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Bellone ML, Syed AA, Vitale RM, Sigismondo G, Mensitieri F, Pollastro F, Amodeo P, Appendino G, De Tommasi N, Krijgsveld J, Dal Piaz F. Eukaryotic Initiation Translation Factor 2A activation by cannabidiolic acid alters the protein homeostasis balance in glioblastoma cells. Int J Biol Macromol 2024; 273:132968. [PMID: 38871097 DOI: 10.1016/j.ijbiomac.2024.132968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 06/01/2024] [Accepted: 06/05/2024] [Indexed: 06/15/2024]
Abstract
Eukaryotic Initiation Translation Factor 2A (EIF2A) is considered to be primarily responsible for the initiation of translation when a cell is subjected to stressful conditions. However, information regarding this protein is still incomplete. Using a combination of proteomic approaches, we demonstrated that EIF2A is the molecular target of the naturally occurring bioactive compound cannabidiolic acid (CBDA) within human glioblastoma cells. This finding allowed us to undertake a study aimed at obtaining further information on the functions that EIF2A plays in tumor cells. Indeed, our data showed that CBDA is able to activate EIF2A when the cells are in no-stress conditions. It induces conformational changes in the protein structure, thus increasing EIF2A affinity towards the proteins participating in the Eukaryotic Translation Machinery. Consequently, following glioblastoma cells incubation with CBDA we observed an enhanced neosynthesis of proteins involved in the stress response, nucleic acid translation and organization, and protein catabolism. These changes in gene expression resulted in increased levels of ubiquitinated proteins and accumulation of the autophagosome. Our results, in addition to shedding light on the molecular mechanism underlying the biological effect of a phytocannabinoid in cancer cells, demonstrated that EIF2A plays a critical role in regulation of protein homeostasis.
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Affiliation(s)
| | - Azmal Ali Syed
- Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Gianluca Sigismondo
- Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Federica Pollastro
- Department of Pharmaceutical Sciences, University of Eastern Piedmont, Vercelli, Italy
| | - Pietro Amodeo
- Institute of Biomolecular Chemistry (ICB-CNR), Pozzuoli, Italy
| | - Giovanni Appendino
- Department of Pharmaceutical Sciences, University of Eastern Piedmont, Vercelli, Italy
| | | | - Jeroen Krijgsveld
- Division of Proteomics of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Fabrizio Dal Piaz
- Department of Medicine and Surgery, University of Salerno, Baronissi, Italy.
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2
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Nguyen K, Tang J, Cho S, Ying F, Sung HK, Jahng JW, Pantopoulos K, Sweeney G. Salubrinal promotes phospho-eIF2α-dependent activation of UPR leading to autophagy-mediated attenuation of iron-induced insulin resistance. Mol Metab 2024; 83:101921. [PMID: 38527647 PMCID: PMC11027572 DOI: 10.1016/j.molmet.2024.101921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/04/2024] [Accepted: 03/15/2024] [Indexed: 03/27/2024] Open
Abstract
Identification of new mechanisms mediating insulin sensitivity is important to allow validation of corresponding therapeutic targets. In this study, we first used a cellular model of skeletal muscle cell iron overload and found that endoplasmic reticulum (ER) stress and insulin resistance occurred after iron treatment. Insulin sensitivity was assessed using cells engineered to express an Akt biosensor, based on nuclear FoxO localization, as well as western blotting for insulin signaling proteins. Use of salubrinal to elevate eIF2α phosphorylation and promote the unfolded protein response (UPR) attenuated iron-induced insulin resistance. Salubrinal induced autophagy flux and its beneficial effects on insulin sensitivity were not observed in autophagy-deficient cells generated by overexpressing a dominant-negative ATG5 mutant or via knockout of ATG7. This indicated the beneficial effect of salubrinal-induced UPR activation was autophagy-dependent. We translated these observations to an animal model of systemic iron overload-induced skeletal muscle insulin resistance where administration of salubrinal as pretreatment promoted eIF2α phosphorylation, enhanced autophagic flux in skeletal muscle and improved insulin responsiveness. Together, our results show that salubrinal elicited an eIF2α-autophagy axis leading to improved skeletal muscle insulin sensitivity both in vitro and in mice.
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Affiliation(s)
- Khang Nguyen
- Department of Biology, York University, Toronto, ON, Canada
| | - Jialing Tang
- Department of Biology, York University, Toronto, ON, Canada
| | - Sungji Cho
- Department of Biology, York University, Toronto, ON, Canada
| | - Fan Ying
- Department of Biology, York University, Toronto, ON, Canada
| | | | | | - Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Medicine, McGill University, Montreal, Canada
| | - Gary Sweeney
- Department of Biology, York University, Toronto, ON, Canada.
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3
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Brito Querido J, Díaz-López I, Ramakrishnan V. The molecular basis of translation initiation and its regulation in eukaryotes. Nat Rev Mol Cell Biol 2024; 25:168-186. [PMID: 38052923 DOI: 10.1038/s41580-023-00624-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2023] [Indexed: 12/07/2023]
Abstract
The regulation of gene expression is fundamental for life. Whereas the role of transcriptional regulation of gene expression has been studied for several decades, it has been clear over the past two decades that post-transcriptional regulation of gene expression, of which translation regulation is a major part, can be equally important. Translation can be divided into four main stages: initiation, elongation, termination and ribosome recycling. Translation is controlled mainly during its initiation, a process which culminates in a ribosome positioned with an initiator tRNA over the start codon and, thus, ready to begin elongation of the protein chain. mRNA translation has emerged as a powerful tool for the development of innovative therapies, yet the detailed mechanisms underlying the complex process of initiation remain unclear. Recent studies in yeast and mammals have started to shed light on some previously unclear aspects of this process. In this Review, we discuss the current state of knowledge on eukaryotic translation initiation and its regulation in health and disease. Specifically, we focus on recent advances in understanding the processes involved in assembling the 43S pre-initiation complex and its recruitment by the cap-binding complex eukaryotic translation initiation factor 4F (eIF4F) at the 5' end of mRNA. In addition, we discuss recent insights into ribosome scanning along the 5' untranslated region of mRNA and selection of the start codon, which culminates in joining of the 60S large subunit and formation of the 80S initiation complex.
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Affiliation(s)
- Jailson Brito Querido
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Irene Díaz-López
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
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4
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Grove DJ, Russell PJ, Kearse MG. To initiate or not to initiate: A critical assessment of eIF2A, eIF2D, and MCT-1·DENR to deliver initiator tRNA to ribosomes. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1833. [PMID: 38433101 PMCID: PMC11260288 DOI: 10.1002/wrna.1833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 03/05/2024]
Abstract
Selection of the correct start codon is critical for high-fidelity protein synthesis. In eukaryotes, this is typically governed by a multitude of initiation factors (eIFs), including eIF2·GTP that directly delivers the initiator tRNA (Met-tRNAi Met ) to the P site of the ribosome. However, numerous reports, some dating back to the early 1970s, have described other initiation factors having high affinity for the initiator tRNA and the ability of delivering it to the ribosome, which has provided a foundation for further work demonstrating non-canonical initiation mechanisms using alternative initiation factors. Here we provide a critical analysis of current understanding of eIF2A, eIF2D, and the MCT-1·DENR dimer, the evidence surrounding their ability to initiate translation, their implications in human disease, and lay out important key questions for the field. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes Translation > Mechanisms Translation > Regulation.
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Affiliation(s)
- Daisy J. Grove
- The Ohio State Biochemistry Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Paul J. Russell
- The Ohio State Biochemistry Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- The Cellular, Molecular, Biochemical Sciences Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Michael G. Kearse
- The Ohio State Biochemistry Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- The Cellular, Molecular, Biochemical Sciences Program, Department of Biological Chemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
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5
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Tidu A, Martin F. The interplay between cis- and trans-acting factors drives selective mRNA translation initiation in eukaryotes. Biochimie 2024; 217:20-30. [PMID: 37741547 DOI: 10.1016/j.biochi.2023.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/20/2023] [Accepted: 09/14/2023] [Indexed: 09/25/2023]
Abstract
Translation initiation consists in the assembly of the small and large ribosomal subunits on the start codon. This important step directly modulates the general proteome in living cells. Recently, genome wide studies revealed unexpected translation initiation events from unsuspected novel open reading frames resulting in the synthesis of a so-called 'dark proteome'. Indeed, the identification of the start codon by the translation machinery is a critical step that defines the translational landscape of the cell. Therefore, translation initiation is a highly regulated process in all organisms. In this review, we focus on the various cis- and trans-acting factors that rule the regulation of translation initiation in eukaryotes. Recent discoveries have shown that the guidance of the translation machinery for the choice of the start codon require sophisticated molecular mechanisms. In particular, the 5'UTR and the coding sequences contain cis-acting elements that trigger the use of AUG codons but also non-AUG codons to initiate protein synthesis. The use of these alternative start codons is also largely influenced by numerous trans-acting elements that drive selective mRNA translation in response to environmental changes.
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Affiliation(s)
- Antonin Tidu
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, CNRS UPR9002, 2, allée Konrad Roentgen, F-67084 Strasbourg, France
| | - Franck Martin
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, CNRS UPR9002, 2, allée Konrad Roentgen, F-67084 Strasbourg, France.
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dos Santos JV, Medina JM, Dias Teixeira KL, Agostinho DMJ, Chorev M, Diotallevi A, Galluzzi L, Aktas BH, Gazos Lopes U. Activity of the Di-Substituted Urea-Derived Compound I-17 in Leishmania In Vitro Infections. Pathogens 2024; 13:104. [PMID: 38392842 PMCID: PMC10893125 DOI: 10.3390/pathogens13020104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 02/25/2024] Open
Abstract
Protein synthesis has been a very rich target for developing drugs to control prokaryotic and eukaryotic pathogens. Despite the development of new drug formulations, treating human cutaneous and visceral Leishmaniasis still needs significant improvements due to the considerable side effects and low adherence associated with the current treatment regimen. In this work, we show that the di-substituted urea-derived compounds I-17 and 3m are effective in inhibiting the promastigote growth of different Leishmania species and reducing the macrophage intracellular load of amastigotes of the Leishmania (L.) amazonensis and L. major species, in addition to exhibiting low macrophage cytotoxicity. We also show a potential immunomodulatory effect of I-17 and 3m in infected macrophages, which exhibited increased expression of inducible Nitric Oxide Synthase (NOS2) and production of Nitric Oxide (NO). Our data indicate that I-17, 3m, and their analogs may be helpful in developing new drugs for treating leishmaniasis.
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Affiliation(s)
- José Vitorino dos Santos
- Laboratory of Molecular Parasitology, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.V.d.S.); (J.M.M.); (D.M.J.A.)
| | - Jorge Mansur Medina
- Laboratory of Molecular Parasitology, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.V.d.S.); (J.M.M.); (D.M.J.A.)
| | | | - Daniel Marcos Julio Agostinho
- Laboratory of Molecular Parasitology, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.V.d.S.); (J.M.M.); (D.M.J.A.)
| | - Michael Chorev
- Division of Hematology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | - Aurora Diotallevi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy; (A.D.)
| | - Luca Galluzzi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy; (A.D.)
| | - Bertal Huseyin Aktas
- Division of Hematology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | - Ulisses Gazos Lopes
- Laboratory of Molecular Parasitology, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.V.d.S.); (J.M.M.); (D.M.J.A.)
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7
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Gaikwad S, Ghobakhlou F, Zhang H, Hinnebusch AG. Yeast eIF2A has a minimal role in translation initiation and uORF-mediated translational control in vivo. eLife 2024; 12:RP92916. [PMID: 38266075 PMCID: PMC10945734 DOI: 10.7554/elife.92916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
Initiating translation of most eukaryotic mRNAs depends on recruitment of methionyl initiator tRNA (Met-tRNAi) in a ternary complex (TC) with GTP-bound eukaryotic initiation factor 2 (eIF2) to the small (40S) ribosomal subunit, forming a 43S preinitiation complex (PIC) that attaches to the mRNA and scans the 5'-untranslated region (5' UTR) for an AUG start codon. Previous studies have implicated mammalian eIF2A in GTP-independent binding of Met-tRNAi to the 40S subunit and its recruitment to specialized mRNAs that do not require scanning, and in initiation at non-AUG start codons, when eIF2 function is attenuated by phosphorylation of its α-subunit during stress. The role of eIF2A in translation in vivo is poorly understood however, and it was unknown whether the conserved ortholog in budding yeast can functionally substitute for eIF2. We performed ribosome profiling of a yeast deletion mutant lacking eIF2A and isogenic wild-type (WT) cells in the presence or absence of eIF2α phosphorylation induced by starvation for amino acids isoleucine and valine. Whereas starvation of WT confers changes in translational efficiencies (TEs) of hundreds of mRNAs, the eIF2AΔ mutation conferred no significant TE reductions for any mRNAs in non-starved cells, and it reduced the TEs of only a small number of transcripts in starved cells containing phosphorylated eIF2α. We found no evidence that eliminating eIF2A altered the translation of mRNAs containing putative internal ribosome entry site (IRES) elements, or harboring uORFs initiated by AUG or near-cognate start codons, in non-starved or starved cells. Thus, very few mRNAs (possibly only one) appear to employ eIF2A for Met-tRNAi recruitment in yeast cells, even when eIF2 function is attenuated by stress.
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Affiliation(s)
- Swati Gaikwad
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Fardin Ghobakhlou
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Hongen Zhang
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Alan G Hinnebusch
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
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8
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Liu N, Li M, Pang H, Tiantian T, Li X, Su Y, Jin M, Wu H, Qian C, Sun M. Bioinformatics-driven discovery of silica nanoparticles induces apoptosis and renal damage via the unfolded protein response in NRK-52E cells and rat kidney. Comput Biol Med 2024; 168:107816. [PMID: 38064850 DOI: 10.1016/j.compbiomed.2023.107816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/24/2023] [Accepted: 12/03/2023] [Indexed: 01/10/2024]
Abstract
Silica nanoparticles (SiNPs) are nanomaterials with widespread applications in drug delivery and disease diagnosis. Despite their utility, SiNPs can cause chronic kidney disease, hindering their clinical translation. The molecular mechanisms underlying SiNP-induced renal toxicity are complex and require further investigation. To address this challenge, we employed bioinformatics tools to predict the potential mechanisms underlying renal damage caused by SiNPs. We identified 1627 upregulated differentially expressed genes (DEGs) and 1334 downregulated DEGs. Functional enrichment analysis and protein-protein interaction network revealed that SiNP-induced renal damage is associated with apoptosis. Subsequently, we verified that SiNPs induced apoptosis in an in vitro model of NRK-52E cells via the unfolded protein response (UPR) in a dose-dependent manner. Furthermore, in an in vivo rat model, high-dose SiNP administration via tracheal drip caused hyalinization of the renal tubules, renal interstitial lymphocytic infiltration, and collagen fiber accumulation. Concurrently, we observed an increase in UPR-related protein levels at the onset of renal damage. Thus, our study confirmed that SiNPs induce apoptosis and renal damage through the UPR, adding to the theoretical understanding of SiNP-related kidney damage and offering a potential target for preventing and treating kidney injuries in SiNP clinical applications.
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Affiliation(s)
- Naimeng Liu
- Breast Surgery Department, General Surgery Center, The First Hospital of Jilin University, Street Xinmin 1, Changchun, China.
| | - Meng Li
- School of Public Health Jilin University, NO.1163 Xinmin Street, Changchun, China.
| | - Huan Pang
- School of Public Health Jilin University, NO.1163 Xinmin Street, Changchun, China.
| | - Tian Tiantian
- School of Public Health Jilin University, NO.1163 Xinmin Street, Changchun, China.
| | - Xinyue Li
- School of Public Health Jilin University, NO.1163 Xinmin Street, Changchun, China.
| | - Yanchi Su
- School of Artificial Intelligence, Jilin University, No.2699 Qianjin Street, Changchun, China.
| | - Minghua Jin
- School of Public Health Jilin University, NO.1163 Xinmin Street, Changchun, China.
| | - Hao Wu
- Department of Nephrology, The First Hospital of Jilin University, Street Xinmin 1, Changchun, China.
| | - Chuyue Qian
- Department of Nephrology, The First Hospital of Jilin University, Street Xinmin 1, Changchun, China.
| | - Mindan Sun
- Department of Nephrology, The First Hospital of Jilin University, Street Xinmin 1, Changchun, China.
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9
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Hicks D, Giresh K, Wrischnik LA, Weiser DC. The PPP1R15 Family of eIF2-alpha Phosphatase Targeting Subunits (GADD34 and CReP). Int J Mol Sci 2023; 24:17321. [PMID: 38139150 PMCID: PMC10743859 DOI: 10.3390/ijms242417321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 12/01/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
The vertebrate PPP1R15 family consists of the proteins GADD34 (growth arrest and DNA damage-inducible protein 34, the product of the PPP1R15A gene) and CReP (constitutive repressor of eIF2α phosphorylation, the product of the PPP1R15B gene), both of which function as targeting/regulatory subunits for protein phosphatase 1 (PP1) by regulating subcellular localization, modulating substrate specificity and assembling complexes with target proteins. The primary cellular function of these proteins is to facilitate the dephosphorylation of eukaryotic initiation factor 2-alpha (eIF2α) by PP1 during cell stress. In this review, we will provide a comprehensive overview of the cellular function, biochemistry and pharmacology of GADD34 and CReP, starting with a brief introduction of eIF2α phosphorylation via the integrated protein response (ISR). We discuss the roles GADD34 and CReP play as feedback inhibitors of the unfolded protein response (UPR) and highlight the critical function they serve as inhibitors of the PERK-dependent branch, which is particularly important since it can mediate cell survival or cell death, depending on how long the stressful stimuli lasts, and GADD34 and CReP play key roles in fine-tuning this cellular decision. We briefly discuss the roles of GADD34 and CReP homologs in model systems and then focus on what we have learned about their function from knockout mice and human patients, followed by a brief review of several diseases in which GADD34 and CReP have been implicated, including cancer, diabetes and especially neurodegenerative disease. Because of the potential importance of GADD34 and CReP in aspects of human health and disease, we will discuss several pharmacological inhibitors of GADD34 and/or CReP that show promise as treatments and the controversies as to their mechanism of action. This review will finish with a discussion of the biochemical properties of GADD34 and CReP, their regulation and the additional interacting partners that may provide insight into the roles these proteins may play in other cellular pathways. We will conclude with a brief outline of critical areas for future study.
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Affiliation(s)
- Danielle Hicks
- Department of Science, Mathematics and Engineering, Modesto Junior College, Modesto, CA 95350, USA
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Krithika Giresh
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Lisa A. Wrischnik
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
| | - Douglas C. Weiser
- Department of Biological Sciences, University of the Pacific, Stockton, CA 95211, USA
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10
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Gaikwad S, Ghobakhlou F, Zhang H, Hinnebusch AG. Yeast eIF2A has a minimal role in translation initiation and uORF-mediated translational control in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.06.561292. [PMID: 37986989 PMCID: PMC10659434 DOI: 10.1101/2023.10.06.561292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Initiating translation of most eukaryotic mRNAs depends on recruitment of methionyl initiator tRNA (Met-tRNAi) in a ternary complex (TC) with GTP-bound eukaryotic initiation factor 2 (eIF2) to the small (40S) ribosomal subunit, forming a 43S preinitiation complex (PIC) that attaches to the mRNA and scans the 5'-untranslated region (5' UTR) for an AUG start codon. Previous studies have implicated mammalian eIF2A in GTP-independent binding of Met-tRNAi to the 40S subunit and its recruitment to specialized mRNAs that do not require scanning, and in initiation at non-AUG start codons, when eIF2 function is attenuated by phosphorylation of its α-subunit during stress. The role of eIF2A in translation in vivo is poorly understood however, and it was unknown whether the conserved ortholog in budding yeast can functionally substitute for eIF2. We performed ribosome profiling of a yeast deletion mutant lacking eIF2A and isogenic wild-type (WT) cells in the presence or absence of eIF2α phosphorylation induced by starvation for amino acids isoleucine and valine. Whereas starvation of WT confers changes in translational efficiencies (TEs) of hundreds of mRNAs, the eIF2AΔ mutation conferred no significant TE reductions for any mRNAs in non-starved cells, and it reduced the TEs of only a small number of transcripts in starved cells containing phosphorylated eIF2α. We found no evidence that eliminating eIF2A altered the translation of mRNAs containing putative IRES elements, or harboring uORFs initiated by AUG or near-cognate start codons, in non-starved or starved cells. Thus, very few mRNAs (possibly only one) appear to employ eIF2A for Met-tRNAi recruitment in yeast cells, even when eIF2 function is attenuated by stress.
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Affiliation(s)
- Swati Gaikwad
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Fardin Ghobakhlou
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
- Current affiliations: Department of Microbiology, Infectiology & Immunology, Faculty of Medicine, University of Montreal, Canada, H3T 1J4
| | - Hongen Zhang
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Alan G Hinnebusch
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
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Meyer L, Courtin B, Gomard M, Namane A, Permal E, Badis G, Jacquier A, Fromont-Racine M. eIF2A represses cell wall biogenesis gene expression in Saccharomyces cerevisiae. PLoS One 2023; 18:e0293228. [PMID: 38011112 PMCID: PMC10681259 DOI: 10.1371/journal.pone.0293228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/07/2023] [Indexed: 11/29/2023] Open
Abstract
Translation initiation is a complex and highly regulated process that represents an important mechanism, controlling gene expression. eIF2A was proposed as an alternative initiation factor, however, its role and biological targets remain to be discovered. To further gain insight into the function of eIF2A in Saccharomyces cerevisiae, we identified mRNAs associated with the eIF2A complex and showed that 24% of the most enriched mRNAs encode proteins related to cell wall biogenesis and maintenance. In agreement with this result, we showed that an eIF2A deletion sensitized cells to cell wall damage induced by calcofluor white. eIF2A overexpression led to a growth defect, correlated with decreased synthesis of several cell wall proteins. In contrast, no changes were observed in the transcriptome, suggesting that eIF2A controls the expression of cell wall-related proteins at a translational level. The biochemical characterization of the eIF2A complex revealed that it strongly interacts with the RNA binding protein, Ssd1, which is a negative translational regulator, controlling the expression of cell wall-related genes. Interestingly, eIF2A and Ssd1 bind several common mRNA targets and we found that the binding of eIF2A to some targets was mediated by Ssd1. Surprisingly, we further showed that eIF2A is physically and functionally associated with the exonuclease Xrn1 and other mRNA degradation factors, suggesting an additional level of regulation. Altogether, our results highlight new aspects of this complex and redundant fine-tuned regulation of proteins expression related to the cell wall, a structure required to maintain cell shape and rigidity, providing protection against harmful environmental stress.
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Affiliation(s)
- Laura Meyer
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Baptiste Courtin
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Maïté Gomard
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Abdelkader Namane
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Emmanuelle Permal
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Gwenael Badis
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Alain Jacquier
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Micheline Fromont-Racine
- Institut Pasteur, Génétique des Interactions Macromoléculaires, Centre National de la Recherche Scientifique, UMR 3525, Paris, France
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12
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Cyran AM, Kleinegger F, Nass N, Naumann M, Haybaeck J, Arens C. Inhibition of EIF2α Dephosphorylation Decreases Cell Viability and Synergizes with Standard-of-Care Chemotherapeutics in Head and Neck Squamous Cell Carcinoma. Cancers (Basel) 2023; 15:5350. [PMID: 38001610 PMCID: PMC10670742 DOI: 10.3390/cancers15225350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/27/2023] [Accepted: 11/01/2023] [Indexed: 11/26/2023] Open
Abstract
Drug resistance is a common cause of therapy failure in head and neck squamous cell carcinoma (HNSCC). One approach to tackling it is by targeting fundamental cellular processes, such as translation. The eukaryotic translation initiation factor 2α (EIF2α) is a key player in canonical translation initiation and integrates diverse stress signals; when phosphorylated, it curbs global protein synthesis. This study evaluates EIF2α expression and phosphorylation in HNSCC. A small-molecule inhibitor of EIF2α dephosphorylation, salubrinal, was tested in vitro, followed by viability assays, flow cytometry, and immunoblot analyses. Patient-derived 3D tumor spheres (PD3DS) were cultured with salubrinal and their viability assessed. Lastly, salubrinal was evaluated with standard-of-care chemotherapeutics. Our analysis of RNA and proteomics data shows elevated EIF2α expression in HNSCC. Immunohistochemical staining reveals increasing EIF2α abundance from premalignant lesions to invasive and metastatic carcinoma. In immunoblots from intraoperative samples, EIF2α expression and steady-state phosphorylation are higher in HNSCC than in neighboring normal tissue. Inhibition of EIF2α dephosphorylation decreases HNSCC cell viability and clonogenic survival and impairs the G1/S transition. Salubrinal also decreases the viability of PD3DS and acts synergistically with cisplatin, 5-fluorouracil, bleomycin, and proteasome inhibitors. Our results indicate that pharmacological inhibition of EIF2α dephosphorylation is a potential therapeutic strategy for HNSCC.
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Affiliation(s)
- Anna M. Cyran
- Legorreta Cancer Center, Department of Pathology and Laboratory Medicine, Brown University, Providence, RI 02906, USA
- Department of Otorhinolaryngology, Head and Neck Surgery, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Florian Kleinegger
- Diagnostic & Research Center for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, 8010 Graz, Austria (J.H.)
| | - Norbert Nass
- Institute of Pathology, University Hospital Brandenburg, Brandenburg Medical School Theodor Fontane, 14770 Brandenburg an der Havel, Germany;
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Otto von Guericke University, 39120 Magdeburg, Germany;
| | - Johannes Haybaeck
- Diagnostic & Research Center for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, 8010 Graz, Austria (J.H.)
| | - Christoph Arens
- Department of Otorhinolaryngology, Head and Neck Surgery, Giessen and Marburg University Hospitals, Campus Giessen, 35392 Giessen, Germany;
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13
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Grove DJ, Levine DJ, Kearse MG. Increased levels of eIF2A inhibit translation by sequestering 40S ribosomal subunits. Nucleic Acids Res 2023; 51:9983-10000. [PMID: 37602404 PMCID: PMC10570035 DOI: 10.1093/nar/gkad683] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 08/03/2023] [Accepted: 08/09/2023] [Indexed: 08/22/2023] Open
Abstract
eIF2A was the first eukaryotic initiator tRNA carrier discovered but its exact function has remained enigmatic. Uncharacteristic of translation initiation factors, eIF2A is reported to be non-cytosolic in multiple human cancer cell lines. Attempts to study eIF2A mechanistically have been limited by the inability to achieve high yield of soluble recombinant protein. Here, we developed a purification paradigm that yields ∼360-fold and ∼6000-fold more recombinant human eIF2A from Escherichia coli and insect cells, respectively, than previous reports. Using a mammalian in vitro translation system, we found that increased levels of recombinant human eIF2A inhibit translation of multiple reporter mRNAs, including those that are translated by cognate and near-cognate start codons, and does so prior to start codon recognition. eIF2A also inhibited translation directed by all four types of cap-independent viral IRESs, including the CrPV IGR IRES that does not require initiation factors or initiator tRNA, suggesting excess eIF2A sequesters 40S subunits. Supplementation with additional 40S subunits prevented eIF2A-mediated inhibition and pull-down assays demonstrated direct binding between recombinant eIF2A and purified 40S subunits. These data support a model that eIF2A must be kept away from the translation machinery to avoid sequestering 40S ribosomal subunits.
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Affiliation(s)
- Daisy J Grove
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
- Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Daniel J Levine
- Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Michael G Kearse
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
- Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
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14
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Wei LH, Sun Y, Guo JU. Genome-wide CRISPR screens identify noncanonical translation factor eIF2A as an enhancer of SARS-CoV-2 programmed -1 ribosomal frameshifting. Cell Rep 2023; 42:112987. [PMID: 37581984 DOI: 10.1016/j.celrep.2023.112987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 06/23/2023] [Accepted: 07/31/2023] [Indexed: 08/17/2023] Open
Abstract
Many positive-strand RNA viruses, including all known coronaviruses, employ programmed -1 ribosomal frameshifting (-1 PRF) to regulate the translation of polycistronic viral RNAs. However, only a few host factors have been shown to regulate -1 PRF. Through a genome-wide CRISPR-Cas9 knockout screen, we have identified host factors that either suppress or enhance severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) -1 PRF. Among them, eukaryotic translation initiation factor 2A (eIF2A) specifically and directly enhances -1 PRF independent of changes in initiation. Consistent with the crucial role of efficient -1 PRF in transcriptase/replicase expression, loss of eIF2A reduces SARS-CoV-2 replication in cells. Furthermore, transcriptome-wide analysis shows that eIF2A preferentially binds CG-rich RNA motifs, including a region within 18S ribosomal RNA near the contacts between the SARS-CoV-2 frameshift-stimulatory element (FSE) and the ribosome. Thus, our results indicate a role for eIF2A in modulating the translation of specific RNAs independent of its role during initiation.
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Affiliation(s)
- Lian-Huan Wei
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Yu Sun
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Junjie U Guo
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA.
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15
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Lyons LC, Vanrobaeys Y, Abel T. Sleep and memory: The impact of sleep deprivation on transcription, translational control, and protein synthesis in the brain. J Neurochem 2023; 166:24-46. [PMID: 36802068 PMCID: PMC10919414 DOI: 10.1111/jnc.15787] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 01/31/2023] [Accepted: 02/07/2023] [Indexed: 02/20/2023]
Abstract
In countries around the world, sleep deprivation represents a widespread problem affecting school-age children, teenagers, and adults. Acute sleep deprivation and more chronic sleep restriction adversely affect individual health, impairing memory and cognitive performance as well as increasing the risk and progression of numerous diseases. In mammals, the hippocampus and hippocampus-dependent memory are vulnerable to the effects of acute sleep deprivation. Sleep deprivation induces changes in molecular signaling, gene expression and may cause changes in dendritic structure in neurons. Genome wide studies have shown that acute sleep deprivation alters gene transcription, although the pool of genes affected varies between brain regions. More recently, advances in research have drawn attention to differences in gene regulation between the level of the transcriptome compared with the pool of mRNA associated with ribosomes for protein translation following sleep deprivation. Thus, in addition to transcriptional changes, sleep deprivation also affects downstream processes to alter protein translation. In this review, we focus on the multiple levels through which acute sleep deprivation impacts gene regulation, highlighting potential post-transcriptional and translational processes that may be affected by sleep deprivation. Understanding the multiple levels of gene regulation impacted by sleep deprivation is essential for future development of therapeutics that may mitigate the effects of sleep loss.
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Affiliation(s)
- Lisa C Lyons
- Program in Neuroscience, Department of Biological Science, Florida State University, Tallahassee, Florida, USA
| | - Yann Vanrobaeys
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Iowa Neuroscience Institute, Iowa City, Iowa, USA
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, Iowa, USA
| | - Ted Abel
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Iowa Neuroscience Institute, Iowa City, Iowa, USA
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16
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Marcelino TDP, Fala AM, da Silva MM, Souza-Melo N, Malvezzi AM, Klippel AH, Zoltner M, Padilla-Mejia N, Kosto S, Field MC, Burle-Caldas GDA, Teixeira SMR, Couñago RM, Massirer KB, Schenkman S. Identification of inhibitors for the transmembrane Trypanosoma cruzi eIF2α kinase relevant for parasite proliferation. J Biol Chem 2023; 299:104857. [PMID: 37230387 PMCID: PMC10300260 DOI: 10.1016/j.jbc.2023.104857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/02/2023] [Accepted: 05/05/2023] [Indexed: 05/27/2023] Open
Abstract
The TcK2 protein kinase of Trypanosoma cruzi, the causative agent of Chagas disease, is structurally similar to the human kinase PERK, which phosphorylates the initiation factor eIF2α and, in turn, inhibits translation initiation. We have previously shown that absence of TcK2 kinase impairs parasite proliferation within mammalian cells, positioning it as a potential target for treatment of Chagas disease. To better understand its role in the parasite, here we initially confirmed the importance of TcK2 in parasite proliferation by generating CRISPR/Cas9 TcK2-null cells, albeit they more efficiently differentiate into infective forms. Proteomics indicates that the TcK2 knockout of proliferative forms expresses proteins including trans-sialidases, normally restricted to infective and nonproliferative trypomastigotes explaining decreased proliferation and better differentiation. TcK2 knockout cells lost phosphorylation of eukaryotic initiation factor 3 and cyclic AMP responsive-like element, recognized to promote growth, likely explaining both decreased proliferation and augmented differentiation. To identify specific inhibitors, a library of 379 kinase inhibitors was screened by differential scanning fluorimetry using a recombinant TcK2 encompassing the kinase domain and selected molecules were tested for kinase inhibition. Only Dasatinib and PF-477736, inhibitors of Src/Abl and ChK1 kinases, showed inhibitory activity with IC50 of 0.2 ± 0.02 mM and 0.8 ± 0.1, respectively. In infected cells Dasatinib inhibited growth of parental amastigotes (IC50 = 0.6 ± 0.2 mM) but not TcK2 of depleted parasites (IC50 > 34 mM) identifying Dasatinib as a potential lead for development of therapeutics for Chagas disease targeting TcK2.
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Affiliation(s)
- Tiago de Paula Marcelino
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Angela Maria Fala
- Center for Molecular Biology and Genetic Engineering - CBMEG, Center of Medicinal Chemistry - CQMED, Structural Genomics Consortium - SGC, University of Campinas - UNICAMP, Campinas, SP, Brazil
| | - Matheus Monteiro da Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Normanda Souza-Melo
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Amaranta Muniz Malvezzi
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Angélica Hollunder Klippel
- Center for Molecular Biology and Genetic Engineering - CBMEG, Center of Medicinal Chemistry - CQMED, Structural Genomics Consortium - SGC, University of Campinas - UNICAMP, Campinas, SP, Brazil; Departamento de Ciências Biológicas da Faculdade de Ciências Farmacêuticas da Universidade Estadual Paulista "Júlio de Mesquita Filho"-Unesp, Araraquara, SP, Brazil
| | - Martin Zoltner
- Drug Discovery and Evaluation Unit, Department of Parasitology, Faculty of Science, Charles University in Prague, BIOCEV, Vestec, Czech Republic
| | | | - Samantha Kosto
- School of Life Sciences, University of Dundee, Dundee, UK
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, UK; Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | | | | | - Rafael Miguez Couñago
- Center for Molecular Biology and Genetic Engineering - CBMEG, Center of Medicinal Chemistry - CQMED, Structural Genomics Consortium - SGC, University of Campinas - UNICAMP, Campinas, SP, Brazil
| | - Katlin Brauer Massirer
- Center for Molecular Biology and Genetic Engineering - CBMEG, Center of Medicinal Chemistry - CQMED, Structural Genomics Consortium - SGC, University of Campinas - UNICAMP, Campinas, SP, Brazil.
| | - Sergio Schenkman
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
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17
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Zhao X, Zhang J, Zhang W, Guo Z, Wei W, Wang X, Zhao J. A chiral fluorescent Ir(iii) complex that targets the GPX4 and ErbB pathways to induce cellular ferroptosis. Chem Sci 2023; 14:1114-1122. [PMID: 36756328 PMCID: PMC9891362 DOI: 10.1039/d2sc06171f] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/05/2022] [Indexed: 01/11/2023] Open
Abstract
Ferroptosis has recently emerged as a non-apoptotic form of programmed cell death and promising target for anticancer treatment. However, it is challenging to discover ferroptosis inducers with both highly selective tumour targeting and low cytotoxicity to normal cells. Here, we report an Ir(iii) complex, Ir1, that contains a novel chiral pyridine RAS-selective lethal ligand (Py-RSL). This complex effectively inhibits glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) to induce ferroptosis in human fibrosarcoma (HT-1080) cells. Notably, metal coordination not only endows Ir1 with fluorescent properties for convenient cellular real-time tracking but also efficiently reduces the off-target toxicity of the Py-RSL ligand. Furthermore, label-free quantitative proteomic profiling revealed that Ir1 simultaneously inhibits the ErbB signalling pathway to enhance tumour suppression. Our work is the first to report a ferroptosis-inducing iridium complex with dual mechanisms of inhibition and provides a highly selective and efficient route to develop new ferroptosis-inducing metallodrugs.
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Affiliation(s)
- Xinyang Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Jingyi Zhang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Wei Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University Nanjing 210023 China
| | - Zijian Guo
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Wei Wei
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University Nanjing 210023 China
| | - Xiuxiu Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Jing Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
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18
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Shojaei S, Menbari P, Jamshidi S, Taherkhani A. MicroRNA-Based Markers of Oral Tongue Squamous Cell Carcinoma and Buccal Squamous Cell Carcinoma: A Systems Biology Approach. Biochem Res Int 2023; 2023:5512894. [PMID: 37143570 PMCID: PMC10151719 DOI: 10.1155/2023/5512894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/08/2023] [Accepted: 04/18/2023] [Indexed: 05/06/2023] Open
Abstract
Objective Oral tongue squamous cell carcinoma (OTSCC) and buccal squamous cell carcinoma (BSCC) are the first and second leading causes of oral cancer, respectively. OTSCC and BSCC are associated with poor prognosis in patients with oral cancer. Thus, we aimed to indicate signaling pathways, Gene Ontology terms, and prognostic markers mediating the malignant transformation of the normal oral tissue to OTSCC and BSCC. Methods The dataset GSE168227 was downloaded and reanalyzed from the GEO database. Orthogonal partial least square (OPLS) analysis identified common differentially expressed miRNAs (DEMs) in OTSCC and BSCC compared to their adjacent normal mucosa. Next, validated targets of DEMs were identified using the TarBase web server. With the use of the STRING database, a protein interaction map (PIM) was created. Using the Cytoscape program, hub genes and clusters within the PIM were shown. Next, gene-set enrichment analysis was carried out using the g:Profiler tool. Using the GEPIA2 web tool, analyses of gene expression and survival analysis were also performed. Results Two DEMs, including has-miR-136 and has-miR-377, were common in OTSCC and BSCC (p value <0.01; |Log2 FC| > 1). A total of 976 targets were indicated for common DEMs. PIM included 96 hubs, and the upregulation of EIF2S1, CAV1, RAN, ANXA5, CYCS, CFL1, MYC, HSP90AA1, PKM, and HSPA5 was significantly associated with a poor prognosis in the head and neck squamous cell carcinoma (HNSCC), while NTRK2, HNRNPH1, DDX17, and WDR82 overexpression was significantly linked to favorable prognosis in the patients with HNSCC. "Clathrin-mediated endocytosis" was considerably dysregulated in OTSCC and BSCC. Conclusion The present study suggests that has-miR-136 and has-miR-377 are underexpressed in OTSCC and BSCC than in normal oral mucosa. Moreover, EIF2S1, CAV1, RAN, ANXA5, CYCS, CFL1, MYC, HSP90AA1, PKM, HSPA5, NTRK2, HNRNPH1, DDX17, and WDR82 demonstrated prognostic markers in HNSCC. These findings may benefit the prognosis and management of individuals with OTSCC/BSCC. However, additional experimental verification is required.
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Affiliation(s)
- Setareh Shojaei
- Department of Oral and Maxillofacial Pathology, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Pouya Menbari
- Department of Oral and Maxillofacial Pathology, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Shokoofeh Jamshidi
- Department of Oral and Maxillofacial Pathology, School of Dentistry, Dental Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Amir Taherkhani
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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19
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Kim H, Aponte-Diaz D, Sotoudegan MS, Shengjuler D, Arnold JJ, Cameron CE. The enterovirus genome can be translated in an IRES-independent manner that requires the initiation factors eIF2A/eIF2D. PLoS Biol 2023; 21:e3001693. [PMID: 36689548 PMCID: PMC9894558 DOI: 10.1371/journal.pbio.3001693] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 02/02/2023] [Accepted: 01/04/2023] [Indexed: 01/24/2023] Open
Abstract
RNA recombination in positive-strand RNA viruses is a molecular-genetic process, which permits the greatest evolution of the genome and may be essential to stabilizing the genome from the deleterious consequences of accumulated mutations. Enteroviruses represent a useful system to elucidate the details of this process. On the biochemical level, it is known that RNA recombination is catalyzed by the viral RNA-dependent RNA polymerase using a template-switching mechanism. For this mechanism to function in cells, the recombining genomes must be located in the same subcellular compartment. How a viral genome is trafficked to the site of genome replication and recombination, which is membrane associated and isolated from the cytoplasm, is not known. We hypothesized that genome translation was essential for colocalization of genomes for recombination. We show that complete inactivation of internal ribosome entry site (IRES)-mediated translation of a donor enteroviral genome enhanced recombination instead of impairing it. Recombination did not occur by a nonreplicative mechanism. Rather, sufficient translation of the nonstructural region of the genome occurred to support subsequent steps required for recombination. The noncanonical translation initiation factors, eIF2A and eIF2D, were required for IRES-independent translation. Our results support an eIF2A/eIF2D-dependent mechanism under conditions in which the eIF2-dependent mechanism is inactive. Detection of an IRES-independent mechanism for translation of the enterovirus genome provides an explanation for a variety of debated observations, including nonreplicative recombination and persistence of enteroviral RNA lacking an IRES. The existence of an eIF2A/eIF2D-dependent mechanism in enteroviruses predicts the existence of similar mechanisms in other viruses.
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Affiliation(s)
- Hyejeong Kim
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - David Aponte-Diaz
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Mohamad S. Sotoudegan
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | | | - Jamie J. Arnold
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Craig E. Cameron
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
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20
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Hagen-Lillevik S, Johnson J, Lai K. Early postnatal alterations in follicular stress response and survival in a mouse model of Classic Galactosemia. J Ovarian Res 2022; 15:122. [PMID: 36414970 PMCID: PMC9682695 DOI: 10.1186/s13048-022-01049-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 10/07/2022] [Indexed: 11/24/2022] Open
Abstract
Primary ovarian insufficiency is characterized by accelerated loss of primordial follicles, which results in ovarian failure and concomitant menopause before age 40. About 1-3% of females in the general population are diagnosed with POI; however, greater than 80% of females with the inherited disease Classic Galactosemia will develop POI. Classic Galactosemia is caused by mutations in the GALT gene encoding the enzyme galactose-1 phosphate uridylyltransferase. While dietary restriction of galactose is lifesaving in the neonatal period, the development of complications including primary ovarian insufficiency is not mitigated. Additionally, the pattern(s) of follicle loss have not been completely characterized. The chronic accumulation of aberrant metabolites such as galactose-1-phosphate and galactitol are suspected culprits in the development of the sequelae, yet the mechanisms remain elusive.Our group uses a GalT gene-trapped mouse model to study the pathophysiology of primary ovarian insufficiency in Classic Galactosemia. We recently showed that differences in the Integrated Stress Response pathway occur in mutant ovaries that likely contribute to their primary ovarian insufficiency phenotype. Using immunofluorescent staining of histological sections of ovaries at progressive ages, we saw evidence of altered Integrated Stress Response activity in granulosa cells and primordial oocytes consistent with accelerated primordial follicle growth activation, aberrant DNA damage and/or repair, and increased cellular stress/death. Overall, our findings indicate that abnormal Integrated Stress Response in the Classic Galactosemia model ovary results in accelerated primordial follicle growth activation, sometimes referred to as "burnout." These aberrant early events help further clarify when/how the primary ovarian insufficiency phenotype arises under galactosemic conditions.
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Affiliation(s)
- Synneva Hagen-Lillevik
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT 84108 USA ,grid.223827.e0000 0001 2193 0096Department of Nutrition and Integrative Physiology, University of Utah College of Health, 250 South 1850 East Room 214, Salt Lake City, UT 84112 USA
| | - Joshua Johnson
- grid.430503.10000 0001 0703 675XDivision of Reproductive Sciences, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Colorado Denver (AMC), Building RC2, Room P15 3103, Mail Stop 8613, Aurora, CO 80045 USA
| | - Kent Lai
- grid.223827.e0000 0001 2193 0096Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT 84108 USA ,grid.223827.e0000 0001 2193 0096Department of Nutrition and Integrative Physiology, University of Utah College of Health, 250 South 1850 East Room 214, Salt Lake City, UT 84112 USA
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21
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Rubio A, Garland GD, Sfakianos A, Harvey RF, Willis AE. Aberrant protein synthesis and cancer development: The role of canonical eukaryotic initiation, elongation and termination factors in tumorigenesis. Semin Cancer Biol 2022; 86:151-165. [PMID: 35487398 DOI: 10.1016/j.semcancer.2022.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/11/2022] [Accepted: 04/20/2022] [Indexed: 01/27/2023]
Abstract
In tumourigenesis, oncogenes or dysregulated tumour suppressor genes alter the canonical translation machinery leading to a reprogramming of the translatome that, in turn, promotes the translation of selected mRNAs encoding proteins involved in proliferation and metastasis. It is therefore unsurprising that abnormal expression levels and activities of eukaryotic initiation factors (eIFs), elongation factors (eEFs) or termination factors (eRFs) are associated with poor outcome for patients with a wide range of cancers. In this review we discuss how RNA binding proteins (RBPs) within the canonical translation factor machinery are dysregulated in cancers and how targeting such proteins is leading to new therapeutic avenues.
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Affiliation(s)
- Angela Rubio
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Gavin D Garland
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Aristeidis Sfakianos
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Robert F Harvey
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK.
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22
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Li Z, Chen Y, Yao X, Liu Q, Zhu H, Zhang Y, Feng J, Gao H. The Integrated Stress Response Is Tumorigenic and Constitutes a Therapeutic Liability in Somatotroph Adenomas. Int J Mol Sci 2022; 23:ijms232113067. [PMID: 36361871 PMCID: PMC9653568 DOI: 10.3390/ijms232113067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/20/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022] Open
Abstract
Somatotroph adenomas are the leading cause of acromegaly, with the nearly sparsely granulated somatotroph subtype belonging to high-risk adenomas, and they are less responsive to medical treatment. The integrated stress response (ISR) is an essential stress-support pathway increasingly recognized as a determinant of tumorigenesis. In this study, we identified the characteristic profiling of the integrated stress response in translocation and translation initiation factor activity in somatotroph adenomas, normal pituitary, or other adenoma subtypes through proteomics. Immunohistochemistry exhibited the differential significance and the priority of eukaryotic translation initiation factor 2β (EIF2β) in somatotroph adenomas compared with gonadotroph and corticotroph adenomas. Differentially expressed genes based on the level of EIF2β in somatotroph adenomas were revealed. MetaSape pathways showed that EIF2β was involved in regulating growth and cell activation, immune system, and extracellular matrix organization processes. The correlation analysis showed Spearman correlation coefficients of r = 0.611 (p < 0.001) for EIF2β and eukaryotic translation initiation factor 2 alpha kinase 1 (HRI), r = 0.765 (p < 0.001) for eukaryotic translation initiation factor 2 alpha kinase 2 (PKR), r = 0.813 (p < 0.001) for eukaryotic translation initiation factor 2 alpha kinase 3 (PERK), r = 0.728 (p < 0.001) for GCN2, and r = 0.732 (p < 0.001) for signal transducer and activator of transcription 3 (STAT3). Furthermore, the invasive potential in patients with a high EIF2β was greater than that in patients with a low EIF2β (7/10 vs. 4/18, p = 0.038), with a lower immune-cell infiltration probability (p < 0.05). The ESTIMATE algorithm showed that the levels of activation of the EIF2 pathway were negatively correlated with the immune score in somatotroph adenomas (p < 0.001). In in vitro experiments, the knockdown of EIF2β changed the phenotype of somatotroph adenomas, including cell proliferation, migration, and the secretion ability of growth hormone/insulin-like growth factor-1. In this study, we demonstrate that the ISR is pivotal in somatotroph adenomas and provide a rationale for implementing ISR-based regimens in future treatment strategies.
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Affiliation(s)
- Zhenye Li
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Yiyuan Chen
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Beijing Neurosurgical Institute, Capital Medical University, Beijing 100070, China
| | - Xiaohui Yao
- Beijing Neurosurgical Institute, Capital Medical University, Beijing 100070, China
- Shanxi Provincial People’s Hospital, Taiyuan 030000, China
| | - Qian Liu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing 100070, China
| | - Haibo Zhu
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Yazhuo Zhang
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- Beijing Neurosurgical Institute, Capital Medical University, Beijing 100070, China
| | - Jie Feng
- Beijing Neurosurgical Institute, Capital Medical University, Beijing 100070, China
- Correspondence: (J.F.); (H.G.)
| | - Hua Gao
- Beijing Neurosurgical Institute, Capital Medical University, Beijing 100070, China
- China National Clinical Research Center for Neurological Diseases, Beijing 100070, China
- Key Laboratory of Central Nervous System Injury Research, Beijing 100070, China
- Correspondence: (J.F.); (H.G.)
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23
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Malekos E, Carpenter S. Short open reading frame genes in innate immunity: from discovery to characterization. Trends Immunol 2022; 43:741-756. [PMID: 35965152 PMCID: PMC10118063 DOI: 10.1016/j.it.2022.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 12/27/2022]
Abstract
Next-generation sequencing (NGS) technologies have greatly expanded the size of the known transcriptome. Many newly discovered transcripts are classified as long noncoding RNAs (lncRNAs) which are assumed to affect phenotype through sequence and structure and not via translated protein products despite the vast majority of them harboring short open reading frames (sORFs). Recent advances have demonstrated that the noncoding designation is incorrect in many cases and that sORF-encoded peptides (SEPs) translated from these transcripts are important contributors to diverse biological processes. Interest in SEPs is at an early stage and there is evidence for the existence of thousands of SEPs that are yet unstudied. We hope to pique interest in investigating this unexplored proteome by providing a discussion of SEP characterization generally and describing specific discoveries in innate immunity.
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Affiliation(s)
- Eric Malekos
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, CA, USA; Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Susan Carpenter
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA; Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA, USA.
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24
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Hagen-Lillevik S, Johnson J, Siddiqi A, Persinger J, Hale G, Lai K. Harnessing the Power of Purple Sweet Potato Color and Myo-Inositol to Treat Classic Galactosemia. Int J Mol Sci 2022; 23:ijms23158654. [PMID: 35955788 PMCID: PMC9369367 DOI: 10.3390/ijms23158654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 01/25/2023] Open
Abstract
Classic Galactosemia (CG) is a devastating inborn error of the metabolism caused by mutations in the GALT gene encoding the enzyme galactose-1 phosphate uridylyltransferase in galactose metabolism. Severe complications of CG include neurological impairments, growth restriction, cognitive delays, and, for most females, primary ovarian insufficiency. The absence of the GALT enzyme leads to an accumulation of aberrant galactose metabolites, which are assumed to be responsible for the sequelae. There is no treatment besides the restriction of dietary galactose, which does not halt the development of the complications; thus, additional treatments are sorely needed. Supplements have been used in other inborn errors of metabolism but are not part of the therapeutic regimen for CG. The goal of this study was to test two generally recognized as safe supplements (purple sweet potato color (PSPC) and myo-inositol (MI)) that may impact cellular pathways contributing to the complications in CG. Our group uses a GalT gene-trapped mouse model to study the pathophysiology in CG, which phenocopy many of the complications. Here we report the ability of PSPC to ameliorate dysregulation in the ovary, brain, and liver of our mutant mice as well as positive results of MI supplementation in the ovary and brain.
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Affiliation(s)
- Synneva Hagen-Lillevik
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT 84108, USA
- Correspondence: (S.H.-L.); (K.L.); Tel.: +1-253-592-8692 (S.H.-L.)
| | - Joshua Johnson
- Division of Reproductive Sciences, Aurora, CO 80045, USA
- Division of Reproductive Endocrinology and Infertility, Aurora, CO 80045, USA
- Department of Obstetrics and Gynecology, Aurora, CO 80045, USA
| | - Anwer Siddiqi
- College of Medicine, University of Florida, Jacksonville, FL 32209, USA
| | - Jes Persinger
- Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80302, USA
| | - Gillian Hale
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Kent Lai
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT 84108, USA
- Correspondence: (S.H.-L.); (K.L.); Tel.: +1-253-592-8692 (S.H.-L.)
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25
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Baud A, Derbis M, Tutak K, Sobczak K. Partners in crime: Proteins implicated in
RNA
repeat expansion diseases. WIRES RNA 2022; 13:e1709. [PMID: 35229468 PMCID: PMC9539487 DOI: 10.1002/wrna.1709] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Anna Baud
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Magdalena Derbis
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Katarzyna Tutak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Krzysztof Sobczak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
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26
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Regulation and function of elF2B in neurological and metabolic disorders. Biosci Rep 2022; 42:231311. [PMID: 35579296 PMCID: PMC9208314 DOI: 10.1042/bsr20211699] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/28/2022] [Accepted: 05/12/2022] [Indexed: 11/27/2022] Open
Abstract
Eukaryotic initiation factor 2B, eIF2B is a guanine nucleotide exchange, factor with a central role in coordinating the initiation of translation. During stress and disease, the activity of eIF2B is inhibited via the phosphorylation of its substrate eIF2 (p-eIF2α). A number of different kinases respond to various stresses leading to the phosphorylation of the alpha subunit of eIF2, and collectively this regulation is known as the integrated stress response, ISR. This targeting of eIF2B allows the cell to regulate protein synthesis and reprogramme gene expression to restore homeostasis. Advances within structural biology have furthered our understanding of how eIF2B interacts with eIF2 in both the productive GEF active form and the non-productive eIF2α phosphorylated form. Here, current knowledge of the role of eIF2B in the ISR is discussed within the context of normal and disease states focusing particularly on diseases such as vanishing white matter disease (VWMD) and permanent neonatal diabetes mellitus (PNDM), which are directly linked to mutations in eIF2B. The role of eIF2B in synaptic plasticity and memory formation is also discussed. In addition, the cellular localisation of eIF2B is reviewed and considered along with the role of additional in vivo eIF2B binding factors and protein modifications that may play a role in modulating eIF2B activity during health and disease.
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27
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Hernández-Elvira M, Sunnerhagen P. Post-transcriptional regulation during stress. FEMS Yeast Res 2022; 22:6585650. [PMID: 35561747 PMCID: PMC9246287 DOI: 10.1093/femsyr/foac025] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/25/2022] [Accepted: 05/10/2022] [Indexed: 11/12/2022] Open
Abstract
To remain competitive, cells exposed to stress of varying duration, rapidity of onset, and intensity, have to balance their expenditure on growth and proliferation versus stress protection. To a large degree dependent on the time scale of stress exposure, the different levels of gene expression control: transcriptional, post-transcriptional and post-translational, will be engaged in stress responses. The post-transcriptional level is appropriate for minute-scale responses to transient stress, and for recovery upon return to normal conditions. The turnover rate, translational activity, covalent modifications, and subcellular localisation of RNA species are regulated under stress by multiple cellular pathways. The interplay between these pathways is required to achieve the appropriate signalling intensity and prevent undue triggering of stress-activated pathways at low stress levels, avoid overshoot, and down-regulate the response in a timely fashion. As much of our understanding of post-transcriptional regulation has been gained in yeast, this review is written with a yeast bias, but attempts to generalise to other eukaryotes. It summarises aspects of how post-transcriptional events in eukaryotes mitigate short-term environmental stresses, and how different pathways interact to optimise the stress response under shifting external conditions.
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Affiliation(s)
- Mariana Hernández-Elvira
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, P.O. Box 462, S-405 30 Göteborg, Sweden
| | - Per Sunnerhagen
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, P.O. Box 462, S-405 30 Göteborg, Sweden
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28
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Sánchez-Adriá IE, Sanmartín G, Prieto JA, Estruch F, Randez-Gil F. Slt2 Is Required to Activate ER-Stress-Protective Mechanisms through TORC1 Inhibition and Hexosamine Pathway Activation. J Fungi (Basel) 2022; 8:jof8020092. [PMID: 35205847 PMCID: PMC8877190 DOI: 10.3390/jof8020092] [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: 12/14/2021] [Revised: 01/13/2022] [Accepted: 01/15/2022] [Indexed: 02/07/2023] Open
Abstract
Slt2, the MAPK of the cell wall integrity (CWI) pathway, connects different signaling pathways and performs different functions in the protective response of S. cerevisiae to stress. Previous work has evidenced the relation of the CWI pathway and the unfolded protein response (UPR), a transcriptional program activated upon endoplasmic reticulum (ER) stress. However, the mechanisms of crosstalk between these pathways and the targets regulated by Slt2 under ER stress remain unclear. Here, we demonstrated that ectopic expression of GFA1, the gene encoding the first enzyme in the synthesis of UDP-GlcNAc by the hexosamine biosynthetic pathway (HBP) or supplementation of the growth medium with glucosamine (GlcN), increases the tolerance of slt2 mutant cells to different ER-stress inducers. Remarkably, GlcN also alleviates the sensitivity phenotype of cells lacking IRE1 or HAC1, the main actors in controlling the UPR. The exogenous addition of GlcN reduced the abundance of glycosylated proteins and triggered autophagy. We also found that TORC1, the central stress and growth controller, is inhibited by tunicamycin exposure in cells of the wild-type strain but not in those lacking Slt2. Consistent with this, the tunicamycin-induced activation of autophagy and the increased synthesis of ATP in response to ER stress were absent by knock-out of SLT2. Altogether, our data placed Slt2 as an essential actor of the ER stress response by regulating the HBP activity and the TORC1-dependent signaling.
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Affiliation(s)
- Isabel E. Sánchez-Adriá
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Avda. Agustín Escardino 7, 46980 Paterna, Valencia, Spain; (I.E.S.-A.); (G.S.); (J.A.P.)
| | - Gemma Sanmartín
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Avda. Agustín Escardino 7, 46980 Paterna, Valencia, Spain; (I.E.S.-A.); (G.S.); (J.A.P.)
| | - Jose A. Prieto
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Avda. Agustín Escardino 7, 46980 Paterna, Valencia, Spain; (I.E.S.-A.); (G.S.); (J.A.P.)
| | - Francisco Estruch
- Departament of Biochemistry and Molecular Biology, Universitat de València, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain;
| | - Francisca Randez-Gil
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Avda. Agustín Escardino 7, 46980 Paterna, Valencia, Spain; (I.E.S.-A.); (G.S.); (J.A.P.)
- Correspondence:
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29
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Schatz C, Sprung S, Schartinger V, Codina-Martínez H, Lechner M, Hermsen M, Haybaeck J. Dysregulation of Translation Factors EIF2S1, EIF5A and EIF6 in Intestinal-Type Adenocarcinoma (ITAC). Cancers (Basel) 2021; 13:cancers13225649. [PMID: 34830804 PMCID: PMC8616251 DOI: 10.3390/cancers13225649] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 11/16/2022] Open
Abstract
Intestinal-type adenocarcinoma (ITAC) is a rare cancer of the nasal cavity and paranasal sinuses that occurs sporadically or secondary to exposure to occupational hazards, such as wood dust and leather. Eukaryotic translation initiation factors have been described as promising targets for novel cancer treatments in many cancers, but hardly anything is known about these factors in ITAC. Here we performed in silico analyses, evaluated the protein levels of EIF2S1, EIF5A and EIF6 in tumour samples and non-neoplastic tissue controls obtained from 145 patients, and correlated these results with clinical outcome data, including tumour site, stage, adjuvant radiotherapy and survival. In silico analyses revealed significant upregulation of the translation factors EIF6 (ITGB4BP), EIF5, EIF2S1 and EIF2S2 (p < 0.05) with a higher arithmetic mean expression in ITAC compared to non-neoplastic tissue (NNT). Immunohistochemical analyses using antibodies against EIF2S1 and EIF6 confirmed a significantly different expression at the protein level (p < 0.05). In conclusion, this work identifies the eukaryotic translation initiation factors EIF2S1 and EIF6 to be significantly upregulated in ITAC. As these factors have been described as promising therapeutic targets in other cancers, this work identifies candidate therapeutic targets in this rare but often deadly cancer.
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Affiliation(s)
- Christoph Schatz
- Institute of Pathology, Neuropathology and Molecular Pathology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.S.); (S.S.)
| | - Susanne Sprung
- Institute of Pathology, Neuropathology and Molecular Pathology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.S.); (S.S.)
| | - Volker Schartinger
- Institute of Otorhinolaryngology, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria;
| | - Helena Codina-Martínez
- Department Head and Neck Oncology, Instituto de Investigación Sanitaria del Principado de Asturias, 33011 Oviedo, Spain; (H.C.-M.); (M.H.)
| | - Matt Lechner
- UCL Cancer Institute, University College London, London WC1E 6AG, UK;
- Barts Health NHS Trust, London E1 1BB, UK
| | - Mario Hermsen
- Department Head and Neck Oncology, Instituto de Investigación Sanitaria del Principado de Asturias, 33011 Oviedo, Spain; (H.C.-M.); (M.H.)
| | - Johannes Haybaeck
- Institute of Pathology, Neuropathology and Molecular Pathology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.S.); (S.S.)
- Diagnostic & Research Center for Molecular BioMedicine, Institute of Pathology, Medical University of Graz, 8036 Graz, Austria
- Correspondence:
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30
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Anderson R, Agarwal A, Ghosh A, Guan B, Casteel J, Dvorina N, Baldwin WM, Mazumder B, Nazarko TY, Merrick WC, Buchner DA, Hatzoglou M, Kondratov RV, Komar AA. eIF2A-knockout mice reveal decreased life span and metabolic syndrome. FASEB J 2021; 35:e21990. [PMID: 34665898 PMCID: PMC8848898 DOI: 10.1096/fj.202101105r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/02/2021] [Accepted: 09/29/2021] [Indexed: 01/07/2023]
Abstract
Eukaryotic initiation factor 2A (eIF2A) is a 65 kDa protein that functions in minor initiation pathways, which affect the translation of only a subset of messenger ribonucleic acid (mRNAs), such as internal ribosome entry site (IRES)-containing mRNAs and/or mRNAs harboring upstream near cognate/non-AUG start codons. These non-canonical initiation events are important for regulation of protein synthesis during cellular development and/or the integrated stress response. Selective eIF2A knockdown in cellular systems significantly inhibits translation of such mRNAs, which rely on alternative initiation mechanisms for their translation. However, there exists a gap in our understanding of how eIF2A functions in mammalian systems in vivo (on the organismal level) and ex vivo (in cells). Here, using an eIF2A-knockout (KO) mouse model, we present evidence implicating eIF2A in the biology of aging, metabolic syndrome and central tolerance. We discovered that eIF2A-KO mice have reduced life span and that eIF2A plays an important role in maintenance of lipid homeostasis, the control of glucose tolerance, insulin resistance and also reduces the abundance of B lymphocytes and dendritic cells in the thymic medulla of mice. We also show the eIF2A KO affects male and female mice differently, suggesting that eIF2A may affect sex-specific pathways. Interestingly, our experiments involving pharmacological induction of endoplasmic reticulum (ER) stress with tunicamycin did not reveal any substantial difference between the response to ER stress in eIF2A-KO and wild-type mice. The identification of eIF2A function in the development of metabolic syndrome bears promise for the further identification of specific eIF2A targets responsible for these changes.
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Affiliation(s)
- Richard Anderson
- Center for Gene Regulation in Health and DiseaseDepartment of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA
| | - Anchal Agarwal
- Center for Gene Regulation in Health and DiseaseDepartment of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA
| | - Arnab Ghosh
- Center for Gene Regulation in Health and DiseaseDepartment of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA
| | - Bo‐Jhih Guan
- Department of Genetics and Genome SciencesCase Western Reserve University School of MedicineClevelandOhioUSA
| | - Jackson Casteel
- Center for Gene Regulation in Health and DiseaseDepartment of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA
| | - Nina Dvorina
- Department of Inflammation and ImmunityCleveland Clinic Lerner College of MedicineClevelandOhioUSA
| | - William M. Baldwin
- Department of Inflammation and ImmunityCleveland Clinic Lerner College of MedicineClevelandOhioUSA
| | - Barsanjit Mazumder
- Center for Gene Regulation in Health and DiseaseDepartment of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA
| | | | - William C. Merrick
- Department of BiochemistryCase Western Reserve University School of MedicineClevelandOhioUSA
| | - David A. Buchner
- Department of Genetics and Genome SciencesCase Western Reserve University School of MedicineClevelandOhioUSA,Department of BiochemistryCase Western Reserve University School of MedicineClevelandOhioUSA
| | - Maria Hatzoglou
- Department of Genetics and Genome SciencesCase Western Reserve University School of MedicineClevelandOhioUSA
| | - Roman V. Kondratov
- Center for Gene Regulation in Health and DiseaseDepartment of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA
| | - Anton A. Komar
- Center for Gene Regulation in Health and DiseaseDepartment of Biological, Geological and Environmental SciencesCleveland State UniversityClevelandOhioUSA,Department of BiochemistryCase Western Reserve University School of MedicineClevelandOhioUSA
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31
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Schmitt K, Kraft AA, Valerius O. A Multi-Perspective Proximity View on the Dynamic Head Region of the Ribosomal 40S Subunit. Int J Mol Sci 2021; 22:ijms222111653. [PMID: 34769086 PMCID: PMC8583833 DOI: 10.3390/ijms222111653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/23/2021] [Accepted: 10/25/2021] [Indexed: 11/25/2022] Open
Abstract
A comparison of overlapping proximity captures at the head region of the ribosomal 40S subunit (hr40S) in Saccharomyces cerevisiae from four adjacent perspectives, namely Asc1/RACK1, Rps2/uS5, Rps3/uS3, and Rps20/uS10, corroborates dynamic co-localization of proteins that control activity and fate of both ribosomes and mRNA. Co-locating factors that associate with the hr40S are involved in (i) (de)ubiquitination of ribosomal proteins (Hel2, Bre5-Ubp3), (ii) clamping of inactive ribosomal subunits (Stm1), (iii) mRNA surveillance and vesicular transport (Smy2, Syh1), (iv) degradation of mRNA (endo- and exonucleases Ypl199c and Xrn1, respectively), (v) autophagy (Psp2, Vps30, Ykt6), and (vi) kinase signaling (Ste20). Additionally, they must be harmonized with translation initiation factors (eIF3, cap-binding protein Cdc33, eIF2A) and mRNA-binding/ribosome-charging proteins (Scp160, Sro9). The Rps/uS-BioID perspectives revealed substantial Asc1/RACK1-dependent hr40S configuration indicating a function of the β-propeller in context-specific spatial organization of this microenvironment. Toward resolving context-specific constellations, a Split-TurboID analysis emphasized the ubiquitin-associated factors Def1 and Lsm12 as neighbors of Bre5 at hr40S. These shuttling proteins indicate a common regulatory axis for the fate of polymerizing machineries for the biosynthesis of proteins in the cytoplasm and RNA/DNA in the nucleus.
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32
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Jobava R, Mao Y, Guan BJ, Hu D, Krokowski D, Chen CW, Shu XE, Chukwurah E, Wu J, Gao Z, Zagore LL, Merrick WC, Trifunovic A, Hsieh AC, Valadkhan S, Zhang Y, Qi X, Jankowsky E, Topisirovic I, Licatalosi DD, Qian SB, Hatzoglou M. Adaptive translational pausing is a hallmark of the cellular response to severe environmental stress. Mol Cell 2021; 81:4191-4208.e8. [PMID: 34686314 PMCID: PMC8559772 DOI: 10.1016/j.molcel.2021.09.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/27/2021] [Accepted: 09/28/2021] [Indexed: 12/12/2022]
Abstract
To survive, mammalian cells must adapt to environmental challenges. While the cellular response to mild stress has been widely studied, how cells respond to severe stress remains unclear. We show here that under severe hyperosmotic stress, cells enter a transient hibernation-like state in anticipation of recovery. We demonstrate this adaptive pausing response (APR) is a coordinated cellular response that limits ATP supply and consumption through mitochondrial fragmentation and widespread pausing of mRNA translation. This pausing is accomplished by ribosome stalling at translation initiation codons, which keeps mRNAs poised to resume translation upon recovery. We further show that recovery from severe stress involves ISR (integrated stress response) signaling that permits cell cycle progression, resumption of growth, and reversal of mitochondria fragmentation. Our findings indicate that cells can respond to severe stress via a hibernation-like mechanism that preserves vital elements of cellular function under harsh environmental conditions.
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Affiliation(s)
- Raul Jobava
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Yuanhui Mao
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Bo-Jhih Guan
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Di Hu
- Department of Physiology & Biophysics, CWRU, Cleveland, OH 44106, USA
| | - Dawid Krokowski
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA; Department of Molecular Biology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Lublin 20-033, Poland
| | - Chien-Wen Chen
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Xin Erica Shu
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Evelyn Chukwurah
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Jing Wu
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Zhaofeng Gao
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Leah L Zagore
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Center for RNA Science and Therapeutics, CWRU, Cleveland, OH 44106, USA
| | | | - Aleksandra Trifunovic
- Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Medical Faculty, University of Cologne, 50931 Cologne, Germany; Institute for Mitochondrial Diseases and Ageing, Medical Faculty and Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Andrew C Hsieh
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Saba Valadkhan
- Department of Molecular Biology and Microbiology, CWRU, Cleveland, OH 44106, USA
| | - Youwei Zhang
- Department of Pharmacology, CWRU, Cleveland, OH 44106, USA
| | - Xin Qi
- Department of Physiology & Biophysics, CWRU, Cleveland, OH 44106, USA
| | - Eckhard Jankowsky
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Center for RNA Science and Therapeutics, CWRU, Cleveland, OH 44106, USA
| | - Ivan Topisirovic
- Gerald Bronfman Department of Oncology, Departments of Biochemistry and Experimental Medicine and Lady Davis Institute for Medical Research, Jewish General Hospital, McGill University, Montréal, QC H3T 1E2, Canada
| | - Donny D Licatalosi
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Center for RNA Science and Therapeutics, CWRU, Cleveland, OH 44106, USA.
| | - Shu-Bing Qian
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
| | - Maria Hatzoglou
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA.
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Mendonsa S, von Kuegelgen N, Bujanic L, Chekulaeva M. Charcot-Marie-Tooth mutation in glycyl-tRNA synthetase stalls ribosomes in a pre-accommodation state and activates integrated stress response. Nucleic Acids Res 2021; 49:10007-10017. [PMID: 34403468 PMCID: PMC8464049 DOI: 10.1093/nar/gkab730] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 08/12/2021] [Indexed: 11/14/2022] Open
Abstract
Toxic gain-of-function mutations in aminoacyl-tRNA synthetases cause a degeneration of peripheral motor and sensory axons, known as Charcot-Marie-Tooth (CMT) disease. While these mutations do not disrupt overall aminoacylation activity, they interfere with translation via an unknown mechanism. Here, we dissect the mechanism of function of CMT mutant glycyl-tRNA synthetase (CMT-GARS), using high-resolution ribosome profiling and reporter assays. We find that CMT-GARS mutants deplete the pool of glycyl-tRNAGly available for translation and inhibit the first stage of elongation, the accommodation of glycyl-tRNA into the ribosomal A-site, which causes ribosomes to pause at glycine codons. Moreover, ribosome pausing activates a secondary repression mechanism at the level of translation initiation, by inducing the phosphorylation of the alpha subunit of eIF2 and the integrated stress response. Thus, CMT-GARS mutant triggers translational repression via two interconnected mechanisms, affecting both elongation and initiation of translation.
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Affiliation(s)
- Samantha Mendonsa
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Free University, Berlin, Germany
| | - Nicolai von Kuegelgen
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Free University, Berlin, Germany
| | - Lucija Bujanic
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Marina Chekulaeva
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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34
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Llerena Cari E, Hagen-Lillevik S, Giornazi A, Post M, Komar AA, Appiah L, Bitler B, Polotsky AJ, Santoro N, Kieft J, Lai K, Johnson J. Integrated stress response control of granulosa cell translation and proliferation during normal ovarian follicle development. Mol Hum Reprod 2021; 27:gaab050. [PMID: 34314477 PMCID: PMC8660582 DOI: 10.1093/molehr/gaab050] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/06/2021] [Indexed: 11/13/2022] Open
Abstract
Mechanisms that directly control mammalian ovarian primordial follicle (PF) growth activation and the selection of individual follicles for survival are largely unknown. Follicle cells produce factors that can act as potent inducers of cellular stress during normal function. Consistent with this, we show here that normal, untreated ovarian cells, including pre-granulosa cells of dormant PFs, express phenotype and protein markers of the activated integrated stress response (ISR), including stress-specific protein translation (phospho-Serine 51 eukaryotic initiation factor 2α; P-EIF2α), active DNA damage checkpoints, and cell-cycle arrest. We further demonstrate that mRNAs upregulated in primary (growing) follicles versus arrested PFs mostly include stress-responsive upstream open reading frames (uORFs). Treatment of a granulosa cell (GC) line with the PF growth trigger tumor necrosis factor alpha results in the upregulation of a 'stress-dependent' translation profile. This includes further elevated P-eIF2α and a shift of uORF-containing mRNAs to polysomes. Because the active ISR corresponds to slow follicle growth and PF arrest, we propose that repair and abrogation of ISR checkpoints (e.g. checkpoint recovery) drives the GC cell cycle and PF growth activation (PFGA). If cellular stress is elevated beyond a threshold(s) or, if damage occurs that cannot be repaired, cell and follicle death ensue, consistent with physiological atresia. These data suggest an intrinsic quality control mechanism for immature and growing follicles, where PFGA and subsequent follicle growth and survival depend causally upon ISR resolution, including DNA repair and thus the proof of genomic integrity.
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Affiliation(s)
- Evelyn Llerena Cari
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Aurora, CO, USA
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Sciences, Aurora, CO, USA
| | - Synneva Hagen-Lillevik
- University of Utah School of Medicine, Department of Pediatrics and Department of Nutrition and Integrative Physiology, Salt Lake City, UT, USA
| | | | - Miriam Post
- University of Colorado-Anschutz Medical Campus, Department of Pathology, Aurora, CO, USA
| | - Anton A Komar
- Cleveland State University, Center for Gene Regulation in Health and Disease (GRHD), Cleveland, OH, USA
| | - Leslie Appiah
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Academic Specialists in Obstetrics and Gynecology, Aurora, CO, USA
| | - Benjamin Bitler
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Sciences, Aurora, CO, USA
| | - Alex J Polotsky
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Aurora, CO, USA
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Sciences, Aurora, CO, USA
| | - Nanette Santoro
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Aurora, CO, USA
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Sciences, Aurora, CO, USA
| | - Jeffrey Kieft
- University of Colorado-Anschutz Medical Campus, Department of Biochemistry and Molecular Genetics, Aurora, CO, USA
| | - Kent Lai
- University of Utah School of Medicine, Department of Pediatrics and Department of Nutrition and Integrative Physiology, Salt Lake City, UT, USA
| | - Joshua Johnson
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Aurora, CO, USA
- University of Colorado-Anschutz Medical Campus, Department of Obstetrics and Gynecology, Division of Reproductive Sciences, Aurora, CO, USA
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35
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Dent P, Booth L, Roberts JL, Poklepovic A, Cridebring D, Reiman EM. Inhibition of heat shock proteins increases autophagosome formation, and reduces the expression of APP, Tau, SOD1 G93A and TDP-43. Aging (Albany NY) 2021; 13:17097-17117. [PMID: 34252884 PMCID: PMC8312464 DOI: 10.18632/aging.203297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 07/02/2021] [Indexed: 12/13/2022]
Abstract
Aberrant expression and denaturation of Tau, amyloid-beta and TDP-43 can lead to cell death and is a major component of pathologies such as Alzheimer’s Disease (AD). AD neurons exhibit a reduced ability to form autophagosomes and degrade proteins via autophagy. Using genetically manipulated colon cancer cells we determined whether drugs that directly inhibit the chaperone ATPase activity or cause chaperone degradation and endoplasmic reticulum stress signaling leading to macroautophagy could reduce the levels of these proteins. The antiviral chaperone ATPase inhibitor AR12 reduced the ATPase activities and total expression of GRP78, HSP90, and HSP70, and of Tau, Tau 301L, APP, APP692, APP715, SOD1 G93A and TDP-43. In parallel, it increased the phosphorylation of ATG13 S318 and eIF2A S51 and caused eIF2A-dependent autophagosome formation and autophagic flux. Knock down of Beclin1 or ATG5 prevented chaperone, APP and Tau degradation. Neratinib, used to treat HER2+ breast cancer, reduced chaperone levels and expression of Tau and APP via macroautophagy, and neratinib interacted with AR12 to cause further reductions in protein levels. The autophagy-regulatory protein ATG16L1 is expressed as two isoforms, T300 or A300: Africans trend to express T300 and Europeans A300. We observed higher basal expression of Tau in T300 cells when compared to isogenic A300 cells. ATG16L1 isoform expression did not alter basal levels of HSP90, HSP70 or HSP27, however, basal levels of GRP78 were reduced in A300 cells. The abilities of both AR12 and neratinib to stimulate ATG13 S318 and eIF2A S51 phosphorylation and autophagic flux was also reduced in A300 cells. Our data support further evaluation of AR12 and neratinib in neuronal cells as repurposed treatments for AD.
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Affiliation(s)
- Paul Dent
- Department of Biochemistry and Molecular Biology, Richmond, VA 23298, USA
| | - Laurence Booth
- Department of Biochemistry and Molecular Biology, Richmond, VA 23298, USA
| | - Jane L Roberts
- Department of Pharmacology and Toxicology, Richmond, VA 23298, USA
| | - Andrew Poklepovic
- Department of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Derek Cridebring
- Translational Genomics Research Institute (TGEN), Phoenix, AZ 85004, USA
| | - Eric M Reiman
- Translational Genomics Research Institute (TGEN), Phoenix, AZ 85004, USA.,Banner Alzheimer's Institute, Phoenix, AZ 85006, USA
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Tusi SK, Nguyen L, Thangaraju K, Li J, Cleary JD, Zu T, Ranum LPW. The alternative initiation factor eIF2A plays key role in RAN translation of myotonic dystrophy type 2 CCUG•CAGG repeats. Hum Mol Genet 2021; 30:1020-1029. [PMID: 33856033 DOI: 10.1093/hmg/ddab098] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/26/2021] [Accepted: 03/31/2021] [Indexed: 01/29/2023] Open
Abstract
Repeat-associated non-ATG (RAN) proteins have been reported in 11 microsatellite expansion disorders but the factors that allow RAN translation to occur and the effects of different repeat motifs and alternative AUG-like initiation codons are unclear. We studied the mechanisms of RAN translation across myotonic dystrophy type 2 (DM2) expansion transcripts with (CCUG) or without (CAGG) efficient alternative AUG-like codons. To better understand how DM2 LPAC and QAGR RAN proteins are expressed, we generated a series of CRISPR/Cas9-edited HEK293T cell lines. We show that LPAC and QAGR RAN protein levels are reduced in protein kinase R (PKR)-/- and PKR-like endoplasmic reticulum kinase (PERK)-/- cells, with more substantial reductions of CAGG-encoded QAGR in PKR-/- cells. Experiments using mutant eIF2α-S51A HEK293T cells show that p-eIF2α is required for QAGR production. In contrast, LPAC levels were only partially reduced in these cells, suggesting that both non-AUG and close-cognate initiation occur across CCUG RNAs. Overexpression of the alternative initiation factor eIF2A increases LPAC and QAGR protein levels but, notably, has a much larger effect on QAGR expressed from CAGG-expansion RNAs that lack efficient close-cognate codons. The effects of eIF2A on increasing LPAC are consistent with previous reports that eIF2A affects CUG-initiation translation. The observation that eIF2A also increases QAGR proteins is novel because CAGG expansion transcripts do not contain CUG or similarly efficient close-cognate AUG-like codons. For QAGR but not LPAC, the eIF2A-dependent increases are not seen when p-eIF2α is blocked. These data highlight the differential regulation of DM2 RAN proteins and eIF2A as a potential therapeutic target for DM2 and other RAN diseases.
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Affiliation(s)
- Solaleh Khoramian Tusi
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Lien Nguyen
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Kiruphagaran Thangaraju
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Jian Li
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - John D Cleary
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Tao Zu
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Laura P W Ranum
- Center for NeuroGenetics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
- McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
- Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
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37
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Yousuf MS, Shiers SI, Sahn JJ, Price TJ. Pharmacological Manipulation of Translation as a Therapeutic Target for Chronic Pain. Pharmacol Rev 2021; 73:59-88. [PMID: 33203717 PMCID: PMC7736833 DOI: 10.1124/pharmrev.120.000030] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dysfunction in regulation of mRNA translation is an increasingly recognized characteristic of many diseases and disorders, including cancer, diabetes, autoimmunity, neurodegeneration, and chronic pain. Approximately 50 million adults in the United States experience chronic pain. This economic burden is greater than annual costs associated with heart disease, cancer, and diabetes combined. Treatment options for chronic pain are inadequately efficacious and riddled with adverse side effects. There is thus an urgent unmet need for novel approaches to treating chronic pain. Sensitization of neurons along the nociceptive pathway causes chronic pain states driving symptoms that include spontaneous pain and mechanical and thermal hypersensitivity. More than a decade of preclinical research demonstrates that translational mechanisms regulate the changes in gene expression that are required for ongoing sensitization of nociceptive sensory neurons. This review will describe how key translation regulation signaling pathways, including the integrated stress response, mammalian target of rapamycin, AMP-activated protein kinase (AMPK), and mitogen-activated protein kinase-interacting kinases, impact the translation of different subsets of mRNAs. We then place these mechanisms of translation regulation in the context of chronic pain states, evaluate currently available therapies, and examine the potential for developing novel drugs. Considering the large body of evidence now published in this area, we propose that pharmacologically manipulating specific aspects of the translational machinery may reverse key neuronal phenotypic changes causing different chronic pain conditions. Therapeutics targeting these pathways could eventually be first-line drugs used to treat chronic pain disorders. SIGNIFICANCE STATEMENT: Translational mechanisms regulating protein synthesis underlie phenotypic changes in the sensory nervous system that drive chronic pain states. This review highlights regulatory mechanisms that control translation initiation and how to exploit them in treating persistent pain conditions. We explore the role of mammalian/mechanistic target of rapamycin and mitogen-activated protein kinase-interacting kinase inhibitors and AMPK activators in alleviating pain hypersensitivity. Modulation of eukaryotic initiation factor 2α phosphorylation is also discussed as a potential therapy. Targeting specific translation regulation mechanisms may reverse changes in neuronal hyperexcitability associated with painful conditions.
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Affiliation(s)
- Muhammad Saad Yousuf
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
| | - Stephanie I Shiers
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
| | - James J Sahn
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
| | - Theodore J Price
- Center for Advanced Pain Studies, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas (M.S.Y., S.I.S., T.J.P.) and 4E Therapeutics Inc, Austin, Texas (J.J.S.)
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