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Roshan P, Biswas A, Anagnos S, Luebbers R, Harish K, Ahmed S, Li M, Nguyen N, Zhou G, Tedeschi F, Hathuc V, Lin Z, Hamilton Z, Origanti S. Modulation of ribosomal subunit associations by eIF6 is critical for mitotic exit and cancer progression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.24.600220. [PMID: 38979253 PMCID: PMC11230244 DOI: 10.1101/2024.06.24.600220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Moderating the pool of active ribosomal subunits is critical for maintaining global translation rates. A factor crucial for modulating the 60S ribosomal subunits is eukaryotic translation initiation factor 6. Release of eIF6 from 60S is essential to permit 60S interactions with 40S. Here, using the N106S mutant of eIF6, we show that disrupting eIF6 interaction with 60S leads to an increase in vacant 80S. It further highlights a dichotomy in the anti-association activity of eIF6 that is distinct from its role in 60S biogenesis and shows that the nucleolar localization of eIF6 is not dependent on uL14-BCCIP interactions. Limiting active ribosomal pools markedly deregulates translation especially in mitosis and leads to chromosome segregation defects, mitotic exit delays and mitotic catastrophe. Ribo-Seq analysis of the eIF6-N106S mutant shows a significant downregulation in the translation efficiencies of mitotic factors and specifically transcripts with long 3'UTRs. eIF6-N106S mutation also limits cancer invasion, and this role is correlated with the overexpression of eIF6 only in high-grade invasive cancers suggesting that deregulation of eIF6 is probably not an early event in cancers. Thus, this study highlights the segregation of eIF6 functions and its role in moderating 80S availability for mitotic translation and cancer progression.
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Carotenuto R, Pallotta MM, Tussellino M, Fogliano C. Xenopus laevis (Daudin, 1802) as a Model Organism for Bioscience: A Historic Review and Perspective. BIOLOGY 2023; 12:890. [PMID: 37372174 DOI: 10.3390/biology12060890] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/15/2023] [Accepted: 06/20/2023] [Indexed: 06/29/2023]
Abstract
In vitro systems have been mainly promoted by authorities to sustain research by following the 3Rs principle, but continuously increasing amounts of evidence point out that in vivo experimentation is also of extreme relevance. Xenopus laevis, an anuran amphibian, is a significant model organism in the study of evolutionary developmental biology, toxicology, ethology, neurobiology, endocrinology, immunology and tumor biology; thanks to the recent development of genome editing, it has also acquired a relevant position in the field of genetics. For these reasons, X. laevis appears to be a powerful and alternative model to the zebrafish for environmental and biomedical studies. Its life cycle, as well as the possibility to obtain gametes from adults during the whole year and embryos by in vitro fertilization, allows experimental studies of several biological endpoints, such as gametogenesis, embryogenesis, larval growth, metamorphosis and, of course, the young and adult stages. Moreover, with respect to alternative invertebrate and even vertebrate animal models, the X. laevis genome displays a higher degree of similarity with that of mammals. Here, we have reviewed the main available literature on the use of X. laevis in the biosciences and, inspired by Feymann's revised view, "Plenty of room for biology at the bottom", suggest that X. laevis is a very useful model for all possible studies.
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Affiliation(s)
- Rosa Carotenuto
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | | | | | - Chiara Fogliano
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
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Elliff J, Biswas A, Roshan P, Kuppa S, Patterson A, Mattice J, Chinnaraj M, Burd R, Walker SE, Pozzi N, Antony E, Bothner B, Origanti S. Dynamic states of eIF6 and SDS variants modulate interactions with uL14 of the 60S ribosomal subunit. Nucleic Acids Res 2023; 51:1803-1822. [PMID: 36651285 PMCID: PMC9976893 DOI: 10.1093/nar/gkac1266] [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: 11/11/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 01/19/2023] Open
Abstract
Assembly of ribosomal subunits into active ribosomal complexes is integral to protein synthesis. Release of eIF6 from the 60S ribosomal subunit primes 60S to associate with the 40S subunit and engage in translation. The dynamics of eIF6 interaction with the uL14 (RPL23) interface of 60S and its perturbation by somatic mutations acquired in Shwachman-Diamond Syndrome (SDS) is yet to be clearly understood. Here, by using a modified strategy to obtain high yields of recombinant human eIF6 we have uncovered the critical interface entailing eight key residues in the C-tail of uL14 that is essential for physical interactions between 60S and eIF6. Disruption of the complementary binding interface by conformational changes in eIF6 disease variants provide a mechanism for weakened interactions of variants with the 60S. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) analyses uncovered dynamic configurational rearrangements in eIF6 induced by binding to uL14 and exposed an allosteric interface regulated by the C-tail of eIF6. Disrupting key residues in the eIF6-60S binding interface markedly limits proliferation of cancer cells, which highlights the significance of therapeutically targeting this interface. Establishing these key interfaces thus provide a therapeutic framework for targeting eIF6 in cancers and SDS.
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Affiliation(s)
- Jonah Elliff
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
- Department of Immunology, The University of Iowa, Iowa City, IA 52242, USA
| | - Aparna Biswas
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA
| | - Poonam Roshan
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA
| | - Sahiti Kuppa
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Angela Patterson
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Jenna Mattice
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Mathivanan Chinnaraj
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Ryan Burd
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Sarah E Walker
- Department of Biological Sciences, State University of New York, Buffalo, NY 14260, USA
| | - Nicola Pozzi
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Edwin Antony
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, MO 63104, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Sofia Origanti
- Department of Biology, Saint Louis University, St. Louis, MO 63103, USA
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Shaiken TE, Grimm SL, Siam M, Williams A, Rezaeian AH, Kraushaar D, Ricco E, Robertson MJ, Coarfa C, Jain A, Malovannaya A, Stossi F, Opekun AR, Price AP, Dubrulle J. Transcriptome, proteome, and protein synthesis within the intracellular cytomatrix. iScience 2023; 26:105965. [PMID: 36824274 PMCID: PMC9941065 DOI: 10.1016/j.isci.2023.105965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 11/07/2022] [Accepted: 01/06/2023] [Indexed: 01/15/2023] Open
Abstract
Despite the knowledge that protein translation and various metabolic reactions that create and sustain cellular life occur in the cytoplasm, the structural organization within the cytoplasm remains unclear. Recent models indicate that cytoplasm contains viscous fluid and elastic solid phases. We separated these viscous fluid and solid elastic compartments, which we call the cytosol and cytomatrix, respectively. The distinctive composition of the cytomatrix included structural proteins, ribosomes, and metabolome enzymes. High-throughput analysis revealed unique biosynthetic pathways within the cytomatrix. Enrichment of biosynthetic pathways in the cytomatrix indicated the presence of immobilized biocatalysis. Enzymatic immobilization and segregation can surmount spatial impediments, and the local pathway segregation may form cytoplasmic organelles. Protein translation was reprogrammed within the cytomatrix under the restriction of protein synthesis by drug treatment. The cytosol and cytomatrix are an elaborately interconnected network that promotes operational flexibility in healthy cells and the survival of malignant cells.
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Affiliation(s)
- Tattym E. Shaiken
- Department of Medicine-Gastroenterology and Hepatology Section, Michael E DeBakey Veteran’s Affairs Medical Center, Baylor College of Medicine, Houston, TX 77030, USA
- PeriNuc Labs, University of Houston Technology Bridge, Houston, TX 77023, USA
| | - Sandra L. Grimm
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mohamad Siam
- Department of Medicine-Gastroenterology and Hepatology Section, Michael E DeBakey Veteran’s Affairs Medical Center, Baylor College of Medicine, Houston, TX 77030, USA
- PeriNuc Labs, University of Houston Technology Bridge, Houston, TX 77023, USA
| | - Amanda Williams
- Department of Medicine-Gastroenterology and Hepatology Section, Michael E DeBakey Veteran’s Affairs Medical Center, Baylor College of Medicine, Houston, TX 77030, USA
- PeriNuc Labs, University of Houston Technology Bridge, Houston, TX 77023, USA
| | - Abdol-Hossein Rezaeian
- PeriNuc Labs, University of Houston Technology Bridge, Houston, TX 77023, USA
- Department of Drug Discovery and Biomedical Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Daniel Kraushaar
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
| | - Emily Ricco
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Cristian Coarfa
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
| | - Antrix Jain
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
| | - Anna Malovannaya
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
| | - Fabio Stossi
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Antone R. Opekun
- Department of Medicine-Gastroenterology and Hepatology Section, Michael E DeBakey Veteran’s Affairs Medical Center, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alyssa P. Price
- Department of Medicine-Gastroenterology and Hepatology Section, Michael E DeBakey Veteran’s Affairs Medical Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Julien Dubrulle
- Advanced Technology Cores, Baylor College of Medicine, Houston, TX 77030, USA
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Kamble VS, Pachpor TA, Khandagale SB, Wagh VV, Khare SP. Translation initiation and dysregulation of initiation factors in rare diseases. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Gao Y, Yuan L, Zeng J, Li F, Li X, Tan F, Liu X, Wan H, Kui X, Liu X, Ke C, Pei Z. eIF6 is potential diagnostic and prognostic biomarker that associated with 18F-FDG PET/CT features and immune signatures in esophageal carcinoma. Lab Invest 2022; 20:303. [PMID: 35794622 PMCID: PMC9258187 DOI: 10.1186/s12967-022-03503-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 06/24/2022] [Indexed: 11/25/2022]
Abstract
Background Although eukaryotic initiation factor 6 (eIF6) is a novel therapeutic target, data on its importance in the development of esophageal carcinoma (ESCA) remains limited. This study evaluated the correlation between eIF6 expression and metabolic analysis using fluorine-18 fluorodeoxyglucose (18F-FDG) -Positron emission tomography (PET) and immune gene signatures in ESCA. Methods This study employed The Cancer Genome Atlas (TCGA) to analyze the expression and prognostic value of eIF6, as well as its relationship with the immune gene signatures in ESCA patients. The qRT-PCR and Western blot analyses were used to profile the expression of eIF6 in ESCA tissues and different ESCA cell lines. The expression of tumor eIF6 and glucose transporter 1 (GLUT1) was examined using immunohistochemical tools in fifty-two ESCA patients undergoing routine 18F-FDG PET/CT before surgery. In addition, the cellular responses to eIF6 knockdown in human ESCA cells were assessed via the MTS, EdU, flow cytometry and wound healing assays. Results Our data demonstrated that compared with the normal esophageal tissues, eIF6 expression was upregulated in ESCA tumor tissues and showed a high diagnostic value with an area under curve of 0.825 for predicting ESCA. High eIF6 expression was significantly correlated with shorter overall survival of patients with esophagus adenocarcinoma (p = 0.038), but not in squamous cell carcinoma of the esophagus (p = 0.078). In addition, tumor eIF6 was significantly associated with 18F-FDG PET/CT parameters: maximal and mean standardized uptake values (SUVmax and SUVmean) and total lesion glycolysis (TLG) (rho = 0.458, 0.460, and 0.300, respectively, p < 0.01) as well as GLUT1 expression (rho = 0.453, p < 0.001). A SUVmax cutoff of 18.2 led to prediction of tumor eIF6 expression with an accuracy of 0.755. Functional analysis studies demonstrated that knockdown of eIF6 inhibited ESCA cell growth and migration, and fueled cell apoptosis. Moreover, the Bulk RNA gene analysis revealed a significant inverse association between eIF6 and the tumor-infiltrating immune cells (macrophages, T cells, or Th1 cells) and immunomodulators in the ESCA microenvironment. Conclusion Our study suggested that eIF6 might serve as a potential prognostic biomarker associated with metabolic variability and immune gene signatures in ESCA tumor microenvironment.
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Pimkova K, Jassinskaja M, Munita R, Ciesla M, Guzzi N, Cao Thi Ngoc P, Vajrychova M, Johansson E, Bellodi C, Hansson J. Quantitative analysis of redox proteome reveals oxidation-sensitive protein thiols acting in fundamental processes of developmental hematopoiesis. Redox Biol 2022; 53:102343. [PMID: 35640380 PMCID: PMC9157258 DOI: 10.1016/j.redox.2022.102343] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/11/2022] [Accepted: 05/14/2022] [Indexed: 11/22/2022] Open
Abstract
Fetal and adult hematopoietic stem and progenitor cells (HSPCs) are characterized by distinct redox homeostasis that may influence their differential cellular behavior in normal and malignant hematopoiesis. In this work, we have applied a quantitative mass spectrometry-based redox proteomic approach to comprehensively describe reversible cysteine modifications in primary mouse fetal and adult HSPCs. We defined the redox state of 4,438 cysteines in fetal and adult HSPCs and demonstrated a higher susceptibility to oxidation of protein thiols in fetal HSPCs. Our data identified ontogenic changes to oxidation state of thiols in proteins with a pronounced role in metabolism and protein homeostasis. Additional redox proteomic analysis identified oxidation changes to thiols acting in mitochondrial respiration as well as protein homeostasis to be triggered during onset of MLL-ENL leukemogenesis in fetal HSPCs. Our data has demonstrated that redox signaling contributes to the regulation of fundamental processes of developmental hematopoiesis and has pinpointed potential targetable redox-sensitive proteins in in utero-initiated MLL-rearranged leukemia.
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Affiliation(s)
- K Pimkova
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden; BIOCEV, 1st Medical Faculty, Charles University, Vestec, Czech Republic.
| | - M Jassinskaja
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden
| | - R Munita
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden
| | - M Ciesla
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden
| | - N Guzzi
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden
| | - P Cao Thi Ngoc
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden
| | - M Vajrychova
- Biomedical Research Center, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - E Johansson
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden
| | - C Bellodi
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden
| | - J Hansson
- Lund Stem Cell Center, Division of Molecular Hematology, Lund University, Lund, Sweden.
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Li J, Liu L, Chen Y, Wu M, Lin X, Shen Z, Cheng Y, Chen X, Weygant N, Wu X, Wei L, Sferra TJ, Han Y, Chen X, Shen A, Shen A, Peng J. Ribosome assembly factor PNO1 is associated with progression and promotes tumorigenesis in triple‑negative breast cancer. Oncol Rep 2022; 47:108. [PMID: 35445733 PMCID: PMC9073417 DOI: 10.3892/or.2022.8319] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/14/2022] [Indexed: 12/24/2022] Open
Abstract
The aim of the present study was to investigate the expression of ribosome assembly factor partner of NOB1 homolog (PNO1) and its association with the progression of breast cancer (BC) in patients, as well as its biological function and underlying mechanism of action in BC cells. Bioinformatics and immunohistochemical analyses revealed that PNO1 expression was significantly increased in BC tissues and its high mRNA expression was associated with shorter overall survival (OS) and relapse-free survival (RFS) of patients with BC, as well as multiple clinical characteristics (including advanced stage of NPI and SBR, etc.) of patients with BC. Biological functional studies revealed that transduction of lentivirus encoding sh-PNO1 significantly downregulated PNO1 expression, reduced cell confluency and the number of BC cells in vitro and inhibited tumor growth in vivo. Moreover, PNO1 knockdown decreased the cell viability and arrested cell cycle progression at the G2/M phase, as well as downregulated cyclin B1 (CCNB1) and cyclin-dependent kinase 1 (CDK1) protein expression in BC cells. Correlation analysis demonstrated that PNO1 expression was positively correlated with both CDK1 and CCNB1 expression in BC samples. Collectively, PNO1 was upregulated in BC and associated with BC patient survival, and PNO1 knockdown suppressed tumor growth in vitro and in vivo. In addition, positive regulation of CCNB1 and CDK1 may be one of the underlying mechanisms.
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Affiliation(s)
- Jie Li
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Liya Liu
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Youqin Chen
- Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, Cleveland, OH 44106, USA
| | - Meizhu Wu
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Xiaoying Lin
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Zhiqing Shen
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Ying Cheng
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Xiaoping Chen
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Nathaniel Weygant
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Xiangyan Wu
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Lihui Wei
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Thomas J Sferra
- Department of Pediatrics, Case Western Reserve University School of Medicine, Rainbow Babies and Children's Hospital, Cleveland, OH 44106, USA
| | - Yuying Han
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Xi Chen
- Department of Oncology, No. 900 Hospital of The Joint Logistic Support Force, Fuzhou, Fujian 350025, P.R. China
| | - Aling Shen
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Aling Shen
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Jun Peng
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
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Keen AN, Payne LA, Mehta V, Rice A, Simpson LJ, Pang KL, del Rio Hernandez A, Reader JS, Tzima E. Eukaryotic initiation factor 6 regulates mechanical responses in endothelial cells. J Cell Biol 2022; 221:e202005213. [PMID: 35024764 PMCID: PMC8763864 DOI: 10.1083/jcb.202005213] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/11/2021] [Accepted: 12/08/2021] [Indexed: 12/22/2022] Open
Abstract
The repertoire of extratranslational functions of components of the protein synthesis apparatus is expanding to include control of key cell signaling networks. However, very little is known about noncanonical functions of members of the protein synthesis machinery in regulating cellular mechanics. We demonstrate that the eukaryotic initiation factor 6 (eIF6) modulates cellular mechanobiology. eIF6-depleted endothelial cells, under basal conditions, exhibit unchanged nascent protein synthesis, polysome profiles, and cytoskeleton protein expression, with minimal effects on ribosomal biogenesis. In contrast, using traction force and atomic force microscopy, we show that loss of eIF6 leads to reduced stiffness and force generation accompanied by cytoskeletal and focal adhesion defects. Mechanistically, we show that eIF6 is required for the correct spatial mechanoactivation of ERK1/2 via stabilization of an eIF6-RACK1-ERK1/2-FAK mechanocomplex, which is necessary for force-induced remodeling. These results reveal an extratranslational function for eIF6 and a novel paradigm for how mechanotransduction, the cellular cytoskeleton, and protein translation constituents are linked.
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Affiliation(s)
- Adam N. Keen
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Luke A. Payne
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Vedanta Mehta
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Alistair Rice
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London, UK
| | - Lisa J. Simpson
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Kar Lai Pang
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Armando del Rio Hernandez
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London, UK
| | - John S. Reader
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Ellie Tzima
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
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10
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Sun L, Liu S, Wang X, Zheng X, Chen Y, Shen H. eIF6 promotes the malignant progression of human hepatocellular carcinoma via the mTOR signaling pathway. J Transl Med 2021; 19:216. [PMID: 34016142 PMCID: PMC8139032 DOI: 10.1186/s12967-021-02877-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Eukaryotic translation initiation factor 6 (eIF6) has a crucial function in the maturation of 60S ribosomal subunits, and it controls the initiation of protein translation. Although emerging studies indicate that eIF6 is aberrantly expressed in various types of cancers, the functions and underlying molecular mechanisms of eIF6 in the pathological progression of hepatocellular carcinoma (HCC) remain unclear. This study aimed to evaluate the potential diagnostic and prognostic value of eIF6 in patients with HCC. METHODS HCC samples enrolled from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and our cohort were used to explore the role and mechanism of eIF6 in HCC. The diagnostic power of eIF6 was verified by receiver operating characteristic curve (ROC) analysis and its prognostic value was assessed by Kaplan-Meier analysis, and then related biological functions of eIF6 were determined in vitro and in vivo cancer models. In addition, potential molecular mechanism of eIF6 in HCC was unveiled by the gene set enrichment analysis and western blot assay. RESULTS We demonstrated that eIF6 expression was markedly increased in HCC, and elevated eIF6 expression correlated with pathological progression of HCC. Besides, eIF6 served as not only a new diagnostic biomarker but also an independent risk factor for OS in HCC patients. Functional studies indicated that the deletion of eIF6 displayed tumor-suppressor activity in HCC cells. Furthermore, we found that eIF6 could activate the mTOR-related signaling pathway and regulate the expression level of its target genes, such as CCND1, CDK4, CDK6, MYC, CASP3 and CTNNBL1, and these activities promoted proliferation and invasion of HCC cells. CONCLUSIONS The findings of this study provided a novel basis for understanding the potential role of eIF6 in promoting tumor growth and invasion, and exploited a promising strategy for improving diagnosis and prognosis of HCC.
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Affiliation(s)
- Liping Sun
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Shuguang Liu
- Department of Pathology, The Eighth Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Xiaopai Wang
- Department of Pathology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Xuefeng Zheng
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, China
| | - Ya Chen
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Hong Shen
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. .,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Targeting the DEAD-Box RNA Helicase eIF4A with Rocaglates-A Pan-Antiviral Strategy for Minimizing the Impact of Future RNA Virus Pandemics. Microorganisms 2021; 9:microorganisms9030540. [PMID: 33807988 PMCID: PMC8001013 DOI: 10.3390/microorganisms9030540] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/01/2021] [Accepted: 03/02/2021] [Indexed: 12/17/2022] Open
Abstract
The increase in pandemics caused by RNA viruses of zoonotic origin highlights the urgent need for broad-spectrum antivirals against novel and re-emerging RNA viruses. Broad-spectrum antivirals could be deployed as first-line interventions during an outbreak while virus-specific drugs and vaccines are developed and rolled out. Viruses depend on the host’s protein synthesis machinery for replication. Several natural compounds that target the cellular DEAD-box RNA helicase eIF4A, a key component of the eukaryotic translation initiation complex eIF4F, have emerged as potential broad-spectrum antivirals. Rocaglates, a group of flavaglines of plant origin that clamp mRNAs with highly structured 5′ untranslated regions (5′UTRs) onto the surface of eIF4A through specific stacking interactions, exhibit the largest selectivity and potential therapeutic indices among all known eIF4A inhibitors. Their unique mechanism of action limits the inhibitory effect of rocaglates to the translation of eIF4A-dependent viral mRNAs and a minor fraction of host mRNAs exhibiting stable RNA secondary structures and/or polypurine sequence stretches in their 5′UTRs, resulting in minimal potential toxic side effects. Maintaining a favorable safety profile while inducing efficient inhibition of a broad spectrum of RNA viruses makes rocaglates into primary candidates for further development as pan-antiviral therapeutics.
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Jungers CF, Elliff JM, Masson-Meyers DS, Phiel CJ, Origanti S. Regulation of eukaryotic translation initiation factor 6 dynamics through multisite phosphorylation by GSK3. J Biol Chem 2020; 295:12796-12813. [PMID: 32703900 DOI: 10.1074/jbc.ra120.013324] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/16/2020] [Indexed: 01/25/2023] Open
Abstract
Eukaryotic translation initiation factor 6 (eIF6) is essential for the synthesis of 60S ribosomal subunits and for regulating the association of 60S and 40S subunits. A mechanistic understanding of how eIF6 modulates translation in response to stress, specifically starvation-induced stress, is lacking. We here show a novel mode of eIF6 regulation by glycogen synthase kinase 3 (GSK3) that is predominantly active in response to serum starvation. Both GSK3α and GSK3β phosphorylate human eIF6. Multiple residues in the C terminus of eIF6 are phosphorylated by GSK3 in a sequential manner. In response to serum starvation, eIF6 accumulates in the cytoplasm, and this altered localization depends on phosphorylation by GSK3. Disruption of eIF6 phosphorylation exacerbates the translation inhibitory response to serum starvation and stalls cell growth. These results suggest that eIF6 regulation by GSK3 contributes to the attenuation of global protein synthesis that is critical for adaptation to starvation-induced stress.
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Affiliation(s)
- Courtney F Jungers
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Jonah M Elliff
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | | | - Christopher J Phiel
- Department of Integrative Biology, University of Colorado Denver, Colorado, USA
| | - Sofia Origanti
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA .,Department of Biology, Saint Louis University, St. Louis, Missouri, USA
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Pesce E, Miluzio A, Turcano L, Minici C, Cirino D, Calamita P, Manfrini N, Oliveto S, Ricciardi S, Grifantini R, Degano M, Bresciani A, Biffo S. Discovery and Preliminary Characterization of Translational Modulators that Impair the Binding of eIF6 to 60S Ribosomal Subunits. Cells 2020; 9:cells9010172. [PMID: 31936702 PMCID: PMC7017188 DOI: 10.3390/cells9010172] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic initiation factor 6 (eIF6) is necessary for the nucleolar biogenesis of 60S ribosomes. However, most of eIF6 resides in the cytoplasm, where it acts as an initiation factor. eIF6 is necessary for maximal protein synthesis downstream of growth factor stimulation. eIF6 is an antiassociation factor that binds 60S subunits, in turn preventing premature 40S joining and thus the formation of inactive 80S subunits. It is widely thought that eIF6 antiassociation activity is critical for its function. Here, we exploited and improved our assay for eIF6 binding to ribosomes (iRIA) in order to screen for modulators of eIF6 binding to the 60S. Three compounds, eIFsixty-1 (clofazimine), eIFsixty-4, and eIFsixty-6 were identified and characterized. All three inhibit the binding of eIF6 to the 60S in the micromolar range. eIFsixty-4 robustly inhibits cell growth, whereas eIFsixty-1 and eIFsixty-6 might have dose- and cell-specific effects. Puromycin labeling shows that eIF6ixty-4 is a strong global translational inhibitor, whereas the other two are mild modulators. Polysome profiling and RT-qPCR show that all three inhibitors reduce the specific translation of well-known eIF6 targets. In contrast, none of them affect the nucleolar localization of eIF6. These data provide proof of principle that the generation of eIF6 translational modulators is feasible.
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Affiliation(s)
- Elisa Pesce
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
| | - Annarita Miluzio
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
| | - Lorenzo Turcano
- Department of Translational and Discovery Research, IRBM S.p.A., Via Pontina km 30, 600, 00071 Pomezia (Roma), Italy;
| | - Claudia Minici
- Biocrystallography Unit, Dept. of Immunology, Transplantation and Infectious Diseases, IRCCS Scientific Institute San Raffaele, Via Olgettina 58, 20132 Milan, Italy; (C.M.); (M.D.)
| | - Delia Cirino
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
- DBS, University of Milan, Via Celoria 26, 20133 Milan, Italy
| | - Piera Calamita
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
- DBS, University of Milan, Via Celoria 26, 20133 Milan, Italy
| | - Nicola Manfrini
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
- DBS, University of Milan, Via Celoria 26, 20133 Milan, Italy
| | - Stefania Oliveto
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
- DBS, University of Milan, Via Celoria 26, 20133 Milan, Italy
| | - Sara Ricciardi
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
- DBS, University of Milan, Via Celoria 26, 20133 Milan, Italy
| | - Renata Grifantini
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
| | - Massimo Degano
- Biocrystallography Unit, Dept. of Immunology, Transplantation and Infectious Diseases, IRCCS Scientific Institute San Raffaele, Via Olgettina 58, 20132 Milan, Italy; (C.M.); (M.D.)
| | - Alberto Bresciani
- Department of Translational and Discovery Research, IRBM S.p.A., Via Pontina km 30, 600, 00071 Pomezia (Roma), Italy;
- Correspondence: (A.B.); (S.B.)
| | - Stefano Biffo
- National Institute of Molecular Genetics, “Fondazione Romeo ed Enrica Invernizzi”, INGM, Via Francesco Sforza 35, 20122 Milan, Italy; (E.P.); (A.M.); (D.C.); (P.C.); (N.M.); (S.O.); (S.R.); (R.G.)
- DBS, University of Milan, Via Celoria 26, 20133 Milan, Italy
- Correspondence: (A.B.); (S.B.)
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Chen HH, Tarn WY. uORF-mediated translational control: recently elucidated mechanisms and implications in cancer. RNA Biol 2019; 16:1327-1338. [PMID: 31234713 DOI: 10.1080/15476286.2019.1632634] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Protein synthesis is tightly regulated, and its dysregulation can contribute to the pathology of various diseases, including cancer. Increased or selective translation of mRNAs can promote cancer cell proliferation, metastasis and tumor expansion. Translational control is one of the most important means for cells to quickly adapt to environmental stresses. Adaptive translation involves various alternative mechanisms of translation initiation. Upstream open reading frames (uORFs) serve as a major regulator of stress-responsive translational control. Since recent advances in omics technologies including ribo-seq have expanded our knowledge of translation, we discuss emerging mechanisms for uORF-mediated translation regulation and its impact on cancer cell biology. A better understanding of dysregulated translational control of uORFs in cancer would facilitate the development of new strategies for cancer therapy.
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Affiliation(s)
- Hung-Hsi Chen
- Institute of Biomedical Sciences, Academia Sinica , Taipei , Taiwan
| | - Woan-Yuh Tarn
- Institute of Biomedical Sciences, Academia Sinica , Taipei , Taiwan
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15
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Rollins MG, Jha S, Bartom ET, Walsh D. RACK1 evolved species-specific multifunctionality in translational control through sequence plasticity within a loop domain. J Cell Sci 2019; 132:jcs.228908. [PMID: 31118235 DOI: 10.1242/jcs.228908] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 05/14/2019] [Indexed: 01/23/2023] Open
Abstract
Receptor of activated protein C kinase 1 (RACK1) is a highly conserved eukaryotic protein that regulates several aspects of mRNA translation; yet, how it does so, remains poorly understood. Here we show that, although RACK1 consists largely of conserved β-propeller domains that mediate binding to several other proteins, a short interconnecting loop between two of these blades varies across species to control distinct RACK1 functions during translation. Mutants and chimeras revealed that the amino acid composition of the loop is optimized to regulate interactions with eIF6, a eukaryotic initiation factor that controls 60S biogenesis and 80S ribosome assembly. Separately, phylogenetics revealed that, despite broad sequence divergence of the loop, there is striking conservation of negatively charged residues amongst protists and dicot plants, which is reintroduced to mammalian RACK1 by poxviruses through phosphorylation. Although both charged and uncharged loop mutants affect eIF6 interactions, only a negatively charged plant - but not uncharged yeast or human loop - enhances translation of mRNAs with adenosine-rich 5' untranslated regions (UTRs). Our findings reveal how sequence plasticity within the RACK1 loop confers multifunctionality in translational control across species.
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Affiliation(s)
- Madeline G Rollins
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sujata Jha
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Elizabeth T Bartom
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Derek Walsh
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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16
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Zhou ZD, Selvaratnam T, Lee JCT, Chao YX, Tan EK. Molecular targets for modulating the protein translation vital to proteostasis and neuron degeneration in Parkinson's disease. Transl Neurodegener 2019; 8:6. [PMID: 30740222 PMCID: PMC6360798 DOI: 10.1186/s40035-019-0145-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/14/2019] [Indexed: 12/13/2022] Open
Abstract
Parkinson's disease (PD) is the most common neurodegenerative movement disorder, which is characterized by the progressive loss of dopaminergic neurons in the Substantia Nigra pars compacta concomitant with Lewy body formation in affected brain areas. The detailed pathogenic mechanisms underlying the selective loss of dopaminergic neurons in PD are unclear, and no drugs or treatments have been developed to alleviate progressive dopaminergic neuron degeneration in PD. However, the formation of α-synuclein-positive protein aggregates in Lewy body has been identified as a common pathological feature of PD, possibly stemming from the consequence of protein misfolding and dysfunctional proteostasis. Proteostasis is the mechanism for maintaining protein homeostasis via modulation of protein translation, enhancement of chaperone capacity and the prompt clearance of misfolded protein by the ubiquitin proteasome system and autophagy. Deregulated protein translation and impaired capacities of chaperone or protein degradation can disturb proteostasis processes, leading to pathological protein aggregation and neurodegeneration in PD. In recent years, multiple molecular targets in the modulation of protein translation vital to proteostasis and dopaminergic neuron degeneration have been identified. The potential pathophysiological and therapeutic significance of these molecular targets to neurodegeneration in PD is highlighted.
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Affiliation(s)
- Zhi Dong Zhou
- Department of Research, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433 Singapore
- Signature Research Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School Singapore, 8 College Road, Singapore, Singapore
| | - Thevapriya Selvaratnam
- Department of Research, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433 Singapore
| | - Ji Chao Tristan Lee
- Department of Research, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433 Singapore
| | - Yin Xia Chao
- Department of Research, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433 Singapore
| | - Eng-King Tan
- Department of Research, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433 Singapore
- Department of Neurology, Singapore General Hospital, Outram Road, Singapore, 169608 Singapore
- Signature Research Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School Singapore, 8 College Road, Singapore, Singapore
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17
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Roy D, Kahler DJ, Yun C, Hubbard EJA. Functional Interactions Between rsks-1/S6K, glp-1/Notch, and Regulators of Caenorhabditis elegans Fertility and Germline Stem Cell Maintenance. G3 (BETHESDA, MD.) 2018; 8:3293-3309. [PMID: 30126834 PMCID: PMC6169383 DOI: 10.1534/g3.118.200511] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/06/2018] [Indexed: 12/17/2022]
Abstract
The proper accumulation and maintenance of stem cells is critical for organ development and homeostasis. The Notch signaling pathway maintains stem cells in diverse organisms and organ systems. In Caenorhabditis elegans, GLP-1/Notch activity prevents germline stem cell (GSC) differentiation. Other signaling mechanisms also influence the maintenance of GSCs, including the highly-conserved TOR substrate ribosomal protein S6 kinase (S6K). Although C. elegans bearing either a null mutation in rsks-1/S6K or a reduction-of-function (rf) mutation in glp-1/Notch produce half the normal number of adult germline progenitors, virtually all these single mutant animals are fertile. However, glp-1(rf) rsks-1(null) double mutant animals are all sterile, and in about half of their gonads, all GSCs differentiate, a distinctive phenotype associated with a significant reduction or loss of GLP-1 signaling. How rsks-1/S6K promotes GSC fate is unknown. Here, we determine that rsks-1/S6K acts germline-autonomously to maintain GSCs, and that it does not act through Cyclin-E or MAP kinase in this role. We found that interfering with translation also enhances glp-1(rf), but that regulation through rsks-1 cannot fully account for this effect. In a genome-scale RNAi screen for genes that act similarly to rsks-1/S6K, we identified 56 RNAi enhancers of glp-1(rf) sterility, many of which were previously not known to interact functionally with Notch. Further investigation revealed at least six candidates that, by genetic criteria, act linearly with rsks-1/S6K. These include genes encoding translation-related proteins, cacn-1/Cactin, an RNA exosome component, and a Hedgehog-related ligand. We found that additional Hedgehog-related ligands may share functional relationships with glp-1/Notch and rsks-1/S6K in maintaining germline progenitors.
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Affiliation(s)
- Debasmita Roy
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016
| | - David J Kahler
- NYU High Throughput Biology Laboratory, NYU Langone Health, New York, NY 10016
| | - Chi Yun
- NYU High Throughput Biology Laboratory, NYU Langone Health, New York, NY 10016
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016
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18
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Wang K, Wang C, Zhu CJ, Li G, Li Y, Feng YB, Ruan JJ, Zhu F, Meng Y, Zhou RP, Chen FH. 4-Amino-2-Trifluoromethyl-Phenyl Retinate induced leukemia cell differentiation by decreasing eIF6. Biochem Biophys Res Commun 2018; 503:2033-2039. [PMID: 30078681 DOI: 10.1016/j.bbrc.2018.07.153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 07/30/2018] [Indexed: 11/30/2022]
Abstract
4-Amino-2-Trifluoromethyl-Phenyl Retinate (ATPR), an all-trans retinoic acid (ATRA) derivative, possesses the ability to relief several carcinoma. Here, we explored the potential molecular mechanism of eukaryotic translation initiation factor 6 (eIF6) in ATPR-induced leukemia cell differentiation. Our research showed that ATPR could inhibit cell proliferation and promote cell differentiation in several leukemia cell lines. Besides, ATPR remarkably reduced the expression of eIF6 in vitro. Interestingly, the reduction of eIF6 contributed to restraining proliferation of K562 cells by inhibiting CyclinD1, C-myc and blocking cell cycle, as well as promoting differentiation of K562 cells by increasing the expression of C/EBPε, cell surface antigen CD11b and inducing renal-shrinkage of nuclear. Furthermore, the over-expression of eIF6 restrained the effects of ATPR on cell proliferation and maturation in K562 cells. In Addition, Notch1/CBF-1 signal activated by Chrysin could increase expression of eIF6 and restrain the differentiation in ATPR-induced K562 cells. Taken together, all above results indicated that ATPR induced differentiation of leukemia cells by decreasing eIF6 through Notch1/CBF-1 signal, which might exert an innovative treatment for leukemia.
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Affiliation(s)
- Ke Wang
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Cong Wang
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Chuan-Jun Zhu
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Ge Li
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Yue Li
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Yu-Bin Feng
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Jing-Jing Ruan
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Fei Zhu
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Yao Meng
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Ren-Peng Zhou
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China
| | - Fei-Hu Chen
- Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, China; The Key laboratory of Anti-inflammatory and Immune medicines, Ministry of Education, China.
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Gantenbein N, Bernhart E, Anders I, Golob-Schwarzl N, Krassnig S, Wodlej C, Brcic L, Lindenmann J, Fink-Neuboeck N, Gollowitsch F, Stacher-Priehse E, Asslaber M, Gogg-Kamerer M, Rolff J, Hoffmann J, Silvestri A, Regenbrecht C, Reinhard C, Pehserl AM, Pichler M, Sokolova O, Naumann M, Mitterer V, Pertschy B, Bergler H, Popper H, Sattler W, Haybaeck J. Influence of eukaryotic translation initiation factor 6 on non-small cell lung cancer development and progression. Eur J Cancer 2018; 101:165-180. [PMID: 30077122 DOI: 10.1016/j.ejca.2018.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/22/2018] [Accepted: 07/02/2018] [Indexed: 12/12/2022]
Abstract
Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Dysregulation of protein synthesis plays a major role in carcinogenesis, a process regulated at multiple levels, including translation of mRNA into proteins. Ribosome assembly requires correct association of ribosome subunits, which is ensured by eukaryotic translation initiation factors (eIFs). eIFs have become targets in cancer therapy studies, and promising data on eIF6 in various cancer entities have been reported. Therefore, we hypothesised that eIF6 represents a crossroad for pulmonary carcinogenesis. High levels of eIF6 are associated with shorter patient overall survival in adenocarcinoma (ADC), but not in squamous cell carcinoma (SQC) of the lung. We demonstrate significantly higher protein expression of eIF6 in ADC and SQC than in healthy lung tissue based on immunohistochemical data from tissue microarrays (TMAs) and on fresh frozen lung tissue. Depletion of eIF6 in ADC and SQC lung cancer cell lines inhibited cell proliferation and induced apoptosis. Knockdown of eIF6 led to pre-rRNA processing and ribosomal 60S maturation defects. Our data indicate that eIF6 is upregulated in NSCLC, suggesting an important contribution of eIF6 to the development and progression of NSCLC and a potential for new treatment strategies against NSCLC.
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Affiliation(s)
- Nadine Gantenbein
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria
| | - Eva Bernhart
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Ines Anders
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Nicole Golob-Schwarzl
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria
| | - Stefanie Krassnig
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Christina Wodlej
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria
| | - Luka Brcic
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Joerg Lindenmann
- Division of Thoracic and Hyperbaric Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
| | - Nicole Fink-Neuboeck
- Division of Thoracic and Hyperbaric Surgery, Medical University of Graz, Auenbruggerplatz 29, 8036 Graz, Austria
| | - Franz Gollowitsch
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Elvira Stacher-Priehse
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Martin Asslaber
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Margit Gogg-Kamerer
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Jana Rolff
- Experimental Pharmacology & Oncology Berlin GmbH-Berlin-Buch, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Jens Hoffmann
- Experimental Pharmacology & Oncology Berlin GmbH-Berlin-Buch, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Alessandra Silvestri
- Cpo - Cellular Phenomics & Oncology Berlin-Buch GmbH, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Christian Regenbrecht
- Cpo - Cellular Phenomics & Oncology Berlin-Buch GmbH, Robert-Rössle-Str. 10, 13125 Berlin-Buch, Germany
| | - Christoph Reinhard
- Eli Lilly & Company, Lilly Corporate Center, 46285 Indiana, Indianapolis, USA
| | - Anna-Maria Pehserl
- Division of Oncology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Martin Pichler
- Division of Oncology, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria
| | - Olga Sokolova
- Institute of Experimental Internal Medicine, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany
| | - Valentin Mitterer
- Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Brigitte Pertschy
- Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Helmut Bergler
- Institute of Molecular Biosciences, Karl-Franzens-University of Graz, Humboldtstraße 50, 8010 Graz, Austria
| | - Helmut Popper
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Wolfgang Sattler
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Johannes Haybaeck
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria; Center for Biomarker Research in Medicine, Stiftingtalstrasse 5, 8010 Graz, Austria; Department of Pathology, Medical Faculty, Otto-von-Guericke-University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany.
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20
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Carotenuto R, Tussellino M. Xenopus laevis oocyte as a model for the study of the cytoskeleton. C R Biol 2018; 341:219-227. [PMID: 29705198 DOI: 10.1016/j.crvi.2018.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/06/2018] [Indexed: 11/28/2022]
Abstract
At the beginning of diplotene, the oocyte of Xenopus laevis is a cell of about 10-20 microns destined to increase 10,000-fold its size when the oocyte becomes filled with yolk platelets and has accumulated a great number of pigment granules in a half of its periphery. Its internal architecture is gradually accomplished during growth because of several factors, especially because of cytoskeletal changes. In the fully-grown oocyte, the cytoskeleton appears to sustain the eccentrically located germinal vesicle through arms radiating from the cortex to the germinal vesicle, a unique organization not to be found in other Amphibians. In this report, we summarized and analysed steps of cytoskeletal proteins and related mRNAs organization and function throughout diplotene stage, highlighting our studies in this animal model. The cytoskeletal proteins appear to exploit their activity with respect to ribosomal 60S subunit maturation and during translation. Most importantly, the polarity of the oocyte is achieved through a sophisticated and highly organized localization of mRNAs and cytoskeletal proteins in one side of the cell. This asymmetry will start the construction of the oocyte polarity that is instrumental for determining the characteristic of this cell, which will become an embryo. Moreover, in the same time membrane composition, conditioned by the underlying cytoskeletal organization, will acquire the prerequisites for sperm binding and fusion.
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Affiliation(s)
- Rosa Carotenuto
- Department of Biology, University of Naples Federico II, Napoli, Italy.
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21
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Zhu W, Li GX, Chen HL, Liu XY. The role of eukaryotic translation initiation factor 6 in tumors. Oncol Lett 2017; 14:3-9. [PMID: 28693127 PMCID: PMC5494901 DOI: 10.3892/ol.2017.6161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 10/26/2016] [Indexed: 12/28/2022] Open
Abstract
Eukaryotic translation initiation factor 6 (eIF6) affects the maturation of 60S ribosomal subunits. Found in yeast and mammalian cells, eIF6 is primarily located in the cytoplasm of mammalian cells. Emerging evidence has demonstrated that the dysregulated expression of eIF6 is important in several types of human cancer, including head and neck carcinoma, colorectal cancer, non-small cell lung cancer and ovarian serous adenocarcinoma. However, the molecular mechanisms by which eIF6 functions during tumor formation and progression remain elusive. The present review focuses on recent progress in terms of the mechanisms and functions of eIF6 in human tumorigenesis or cancer cell lines, along with the signal transduction pathways in which this novel translation initiation factor may participate. Oncogenic Ras activates Notch-1 and promotes transcription of eIF6 via a recombining binding protein suppressor of Hairless-dependent mechanism. In addition, overexpression of eIF6 results in aberrant activation of the Wnt/β-catenin signaling pathway. Similarly, overexpressed eIF6 regulates its downstream modulator, cell division control protein 42, which in turn affects oncogenesis. Finally, the potential of eIF6 as a biomarker for diagnosis of cancer is also discussed in the present review.
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Affiliation(s)
- Wei Zhu
- Department of Pathology, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
| | - Gui Xian Li
- Department of Pathology, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
| | - Hong Lang Chen
- Department of Pharmacology, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
| | - Xing Yan Liu
- Sino-American Cancer Research Institute, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
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22
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Calamita P, Miluzio A, Russo A, Pesce E, Ricciardi S, Khanim F, Cheroni C, Alfieri R, Mancino M, Gorrini C, Rossetti G, Peluso I, Pagani M, Medina DL, Rommens J, Biffo S. SBDS-Deficient Cells Have an Altered Homeostatic Equilibrium due to Translational Inefficiency Which Explains their Reduced Fitness and Provides a Logical Framework for Intervention. PLoS Genet 2017; 13:e1006552. [PMID: 28056084 PMCID: PMC5249248 DOI: 10.1371/journal.pgen.1006552] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 01/20/2017] [Accepted: 12/24/2016] [Indexed: 12/26/2022] Open
Abstract
Ribosomopathies are a family of inherited disorders caused by mutations in genes necessary for ribosomal function. Shwachman-Diamond Bodian Syndrome (SDS) is an autosomal recessive disease caused, in most patients, by mutations of the SBDS gene. SBDS is a protein required for the maturation of 60S ribosomes. SDS patients present exocrine pancreatic insufficiency, neutropenia, chronic infections, and skeletal abnormalities. Later in life, patients are prone to myelodisplastic syndrome and acute myeloid leukemia (AML). It is unknown why patients develop AML and which cellular alterations are directly due to the loss of the SBDS protein. Here we derived mouse embryonic fibroblast lines from an SbdsR126T/R126T mouse model. After their immortalization, we reconstituted them by adding wild type Sbds. We then performed a comprehensive analysis of cellular functions including colony formation, translational and transcriptional RNA-seq, stress and drug sensitivity. We show that: 1. Mutant Sbds causes a reduction in cellular clonogenic capability and oncogene-induced transformation. 2. Mutant Sbds causes a marked increase in immature 60S subunits, limited impact on mRNA specific initiation of translation, but reduced global protein synthesis capability. 3. Chronic loss of SBDS activity leads to a rewiring of gene expression with reduced ribosomal capability, but increased lysosomal and catabolic activity. 4. Consistently with the gene signature, we found that SBDS loss causes a reduction in ATP and lactate levels, and increased susceptibility to DNA damage. Combining our data, we conclude that a cell-specific fragile phenotype occurs when SBDS protein drops below a threshold level, and propose a new interpretation of the disease. Shwachman Diamond syndrome (SDS) is an inherited disease. SDS presents, as hallmarks, exocrine pancreatic insufficiency, increased rate of infections, and higher incidence of leukemia. Most cases are due to mutations in the SBDS gene. SBDS encodes for a ribosome maturation factor. In this study, we immortalized mouse fibroblasts carrying one of the most common mutation of SDS patients and performed a thorough analysis of their properties. We show that the loss of SBDS activity causes a rewiring of gene expression and cellular metabolism. Overall we find a reduction of protein synthesis capability, a lower energy status, and increased lysosomal capability. SBDS mutant cells have an increased susceptibility to various forms of stress, but are strikingly resistant to oncogene-induced transformation. We propose a model that explains the complex phenotype of SDS patients and suggests roads for a rationale treatment.
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Affiliation(s)
- Piera Calamita
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
- * E-mail: (SB); (PC)
| | - Annarita Miluzio
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
| | - Arianna Russo
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
- DiSIT, University of Eastern Piedmont, Alessandria, Italy
| | - Elisa Pesce
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
| | - Sara Ricciardi
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
| | - Farhat Khanim
- School of Biosciences, University of Birmingham Edgbaston Birmingham, United Kingdom
| | - Cristina Cheroni
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
| | - Roberta Alfieri
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
| | - Marilena Mancino
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
| | - Chiara Gorrini
- Campbell Family Institute for Breast Cancer Research, University Health Network, Toronto, Ontario, Canada
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Grazisa Rossetti
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
| | - Ivana Peluso
- Telethon Institute of Genetics and Medicine (TIGEM)-Fondazione Telethon, Pozzuoli, Italy
| | - Massimiliano Pagani
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Diego L. Medina
- Telethon Institute of Genetics and Medicine (TIGEM)-Fondazione Telethon, Pozzuoli, Italy
| | | | - Stefano Biffo
- INGM, National Institute of Molecular Genetics, “Romeo ed Enrica Invernizzi”, Milan, Italy
- DBS, Università degli Studi di Milano, Milan, Italy
- * E-mail: (SB); (PC)
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23
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Yang QQ, Yang SS, Tan JL, Luo GX, He WF, Wu J. Process of Hypertrophic Scar Formation: Expression of Eukaryotic Initiation Factor 6. Chin Med J (Engl) 2016; 128:2787-91. [PMID: 26481747 PMCID: PMC4736889 DOI: 10.4103/0366-6999.167359] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: Hypertrophic scar is one of the most common complications and often causes the disfigurement or deformity in burn or trauma patients. Therapeutic methods on hypertrophic scar treatment have limitations due to the poor understanding of mechanisms of hypertrophic scar formation. To throw light on the molecular mechanism of hypertrophic scar formation will definitely improve the outcome of the treatment. This study aimed to illustrate the negative role of eukaryotic initiation factor 6 (eIF6) in the process of human hypertrophic scar formation, and provide a possible indicator of hypertrophic scar treatment and a potential target molecule for hypertrophic scar. Methods: In the present study, we investigated the protein expression of eIF6 in the human hypertrophic scar of different periods by immunohistochemistry and Western blot analysis. Results: In the hypertrophic scar tissue, eIF6 expression was significantly decreased and absent in the basal layer of epidermis in the early period, and increased slowly and began to appear in the basal layer of epidermis by the scar formation time. Conclusions: This study confirmed that eIF6 expression was significantly related to the development of hypertrophic scar, and the eIF6 may be a target molecule for hypertrophic scar control or could be an indicator of the outcomes for other treatment modalities.
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Affiliation(s)
| | | | | | | | | | - Jun Wu
- Institute of Burn Research, State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, The Third Military Medical University, Chongqing 400038; Chongqing Key Laboratory for Disease Proteomics, The Third Military Medical University, Chongqing 400038, China
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24
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Miluzio A, Oliveto S, Pesce E, Mutti L, Murer B, Grosso S, Ricciardi S, Brina D, Biffo S. Expression and activity of eIF6 trigger malignant pleural mesothelioma growth in vivo. Oncotarget 2016; 6:37471-85. [PMID: 26462016 PMCID: PMC4741942 DOI: 10.18632/oncotarget.5462] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 09/24/2015] [Indexed: 12/13/2022] Open
Abstract
eIF6 is an antiassociation factor that regulates the availability of active 80S. Its activation is driven by the RACK1/PKCβ axis, in a mTORc1 independent manner. We previously described that eIF6 haploinsufficiency causes a striking survival in the Eμ-Myc mouse lymphoma model, with lifespans extended up to 18 months. Here we screen for eIF6 expression in human cancers. We show that Malignant Pleural Mesothelioma tumors (MPM) and a MPM cell line (REN cells) contain high levels of hyperphosphorylated eIF6. Enzastaurin is a PKC beta inhibitor used in clinical trials. We prove that Enzastaurin treatment decreases eIF6 phosphorylation rate, but not eIF6 protein stability. The growth of REN, in vivo, and metastasis are reduced by either Enzastaurin treatment or eIF6 shRNA. Molecular analysis reveals that eIF6 manipulation affects the metabolic status of malignant mesothelioma cells. Less glycolysis and less ATP content are evident in REN cells depleted for eIF6 or treated with Enzastaurin (Anti-Warburg effect). We propose that eIF6 is necessary for malignant mesothelioma growth, in vivo, and can be targeted by kinase inhibitors.
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Affiliation(s)
- Annarita Miluzio
- Molecular Histology and Cell Growth Unit, Istituto Nazionale Genetica Molecolare, "Romeo ed Enrica Invernizzi", Milano, Italy
| | - Stefania Oliveto
- Molecular Histology and Cell Growth Unit, Istituto Nazionale Genetica Molecolare, "Romeo ed Enrica Invernizzi", Milano, Italy.,Dipartimento di Scienze e Innovazione Tecnologica, University of Eastern Piedmont, Alessandria, Italy
| | - Elisa Pesce
- Molecular Histology and Cell Growth Unit, Istituto Nazionale Genetica Molecolare, "Romeo ed Enrica Invernizzi", Milano, Italy
| | - Luciano Mutti
- Biomedicine Institute, The University of Salford, The Crescent, Salford, UK
| | - Bruno Murer
- Hospital Dall'Angelo, Pathology Unit, Venice, Italy
| | | | - Sara Ricciardi
- Molecular Histology and Cell Growth Unit, Istituto Nazionale Genetica Molecolare, "Romeo ed Enrica Invernizzi", Milano, Italy
| | - Daniela Brina
- Molecular Histology and Cell Growth Unit, Istituto Nazionale Genetica Molecolare, "Romeo ed Enrica Invernizzi", Milano, Italy
| | - Stefano Biffo
- Molecular Histology and Cell Growth Unit, Istituto Nazionale Genetica Molecolare, "Romeo ed Enrica Invernizzi", Milano, Italy.,Department of Biosciences, University of Milan, Milan, Italy
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25
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Smethurst DGJ, Cooper KF. ER fatalities-The role of ER-mitochondrial contact sites in yeast life and death decisions. Mech Ageing Dev 2016; 161:225-233. [PMID: 27507669 DOI: 10.1016/j.mad.2016.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/22/2016] [Accepted: 07/19/2016] [Indexed: 12/22/2022]
Abstract
Following extracellular stress signals, all eukaryotic cells choose whether to elicit a pro-survival or pro-death response. The decision over which path to take is governed by the severity and duration of the damage. In response to mild stress, pro-survival programs are initiated (unfolded protein response, autophagy, mitophagy) whereas severe or chronic stress forces the cell to abandon these adaptive programs and shift towards regulated cell death to remove irreversibly damaged cells. Both pro-survival and pro-death programs involve regulated communication between the endoplasmic reticulum (ER) and mitochondria. In yeast, recent data suggest this inter-organelle contact is facilitated by the endoplasmic reticulum mitochondria encounter structure (ERMES). These membrane contacts are not only important for the exchange of cellular signals, but also play a role in mitochondrial tethering during mitophagy, mitochondrial fission and mitochondrial inheritance. This review focuses on recent findings in yeast that shed light on how ER-mitochondrial communication mediates critical cell fate decisions.
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Affiliation(s)
- Daniel G J Smethurst
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, NJ, 08055 USA
| | - Katrina F Cooper
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, NJ, 08055 USA.
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26
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Bai D, Zhang J, Li T, Hang R, Liu Y, Tian Y, Huang D, Qu L, Cao X, Ji J, Zheng X. The ATPase hCINAP regulates 18S rRNA processing and is essential for embryogenesis and tumour growth. Nat Commun 2016; 7:12310. [PMID: 27477389 PMCID: PMC4974663 DOI: 10.1038/ncomms12310] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/20/2016] [Indexed: 12/29/2022] Open
Abstract
Dysfunctions in ribosome biogenesis cause developmental defects and increased cancer susceptibility; however, the connection between ribosome assembly and tumorigenesis remains unestablished. Here we show that hCINAP (also named AK6) is required for human 18S rRNA processing and 40S subunit assembly. Homozygous CINAP−/− mice show embryonic lethality. The heterozygotes are viable and show defects in 18S rRNA processing, whereas no delayed cell growth is observed. However, during rapid growth, CINAP haploinsufficiency impairs protein synthesis. Consistently, hCINAP depletion in fast-growing cancer cells inhibits ribosome assembly and abolishes tumorigenesis. These data demonstrate that hCINAP reduction is a specific rate-limiting controller during rapid growth. Notably, hCINAP is highly expressed in cancers and correlated with a worse prognosis. Genome-wide polysome profiling shows that hCINAP selectively modulates cancer-associated translatome to promote malignancy. Our results connect the role of hCINAP in ribosome assembly with tumorigenesis. Modulation of hCINAP expression may be a promising target for cancer therapy. Perturbations in ribosome biogenesis affect development and increase cancer susceptibility. Here, the authors show that hCINAP is required for 18S rRNA processing, is highly expressed in cancers, and promotes cancer cell growth by upregulating the translation of cancer-associated genes.
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Affiliation(s)
- Dongmei Bai
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Jinfang Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Tingting Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Runlai Hang
- State key Laboratory of Plant Genetics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100039, China
| | - Yong Liu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Yonglu Tian
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Dadu Huang
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Linglong Qu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
| | - Xiaofeng Cao
- State key Laboratory of Plant Genetics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,College of Life Sciences, University of the Chinese Academy of Sciences, Beijing 100039, China
| | - Jiafu Ji
- Key Laboratory of Carcinogenesis and Translational Research, Department of Gastrointestinal Surgery, Peking University Caner Hospital and Institute, Beijing 100142, China
| | - Xiaofeng Zheng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.,Department of Biochemistry and Molecular Biology, School of Life Sciences, Peking University, Yiheyuan Road No. 5, Beijing 100871, China
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27
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Wilson-Edell KA, Kehasse A, Scott GK, Yau C, Rothschild DE, Schilling B, Gabriel BS, Yevtushenko MA, Hanson IM, Held JM, Gibson BW, Benz CC. RPL24: a potential therapeutic target whose depletion or acetylation inhibits polysome assembly and cancer cell growth. Oncotarget 2015; 5:5165-76. [PMID: 24970821 PMCID: PMC4148130 DOI: 10.18632/oncotarget.2099] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Partial loss of large ribosomal subunit protein 24 (RPL24) function is known to protect mice against Akt or Myc-driven cancers, in part via translational inhibition of a subset of cap(eIF4E)-dependently translated mRNAs. The role of RPL24 in human malignancies is unknown. By analyzing a public dataset of matched human breast cancers and normal mammary tissue, we found that breast cancers express significantly more RPL24 than matched normal breast samples. Depletion of RPL24 in breast cancer cells by >70% reduced cell viability by 80% and decreased protein expression of the eIF4E-dependently translated proteins cyclin D1 (75%), survivin (46%) and NBS1 (30%) without altering GAPDH or beta-tubulin levels. RPL24 knockdown also reduced 80S subunit levels relative to 40S and 60S levels. These effects on expression of eIF4E-dependent proteins and ribosome assembly were mimicked by 2-24 h treatment with the pan-HDACi, trichostatin A (TSA), which induced acetylation of 15 different polysome-associated proteins including RPL24. Furthermore, HDAC6-selective inhibition or HDAC6 knockdown induced ribosomal protein acetylation. Via mass spectrometry, we found that 60S-associated, but not, polysome-associated, RPL24 undergoes HDACi-induced acetylation on K27. Thus, RPL24 K27 acetylation may play a role in ribosome assembly. These findings point toward a novel acetylation-dependent polysome assembly mechanism regulating tumorigenesis.
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Affiliation(s)
| | | | - Gary K Scott
- Buck Institute for Research on Aging; Novato, CA, USA
| | - Christina Yau
- Buck Institute for Research on Aging; Novato, CA, USA
| | | | | | - Bianca S Gabriel
- Buck Institute for Research on Aging; Novato, CA, USA. Master of Science in Biology Program; Dominican University; San Rafael, CA, USA
| | - Mariya A Yevtushenko
- Buck Institute for Research on Aging; Novato, CA, USA. Master of Science in Biology Program; Dominican University; San Rafael, CA, USA
| | | | - Jason M Held
- Buck Institute for Research on Aging; Novato, CA, USA
| | - Bradford W Gibson
- Buck Institute for Research on Aging; Novato, CA, USA. Department of Pharmaceutical Chemistry, University of California, San Francisco, CA USA
| | - Christopher C Benz
- Buck Institute for Research on Aging; Novato, CA, USA. Oncology-Hematology Division, Department of Medicine, University of California, San Francisco, CA USA
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28
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Browning KS, Bailey-Serres J. Mechanism of cytoplasmic mRNA translation. THE ARABIDOPSIS BOOK 2015; 13:e0176. [PMID: 26019692 PMCID: PMC4441251 DOI: 10.1199/tab.0176] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein synthesis is a fundamental process in gene expression that depends upon the abundance and accessibility of the mRNA transcript as well as the activity of many protein and RNA-protein complexes. Here we focus on the intricate mechanics of mRNA translation in the cytoplasm of higher plants. This chapter includes an inventory of the plant translational apparatus and a detailed review of the translational processes of initiation, elongation, and termination. The majority of mechanistic studies of cytoplasmic translation have been carried out in yeast and mammalian systems. The factors and mechanisms of translation are for the most part conserved across eukaryotes; however, some distinctions are known to exist in plants. A comprehensive understanding of the complex translational apparatus and its regulation in plants is warranted, as the modulation of protein production is critical to development, environmental plasticity and biomass yield in diverse ecosystems and agricultural settings.
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Affiliation(s)
- Karen S. Browning
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin TX 78712-0165
- Both authors contributed equally to this work
| | - Julia Bailey-Serres
- Department of Botany and Plant Sciences and Center for Plant Cell Biology, University of California, Riverside, CA, 92521 USA
- Both authors contributed equally to this work
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29
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Cytoskeletal proteins associate with components of the ribosomal maturation and translation apparatus in Xenopus stage I oocytes. ZYGOTE 2014; 23:669-82. [DOI: 10.1017/s0967199414000409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SummaryActin-based cytoskeleton (CSK) and microtubules may bind to RNAs and related molecules implicated in translation. However, many questions remain to be answered regarding the role of cytoskeletal components in supporting the proteins involved in steps in the maturation and translation processes. Here, we performed co-immunoprecipitation and immunofluorescence to examine the association between spectrins, keratins and tubulin and proteins involved in 60S ribosomal maturation and translation in Xenopus stage I oocytes, including ribosomal rpl10, eukaryotic initiation factor 6 (Eif6), thesaurins A/B, homologs of the eEF1α elongation factor, and P0, the ribosomal stalk protein. We found that rpl10 and eif6 cross-reacted with the actin-based CSK and with tubulin. rpl10 co-localizes with spectrin, particularly in the perinuclear region. eif6 is similarly localized. Given that upon ribosomal maturation, the insertion of rpl10 into the 60S subunit occurs simultaneously with the release of eif6, one can hypothesise that actin-based CSK and microtubules provide the necessary scaffold for the insertion/release of these two molecules and, subsequently, for eif6 transport and binding to the mature 60S subunit. P0 and thesaurins cross-reacted with only spectrin and cytokeratins. Thesaurins aggregated at the oocyte periphery, rendering this a territory favourable site for protein synthesis; the CSK may support the interaction between thesaurins and sites of the translating ribosome. Moreover, given that the assembly of the ribosome stalk, where P0 is located, to the 60S subunit is essential for the release of eif6, it can be hypothesised that the CSK can facilitate the binding of the stalk to the 60S.
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30
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Ponti D, Bellenchi GC, Puca R, Bastianelli D, Maroder M, Ragona G, Roussel P, Thiry M, Mercola D, Calogero A. The transcription factor EGR1 localizes to the nucleolus and is linked to suppression of ribosomal precursor synthesis. PLoS One 2014; 9:e96037. [PMID: 24787739 PMCID: PMC4006901 DOI: 10.1371/journal.pone.0096037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 04/03/2014] [Indexed: 01/13/2023] Open
Abstract
EGR1 is an immediate early gene with a wide range of activities as transcription factor, spanning from regulation of cell growth to differentiation. Numerous studies show that EGR1 either promotes the proliferation of stimulated cells or suppresses the tumorigenic growth of transformed cells. Upon interaction with ARF, EGR1 is sumoylated and acquires the ability to bind to specific targets such as PTEN and in turn to regulate cell growth. ARF is mainly localized to the periphery of nucleolus where is able to negatively regulate ribosome biogenesis. Since EGR1 colocalizes with ARF under IGF-1 stimulation we asked the question of whether EGR1 also relocate to the nucleolus to interact with ARF. Here we show that EGR1 colocalizes with nucleolar markers such as fibrillarin and B23 in the presence of ARF. Western analysis of nucleolar extracts from HeLa cells was used to confirm the presence of EGR1 in the nucleolus mainly as the 100 kDa sumoylated form. We also show that the level of the ribosomal RNA precursor 47S is inversely correlated to the level of EGR1 transcripts. The EGR1 iseffective to regulate the synthesis of the 47S rRNA precursor. Then we demonstrated that EGR1 binds to the Upstream Binding Factor (UBF) leading us to hypothesize that the regulating activity of EGR1 is mediated by its interaction within the transcriptional complex of RNA polymerase I. These results confirm the presence of EGR1 in the nucleolus and point to a role for EGR1 in the control of nucleolar metabolism.
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Affiliation(s)
- Donatella Ponti
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | | | - Rosa Puca
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Daniela Bastianelli
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Marella Maroder
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Giuseppe Ragona
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
| | - Pascal Roussel
- RNA Biology, FRE 3402 CNRS-Universitè Pierre et Marie Curie, Paris, France
| | - Marc Thiry
- Unit of Cell Biology, GIGA-Neuroscience, University of Liege, CHU SartTilman, Liege, Belgium
| | - Dan Mercola
- Department of Pathology and Laboratory Medicine, University of California, Irvine, California, United States of America
| | - Antonella Calogero
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome La Sapienza, Latina, Italy
- * E-mail:
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Loreni F, Mancino M, Biffo S. Translation factors and ribosomal proteins control tumor onset and progression: how? Oncogene 2014; 33:2145-56. [PMID: 23644661 DOI: 10.1038/onc.2013.153] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/12/2013] [Accepted: 03/13/2013] [Indexed: 12/18/2022]
Abstract
Gene expression is shaped by translational control. The modalities and the extent by which translation factors modify gene expression have revealed therapeutic scenarios. For instance, eukaryotic initiation factor (eIF)4E activity is controlled by the signaling cascade of growth factors, and drives tumorigenesis by favoring the translation of specific mRNAs. Highly specific drugs target the activity of eIF4E. Indeed, the antitumor action of mTOR complex 1 (mTORc1) blockers like rapamycin relies on their capability to inhibit eIF4E assembly into functional eIF4F complexes. eIF4E biology, from its inception to recent pharmacological targeting, is proof-of-principle that translational control is druggable. The case for eIF4E is not isolated. The translational machinery is involved in the biology of cancer through many other mechanisms. First, untranslated sequences on mRNAs as well as noncoding RNAs regulate the translational efficiency of mRNAs that are central for tumor progression. Second, other initiation factors like eIF6 show a tumorigenic potential by acting downstream of oncogenic pathways. Third, genetic alterations in components of the translational apparatus underlie an entire class of inherited syndromes known as 'ribosomopathies' that are associated with increased cancer risk. Taken together, data suggest that in spite of their evolutionary conservation and ubiquitous nature, variations in the activity and levels of ribosomal proteins and translation factors generate highly specific effects. Beside, as the structures and biochemical activities of several noncoding RNAs and initiation factors are known, these factors may be amenable to rational pharmacological targeting. The future is to design highly specific drugs targeting the translational apparatus.
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Affiliation(s)
- F Loreni
- Department of Biology, University 'Tor Vergata', Roma, Italy
| | - M Mancino
- 1] San Raffaele Scientific Institute, Ospedale San Raffaele, Milan, Italy [2] DISIT, Alessandria, Italy
| | - S Biffo
- 1] San Raffaele Scientific Institute, Ospedale San Raffaele, Milan, Italy [2] DISIT, Alessandria, Italy
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Ammerman ML, Tomasello DL, Faktorová D, Kafková L, Hashimi H, Lukeš J, Read LK. A core MRB1 complex component is indispensable for RNA editing in insect and human infective stages of Trypanosoma brucei. PLoS One 2013; 8:e78015. [PMID: 24250748 PMCID: PMC3820961 DOI: 10.1371/journal.pone.0078015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 09/11/2013] [Indexed: 11/18/2022] Open
Abstract
Uridine insertion/deletion RNA editing is a unique and vital process in kinetoplastids, required for creation of translatable open reading frames in most mitochondrially-encoded RNAs. Emerging as a key player in this process is the mitochondrial RNA binding 1 (MRB1) complex. MRB1 comprises an RNA-independent core complex of at least six proteins, including the GAP1/2 guide RNA (gRNA) binding proteins. The core interacts in an RNA-enhanced or -dependent manner with imprecisely defined TbRGG2 subcomplexes, Armadillo protein MRB10130, and additional factors that comprise the dynamic MRB1 complex. Towards understanding MRB1 complex function in RNA editing, we present here functional characterization of the pentein domain-containing MRB1 core protein, MRB11870. Inducible RNAi studies demonstrate that MRB11870 is essential for proliferation of both insect vector and human infective stage T. brucei. MRB11870 ablation causes a massive defect in RNA editing, affecting both pan-edited and minimally edited mRNAs, but does not substantially affect mitochondrial RNA stability or processing of precursor transcripts. The editing defect in MRB1-depleted cells occurs at the initiation stage of editing, as pre-edited mRNAs accumulate. However, the gRNAs that direct editing remain abundant in the knockdown cells. To examine the contribution of MRB11870 to MRB1 macromolecular interactions, we tagged core complexes and analyzed their composition and associated proteins in the presence and absence of MRB11870. These studies demonstrated that MRB11870 is essential for association of GAP1/2 with the core, as well as for interaction of the core with other proteins and subcomplexes. Together, these data support a model in which the MRB1 core mediates functional interaction of gRNAs with the editing machinery, having GAP1/2 as its gRNA binding constituents. MRB11870 is a critical component of the core, essential for its structure and function.
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Affiliation(s)
- Michelle L. Ammerman
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
| | - Danielle L. Tomasello
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
| | - Drahomíra Faktorová
- Institute of Parasitology, Biology Center, Czech Academy of Sciences and Faculty of Science, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Lucie Kafková
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
| | - Hassan Hashimi
- Institute of Parasitology, Biology Center, Czech Academy of Sciences and Faculty of Science, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Center, Czech Academy of Sciences and Faculty of Science, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Laurie K. Read
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, United States of America
- * E-mail:
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Chen L, Aktas BH, Wang Y, He X, Sahoo R, Zhang N, Denoyelle S, Kabha E, Yang H, Freedman RY, Supko JG, Chorev M, Wagner G, Halperin JA. Tumor suppression by small molecule inhibitors of translation initiation. Oncotarget 2013; 3:869-81. [PMID: 22935625 PMCID: PMC3478463 DOI: 10.18632/oncotarget.598] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Translation initiation factors are over-expressed and/or activated in many human cancers and may contribute to their genesis and/or progression. Removal of physiologic restraints on translation initiation causes malignant transformation. Conversely, restoration of physiological restrains on translation initiation reverts malignant phenotypes. Here, we extensively characterize the anti-cancer activity of two small molecule inhibitors of translation initiation: #1181, which targets the eIF2-GTP-Met-tRNAi ternary complex, and 4EGI-1, which targets the eIF4F complex. In vitro, both molecules inhibit translation initiation, abrogate preferentially translation of mRNAs coding for oncogenic proteins, and inhibit proliferation of human cancer cells. In vivo, both #1181 and 4EGI-1 strongly inhibit growth of human breast and melanoma cancer xenografts without any apparent macroscopic- or microscopic-toxicity. Mechanistically, #1181 phosphorylates eIF2α while 4EGI-1 disrupts eIF4G/eIF4E interaction in the tumors excised from mice treated with these agents. These data indicate that inhibition of translation initiation is a new paradigm in cancer therapy.
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Voigts-Hoffmann F, Klinge S, Ban N. Structural insights into eukaryotic ribosomes and the initiation of translation. Curr Opin Struct Biol 2012; 22:768-77. [DOI: 10.1016/j.sbi.2012.07.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/09/2012] [Accepted: 07/10/2012] [Indexed: 01/05/2023]
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Wilson DN, Doudna Cate JH. The structure and function of the eukaryotic ribosome. Cold Spring Harb Perspect Biol 2012; 4:4/5/a011536. [PMID: 22550233 DOI: 10.1101/cshperspect.a011536] [Citation(s) in RCA: 215] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Structures of the bacterial ribosome have provided a framework for understanding universal mechanisms of protein synthesis. However, the eukaryotic ribosome is much larger than it is in bacteria, and its activity is fundamentally different in many key ways. Recent cryo-electron microscopy reconstructions and X-ray crystal structures of eukaryotic ribosomes and ribosomal subunits now provide an unprecedented opportunity to explore mechanisms of eukaryotic translation and its regulation in atomic detail. This review describes the X-ray crystal structures of the Tetrahymena thermophila 40S and 60S subunits and the Saccharomyces cerevisiae 80S ribosome, as well as cryo-electron microscopy reconstructions of translating yeast and plant 80S ribosomes. Mechanistic questions about translation in eukaryotes that will require additional structural insights to be resolved are also presented.
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