously and non-competitively bind eIF3 in the presence of active helicase factors forming a single, macromolecular complex. Further, quantitative studies showed eIF3 increased recruitment of the 40S subunit by more than 25-fold. We propose a new role for eIF3, where eIF3 bridges BYDV’s UTRs, stabilizes the long-range 5′-3′ interaction, and facilitates recruitment of the 40S–eIF complex to the 5′UTR, leading to translation initiation.
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Affiliation(s)
- Usha Bhardwaj
- Department of Chemistry, Hunter College, CUNY, New York, NY 10065, USA
| | - Paul Powell
- Department of Chemistry, Hunter College, CUNY, New York, NY 10065, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
| | - Dixie J Goss
- Department of Chemistry, Hunter College, CUNY, New York, NY 10065, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, USA
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38
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Panthu B, Denolly S, Faivre-Moskalenko C, Ohlmann T, Cosset FL, Jalinot P. Unlike for cellular mRNAs and other viral internal ribosome entry sites (IRESs), the eIF3 subunit e is not required for the translational activity of the HCV IRES. J Biol Chem 2020; 295:1843-1856. [PMID: 31929110 DOI: 10.1074/jbc.ra119.009502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 12/20/2019] [Indexed: 11/06/2022] Open
Abstract
Viruses depend on the host cell translation machinery for their replication, and one common strategy is the presence of internal ribosome entry sites (IRESs) in the viral RNAs, using different sets of host translation initiation factors. The hepatitis C virus (HCV) IRES binds eukaryotic translation initiation factor 3 (eIF3), but the exact functional role of the eIF3 complex and of its subunits remains to be precisely defined. Toward this goal, here we focused on eIF3 subunit e. We used an in vitro assay combining a ribosome-depleted rabbit reticulocyte lysate and ribosomes prepared from HeLa or Huh-7.5 cells transfected with either control or eIF3e siRNAs. eIF3e silencing reduced translation mediated by the 5'UTR of various cellular genes and HCV-like IRESs. However, this effect was not observed with the bona fide HCV IRES. Silencing of eIF3e reduced the intracellular levels of the c, d, and l subunits of eIF3 and their association with the eIF3 core subunit a. A pulldown analysis of eIF3 subunits associated with the HCV IRES disclosed similar effects and that the a subunit is critical for binding to the HCV IRES. Carrying out HCV infections of control and eIF3e-silenced Huh-7.5 cells, we found that in agreement with the in vitro findings, eIF3e silencing does not reduce HCV replication and viral protein expression. We conclude that unlike for host cellular mRNAs, the entire eIF3 is not required for HCV RNA translation, favoring viral expression under conditions of low eIF3e levels.
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Affiliation(s)
- Baptiste Panthu
- Univ Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5239, INSERM U1210, LBMC, 46 Allée d'Italie Site Jacques Monod, F-69007 Lyon, France
| | - Solène Denolly
- CIRI-Centre International de Recherche en Infectiologie, Univ Lyon, Université Claude Bernard Lyon 1, INSERM U1111, CNRS UMR5308, ENS de Lyon, 46 Allée d'Italie Site Jacques Monod, F-69007 Lyon, France
| | - Cendrine Faivre-Moskalenko
- Univ Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5672, Laboratoire de Physique, 46 Allée d'Italie Site Jacques Monod, F-69007 Lyon, France
| | - Théophile Ohlmann
- CIRI-Centre International de Recherche en Infectiologie, Univ Lyon, Université Claude Bernard Lyon 1, INSERM U1111, CNRS UMR5308, ENS de Lyon, 46 Allée d'Italie Site Jacques Monod, F-69007 Lyon, France
| | - François-Loïc Cosset
- CIRI-Centre International de Recherche en Infectiologie, Univ Lyon, Université Claude Bernard Lyon 1, INSERM U1111, CNRS UMR5308, ENS de Lyon, 46 Allée d'Italie Site Jacques Monod, F-69007 Lyon, France.
| | - Pierre Jalinot
- Univ Lyon, ENS de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5239, INSERM U1210, LBMC, 46 Allée d'Italie Site Jacques Monod, F-69007 Lyon, France.
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39
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Ribosomal Protein L13 Promotes IRES-Driven Translation of Foot-and-Mouth Disease Virus in a Helicase DDX3-Dependent Manner. J Virol 2020; 94:JVI.01679-19. [PMID: 31619563 DOI: 10.1128/jvi.01679-19] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 10/11/2019] [Indexed: 12/22/2022] Open
Abstract
Internal ribosome entry site (IRES)-driven translation is a common strategy among positive-sense, single-stranded RNA viruses for bypassing the host cell requirement of a 5' cap structure. In the current study, we identified the ribosomal protein L13 (RPL13) as a critical regulator of IRES-driven translation of foot-and-mouth disease virus (FMDV) but found that it is not essential for cellular global translation. RPL13 is also a determinant for translation and infection of Seneca Valley virus (SVV) and classical swine fever virus (CSFV), and this suggests that its function may also be conserved in unrelated IRES-containing viruses. We further showed that depletion of DEAD box helicase DDX3 disrupts binding of RPL13 to the FMDV IRES, whereas the reduction in RPL13 expression impairs the ability of DDX3 to promote IRES-driven translation directly. DDX3 cooperates with RPL13 to support the assembly of 80S ribosomes for optimal translation initiation of viral mRNA. Finally, we demonstrated that DDX3 affects the recruitment of the eukaryotic initiation factor eIF3 subunits e and j to the viral IRES. This work provides the first connection between DDX3 and eIF3e/j and recognition of the role of RPL13 in modulating viral IRES-dependent translation. This previously uncharacterized process may be involved in selective mRNA translation.IMPORTANCE Accumulating evidence has unveiled the roles of ribosomal proteins (RPs) belonging to the large 60S subunit in regulating selective translation of specific mRNAs. The translation specificity of the large-subunit RPs in this process is thought provoking, given the role they play canonically in catalyzing peptide bond formation. Here, we have identified the ribosomal protein L13 (RPL13) as a critical regulator of IRES-driven translation during FMDV infection. Our study supports a model whereby the FMDV IRESs recruit helicase DDX3 recognizing RPL13 to facilitate IRES-driven translation, with the assistance of eIF3e and eIF3j. A better understanding of these specific interactions surrounding IRES-mediated translation initiation could have important implications for the selective translation of viral mRNA and thus for the development of effective prevention of viral infection.
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40
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Raabe K, Honys D, Michailidis C. The role of eukaryotic initiation factor 3 in plant translation regulation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 145:75-83. [PMID: 31665669 DOI: 10.1016/j.plaphy.2019.10.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/07/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Regulation of translation represents a critical step in the regulation of gene expression. In plants, the translation regulation plays an important role at all stages of development and, during stress responses, functions as a fast and flexible tool which not only modulates the global translation rate but also controls the production of specific proteins. Regulation of translation is mostly focused on the initiation phase. There, one of essential initiation factors is the large multisubunit protein complex of eukaryotic translation initiation factor 3 (eIF3). In all eukaryotes, the general eIF3 function is to scaffold the formation of the translation initiation complex and to enhance the accuracy of scanning mechanism for start codon selection. Over the past decades, additional eIF3 functions were described as necessary for development in various eukaryotic organisms, including plants. The importance of the eIF3 complex lies not only at the global level of initiation event, but also in the precise translation regulation of specific transcripts. This review gathers the available information on functions of the plant eIF3 complex.
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Affiliation(s)
- Karel Raabe
- Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - David Honys
- Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojová 263, 165 02, Praha 6, Czech Republic
| | - Christos Michailidis
- Institute of Experimental Botany, The Czech Academy of Sciences, Rozvojová 263, 165 02, Praha 6, Czech Republic.
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41
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Wang QH, Zhang M, Zhou MH, Gao XJ, Chen F, Yan X, Lu F. High expression of eukaryotic initiation factor 3M predicts poor prognosis in colon adenocarcinoma patients. Oncol Lett 2019; 19:876-884. [PMID: 31897202 PMCID: PMC6924177 DOI: 10.3892/ol.2019.11164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 10/03/2019] [Indexed: 12/19/2022] Open
Abstract
Eukaryotic initiation factor 3 subunit M (EIF3M) is required for key steps in the initiation of protein synthesis, and dysregulation of EIF3M is associated with tumorigenesis. This study aimed to explore the clinicopathological and prognostic role of EIF3M in patients with colon adenocarcinoma. A total of 82 pathology specimens, 20 freeze-thawed tumors and 80 healthy controls were used to investigate the expression of EIF3M in colon adenocarcinoma through immunohistochemistry, western blotting, RT-qPCR and ELISA. In addition, Kaplan-Meier curves and Cox regression analysis were used to analyze overall survival (OS) and disease-free survival (DFS). Furthermore, the Oncomine database was used for analyzing EIF3M expression. The positive rate of EIF3M in colon adenocarcinoma was higher compared with that in normal colon tissues (62.20% vs. 29.27%; P<0.001). The mean score of EIF3M was also higher in colon adenocarcinoma compared with normal colon tissue (17.28±10.05 vs. 6.53±4.87; P<0.001). The levels of EIF3M expression in freeze-thawed tumors and serum from 20 patients with colon adenocarcinoma were higher than those in normal tissues and serum from healthy controls, respectively (P<0.001). In addition, positive expression of EIF3M was associated with tumor size (P=0.002) and Dukes' stage (P<0.001). In multivariate Cox regression analysis, EIF3M expression was an independent prognostic factor for OS (P=0.003) and DFS (P=0.001). Oncomine database analysis showed a higher expression of EIF3M expression in colon adenocarcinoma compared with normal colon tissues, colon squamous cell carcinomas or gastrointestinal stromal tumors. In conclusion, EIF3M expression was associated with tumor size and Dukes' stage in colon adenocarcinoma. Hence, EIF3M is a potential prognostic indicator for colon adenocarcinoma.
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Affiliation(s)
- Qing-Hua Wang
- Digestion Department, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu 215300, P.R. China
| | - Min Zhang
- No. 1 Department of General Surgery, Wuxi Second Hospital of Traditional Chinese Medicine, Wuxi, Jiangsu 214000, P.R. China
| | - Ming-Hui Zhou
- Centralab Department, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu 215300, P.R. China
| | - Xiao-Jiao Gao
- Pathology Department, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu 215300, P.R. China
| | - Fang Chen
- Pathology Department, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu 215300, P.R. China
| | - Xun Yan
- Department of General Surgery, Binhai County People's Hospital, Yancheng, Jiangsu 224000, P.R. China
| | - Feng Lu
- Department of General Surgery, Binhai County People's Hospital, Yancheng, Jiangsu 224000, P.R. China
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42
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Min J, Chen H. Eukaryotic initiation factor 3B downregulation suppresses cell proliferation, migration and invasion while it induces cell apoptosis by blocking the β-catenin pathway in endometrial cancer. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2019; 12:3595-3603. [PMID: 31934209 PMCID: PMC6949831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/25/2019] [Indexed: 06/10/2023]
Abstract
This study aimed to evaluate the effect of eukaryotic initiation factor 3B (EIF3B) downregulation on cell proliferation, apoptosis, migration, invasion and the β-catenin pathway in endometrial cancer. EIF3B mRNA and protein expressions were determined in human endometrial cancer cell lines (Ishikawa, HEC-1A, RL95-2 and EFE-184) and in the normal human endometrial epithelial cell line (HEEC). EIF3B siRNA and a control siRNA were transfected into HEC-1A cells, then cell proliferation, apoptosis, apoptotic marker (C-caspase 3 and Bcl-2) expressions, cell migration, and invasion were determined. β-catenin and cyclin E1 (CCNE1) expressions were also measured. EIF3B mRNA and protein expressions were increased in the Ishikawa, HEC-1A and RL95-2 cell lines, but they were similar in the EFE-184 cell line compared to the HEEC cell line. In HEC-1A cells, EIF3B siRNA suppressed cell proliferation, but it elevated the cell apoptosis rate compared to the control siRNA, and EIF3B siRNA also enhanced C-caspase 3 expression, but it inhibited Bcl-2 expression. Also, EIF3B siRNA reduced cell migration and cell invasion compared to the control siRNA in HEC-1A cells. More interestingly, EIF3B siRNA reduced β-catenin and CCNE1 mRNA as well as protein expressions compared with the control siRNA in HEC-1A cells. In conclusion, EIF3B downregulation suppresses cell proliferation, migration, and invasion, but it induces cell apoptosis by blocking the β-catenin pathway in endometrial cancer.
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Affiliation(s)
- Jie Min
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
| | - Hui Chen
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, China
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43
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Johnson AG, Petrov AN, Fuchs G, Majzoub K, Grosely R, Choi J, Puglisi JD. Fluorescently-tagged human eIF3 for single-molecule spectroscopy. Nucleic Acids Res 2019; 46:e8. [PMID: 29136179 PMCID: PMC5778468 DOI: 10.1093/nar/gkx1050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/24/2017] [Indexed: 01/09/2023] Open
Abstract
Human translation initiation relies on the combined activities of numerous ribosome-associated eukaryotic initiation factors (eIFs). The largest factor, eIF3, is an ∼800 kDa multiprotein complex that orchestrates a network of interactions with the small 40S ribosomal subunit, other eIFs, and mRNA, while participating in nearly every step of initiation. How these interactions take place during the time course of translation initiation remains unclear. Here, we describe a method for the expression and affinity purification of a fluorescently-tagged eIF3 from human cells. The tagged eIF3 dodecamer is structurally intact, functions in cell-based assays, and interacts with the HCV IRES mRNA and the 40S-IRES complex in vitro. By tracking the binding of single eIF3 molecules to the HCV IRES RNA with a zero-mode waveguides-based instrument, we show that eIF3 samples both wild-type IRES and an IRES that lacks the eIF3-binding region, and that the high-affinity eIF3-IRES interaction is largely determined by slow dissociation kinetics. The application of single-molecule methods to more complex systems involving eIF3 may unveil dynamics underlying mRNA selection and ribosome loading during human translation initiation.
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Affiliation(s)
- Alex G Johnson
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA.,Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
| | - Alexey N Petrov
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Gabriele Fuchs
- The RNA Institute, Department of Biological Sciences, University of Albany, Albany, NY 12222, USA
| | - Karim Majzoub
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA
| | - Rosslyn Grosely
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
| | - Junhong Choi
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
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44
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Abstract
Left-handed Z-DNA/Z-RNA is bound with high affinity by the Zα domain protein family that includes ADAR (a double-stranded RNA editing enzyme), ZBP1 and viral orthologs regulating innate immunity. Loss-of-function mutations in ADAR p150 allow persistent activation of the interferon system by Alu dsRNAs and are causal for Aicardi-Goutières Syndrome. Heterodimers of ADAR and DICER1 regulate the switch from RNA- to protein-centric immunity. Loss of DICER1 function produces age-related macular degeneration, a different type of Alu-mediated disease. The overlap of Z-forming sites with those for the signal recognition particle likely limits invasion of primate genomes by Alu retrotransposons.
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Affiliation(s)
- Alan Herbert
- Discovery, InsideOutBio, 42, 8th Street, Unit 3412, Charlestown, MA 02129 USA
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45
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Major structural rearrangements of the canonical eukaryotic translation initiation complex. Curr Opin Struct Biol 2018; 53:151-158. [DOI: 10.1016/j.sbi.2018.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 08/28/2018] [Indexed: 12/24/2022]
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46
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Ayhan F, Perez BA, Shorrock HK, Zu T, Banez-Coronel M, Reid T, Furuya H, Clark HB, Troncoso JC, Ross CA, Subramony SH, Ashizawa T, Wang ET, Yachnis AT, Ranum LP. SCA8 RAN polySer protein preferentially accumulates in white matter regions and is regulated by eIF3F. EMBO J 2018; 37:embj.201899023. [PMID: 30206144 DOI: 10.15252/embj.201899023] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 12/12/2022] Open
Abstract
Spinocerebellar ataxia type 8 (SCA8) is caused by a bidirectionally transcribed CTG·CAG expansion that results in the in vivo accumulation of CUG RNA foci, an ATG-initiated polyGln and a polyAla protein expressed by repeat-associated non-ATG (RAN) translation. Although RAN proteins have been reported in a growing number of diseases, the mechanisms and role of RAN translation in disease are poorly understood. We report a novel toxic SCA8 polySer protein which accumulates in white matter (WM) regions as aggregates that increase with age and disease severity. WM regions with polySer aggregates show demyelination and axonal degeneration in SCA8 human and mouse brains. Additionally, knockdown of the eukaryotic translation initiation factor eIF3F in cells reduces steady-state levels of SCA8 polySer and other RAN proteins. Taken together, these data show polySer and WM abnormalities contribute to SCA8 and identify eIF3F as a novel modulator of RAN protein accumulation.
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Affiliation(s)
- Fatma Ayhan
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Barbara A Perez
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Hannah K Shorrock
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Tao Zu
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Monica Banez-Coronel
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Tammy Reid
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Hirokazu Furuya
- Department of Neurology, Kochi Medical School, Kochi University, Kochi, Japan.,Department of Neurology, Neuro-Muscular Center, NHO Omuta Hospital, Fukuoka, Japan
| | - H Brent Clark
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Juan C Troncoso
- Department of Pathology and Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Christopher A Ross
- Department of Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pharmacology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Huntington's Disease Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - S H Subramony
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Tetsuo Ashizawa
- Department of Neurology, Houston Methodist Hospital, Houston, TX, USA
| | - Eric T Wang
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Anthony T Yachnis
- Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Laura Pw Ranum
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL, USA .,Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA.,Genetics Institute, University of Florida, Gainesville, FL, USA
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47
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Garcia-Moreno M, Järvelin AI, Castello A. Unconventional RNA-binding proteins step into the virus-host battlefront. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1498. [PMID: 30091184 PMCID: PMC7169762 DOI: 10.1002/wrna.1498] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/01/2018] [Accepted: 06/05/2018] [Indexed: 12/15/2022]
Abstract
The crucial participation of cellular RNA‐binding proteins (RBPs) in virtually all steps of virus infection has been known for decades. However, most of the studies characterizing this phenomenon have focused on well‐established RBPs harboring classical RNA‐binding domains (RBDs). Recent proteome‐wide approaches have greatly expanded the census of RBPs, discovering hundreds of proteins that interact with RNA through unconventional RBDs. These domains include protein–protein interaction platforms, enzymatic cores, and intrinsically disordered regions. Here, we compared the experimentally determined census of RBPs to gene ontology terms and literature, finding that 472 proteins have previous links with viruses. We discuss what these proteins are and what their roles in infection might be. We also review some of the pioneering examples of unorthodox RBPs whose RNA‐binding activity has been shown to be critical for virus infection. Finally, we highlight the potential of these proteins for host‐based therapies against viruses. This article is categorized under:
RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes
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Affiliation(s)
| | - Aino I Järvelin
- Department of Biochemistry, University of Oxford, Oxford, UK
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48
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Differential Requirement for Translation Initiation Factor Pathways during Ecdysone-Dependent Neuronal Remodeling in Drosophila. Cell Rep 2018; 24:2287-2299.e4. [DOI: 10.1016/j.celrep.2018.07.074] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 06/22/2018] [Accepted: 07/23/2018] [Indexed: 11/23/2022] Open
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49
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Hutt DM, Loguercio S, Roth DM, Su AI, Balch WE. Correcting the F508del-CFTR variant by modulating eukaryotic translation initiation factor 3-mediated translation initiation. J Biol Chem 2018; 293:13477-13495. [PMID: 30006345 DOI: 10.1074/jbc.ra118.003192] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/05/2018] [Indexed: 12/31/2022] Open
Abstract
Inherited and somatic rare diseases result from >200,000 genetic variants leading to loss- or gain-of-toxic function, often caused by protein misfolding. Many of these misfolded variants fail to properly interact with other proteins. Understanding the link between factors mediating the transcription, translation, and protein folding of these disease-associated variants remains a major challenge in cell biology. Herein, we utilized the cystic fibrosis transmembrane conductance regulator (CFTR) protein as a model and performed a proteomics-based high-throughput screen (HTS) to identify pathways and components affecting the folding and function of the most common cystic fibrosis-associated mutation, the F508del variant of CFTR. Using a shortest-path algorithm we developed, we mapped HTS hits to the CFTR interactome to provide functional context to the targets and identified the eukaryotic translation initiation factor 3a (eIF3a) as a central hub for the biogenesis of CFTR. Of note, siRNA-mediated silencing of eIF3a reduced the polysome-to-monosome ratio in F508del-expressing cells, which, in turn, decreased the translation of CFTR variants, leading to increased CFTR stability, trafficking, and function at the cell surface. This finding suggested that eIF3a is involved in mediating the impact of genetic variations in CFTR on the folding of this protein. We posit that the number of ribosomes on a CFTR mRNA transcript is inversely correlated with the stability of the translated polypeptide. Polysome-based translation challenges the capacity of the proteostasis environment to balance message fidelity with protein folding, leading to disease. We suggest that this deficit can be corrected through control of translation initiation.
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Affiliation(s)
| | | | | | - Andrew I Su
- Integrative Structural and Computational Biology and
| | - William E Balch
- From the Departments of Molecular Medicine and .,the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037
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50
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Steitz TA, Moore PB. Perspectives on the ribosome. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0537. [PMID: 28138074 DOI: 10.1098/rstb.2016.0537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2016] [Indexed: 12/18/2022] Open
Affiliation(s)
- Thomas A Steitz
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA
| | - Peter B Moore
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06520-8107, USA
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