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Martinez-Canton M, Galvan-Alvarez V, Gallego-Selles A, Gelabert-Rebato M, Garcia-Gonzalez E, Gonzalez-Henriquez JJ, Martin-Rincon M, Calbet JAL. Activation of macroautophagy and chaperone-mediated autophagy in human skeletal muscle by high-intensity exercise in normoxia and hypoxia and after recovery with or without post-exercise ischemia. Free Radic Biol Med 2024; 222:607-624. [PMID: 39009244 DOI: 10.1016/j.freeradbiomed.2024.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/25/2024] [Accepted: 07/11/2024] [Indexed: 07/17/2024]
Abstract
Autophagy is essential for the adaptive response to exercise and physiological skeletal muscle functionality. However, the mechanisms leading to the activation of macroautophagy and chaperone-mediated autophagy in human skeletal muscle in response to high-intensity exercise remain elusive. Our findings demonstrate that macroautophagy and chaperone-mediated autophagy are stimulated by high-intensity exercise in normoxia (PIO2: 143 mmHg) and severe acute hypoxia (PIO2: 73 mmHg) in healthy humans. High-intensity exercise induces macroautophagy initiation through AMPKα phosphorylation, which phosphorylates and activates ULK1. ULK1 phosphorylates BECN1 at Ser15, eliciting the dissociation of BECN1-BCL2 crucial for phagophore formation. Besides, high-intensity exercise elevates the LC3B-II:LC3B-I ratio, reduces total SQSTM1/p62 levels, and induces p-Ser349 SQSTM1/p62 phosphorylation, suggesting heightened autophagosome degradation. PHAF1/MYTHO, a novel macroautophagy biomarker, is highly upregulated in response to high-intensity exercise. The latter is accompanied by elevated LAMP2A expression, indicating chaperone-mediated autophagy activation regardless of post-exercise HSPA8/HSC70 downregulation. Despite increased glycolytic metabolism, severe acute hypoxia does not exacerbate the autophagy signaling response. Signaling changes revert within 1 min of recovery with free circulation, while the application of immediate post-exercise ischemia impedes recovery. Our study concludes that macroautophagy and chaperone-mediated autophagy pathways are strongly activated by high-intensity exercise, regardless of PO2, and that oxygenation is necessary to revert these signals to pre-exercise values. PHAF1/MYTHO emerges as a pivotal exercise-responsive autophagy marker positively associated with the LC3B-II:LC3B-I ratio.
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Affiliation(s)
- Miriam Martinez-Canton
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Victor Galvan-Alvarez
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Angel Gallego-Selles
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Miriam Gelabert-Rebato
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Eduardo Garcia-Gonzalez
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Juan Jose Gonzalez-Henriquez
- Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain; Department of Mathematics, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain
| | - Marcos Martin-Rincon
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Jose A L Calbet
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Canary Islands, Spain; Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway.
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Wang X, Yang Q, Zhou X, Keene CD, Ryazanov AG, Ma T. Suppression of eEF2 phosphorylation alleviates synaptic failure and cognitive deficits in mouse models of Down syndrome. Alzheimers Dement 2024. [PMID: 38934363 DOI: 10.1002/alz.13916] [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: 01/12/2024] [Revised: 04/11/2024] [Accepted: 05/01/2024] [Indexed: 06/28/2024]
Abstract
INTRODUCTION Cognitive impairment is a core feature of Down syndrome (DS), and the underlying neurobiological mechanisms remain unclear. Translation dysregulation is linked to multiple neurological disorders characterized by cognitive impairments. Phosphorylation of the translational factor eukaryotic elongation factor 2 (eEF2) by its kinase eEF2K results in inhibition of general protein synthesis. METHODS We used genetic and pharmacological methods to suppress eEF2K in two lines of DS mouse models. We further applied multiple approaches to evaluate the effects of eEF2K inhibition on DS pathophysiology. RESULTS We found that eEF2K signaling was overactive in the brain of patients with DS and DS mouse models. Inhibition of eEF2 phosphorylation through suppression of eEF2K in DS model mice improved multiple aspects of DS-associated pathophysiology including de novo protein synthesis deficiency, synaptic morphological defects, long-term synaptic plasticity failure, and cognitive impairments. DISCUSSION Our data suggested that eEF2K signaling dysregulation mediates DS-associated synaptic and cognitive impairments. HIGHLIGHTS Phosphorylation of the translational factor eukaryotic elongation factor 2 (eEF2) is increased in the Down syndrome (DS) brain. Suppression of the eEF2 kinase (eEF2K) alleviates cognitive deficits in DS models. Suppression of eEF2K improves synaptic dysregulation in DS models. Cognitive and synaptic impairments in DS models are rescued by eEF2K inhibitors.
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Affiliation(s)
- Xin Wang
- Department of Internal Medicine, Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Qian Yang
- Department of Internal Medicine, Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Xueyan Zhou
- Department of Internal Medicine, Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - C Dirk Keene
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Alexey G Ryazanov
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Tao Ma
- Department of Internal Medicine, Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
- Department of Translational Neuroscience, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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Mir DA, Ma Z, Horrocks J, Rogers AN. Stress-induced Eukaryotic Translational Regulatory Mechanisms. ARXIV 2024:arXiv:2405.01664v1. [PMID: 38745702 PMCID: PMC11092689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The eukaryotic protein synthesis process entails intricate stages governed by diverse mechanisms to tightly regulate translation. Translational regulation during stress is pivotal for maintaining cellular homeostasis, ensuring the accurate expression of essential proteins crucial for survival. This selective translational control mechanism is integral to cellular adaptation and resilience under adverse conditions. This review manuscript explores various mechanisms involved in selective translational regulation, focusing on mRNA-specific and global regulatory processes. Key aspects of translational control include translation initiation, which is often a rate-limiting step, and involves the formation of the eIF4F complex and recruitment of mRNA to ribosomes. Regulation of translation initiation factors, such as eIF4E, eIF4E2, and eIF2, through phosphorylation and interactions with binding proteins, modulates translation efficiency under stress conditions. This review also highlights the control of translation initiation through factors like the eIF4F complex and the ternary complex and also underscores the importance of eIF2α phosphorylation in stress granule formation and cellular stress responses. Additionally, the impact of amino acid deprivation, mTOR signaling, and ribosome biogenesis on translation regulation and cellular adaptation to stress is also discussed. Understanding the intricate mechanisms of translational regulation during stress provides insights into cellular adaptation mechanisms and potential therapeutic targets for various diseases, offering valuable avenues for addressing conditions associated with dysregulated protein synthesis.
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Affiliation(s)
- Dilawar Ahmad Mir
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Zhengxin Ma
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Jordan Horrocks
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Aric N Rogers
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
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Henis M, Rücker T, Scharrenberg R, Richter M, Baltussen L, Hong S, Meka DP, Schwanke B, Neelagandan N, Daaboul D, Murtaza N, Krisp C, Harder S, Schlüter H, Kneussel M, Hermans-Borgmeyer I, de Wit J, Singh KK, Duncan KE, de Anda FC. The autism susceptibility kinase, TAOK2, phosphorylates eEF2 and modulates translation. SCIENCE ADVANCES 2024; 10:eadf7001. [PMID: 38608030 PMCID: PMC11014455 DOI: 10.1126/sciadv.adf7001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 03/12/2024] [Indexed: 04/14/2024]
Abstract
Genes implicated in translation control have been associated with autism spectrum disorders (ASDs). However, some important genetic causes of autism, including the 16p11.2 microdeletion, bear no obvious connection to translation. Here, we use proteomics, genetics, and translation assays in cultured cells and mouse brain to reveal altered translation mediated by loss of the kinase TAOK2 in 16p11.2 deletion models. We show that TAOK2 associates with the translational machinery and functions as a translational brake by phosphorylating eukaryotic elongation factor 2 (eEF2). Previously, all signal-mediated regulation of translation elongation via eEF2 phosphorylation was believed to be mediated by a single kinase, eEF2K. However, we show that TAOK2 can directly phosphorylate eEF2 on the same regulatory site, but functions independently of eEF2K signaling. Collectively, our results reveal an eEF2K-independent signaling pathway for control of translation elongation and suggest altered translation as a molecular component in the etiology of some forms of ASD.
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Affiliation(s)
- Melad Henis
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, New Valley University, 72511 El-Kharga, Egypt
| | - Tabitha Rücker
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Robin Scharrenberg
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Melanie Richter
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lucas Baltussen
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium
- KU Leuven Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Shuai Hong
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Durga Praveen Meka
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Birgit Schwanke
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nagammal Neelagandan
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Falkenried 94, 20251 Hamburg, Germany
- Institute of Bioengineering (IBI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Danie Daaboul
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium
- KU Leuven Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Nadeem Murtaza
- Krembil Research Institute, Donald K. Johnson Eye Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario M5T 0S8, Canada
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, Ontario L8S 4A9, Canada
| | - Christoph Krisp
- Institute for Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics Group, Campus Forschung, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany
| | - Sönke Harder
- Institute for Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics Group, Campus Forschung, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany
| | - Hartmut Schlüter
- Institute for Clinical Chemistry and Laboratory Medicine, Mass Spectrometric Proteomics Group, Campus Forschung, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany
| | - Matthias Kneussel
- Institute of Neurogenetics, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Irm Hermans-Borgmeyer
- Transgenic Service Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Falkenried 94, 20251 Hamburg, Germany
| | - Joris de Wit
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium
- KU Leuven Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Karun K. Singh
- Krembil Research Institute, Donald K. Johnson Eye Institute, University Health Network, 60 Leonard Ave, Toronto, Ontario M5T 0S8, Canada
- Faculty of Medicine, University of Toronto, Medical Sciences Building, 1 King's College Cir, Toronto, Ontario M5S 1 A8, Canada
| | - Kent E. Duncan
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Falkenried 94, 20251 Hamburg, Germany
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, 22419 Hamburg, Germany
| | - Froylan Calderón de Anda
- Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
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Kharouf N, Flanagan TW, Alamodi AA, Al Hmada Y, Hassan SY, Shalaby H, Santourlidis S, Hassan SL, Haikel Y, Megahed M, Brodell RT, Hassan M. CD133-Dependent Activation of Phosphoinositide 3-Kinase /AKT/Mammalian Target of Rapamycin Signaling in Melanoma Progression and Drug Resistance. Cells 2024; 13:240. [PMID: 38334632 PMCID: PMC10854812 DOI: 10.3390/cells13030240] [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: 11/29/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/10/2024] Open
Abstract
Melanoma frequently harbors genetic alterations in key molecules leading to the aberrant activation of PI3K and its downstream pathways. Although the role of PI3K/AKT/mTOR in melanoma progression and drug resistance is well documented, targeting the PI3K/AKT/mTOR pathway showed less efficiency in clinical trials than might have been expected, since the suppression of the PI3K/mTOR signaling pathway-induced feedback loops is mostly associated with the activation of compensatory pathways such as MAPK/MEK/ERK. Consequently, the development of intrinsic and acquired resistance can occur. As a solid tumor, melanoma is notorious for its heterogeneity. This can be expressed in the form of genetically divergent subpopulations including a small fraction of cancer stem-like cells (CSCs) and non-cancer stem cells (non-CSCs) that make the most of the tumor mass. Like other CSCs, melanoma stem-like cells (MSCs) are characterized by their unique cell surface proteins/stemness markers and aberrant signaling pathways. In addition to its function as a robust marker for stemness properties, CD133 is crucial for the maintenance of stemness properties and drug resistance. Herein, the role of CD133-dependent activation of PI3K/mTOR in the regulation of melanoma progression, drug resistance, and recurrence is reviewed.
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Affiliation(s)
- Naji Kharouf
- Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 67000 Strasbourg, France; (N.K.); (Y.H.)
- Department of Operative Dentistry and Endodontics, Dental Faculty, University of Strasbourg, 67000 Strasbourg, France
| | - Thomas W. Flanagan
- Department of Pharmacology and Experimental Therapeutics, LSU Health Sciences Center, New Orleans, LA 70112, USA;
| | | | - Youssef Al Hmada
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA; (Y.A.H.); (R.T.B.)
| | - Sofie-Yasmin Hassan
- Department of Pharmacy, Faculty of Science, Heinrich-Heine University Duesseldorf, 40225 Dusseldorf, Germany;
| | - Hosam Shalaby
- Department of Urology, School of Medicine, Tulane University, New Orleans, LA 70112, USA;
| | - Simeon Santourlidis
- Epigenetics Core Laboratory, Institute of Transplantation Diagnostics and Cell Therapeutics, Medical Faculty, Heinrich-Heine University Duesseldorf, 40225 Duesseldorf, Germany;
| | - Sarah-Lilly Hassan
- Department of Chemistry, Faculty of Science, Heinrich-Heine University Duesseldorf, 40225 Dusseldorf, Germany;
| | - Youssef Haikel
- Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 67000 Strasbourg, France; (N.K.); (Y.H.)
- Department of Operative Dentistry and Endodontics, Dental Faculty, University of Strasbourg, 67000 Strasbourg, France
- Pôle de Médecine et Chirurgie Bucco-Dentaire, Hôpital Civil, Hôpitaux Universitaire de Strasbourg, 67000 Strasbourg, France
| | - Mossad Megahed
- Clinic of Dermatology, University Hospital of Aachen, 52074 Aachen, Germany;
| | - Robert T. Brodell
- Department of Pathology, University of Mississippi Medical Center, Jackson, MS 39216, USA; (Y.A.H.); (R.T.B.)
| | - Mohamed Hassan
- Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 67000 Strasbourg, France; (N.K.); (Y.H.)
- Department of Operative Dentistry and Endodontics, Dental Faculty, University of Strasbourg, 67000 Strasbourg, France
- Research Laboratory of Surgery-Oncology, Department of Surgery, Tulane University School of Medicine, New Orleans, LA 70112, USA
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Fard SS, Holz MK. Regulation of mRNA translation by estrogen receptor in breast cancer. Steroids 2023; 200:109316. [PMID: 37806603 PMCID: PMC10841406 DOI: 10.1016/j.steroids.2023.109316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/15/2023] [Accepted: 09/28/2023] [Indexed: 10/10/2023]
Abstract
Breast cancer is one of the leading causes of cancer-related fatalities and the most often diagnosed malignancy in women globally. Dysregulation of sex hormone signaling pathways mediated by the estrogen receptor (ER) in breast cancer is well characterized. Although ER is known to promote cell growth and survival by altering gene transcription, recent research suggests that its effects in cancers are also mediated through dysregulation of protein synthesis. This implies that ER can coordinately affect gene expression through both translational and transcriptional pathways, leading to the development of malignancy. In this review, we will cover the current understanding of how the ER controls mRNA translation in breast cancer and discuss any potential clinical implications of this phenomenon.
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Affiliation(s)
- Shahrzad S Fard
- Department of Cell Biology and Anatomy, Graduate School of Biomedical Sciences, New York Medical College, Valhalla, NY, USA
| | - Marina K Holz
- Department of Cell Biology and Anatomy, Graduate School of Biomedical Sciences, New York Medical College, Valhalla, NY, USA; Department of Biochemistry and Molecular Biology, Graduate School of Biomedical Sciences, New York Medical College, Valhalla, NY, USA.
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7
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Wittenstein A, Caspi M, Rippin I, Elroy-Stein O, Eldar-Finkelman H, Thoms S, Rosin-Arbesfeld R. Nonsense mutation suppression is enhanced by targeting different stages of the protein synthesis process. PLoS Biol 2023; 21:e3002355. [PMID: 37943958 PMCID: PMC10684085 DOI: 10.1371/journal.pbio.3002355] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/28/2023] [Accepted: 09/29/2023] [Indexed: 11/12/2023] Open
Abstract
The introduction of premature termination codons (PTCs), as a result of splicing defects, insertions, deletions, or point mutations (also termed nonsense mutations), lead to numerous genetic diseases, ranging from rare neuro-metabolic disorders to relatively common inheritable cancer syndromes and muscular dystrophies. Over the years, a large number of studies have demonstrated that certain antibiotics and other synthetic molecules can act as PTC suppressors by inducing readthrough of nonsense mutations, thereby restoring the expression of full-length proteins. Unfortunately, most PTC readthrough-inducing agents are toxic, have limited effects, and cannot be used for therapeutic purposes. Thus, further efforts are required to improve the clinical outcome of nonsense mutation suppressors. Here, by focusing on enhancing readthrough of pathogenic nonsense mutations in the adenomatous polyposis coli (APC) tumor suppressor gene, we show that disturbing the protein translation initiation complex, as well as targeting other stages of the protein translation machinery, enhances both antibiotic and non-antibiotic-mediated readthrough of nonsense mutations. These findings strongly increase our understanding of the mechanisms involved in nonsense mutation readthrough and facilitate the development of novel therapeutic targets for nonsense suppression to restore protein expression from a large variety of disease-causing mutated transcripts.
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Affiliation(s)
- Amnon Wittenstein
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michal Caspi
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ido Rippin
- The Department of Human Molecular Genetics & Biochemistry School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Orna Elroy-Stein
- Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Hagit Eldar-Finkelman
- The Department of Human Molecular Genetics & Biochemistry School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sven Thoms
- Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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8
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Barros GC, Guerrero S, Silva GM. The central role of translation elongation in response to stress. Biochem Soc Trans 2023; 51:959-969. [PMID: 37318088 PMCID: PMC11160351 DOI: 10.1042/bst20220584] [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: 02/06/2023] [Revised: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023]
Abstract
Protein synthesis is essential to support homeostasis, and thus, must be highly regulated during cellular response to harmful environments. All stages of translation are susceptible to regulation under stress, however, the mechanisms involved in translation regulation beyond initiation have only begun to be elucidated. Methodological advances enabled critical discoveries on the control of translation elongation, highlighting its important role in translation repression and the synthesis of stress-response proteins. In this article, we discuss recent findings on mechanisms of elongation control mediated by ribosome pausing and collisions and the availability of tRNAs and elongation factors. We also discuss how elongation intersects with distinct modes of translation control, further supporting cellular viability and gene expression reprogramming. Finally, we highlight how several of these pathways are reversibly regulated, emphasizing the dynamics of translation control during stress-response progression. A comprehensive understanding of translation regulation under stress will produce fundamental knowledge of protein dynamics while opening new avenues and strategies to overcome dysregulated protein production and cellular sensitivity to stress.
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Affiliation(s)
| | | | - Gustavo M. Silva
- Department of Biology, Duke University, Durham, NC, USA
- Lead contact
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9
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Piserchio A, Long K, Browning L, Bohanon A, Isiorho E, Dalby K, Ghose R. ADP enhances the allosteric activation of eukaryotic elongation factor 2 kinase by calmodulin. Proc Natl Acad Sci U S A 2023; 120:e2300902120. [PMID: 37068230 PMCID: PMC10151598 DOI: 10.1073/pnas.2300902120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/06/2023] [Indexed: 04/19/2023] Open
Abstract
Protein translation, one of the most energy-consumptive processes in a eukaryotic cell, requires robust regulation, especially under energy-deprived conditions. A critical component of this regulation is the suppression of translational elongation through reduced ribosome association of the GTPase eukaryotic elongation factor 2 (eEF-2) resulting from its specific phosphorylation by the calmodulin (CaM)-activated α-kinase eEF-2 kinase (eEF-2K). It has been suggested that the eEF-2K response to reduced cellular energy levels is indirect and mediated by the universal energy sensor AMP-activated protein kinase (AMPK) through direct stimulatory phosphorylation and/or downregulation of the eEF-2K-inhibitory nutrient-sensing mTOR pathway. Here, we provide structural, biochemical, and cell-biological evidence of a direct energy-sensing role of eEF-2K through its stimulation by ADP. A crystal structure of the nucleotide-bound complex between CaM and the functional core of eEF-2K phosphorylated at its primary stimulatory site (T348) reveals ADP bound at a unique pocket located on the face opposite that housing the kinase active site. Within this basic pocket (BP), created at the CaM/eEF-2K interface upon complex formation, ADP is stabilized through numerous interactions with both interacting partners. Biochemical analyses using wild-type eEF-2K and specific BP mutants indicate that ADP stabilizes CaM within the active complex, increasing the sensitivity of the kinase to CaM. Induction of energy stress through glycolysis inhibition results in significantly reduced enhancement of phosphorylated eEF-2 levels in cells expressing ADP-binding compromised BP mutants compared to cells expressing wild-type eEF-2K. These results suggest a direct energy-sensing role for eEF-2K through its cooperative interaction with CaM and ADP.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY10031
| | - Kimberly J. Long
- Division of Chemical Biology and Medicinal Chemistry, the University of Texas, Austin, TX78712
| | - Luke S. Browning
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Amanda L. Bohanon
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Eta A. Isiorho
- Macromolecular Crystallization Facility CUNY Advanced Science Research Center, New York, NY10031
| | - Kevin N. Dalby
- Division of Chemical Biology and Medicinal Chemistry, the University of Texas, Austin, TX78712
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY10031
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY10016
- PhD Program in Chemistry, The Graduate Center of CUNY, New York, NY10016
- PhD Program in Physics, The Graduate Center of CUNY, New York, NY10016
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10
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Aydemir E, Tüysüz EC, Bayrak ÖF, Tecimel D, Hızlı-Deniz AA, Şahin F. Impact of silencing eEF2K expression on the malignant properties of chordoma. Mol Biol Rep 2023; 50:3011-3022. [PMID: 36652154 DOI: 10.1007/s11033-023-08257-z] [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: 09/13/2022] [Accepted: 01/06/2023] [Indexed: 01/19/2023]
Abstract
BACKGROUND Eukaryotic elongation factor 2 kinase (eukaryotic elongation factor 2 kinase, eEF2K) is a calcium calmodulin dependent protein kinase that keeps the highest energy consuming cellular process of protein synthesis under check through negative regulation. eEF2K pauses global protein synthesis rates at the translational elongation step by phosphorylating its only kown substrate elongation factor 2 (eEF2), a unique translocase activity in ekaryotic cells enabling the polypeptide chain elongation. Therefore, eEF2K is thought to preserve cellular energy pools particularly upon acute development of cellular stress conditions such as nutrient deprivation, hypoxia, or infections. Recently, high expression of this enzyme has been associated with poor prognosis in an array of solid tumor types. Therefore, in a growing number of studies tremendous effort is being directed to the development of treatment methods aiming to suppress eEF2K as a novel therapeutic approach in the fight against cancer. METHODS In our study, we aimed to investigate the changes in the tumorigenicity of chordoma cells in presence of gene silencing for eEF2K. Taking a transient gene silencing approach using siRNA particles, eEF2K gene expression was suppressed in chordoma cells. RESULTS Silencing eEF2K expression was associated with a slight increase in cellular proliferation and a decrease in death rates. Furthermore, no alteration in the sensitivity of chordoma cells to chemotherapy was detected in response to the decrease in eEF2K expression which intriguingly promoted suppression of cell migratory and invasion related properties. CONCLUSION Our findings indicate that the loss of eEF2K expression in chordoma cell lines results in the reduction of metastatic capacity.
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Affiliation(s)
- Esra Aydemir
- Department of Biomedical Engineering, Faculty of Engineering and Natural Sciences, Biruni University, 10. Yil Cad, Protokol Yolu, No: 45 Topkapı, 34010, Istanbul, Turkey.
| | - Emre Can Tüysüz
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey.,Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul, Turkey.,Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Ömer Faruk Bayrak
- Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul, Turkey
| | - Didem Tecimel
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey.,Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul, Turkey
| | - Ayşen Aslı Hızlı-Deniz
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Fikrettin Şahin
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
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11
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Salimi K, Alvandi M, Saberi Pirouz M, Rakhshan K, Howatson G. Regulating eEF2 and eEF2K in skeletal muscle by exercise. Arch Physiol Biochem 2023:1-12. [PMID: 36633938 DOI: 10.1080/13813455.2023.2164898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 12/15/2022] [Accepted: 12/29/2022] [Indexed: 01/13/2023]
Abstract
Skeletal muscle is a flexible and adaptable tissue that strongly responds to exercise training. The skeletal muscle responds to exercise by increasing muscle protein synthesis (MPS) when energy is available. One of protein synthesis's major rate-limiting and critical regulatory steps is the translation elongation pathway. The process of translation elongation in skeletal muscle is highly regulated. It requires elongation factors that are intensely affected by various physiological stimuli such as exercise and the total available energy of cells. Studies have shown that exercise involves the elongation pathway by numerous signalling pathways. Since the elongation pathway, has been far less studied than the other translation steps, its comprehensive prospect and quantitative understanding remain in the dark. This study highlights the current understanding of the effect of exercise training on the translation elongation pathway focussing on the molecular factors affecting the pathway, including Ca2+, AMPK, PKA, mTORC1/P70S6K, MAPKs, and myostatin. We further discussed the mode and volume of exercise training intervention on the translation elongation pathway.What is the topic of this review? This review summarises the impacts of exercise training on the translation elongation pathway in skeletal muscle focussing on eEF2 and eEF2K.What advances does it highlight? This review highlights mechanisms and factors that profoundly influence the translation elongation pathway and argues that exercise might modulate the response. This review also combines the experimental observations focussing on the regulation of translation elongation during and after exercise. The findings widen our horizon to the notion of mechanisms involved in muscle protein synthesis (MPS) through translation elongation response to exercise training.
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Affiliation(s)
- Kia Salimi
- Department of Exercise Physiology, Faculty of Sport and Exercise Sciences, University of Tehran, Tehran, Iran
| | - Masoomeh Alvandi
- Department of Biological Science in Sport and Health, University of Shahid Beheshti, Tehran, Iran
| | - Mahdi Saberi Pirouz
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran
| | - Kamran Rakhshan
- Department of Medical Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Electrophysiology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Glyn Howatson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
- Water Research Group, North West University, Potchefstroom, South Africa
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12
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Zhdanov AV, Golubeva AV, Yordanova MM, Andreev DE, Ventura-Silva AP, Schellekens H, Baranov PV, Cryan JF, Papkovsky DB. Ghrelin rapidly elevates protein synthesis in vitro by employing the rpS6K-eEF2K-eEF2 signalling axis. Cell Mol Life Sci 2022; 79:426. [PMID: 35841486 PMCID: PMC9288388 DOI: 10.1007/s00018-022-04446-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 06/16/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022]
Abstract
Activated ghrelin receptor GHS-R1α triggers cell signalling pathways that modulate energy homeostasis and biosynthetic processes. However, the effects of ghrelin on mRNA translation are unknown. Using various reporter assays, here we demonstrate a rapid elevation of protein synthesis in cells within 15–30 min upon stimulation of GHS-R1α by ghrelin. We further show that ghrelin-induced activation of translation is mediated, at least in part, through the de-phosphorylation (de-suppression) of elongation factor 2 (eEF2). The levels of eEF2 phosphorylation at Thr56 decrease due to the reduced activity of eEF2 kinase, which is inhibited via Ser366 phosphorylation by rpS6 kinases. Being stress-susceptible, the ghrelin-mediated decrease in eEF2 phosphorylation can be abolished by glucose deprivation and mitochondrial uncoupling. We believe that the observed burst of translation benefits rapid restocking of neuropeptides, which are released upon GHS-R1α activation, and represents the most time- and energy-efficient way of prompt recharging the orexigenic neuronal circuitry.
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Affiliation(s)
- Alexander V Zhdanov
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Anna V Golubeva
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
| | - Martina M Yordanova
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - Dmitry E Andreev
- Belozersky Research Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Ana Paula Ventura-Silva
- APC Microbiome Institute, University College Cork, Cork, Ireland.,School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Harriet Schellekens
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Pavel V Baranov
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - John F Cryan
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Dmitri B Papkovsky
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
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13
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Glutamine deficiency in solid tumor cells confers resistance to ribosomal RNA synthesis inhibitors. Nat Commun 2022; 13:3706. [PMID: 35764642 PMCID: PMC9240073 DOI: 10.1038/s41467-022-31418-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 06/16/2022] [Indexed: 11/22/2022] Open
Abstract
Ribosome biogenesis is an energetically expensive program that is dictated by nutrient availability. Here we report that nutrient deprivation severely impairs precursor ribosomal RNA (pre-rRNA) processing and leads to the accumulation of unprocessed rRNAs. Upon nutrient restoration, pre-rRNAs stored under starvation are processed into mature rRNAs that are utilized for ribosome biogenesis. Failure to accumulate pre-rRNAs under nutrient stress leads to perturbed ribosome assembly upon nutrient restoration and subsequent apoptosis via uL5/uL18-mediated activation of p53. Restoration of glutamine alone activates p53 by triggering uL5/uL18 translation. Induction of uL5/uL18 protein synthesis by glutamine is dependent on the translation factor eukaryotic elongation factor 2 (eEF2), which is in turn dependent on Raf/MEK/ERK signaling. Depriving cells of glutamine prevents the activation of p53 by rRNA synthesis inhibitors. Our data reveals a mechanism that tumor cells can exploit to suppress p53-mediated apoptosis during fluctuations in environmental nutrient availability. Small molecules that target RNA Polymerase I inhibit ribosome biogenesis to activate p53 through the nucleolar surveillance response pathway. Here, the authors show that p53 induction by ribosome stress is dependent on extracellular glutamine availability.
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14
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Hijazi M, Casado P, Akhtar N, Alvarez-Teijeiro S, Rajeeve V, Cutillas PR. eEF2K Activity Determines Synergy to Cotreatment of Cancer Cells With PI3K and MEK Inhibitors. Mol Cell Proteomics 2022; 21:100240. [PMID: 35513296 PMCID: PMC9184568 DOI: 10.1016/j.mcpro.2022.100240] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 03/17/2022] [Accepted: 04/25/2022] [Indexed: 10/31/2022] Open
Abstract
PI3K-mammalian target of rapamycin and MAPK/ERK kinase (MEK)/mitogen-activated protein kinase (MAPK) are the most frequently dysregulated signaling pathways in cancer. A problem that limits the success of therapies that target individual PI3K-MAPK members is that these pathways converge to regulate downstream functions and often compensate each other, leading to drug resistance and transient responses to therapy. In order to overcome resistance, therapies based on cotreatments with PI3K/AKT and MEK/MAPK inhibitors are now being investigated in clinical trials, but the mechanisms of sensitivity to cotreatment are not fully understood. Using LC-MS/MS-based phosphoproteomics, we found that eukaryotic elongation factor 2 kinase (eEF2K), a key convergence point downstream of MAPK and PI3K pathways, mediates synergism to cotreatment with trametinib plus pictilisib (which target MEK1/2 and PI3Kα/δ, respectively). Inhibition of eEF2K by siRNA or with a small molecule inhibitor reversed the antiproliferative effects of the cotreatment with PI3K plus MEK inhibitors in a cell model-specific manner. Systematic analysis in 12 acute myeloid leukemia cell lines revealed that eEF2K activity was increased in cells for which PI3K plus MEKi cotreatment is synergistic, while PKC potentially mediated resistance to such cotreatment. Together, our study uncovers eEF2K activity as a key mediator of responses to PI3Ki plus MEKi and as a potential biomarker to predict synergy to cotreatment in cancer cells.
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Affiliation(s)
- Maruan Hijazi
- Signalling & Proteomics Group, Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom.
| | - Pedro Casado
- Signalling & Proteomics Group, Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Nosheen Akhtar
- Signalling & Proteomics Group, Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Saul Alvarez-Teijeiro
- Signalling & Proteomics Group, Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Vinothini Rajeeve
- Signalling & Proteomics Group, Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Pedro R Cutillas
- Signalling & Proteomics Group, Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom; The Alan Turing Institute, British Library, London, United Kingdom.
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15
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mTOR substrate phosphorylation in growth control. Cell 2022; 185:1814-1836. [PMID: 35580586 DOI: 10.1016/j.cell.2022.04.013] [Citation(s) in RCA: 118] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 12/20/2022]
Abstract
The target of rapamycin (TOR), discovered 30 years ago, is a highly conserved serine/threonine protein kinase that plays a central role in regulating cell growth and metabolism. It is activated by nutrients, growth factors, and cellular energy. TOR forms two structurally and functionally distinct complexes, TORC1 and TORC2. TOR signaling activates cell growth, defined as an increase in biomass, by stimulating anabolic metabolism while inhibiting catabolic processes. With emphasis on mammalian TOR (mTOR), we comprehensively reviewed the literature and identified all reported direct substrates. In the context of recent structural information, we discuss how mTORC1 and mTORC2, despite having a common catalytic subunit, phosphorylate distinct substrates. We conclude that the two complexes recruit different substrates to phosphorylate a common, minimal motif.
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16
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Surya A, Sarinay-Cenik E. Cell autonomous and non-autonomous consequences of deviations in translation machinery on organism growth and the connecting signalling pathways. Open Biol 2022; 12:210308. [PMID: 35472285 PMCID: PMC9042575 DOI: 10.1098/rsob.210308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/31/2022] [Indexed: 01/09/2023] Open
Abstract
Translation machinery is responsible for the production of cellular proteins; thus, cells devote the majority of their resources to ribosome biogenesis and protein synthesis. Single-copy loss of function in the translation machinery components results in rare ribosomopathy disorders, such as Diamond-Blackfan anaemia in humans and similar developmental defects in various model organisms. Somatic copy number alterations of translation machinery components are also observed in specific tumours. The organism-wide response to haploinsufficient loss-of-function mutations in ribosomal proteins or translation machinery components is complex: variations in translation machinery lead to reduced ribosome biogenesis, protein translation and altered protein homeostasis and cellular signalling pathways. Cells are affected both autonomously and non-autonomously by changes in translation machinery or ribosome biogenesis through cell-cell interactions and secreted hormones. We first briefly introduce the model organisms where mutants or knockdowns of protein synthesis and ribosome biogenesis are characterized. Next, we specifically describe observations in Caenorhabditis elegans and Drosophila melanogaster, where insufficient protein synthesis in a subset of cells triggers cell non-autonomous growth or apoptosis responses that affect nearby cells and tissues. We then cover the characterized signalling pathways that interact with ribosome biogenesis/protein synthesis machinery with an emphasis on their respective functions during organism development.
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Affiliation(s)
- Agustian Surya
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Elif Sarinay-Cenik
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
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17
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Deprogramming metabolism in pancreatic cancer with a bi-functional GPR55 inhibitor and biased β2 adrenergic agonist. Sci Rep 2022; 12:3618. [PMID: 35256673 PMCID: PMC8901637 DOI: 10.1038/s41598-022-07600-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 02/21/2022] [Indexed: 01/14/2023] Open
Abstract
Metabolic reprogramming contributes to oncogenesis, tumor growth, and treatment resistance in pancreatic ductal adenocarcinoma (PDAC). Here we report the effects of (R,S′)-4′-methoxy-1-naphthylfenoterol (MNF), a GPR55 antagonist and biased β2-adrenergic receptor (β2-AR) agonist on cellular signaling implicated in proliferation and metabolism in PDAC cells. The relative contribution of GPR55 and β2-AR in (R,S′)-MNF signaling was explored further in PANC-1 cells. Moreover, the effect of (R,S′)-MNF on tumor growth was determined in a PANC-1 mouse xenograft model. PANC-1 cells treated with (R,S′)-MNF showed marked attenuation in GPR55 signal transduction and function combined with increased β2-AR/Gαs/adenylyl cyclase/PKA signaling, both of which contributing to lower MEK/ERK, PI3K/AKT and YAP/TAZ signaling. (R,S′)-MNF administration significantly reduced PANC-1 tumor growth and circulating l-lactate concentrations. Global metabolic profiling of (R,S′)-MNF-treated tumor tissues revealed decreased glycolytic metabolism, with a shift towards normoxic processes, attenuated glutamate metabolism, and increased levels of ophthalmic acid and its precursor, 2-aminobutyric acid, indicative of elevated oxidative stress. Transcriptomics and immunoblot analyses indicated the downregulation of gene and protein expression of HIF-1α and c-Myc, key initiators of metabolic reprogramming in PDAC. (R,S′)-MNF treatment decreased HIF-1α and c-Myc expression, attenuated glycolysis, shifted fatty acid metabolism towards β-oxidation, and suppressed de novo pyrimidine biosynthesis in PANC-1 tumors. The results indicate a potential benefit of combined GPR55 antagonism and biased β2-AR agonism in PDAC therapy associated with the deprogramming of altered cellular metabolism.
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18
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Woodward K, Shirokikh NE. Translational control in cell ageing: an update. Biochem Soc Trans 2021; 49:2853-2869. [PMID: 34913471 PMCID: PMC8786278 DOI: 10.1042/bst20210844] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 12/28/2022]
Abstract
Cellular ageing is one of the main drivers of organismal ageing and holds keys towards improving the longevity and quality of the extended life. Elucidating mechanisms underlying the emergence of the aged cells as well as their altered responses to the environment will help understanding the evolutionarily defined longevity preferences across species with different strategies of survival. Much is understood about the role of alterations in the DNA, including many epigenetic modifications such as methylation, in relation to the aged cell phenotype. While transcriptomes of the aged cells are beginning to be better-characterised, their translational responses remain under active investigation. Many of the translationally controlled homeostatic pathways are centred around mitigation of DNA damage, cell stress response and regulation of the proliferative potential of the cells, and thus are critical for the aged cell function. Translation profiling-type studies have boosted the opportunities in discovering the function of protein biosynthesis control and are starting to be applied to the aged cells. Here, we provide a summary of the current knowledge about translational mechanisms considered to be commonly altered in the aged cells, including the integrated stress response-, mechanistic target of Rapamycin- and elongation factor 2 kinase-mediated pathways. We enlist and discuss findings of the recent works that use broad profiling-type approaches to investigate the age-related translational pathways. We outline the limitations of the methods and the remaining unknowns in the established ageing-associated translation mechanisms, and flag translational mechanisms with high prospective importance in ageing, for future studies.
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Affiliation(s)
- Katrina Woodward
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The Australian National University, Acton, Canberra, ACT 2601, Australia
| | - Nikolay E. Shirokikh
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The Australian National University, Acton, Canberra, ACT 2601, Australia
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19
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Fabbri L, Chakraborty A, Robert C, Vagner S. The plasticity of mRNA translation during cancer progression and therapy resistance. Nat Rev Cancer 2021; 21:558-577. [PMID: 34341537 DOI: 10.1038/s41568-021-00380-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/14/2021] [Indexed: 02/07/2023]
Abstract
Translational control of mRNAs during gene expression allows cells to promptly and dynamically adapt to a variety of stimuli, including in neoplasia in response to aberrant oncogenic signalling (for example, PI3K-AKT-mTOR, RAS-MAPK and MYC) and microenvironmental stress such as low oxygen and nutrient supply. Such translational rewiring allows rapid, specific changes in the cell proteome that shape specific cancer phenotypes to promote cancer onset, progression and resistance to anticancer therapies. In this Review, we illustrate the plasticity of mRNA translation. We first highlight the diverse mechanisms by which it is regulated, including by translation factors (for example, eukaryotic initiation factor 4F (eIF4F) and eIF2), RNA-binding proteins, tRNAs and ribosomal RNAs that are modulated in response to aberrant intracellular pathways or microenvironmental stress. We then describe how translational control can influence tumour behaviour by impacting on the phenotypic plasticity of cancer cells as well as on components of the tumour microenvironment. Finally, we highlight the role of mRNA translation in the cellular response to anticancer therapies and its promise as a key therapeutic target.
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Affiliation(s)
- Lucilla Fabbri
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France
- Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France
- Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay, France
| | - Alina Chakraborty
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France
- Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France
- Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay, France
| | - Caroline Robert
- INSERM U981, Gustave Roussy Cancer Campus, Villejuif, France
- Université Paris-Sud, Université Paris-Saclay, Kremlin-Bicêtre, France
- Dermato-Oncology, Gustave Roussy Cancer Campus, Villejuif, France
| | - Stéphan Vagner
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France.
- Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France.
- Equipe Labellisée Ligue Nationale Contre le Cancer, Orsay, France.
- Dermato-Oncology, Gustave Roussy Cancer Campus, Villejuif, France.
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20
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Ballard DJ, Peng HY, Das JK, Kumar A, Wang L, Ren Y, Xiong X, Ren X, Yang JM, Song J. Insights Into the Pathologic Roles and Regulation of Eukaryotic Elongation Factor-2 Kinase. Front Mol Biosci 2021; 8:727863. [PMID: 34532346 PMCID: PMC8438118 DOI: 10.3389/fmolb.2021.727863] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 08/16/2021] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic Elongation Factor-2 Kinase (eEF2K) acts as a negative regulator of protein synthesis, translation, and cell growth. As a structurally unique member of the alpha-kinase family, eEF2K is essential to cell survival under stressful conditions, as it contributes to both cell viability and proliferation. Known as the modulator of the global rate of protein translation, eEF2K inhibits eEF2 (eukaryotic Elongation Factor 2) and decreases translation elongation when active. eEF2K is regulated by various mechanisms, including phosphorylation through residues and autophosphorylation. Specifically, this protein kinase is downregulated through the phosphorylation of multiple sites via mTOR signaling and upregulated via the AMPK pathway. eEF2K plays important roles in numerous biological systems, including neurology, cardiology, myology, and immunology. This review provides further insights into the current roles of eEF2K and its potential to be explored as a therapeutic target for drug development.
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Affiliation(s)
- Darby J. Ballard
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Hao-Yun Peng
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Jugal Kishore Das
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Anil Kumar
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Liqing Wang
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Yijie Ren
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Xiaofang Xiong
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Xingcong Ren
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Jin-Ming Yang
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Jianxun Song
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
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21
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Jiang M, Qi L, Jin K, Li L, Wu Y, Song D, Gan J, Huang M, Li Y, Song C. eEF2K as a novel metastatic and prognostic biomarker in gastric cancer patients. Pathol Res Pract 2021; 225:153568. [PMID: 34352439 DOI: 10.1016/j.prp.2021.153568] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/25/2021] [Accepted: 07/26/2021] [Indexed: 01/09/2023]
Abstract
BACKGROUND Although eukaryotic elongation factor 2 kinase (eEF2K) has been reported to be a potential oncogenic factor in many human cancers, its usefulness as a clinical prognostic biomarker for gastric cancer has not been investigated. METHODS In this study, data about 540 patients with stomach adenocarcinoma (STAD) were analyzed from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases to determine the expression of eEF2K. Immunohistochemistry (IHC), western blots, and real-time polymerase chain reaction (RT-PCR) were also performed to determine the clinical significance of eEF2K expression in 96 postoperative patients with gastric cancer. Among the 96 patients, 36 had low expression of eEF2K and 60 had high expression. RESULTS Analysis of the TCGA and GEO datasets revealed that eEF2K expression was significantly higher in the STAD tissue samples than in the non-tumorous gastric tissues. IHC, western blots, and RT-PCR confirmed these findings. The high expression level of eEF2K was found to be related to the presence of lymph node metastasis (p = 0.002). Moreover, multivariate analysis showed that eEF2K was an independent indicator of prognosis for overall survival (OS) (hazard ratio [HR] = 1.72, 95% confidence interval [CI] = 1.06-2.79; p = 0.03) and disease-free survival (DFS) (HR = 1.66, 95% CI = 0.997-2.765; p = 0.052) in patients with surgically resected STAD. CONCLUSION Collectively, our findings suggest that eEF2K is a clinical indicator of metastatic and prognostic significance for STAD survival and could serve as a potential therapeutic target.
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Affiliation(s)
- Mingxia Jiang
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Ling Qi
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Kexin Jin
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Lisha Li
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Yiming Wu
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Dongfeng Song
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Junqing Gan
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Mei Huang
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Yanjing Li
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Chengxin Song
- Department of Colorectal Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China.
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22
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Regulation of mRNA Translation by Hormone Receptors in Breast and Prostate Cancer. Cancers (Basel) 2021; 13:cancers13133254. [PMID: 34209750 PMCID: PMC8268847 DOI: 10.3390/cancers13133254] [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: 05/12/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary The estrogen and androgen receptors (ER, AR) are key oncogenic drivers and therapeutic targets in breast and prostate cancer, respectively. These receptors bind to DNA and regulate gene expression but emerging evidence indicates that they also play important roles in controlling the process of mRNA translation, which dictates cellular protein production. Here, we review the mechanisms by which abnormal activities of ER and AR can dysregulate mRNA translation in breast and prostate cancer cells. Specifically, we explore how the intricate cellular signalling pathways that keep mRNA translation in check are perturbed by aberrant ER and AR signalling, which can lead to enhanced cancer cell growth. We also discuss the potential of targeting mRNA translation as a strategy to treat patients with breast and prostate cancer. Abstract Breast and prostate cancer are the second and third leading causes of death amongst all cancer types, respectively. Pathogenesis of these malignancies is characterised by dysregulation of sex hormone signalling pathways, mediated by the estrogen receptor-α (ER) in breast cancer and androgen receptor (AR) in prostate cancer. ER and AR are transcription factors whose aberrant function drives oncogenic transcriptional programs to promote cancer growth and progression. While ER/AR are known to stimulate cell growth and survival by modulating gene transcription, emerging findings indicate that their effects in neoplasia are also mediated by dysregulation of protein synthesis (i.e., mRNA translation). This suggests that ER/AR can coordinately perturb both transcriptional and translational programs, resulting in the establishment of proteomes that promote malignancy. In this review, we will discuss relatively understudied aspects of ER and AR activity in regulating protein synthesis as well as the potential of targeting mRNA translation in breast and prostate cancer.
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23
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Barreto FS, Ribeiro WLC, Cavalcanti BC, Silva PGDB, Soares CN, Vasconcelos GS, Nunes APN, Moraes Filho MOD, Macedo DS. Early maternal separation enhances melanoma progression in adult female mice by immune mechanisms. Ann N Y Acad Sci 2021; 1502:40-53. [PMID: 34184281 DOI: 10.1111/nyas.14625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/04/2021] [Accepted: 05/25/2021] [Indexed: 01/04/2023]
Abstract
Maternal separation (MS) is a risk factor for major depressive disorder. Both cancer and depression seem to share a common biological link. Here, we evaluated the progression of melanoma and the underlying mechanisms related to this progression, namely cell proliferation and apoptosis, in adult female mice exposed to MS. Female C57BL/6 mice were exposed to MS for 60 min/day during the first 2 postnatal weeks (here called MS mice) or left undisturbed (here called non-MS mice). Melanoma cells were inoculated subcutaneously into the axillary region of adult animals, and tumor progression was evaluated for 25 days. Adult MS mice presented depressive-like behavior and working memory deficits. MS accelerated murine melanoma growth by mechanisms related to decreased apoptosis and increased cell proliferation rate, such as increased expression of IL-6 and mTOR. MS stimulated eukaryotic elongation factor 2 expression and increased the number of circulating monocytes and DNA damage in peripheral blood leukocytes, an effect associated with oxidative DNA damage. In conclusion, MS accelerated the progression of murine melanoma by mechanisms related to tumor proliferation and apoptosis, revealing a relationship between adverse childhood experiences and cancer progression, particularly melanoma.
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Affiliation(s)
- Francisco Stefânio Barreto
- Laboratory of Experimental Oncology, Drug Research and Development Center, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Wesley Lyeverton Correia Ribeiro
- Laboratory of Experimental Oncology, Drug Research and Development Center, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Bruno Coêlho Cavalcanti
- Laboratory of Experimental Oncology, Drug Research and Development Center, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Paulo Goberlânio de Barros Silva
- Division of Oral Pathology, Department of Dental Clinic, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceara, Fortaleza, Ceara, Brazil
| | - Caren Nádia Soares
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Germana Silva Vasconcelos
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Ana Paula Negreiros Nunes
- Division of Oral Pathology, Department of Dental Clinic, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceara, Fortaleza, Ceara, Brazil
| | - Manoel Odorico de Moraes Filho
- Laboratory of Experimental Oncology, Drug Research and Development Center, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Danielle S Macedo
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Ceará, Brazil.,National Institute for Translational Medicine (INCT-TM, CNPq), Ribeirão Preto, Brazil
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24
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Zhu S, Liao M, Tan H, Zhu L, Chen Y, He G, Liu B. Inhibiting Eukaryotic Elongation Factor 2 Kinase: An Update on Pharmacological Small-Molecule Compounds in Cancer. J Med Chem 2021; 64:8870-8883. [PMID: 34162208 DOI: 10.1021/acs.jmedchem.0c02218] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K), a member of the atypical protein kinase family of alpha-kinases, is well-known as a negative regulator of protein synthesis by phosphorylating eEF2. Notably, eEF2K functions as a key regulator of several cellular processes, leading to tumorigenesis. To date, some small-molecule compounds have been reported as potential eEF2K inhibitors in cancer drug discovery. However, an ideal targeted drug design still faces huge challenges. Alternatively, other design strategies, such as repurposed drugs, dual-target drugs, and drug combination strategies, provide insights into the improvement of cancer treatment. Here, we summarize the crucial eEF2K-modulating pathways in cancer, including AMPK, REDD1, and Src. Moreover, we discuss the inhibition of eEF2K with single-target inhibitors, repurposed drugs, dual-target inhibitors, drug combination strategies, and other emerging technologies for therapeutic purposes. Together, these inspiring findings provide insights into a promising strategy for inhibiting eEF2K with small-molecule compounds to improve potential cancer therapy.
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Affiliation(s)
- Shiou Zhu
- State Key Laboratory of Biotherapy and Cancer Center and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Minru Liao
- State Key Laboratory of Biotherapy and Cancer Center and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Huidan Tan
- State Key Laboratory of Biotherapy and Cancer Center and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Lingjuan Zhu
- State Key Laboratory of Biotherapy and Cancer Center and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yi Chen
- State Key Laboratory of Biotherapy and Cancer Center and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Gu He
- State Key Laboratory of Biotherapy and Cancer Center and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Bo Liu
- State Key Laboratory of Biotherapy and Cancer Center and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
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25
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De Poi SP, Xie J, Smales CM, Proud CG. Constitutively active Rheb mutants [T23M] and [E40K] drive increased production and secretion of recombinant protein in Chinese hamster ovary cells. Biotechnol Bioeng 2021; 118:2422-2434. [PMID: 33694218 DOI: 10.1002/bit.27748] [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: 10/07/2020] [Revised: 03/03/2021] [Accepted: 03/08/2021] [Indexed: 11/10/2022]
Abstract
Monoclonal antibodies (mAbs) are high value agents used for disease therapy ("biologic drugs") or as diagnostic tools which are widely used in the healthcare sector. They are generally manufactured in mammalian cells, in particular Chinese hamster ovary (CHO) cells cultured in defined media, and are harvested from the medium. Rheb is a small GTPase which, when bound to GTP, activates mechanistic target of rapamycin complex 1, a protein kinase that drives anabolic processes including protein synthesis and ribosome biogenesis. Here, we show that certain constitutively active mutants of Rheb drive faster protein synthesis in CHO cells and increase the expression of proteins involved in the processing of secreted proteins in the endoplasmic reticulum, which expands in response to expression of Rheb mutants. Active Rheb mutants, in particular Rheb[T23M], drive increased cell number under serum-free conditions similar to those used in the biotechnology industry. Rheb[T23M] also enhances the expression of the reporter protein luciferase and, especially strongly, the secreted Gaussia luciferase. Moreover, Rheb[T23M] markedly (2-3 fold) enhances the amount of this luciferase and of a model immunoglobulin secreted into the medium. Our data clearly demonstrate that expressing Rheb[T23M] in CHO cells provides a simple approach to promoting their growth in defined medium and the production of secreted proteins of high commercial value.
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Affiliation(s)
- Stuart P De Poi
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Department of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Jianling Xie
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,School of Biological Sciences, University of Southampton, Southampton, UK.,Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia, Australia
| | - C Mark Smales
- Centre for Industrial Biotechnology and School of Biosciences, University of Kent, Canterbury, UK
| | - Christopher G Proud
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Department of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia, Australia.,School of Biological Sciences, University of Southampton, Southampton, UK
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26
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eEF2K enhances expression of PD-L1 by promoting the translation of its mRNA. Biochem J 2021; 477:4367-4381. [PMID: 33094805 DOI: 10.1042/bcj20200697] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 12/22/2022]
Abstract
Emerging advances in cancer therapy have transformed the landscape towards cancer immunotherapy regimens. Recent discoveries have resulted in the development of clinical immune checkpoint inhibitors that are 'game-changers' for cancer immunotherapy. Here we show that eEF2K, an atypical protein kinase that negatively modulates the elongation stage of protein synthesis, promotes the synthesis of PD-L1, an immune checkpoint protein which helps cancer cells to escape from immunosurveillance. Ablation of eEF2K in prostate and lung cancer cells markedly reduced the expression levels of the PD-L1 protein. We show that eEF2K promotes the association of PD-L1 mRNAs with translationally active polyribosomes and that translation of the PD-L1 mRNA is regulated by a uORF (upstream open reading-frame) within its 5'-UTR (5'-untranslated region) which starts with a non-canonical CUG as the initiation codon. This inhibitory effect is attenuated by eEF2K thereby allowing higher levels of translation of the PD-L1 coding region and enhanced expression of the PD-L1 protein. Moreover, eEF2K-depleted cancer cells are more vulnerable to immune attack by natural killer cells. Therefore, control of translation elongation can modulate the translation of this specific mRNA, one which contains an uORF that starts with CUG, and perhaps others that contain a similar feature. Taken together, our data reveal that eEF2K regulates PD-L1 expression at the level of the translation of its mRNA by virtue of a uORF in its 5'-region. This, and other roles of eEF2K in cancer cell biology (e.g. in cell survival and migration), may be exploited for the design of future therapeutic strategies.
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27
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Shen Y, Zhang ZC, Cheng S, Liu A, Zuo J, Xia S, Liu X, Liu W, Jia Z, Xie W, Han J. PQBP1 promotes translational elongation and regulates hippocampal mGluR-LTD by suppressing eEF2 phosphorylation. Mol Cell 2021; 81:1425-1438.e10. [PMID: 33662272 DOI: 10.1016/j.molcel.2021.01.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 12/07/2020] [Accepted: 01/21/2021] [Indexed: 10/22/2022]
Abstract
Eukaryotic elongation factor 2 (eEF2) mediates translocation of peptidyl-tRNA from the ribosomal A site to the P site to promote translational elongation. Its phosphorylation on Thr56 by its single known kinase eEF2K inactivates it and inhibits translational elongation. Extensive studies have revealed that different signal cascades modulate eEF2K activity, but whether additional factors regulate phosphorylation of eEF2 remains unclear. Here, we find that the X chromosome-linked intellectual disability protein polyglutamine-binding protein 1 (PQBP1) specifically binds to non-phosphorylated eEF2 and suppresses eEF2K-mediated phosphorylation at Thr56. Loss of PQBP1 significantly reduces general protein synthesis by suppressing translational elongation. Moreover, we show that PQBP1 regulates hippocampal metabotropic glutamate receptor-dependent long-term depression (mGluR-LTD) and mGluR-LTD-associated behaviors by suppressing eEF2K-mediated phosphorylation. Our results identify PQBP1 as a novel regulator in translational elongation and mGluR-LTD, and this newly revealed regulator in the eEF2K/eEF2 pathway is also an excellent therapeutic target for various disease conditions, such as neural diseases, virus infection, and cancer.
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Affiliation(s)
- Yuqian Shen
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Zi Chao Zhang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China.
| | - Shanshan Cheng
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - An Liu
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Jian Zuo
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Shuting Xia
- Institute of Neuroscience, Soochow University, Suzhou 215000, China
| | - Xian Liu
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Wenhua Liu
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Zhengping Jia
- Neurosciences and Mental Health Program, Hospital for Sick Children, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Wei Xie
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Junhai Han
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China; Department of Neurology, Affiliated ZhongDa Hospital, Institute of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China.
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28
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Robinson B, Gu Q, Kanungo J. Antidepressant Actions of Ketamine: Potential Role of L-Type Calcium Channels. Chem Res Toxicol 2021; 34:1198-1207. [PMID: 33566591 DOI: 10.1021/acs.chemrestox.0c00411] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Recently, the United States Food and Drug Administration approved esketamine, the S-enantiomer of ketamine, as a fast-acting therapeutic drug for treatment-resistant depression. Although ketamine is known as an N-methyl-d-aspartate (NMDA) receptor antagonist, the underlying mechanisms of how it elicits an antidepressant effect, specifically at subanesthetic doses, are not clear and remain an advancing field of research interest. On the other hand, high-dose (more than the anesthetic dose) ketamine-induced neurotoxicity in animal models has been reported. There has been progress in understanding the potential pathways involved in ketamine-induced antidepressant effects, some of which include NMDA-receptor antagonism, modulation of voltage-gated calcium channels, and brain-derived neurotrophic factor (BDNF) signaling. Often these pathways have been shown to be linked. Voltage-gated L-type calcium channels have been shown to mediate the rapid-acting antidepressant effects of ketamine, especially involving induction of BDNF synthesis downstream, while BDNF deficiency decreases the expression of L-type calcium channels. This review focuses on the reported studies linking ketamine's rapid-acting antidepressant actions to L-type calcium channels with an objective to present a perspective on the importance of the modulation of intracellular calcium in mediating the effects of subanesthetic (antidepressant) versus high-dose ketamine (anesthetic and potential neurotoxicant), the latter having the ability to reduce intracellular calcium by blocking the calcium-permeable NMDA receptors, which is implicated in potential neurotoxicity.
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Affiliation(s)
- Bonnie Robinson
- Division of Neurotoxicology, United States Food and Drug Administration, 3900 NCTR Road, Jefferson, Arkansas 72079, United States
| | - Qiang Gu
- Division of Neurotoxicology, United States Food and Drug Administration, 3900 NCTR Road, Jefferson, Arkansas 72079, United States
| | - Jyotshna Kanungo
- Division of Neurotoxicology, United States Food and Drug Administration, 3900 NCTR Road, Jefferson, Arkansas 72079, United States
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29
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Xie J, Shen K, Jones AT, Yang J, Tee AR, Shen MH, Yu M, Irani S, Wong D, Merrett JE, Lenchine RV, De Poi S, Jensen KB, Trim PJ, Snel MF, Kamei M, Martin SK, Fitter S, Tian S, Wang X, Butler LM, Zannettino ACW, Proud CG. Reciprocal signaling between mTORC1 and MNK2 controls cell growth and oncogenesis. Cell Mol Life Sci 2021; 78:249-270. [PMID: 32170339 PMCID: PMC11068017 DOI: 10.1007/s00018-020-03491-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/23/2020] [Accepted: 02/17/2020] [Indexed: 12/21/2022]
Abstract
eIF4E plays key roles in protein synthesis and tumorigenesis. It is phosphorylated by the kinases MNK1 and MNK2. Binding of MNKs to eIF4G enhances their ability to phosphorylate eIF4E. Here, we show that mTORC1, a key regulator of mRNA translation and oncogenesis, directly phosphorylates MNK2 on Ser74. This suppresses MNK2 activity and impairs binding of MNK2 to eIF4G. These effects provide a novel mechanism by which mTORC1 signaling impairs the function of MNK2 and thereby decreases eIF4E phosphorylation. MNK2[S74A] knock-in cells show enhanced phosphorylation of eIF4E and S6K1 (i.e., increased mTORC1 signaling), enlarged cell size, and increased invasive and transformative capacities. MNK2[Ser74] phosphorylation was inversely correlated with disease progression in human prostate tumors. MNK inhibition exerted anti-proliferative effects in prostate cancer cells in vitro. These findings define a novel feedback loop whereby mTORC1 represses MNK2 activity and oncogenic signaling through eIF4E phosphorylation, allowing reciprocal regulation of these two oncogenic pathways.
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Affiliation(s)
- Jianling Xie
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - Kaikai Shen
- Medical Research Council Toxicology Unit, Leicester, UK
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Ashley T Jones
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, UK
| | - Jian Yang
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, UK
| | - Andrew R Tee
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, UK
| | - Ming Hong Shen
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff, UK
| | - Mengyuan Yu
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Swati Irani
- Adelaide Medical School and Freemasons Foundation Centre for Men's Health, University of Adelaide, Adelaide, Australia
- Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Derick Wong
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - James E Merrett
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- Department of Molecular and Cellular Biology, University of Adelaide, Adelaide, Australia
| | - Roman V Lenchine
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- Department of Molecular and Cellular Biology, University of Adelaide, Adelaide, Australia
| | - Stuart De Poi
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- Department of Molecular and Cellular Biology, University of Adelaide, Adelaide, Australia
| | - Kirk B Jensen
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- Department of Molecular and Cellular Biology, University of Adelaide, Adelaide, Australia
| | - Paul J Trim
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Marten F Snel
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Makoto Kamei
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Sally Kim Martin
- Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
- Myeloma Research Laboratory, Adelaide Medical School, Faculty of Health and Medical Science, University of Adelaide, Adelaide, Australia
| | - Stephen Fitter
- Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
- Myeloma Research Laboratory, Adelaide Medical School, Faculty of Health and Medical Science, University of Adelaide, Adelaide, Australia
| | - Shuye Tian
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Xuemin Wang
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Lisa M Butler
- Adelaide Medical School and Freemasons Foundation Centre for Men's Health, University of Adelaide, Adelaide, Australia
- Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Andrew C W Zannettino
- Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, Australia
- Myeloma Research Laboratory, Adelaide Medical School, Faculty of Health and Medical Science, University of Adelaide, Adelaide, Australia
| | - Christopher G Proud
- Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia.
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, Australia.
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30
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Jiang SL, Mo JL, Peng J, Lei L, Yin JY, Zhou HH, Liu ZQ, Hong WX. Targeting translation regulators improves cancer therapy. Genomics 2020; 113:1247-1256. [PMID: 33189778 DOI: 10.1016/j.ygeno.2020.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/14/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023]
Abstract
Deregulation of protein synthesis may be involved in multiple aspects of cancer, such as gene expression, signal transduction and drive specific cell biological responses, resulting in promoting cancer growth, invasion and metastasis. Study the molecular mechanisms about translational control may help us to find more effective anti-cancer drugs and develop novel therapeutic opportunities. Recently, the researchers had focused on targeting translational machinery to overcome cancer, and various small molecular inhibitors targeting translation factors or pathways have been tested in clinical trials and exhibited improving outcomes in several cancer types. There is no doubt that an insight into the class of translation regulation protein would provide new target for pharmacologic intervention and further provide opportunities to develop novel anti-tumor therapeutic interventions. In this review, we summarized the developments of translational control in cancer survival and progression et al, and highlighted the therapeutic approach targeted translation regulation to overcome the cancer.
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Affiliation(s)
- Shi-Long Jiang
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China
| | - Jun-Luan Mo
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China; Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China
| | - Ji Peng
- Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China
| | - Lin Lei
- Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China
| | - Ji-Ye Yin
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China
| | - Hong-Hao Zhou
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China
| | - Zhao-Qian Liu
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China.
| | - Wen-Xu Hong
- Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China.
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31
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Hao P, Yu J, Ward R, Liu Y, Hao Q, An S, Xu T. Eukaryotic translation initiation factors as promising targets in cancer therapy. Cell Commun Signal 2020; 18:175. [PMID: 33148274 PMCID: PMC7640403 DOI: 10.1186/s12964-020-00607-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 06/01/2020] [Indexed: 02/08/2023] Open
Abstract
The regulation of the translation of messenger RNA (mRNA) in eukaryotic cells is critical for gene expression, and occurs principally at the initiation phase which is mainly regulated by eukaryotic initiation factors (eIFs). eIFs are fundamental for the translation of mRNA and as such act as the primary targets of several signaling pathways to regulate gene expression. Mis-regulated mRNA expression is a common feature of tumorigenesis and the abnormal activity of eIF complexes triggered by upstream signaling pathways is detected in many tumors, leading to the selective translation of mRNA encoding proteins involved in tumorigenesis, metastasis, or resistance to anti-cancer drugs, and making eIFs a promising therapeutic target for various types of cancers. Here, we briefly outline our current understanding of the biology of eIFs, mainly focusing on the effects of several signaling pathways upon their functions and discuss their contributions to the initiation and progression of tumor growth. An overview of the progress in developing agents targeting the components of translation machinery for cancer treatment is also provided. Video abstract
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Affiliation(s)
- Peiqi Hao
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, 727 Jingming South Road, Kunming, 650500, China.,Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Jiaojiao Yu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, 727 Jingming South Road, Kunming, 650500, China
| | - Richard Ward
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Yin Liu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Qiao Hao
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China
| | - Su An
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China.
| | - Tianrui Xu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China.
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32
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Gladulich LFH, Xie J, Jensen KB, Kamei M, Paes-de-Carvalho R, Cossenza M, Proud CG. Bicuculline regulated protein synthesis is dependent on Homer1 and promotes its interaction with eEF2K through mTORC1-dependent phosphorylation. J Neurochem 2020; 157:1086-1101. [PMID: 32892352 DOI: 10.1111/jnc.15178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/29/2020] [Accepted: 08/26/2020] [Indexed: 02/06/2023]
Abstract
The regulation of protein synthesis is a vital and finely tuned process in cellular physiology. In neurons, this process is very precisely regulated, as which mRNAs undergo translation is highly dependent on context. One of the most prominent regulators of protein synthesis is the enzyme eukaryotic elongation factor kinase 2 (eEF2K) that regulates the elongation stage of protein synthesis. This kinase and its substrate, eukaryotic elongation factor 2 (eEF2) are important in processes such as neuronal development and synaptic plasticity. eEF2K is regulated by multiple mechanisms including Ca2+ -ions and the mTORC1 signaling pathway, both of which play key roles in neurological processes such as learning and memory. In such settings, the localized control of protein synthesis is of crucial importance. In this work, we sought to investigate how the localization of eEF2K is controlled and the impact of this on protein synthesis in neuronal cells. In this study, we used both SH-SY5Y neuroblastoma cells and mouse cortical neurons, and pharmacologically and/or genetic approaches to modify eEF2K function. We show that eEF2K activity and localization can be regulated by its binding partner Homer1b/c, a scaffolding protein known for its participation in calcium-regulated signaling pathways. Furthermore, our results indicate that this interaction is regulated by the mTORC1 pathway, through a known phosphorylation site in eEF2K (S396), and that it affects rates of localized protein synthesis at synapses depending on the presence or absence of this scaffolding protein.
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Affiliation(s)
- Luis F H Gladulich
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil.,Lifelong Health, South Australia Health & Medical Research Institute (SAHMRI) Adelaide, SA, Australia
| | - Jianling Xie
- Lifelong Health, South Australia Health & Medical Research Institute (SAHMRI) Adelaide, SA, Australia
| | - Kirk B Jensen
- Lifelong Health, South Australia Health & Medical Research Institute (SAHMRI) Adelaide, SA, Australia
| | - Makoto Kamei
- Lifelong Health, South Australia Health & Medical Research Institute (SAHMRI) Adelaide, SA, Australia.,Center for Cancer Biology, University of South Australia, Adelaide, SA, Australia
| | - Roberto Paes-de-Carvalho
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil.,Department of Neurobiology, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - Marcelo Cossenza
- Program of Neurosciences, Fluminense Federal University, Niterói, Brazil.,Department of Physiology and Pharmacology, Biomedical Institute, Fluminense Federal University, Niterói, Brazil
| | - Christopher G Proud
- Lifelong Health, South Australia Health & Medical Research Institute (SAHMRI) Adelaide, SA, Australia
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33
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Biswas D, Dao KT, Mercer A, Cowie AM, Duffley L, El Hiani Y, Kienesberger PC, Pulinilkunnil T. Branched-chain ketoacid overload inhibits insulin action in the muscle. J Biol Chem 2020; 295:15597-15621. [PMID: 32878988 DOI: 10.1074/jbc.ra120.013121] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 08/29/2020] [Indexed: 12/18/2022] Open
Abstract
Branched-chain α-keto acids (BCKAs) are catabolites of branched-chain amino acids (BCAAs). Intracellular BCKAs are cleared by branched-chain ketoacid dehydrogenase (BCKDH), which is sensitive to inhibitory phosphorylation by BCKD kinase (BCKDK). Accumulation of BCKAs is an indicator of defective BCAA catabolism and has been correlated with glucose intolerance and cardiac dysfunction. However, it is unclear whether BCKAs directly alter insulin signaling and function in the skeletal and cardiac muscle cell. Furthermore, the role of excess fatty acids (FAs) in perturbing BCAA catabolism and BCKA availability merits investigation. By using immunoblotting and ultra-performance liquid chromatography MS/MS to analyze the hearts of fasted mice, we observed decreased BCAA-catabolizing enzyme expression and increased circulating BCKAs, but not BCAAs. In mice subjected to diet-induced obesity (DIO), we observed similar increases in circulating BCKAs with concomitant changes in BCAA-catabolizing enzyme expression only in the skeletal muscle. Effects of DIO were recapitulated by simulating lipotoxicity in skeletal muscle cells treated with saturated FA, palmitate. Exposure of muscle cells to high concentrations of BCKAs resulted in inhibition of insulin-induced AKT phosphorylation, decreased glucose uptake, and mitochondrial oxygen consumption. Altering intracellular clearance of BCKAs by genetic modulation of BCKDK and BCKDHA expression showed similar effects on AKT phosphorylation. BCKAs increased protein translation and mTORC1 activation. Pretreating cells with mTORC1 inhibitor rapamycin restored BCKA's effect on insulin-induced AKT phosphorylation. This study provides evidence for FA-mediated regulation of BCAA-catabolizing enzymes and BCKA content and highlights the biological role of BCKAs in regulating muscle insulin signaling and function.
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Affiliation(s)
- Dipsikha Biswas
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Khoi T Dao
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Angella Mercer
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Andrew M Cowie
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Luke Duffley
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Yassine El Hiani
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Petra C Kienesberger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
| | - Thomas Pulinilkunnil
- Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada.
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34
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Lee K, Kumar EA, Dalby KN, Ghose R. The role of calcium in the interaction between calmodulin and a minimal functional construct of eukaryotic elongation factor 2 kinase. Protein Sci 2020; 28:2089-2098. [PMID: 31626716 DOI: 10.1002/pro.3753] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF-2K) regulates protein synthesis by phosphorylating eukaryotic elongation factor 2 (eEF-2), thereby reducing its affinity for the ribosome and suppressing global translational elongation rates. eEF-2K is regulated by calmodulin (CaM) through a mechanism that is distinct from that of other CaM-regulated kinases. We had previously identified a minimal construct of eEF-2K (TR) that is activated similarly to the wild-type enzyme by CaM in vitro and retains its ability to phosphorylate eEF-2 efficiently in cells. Here, we employ solution nuclear magnetic resonance techniques relying on Ile δ1-methyls of TR and Ile δ1- and Met ε-methyls of CaM, as probes of their mutual interaction and the influence of Ca2+ thereon. We find that in the absence of Ca2+ , CaM exclusively utilizes its C-terminal lobe (CaMC ) to engage the N-terminal CaM-binding domain (CBD) of TR in a high-affinity interaction. Avidity resulting from additional weak interactions of TR with the Ca2+ -loaded N-terminal lobe of CaM (CaMN ) at increased Ca2+ levels serves to enhance the affinity further. These latter interactions under Ca2+ saturation result in minimal perturbations in the spectra of TR in the context of its complex with CaM, suggesting that the latter is capable of driving TR to its final, presumably active conformation, in the Ca2+ -free state. Our data are consistent with a scenario in which Ca2+ enhances the affinity of the TR/CaM interactions, resulting in the increased effective concentration of the CaM-bound species without significantly modifying the conformation of TR within the final, active complex.
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Affiliation(s)
- Kwangwoon Lee
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York.,Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, New York
| | - Eric A Kumar
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas.,Graduate Program in Cell and Molecular Biology, University of Texas, Austin, Texas
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York.,Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, New York.,Graduate Program in Chemistry, The Graduate Center of CUNY, New York, New York.,Graduate Program in Physics, The Graduate Center of CUNY, New York, New York
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35
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Karakas D, Ozpolat B. Eukaryotic elongation factor-2 kinase (eEF2K) signaling in tumor and microenvironment as a novel molecular target. J Mol Med (Berl) 2020; 98:775-787. [PMID: 32377852 DOI: 10.1007/s00109-020-01917-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/26/2020] [Accepted: 04/28/2020] [Indexed: 12/25/2022]
Abstract
Eukaryotic elongation factor-2 kinase (eEF2K), an atypical member of alpha-kinase family, is highly overexpressed in breast, pancreatic, brain, and lung cancers, and associated with poor survival in patients. eEF2K promotes cell proliferation, survival, and aggressive tumor characteristics, leading to tumor growth and progression. While initial studies indicated that eEF2K acts as a negative regulator of protein synthesis by suppressing peptide elongation phase, later studies demonstrated that it has multiple functions and promotes cell cycle, angiogenesis, migration, and invasion as well as induction of epithelial-mesenchymal transition through induction of integrin β1, SRC/FAK, PI3K/AKT, cyclin D1, VEGF, ZEB1, Snail, and MMP-2. Under stress conditions such as hypoxia and metabolic distress, eEF2K is activated by several signaling pathways and slows down protein synthesis and helping cells to save energy and survive. In vivo therapeutic targeting of eEF2K by genetic methods inhibits tumor growth in various tumor models, validating it as a potential molecular target. Recent studies suggest that eEF2K plays a role in tumor microenvironment cells by monocyte chemoattractant protein-1 (MCP-1) and accumulation of tumor-associated macrophages. Due to its clinical significance and the pivotal role in tumorigenesis and progression, eEF2K is considered as an important therapeutic target in solid tumors. However, currently, there is no specific and potent inhibitor for translation into clinical studies. Here, we aim to systematically review current knowledge regarding eEF2K in tumor biology, microenvironment, and development of eEF2K targeted inhibitors and therapeutics.
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Affiliation(s)
- Didem Karakas
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Istinye University, Istanbul, Turkey
| | - Bulent Ozpolat
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
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36
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Naz I, Ramchandani S, Khan MR, Yang MH, Ahn KS. Anticancer Potential of Raddeanin A, a Natural Triterpenoid Isolated from Anemone raddeana Regel. Molecules 2020; 25:E1035. [PMID: 32106609 PMCID: PMC7179125 DOI: 10.3390/molecules25051035] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 12/24/2022] Open
Abstract
Natural compounds extracted from plants have gained immense importance in the fight against cancer cells due to their lesser toxicity and potential therapeutic effects. Raddeanin A (RA), an oleanane type triterpenoid is a major compound isolated from Anemone raddeana Regel. As an anticancer agent, RA induces apoptosis, cell cycle arrest, inhibits invasion, migration and angiogenesis in malignant cell lines as well as in preclinical models. In this systemic review, the pharmacological effects of RA and its underlying molecular mechanisms were carefully analyzed and potential molecular targets have been highlighted. The apoptotic potential of RA can be mediated through the modulation of Bcl-2, Bax, caspase-3, caspase-8, caspase-9, cytochrome c and poly-ADP ribose polymerase (PARP) cleavage. PI3K/Akt signaling pathway serves as the major molecular target affected by RA. Furthermore, RA can block cell proliferation through inhibition of canonical Wnt/β-catenin signaling pathway in colorectal cancer cells. RA can also alter the activation of NF-κB and STAT3 signaling pathways to suppress invasion and metastasis. RA has also exhibited promising anticancer potential against drug resistant cancer cells and can enhance the anticancer effects of several chemotherapeutic agents. Overall, RA may function as a promising compound in combating cancer, although further in-depth study is required under clinical settings to validate its efficacy in cancer patients.
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Affiliation(s)
- Irum Naz
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan;
| | | | | | - Min Hee Yang
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul 02447, Korea;
| | - Kwang Seok Ahn
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul 02447, Korea;
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37
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Xiao M, Xie J, Wu Y, Wang G, Qi X, Liu Z, Wang Y, Wang X, Hoque A, Oakhill J, Proud CG, Li J. The eEF2 kinase-induced STAT3 inactivation inhibits lung cancer cell proliferation by phosphorylation of PKM2. Cell Commun Signal 2020; 18:25. [PMID: 32054489 PMCID: PMC7020344 DOI: 10.1186/s12964-020-0528-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 02/05/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Eukaryotic elongation factor-2 kinase (eEF2K) is a Ca 2+ /calmodulin (CaM)-dependent protein kinase that inhibits protein synthesis. However, the role of eEF2K in cancer development was reported paradoxically and remains to be elucidated. METHODS Herein, A549 cells with eEF2K depletion or overexpression by stably transfected lentivirus plasmids were used in vitro and in vivo study. MTT and colony assays were used to detect cell proliferation and growth. Extracellular glucose and lactate concentration were measured using test kit. Immunoblot and co-immunoprecipitation assays were used to examine the molecular biology changes and molecular interaction in these cells. LC-MS/MS analysis and [γ- 32 P] ATP kinase assay were used to identify combining protein and phosphorylation site. Nude mice was utilized to study the correlation of eEF2K and tumor growth in vivo. RESULTS We demonstrated that eEF2K inhibited lung cancer cells proliferation and affected the inhibitory effects of EGFR inhibitor gefitinib. Mechanistically, we showed that eEF2K formed a complex with PKM2 and STAT3, thereby phosphorylated PKM2 at T129, leading to reduced dimerization of PKM2. Subsequently, PKM2 impeded STAT3 phosphorylation and STAT3-dependent c-Myc expression. eEF2K depletion promoted the nuclear translocation of PKM2 and increased aerobic glycolysis reflected by increased lactate secretion and glucose. CONCLUSIONS Our findings define a novel mechanism underlying the regulation of cancer cell proliferation by eEF2K independent of its role in protein synthesis, disclosing the diverse roles of eEF2K in cell biology, which lays foundation for the development of new anticancer therapeutic strategies.
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Affiliation(s)
- Min Xiao
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Jianling Xie
- South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - Yu Wu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Genzhu Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Xin Qi
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Zailiang Liu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Yuying Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Xuemin Wang
- South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Ashfaqul Hoque
- St Vincent's Institute of Medical Research, Fitzroy, SA, 4312, Australia
| | - Jon Oakhill
- St Vincent's Institute of Medical Research, Fitzroy, SA, 4312, Australia
| | - Christopher G Proud
- South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Jing Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China.
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, People's Republic of China.
- Open Studio for Druggability Research of Marine Natural Products, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, People's Republic of China.
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38
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What is the impact of eukaryotic elongation factor 2 kinase on cancer: A systematic review. Eur J Pharmacol 2019; 857:172470. [DOI: 10.1016/j.ejphar.2019.172470] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 06/08/2019] [Accepted: 06/17/2019] [Indexed: 11/19/2022]
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39
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Rodríguez-Campuzano AG, Hernández-Kelly LC, Ortega A. Acute Exposure to SiO 2 Nanoparticles Affects Protein Synthesis in Bergmann Glia Cells. Neurotox Res 2019; 37:366-379. [PMID: 31292883 DOI: 10.1007/s12640-019-00084-0] [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: 02/12/2019] [Revised: 06/04/2019] [Accepted: 06/26/2019] [Indexed: 10/26/2022]
Abstract
Attractive due to an alleged high biocompatibility, silica nanoparticles have been widely used in the field of nanomedicine; however, their proven capacity to induce the synthesis and release of pro-inflammatory cytokines in several cellular models has raised concern about their safety. Glutamate, the main excitatory amino acid transmitter triggers a wide variety of signal transduction cascades that regulate protein synthesis at transcriptional and translational levels. A stimulus-dependent dynamic change in the protein repertoire in neurons and glia cells is the molecular framework of higher brain functions. Within the cerebellum, Bergmann glia cells are the most abundant non-neuronal cells and span the entire molecular layer of the cerebellar cortex, wrapping the synapses in this structure. Taking into consideration the functional role of Bergmann glia in terms of the recycling of glutamate, lactate supply to neurons, and prevention of neurotoxic insults, we decided to investigate the possibility that silica nanoparticles affect Bergmann glia and by these means alter the major excitatory neurotransmitter system in the brain. To this end, we exposed cultured chick cerebellar Bergmann glia cells to silica nanoparticles and measured [35S]-methionine incorporation into newly synthesized polypeptides. Our results demonstrate that exposure of the cultured cells to silica nanoparticles exerts a time- and dose-dependent modulation of protein synthesis. Furthermore, altered patterns of eukaryotic initiation factor 2 alpha and eukaryotic elongation factor 2 phosphorylation were present upon nanoparticle exposure. These results demonstrate that glia cells respond to the presence of this nanomaterial modifying their proteome, presumably in an effort to overcome any plausible neurotoxic effect.
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Affiliation(s)
- Ada G Rodríguez-Campuzano
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07000, Mexico City, Mexico
| | - Luisa C Hernández-Kelly
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07000, Mexico City, Mexico
| | - Arturo Ortega
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional No. 2508, Col. San Pedro Zacatenco, Apartado Postal 14-740, 07000, Mexico City, Mexico.
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40
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Piserchio A, Will N, Giles DH, Hajredini F, Dalby KN, Ghose R. Solution Structure of the Carboxy-Terminal Tandem Repeat Domain of Eukaryotic Elongation Factor 2 Kinase and Its Role in Substrate Recognition. J Mol Biol 2019; 431:2700-2717. [PMID: 31108082 PMCID: PMC6599559 DOI: 10.1016/j.jmb.2019.05.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/15/2019] [Accepted: 05/12/2019] [Indexed: 12/31/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF-2K), an atypical calmodulin-activated protein kinase, regulates translational elongation by phosphorylating its substrate, eukaryotic elongation factor 2 (eEF-2), thereby reducing its affinity for the ribosome. The activation and activity of eEF-2K are critical for survival under energy-deprived conditions and is implicated in a variety of essential physiological processes. Previous biochemical experiments have indicated that the binding site for the substrate eEF-2 is located in the C-terminal domain of eEF-2K, a region predicted to harbor several α-helical repeats. Here, using NMR methodology, we have determined the solution structure of a C-terminal fragment of eEF-2K, eEF-2K562-725 that encodes two α-helical repeats. The structure of eEF-2K562-725 shows signatures characteristic of TPR domains and of their SEL1-like sub-family. Furthermore, using the analyses of NMR spectral perturbations and ITC measurements, we have localized the eEF-2 binding site on eEF-2K562-725. We find that eEF-2K562-725 engages eEF-2 with an affinity comparable to that of the full-length enzyme. Furthermore, eEF-2K562-725 is able to inhibit the phosphorylation of eEF-2 by full-length eEF-2K in trans. Our present studies establish that eEF-2K562-725 encodes the major elements necessary to enable the eEF-2K/eEF-2 interactions.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA
| | - Nathan Will
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - David H Giles
- Graduate Program in Cell and Molecular Biology, University of Texas, Austin, TX 78712, USA
| | - Fatlum Hajredini
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - Kevin N Dalby
- Graduate Program in Cell and Molecular Biology, University of Texas, Austin, TX 78712, USA; Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA; Graduate Program in Chemistry, The Graduate Center of CUNY, New York, NY 10016, USA; Graduate Program in Physics, The Graduate Center of CUNY, New York, NY 10016, USA.
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41
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Proud CG. Phosphorylation and Signal Transduction Pathways in Translational Control. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033050. [PMID: 29959191 DOI: 10.1101/cshperspect.a033050] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein synthesis, including the translation of specific messenger RNAs (mRNAs), is regulated by extracellular stimuli such as hormones and by the levels of certain nutrients within cells. This control involves several well-understood signaling pathways and protein kinases, which regulate the phosphorylation of proteins that control the translational machinery. These pathways include the mechanistic target of rapamycin complex 1 (mTORC1), its downstream effectors, and the mitogen-activated protein (MAP) kinase (extracellular ligand-regulated kinase [ERK]) signaling pathway. This review describes the regulatory mechanisms that control translation initiation and elongation factors, in particular the effects of phosphorylation on their interactions or activities. It also discusses current knowledge concerning the impact of these control systems on the translation of specific mRNAs or subsets of mRNAs, both in physiological processes and in diseases such as cancer.
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Affiliation(s)
- Christopher G Proud
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide SA5000, Australia; and School of Biological Sciences, University of Adelaide, Adelaide SA5000, Australia
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42
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Martinetz S, Meinung CP, Jurek B, von Schack D, van den Burg EH, Slattery DA, Neumann ID. De Novo Protein Synthesis Mediated by the Eukaryotic Elongation Factor 2 Is Required for the Anxiolytic Effect of Oxytocin. Biol Psychiatry 2019; 85:802-811. [PMID: 30826070 DOI: 10.1016/j.biopsych.2019.01.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 12/17/2018] [Accepted: 01/02/2019] [Indexed: 01/04/2023]
Abstract
BACKGROUND The neuropeptide oxytocin (OXT) mediates its actions, including anxiolysis, via its G protein-coupled OXT receptor. Within the paraventricular nucleus of the hypothalamus (PVN), OXT-induced anxiolysis is mediated, at least in part, via activation of the mitogen-activated protein kinase pathway following calcium influx through transient receptor potential cation channel subfamily V member 2 channels. In the periphery, OXT activates eukaryotic elongation factor 2 (eEF2), an essential mediator of protein synthesis. METHODS In order to study whether OXT activates eEF2 also in neurons to exert its anxiolytic properties in the PVN, we performed in vivo and cell culture experiments. RESULTS We demonstrate that OXT, in a protein kinase C-dependent manner, activates eEF2 both in a hypothalamic cell line and in vivo within the PVN. Next, we reveal that OXT stimulates de novo protein synthesis, while inhibition of protein synthesis within the PVN prevents the anxiolytic effect of OXT in male rats. Moreover, activation of eEF2 within the PVN conveyed an anxiolytic effect supporting a role of OXT-induced eEF2 activation and protein synthesis for its anxiolysis. Finally, we show that one of the proteins that is upregulated by OXT is the neuropeptide Y receptor 5. Infusion of a specific neuropeptide Y receptor 5 agonist into the PVN consequently led to decreased anxiety-related behavior, while pretreatment with a neuropeptide Y receptor 5 antagonist prevented the anxiolytic effect of OXT. CONCLUSIONS Taken together, these results show that OXT recruits several intracellular signaling cascades to induce protein synthesis, which mediates the anxiolytic effects of OXT within the PVN and suggests that eEF2 represents a novel target for anxiety-related disorders.
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Affiliation(s)
- Stefanie Martinetz
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Carl-Philipp Meinung
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - Benjamin Jurek
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
| | - David von Schack
- Biotherapeutics Clinical Research and Development, Precision Medicine, New York, New York
| | | | - David A Slattery
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany; Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, University Hospital, Goethe University, Frankfurt am Main, Germany
| | - Inga D Neumann
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany.
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Xie J, de Souza Alves V, von der Haar T, O’Keefe L, Lenchine RV, Jensen KB, Liu R, Coldwell MJ, Wang X, Proud CG. Regulation of the Elongation Phase of Protein Synthesis Enhances Translation Accuracy and Modulates Lifespan. Curr Biol 2019; 29:737-749.e5. [DOI: 10.1016/j.cub.2019.01.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 12/12/2018] [Accepted: 01/11/2019] [Indexed: 02/07/2023]
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Bircan HA, Gurbuz N, Pataer A, Caner A, Kahraman N, Bayraktar E, Bayraktar R, Erdogan MA, Kabil N, Ozpolat B. Elongation factor-2 kinase (eEF-2K) expression is associated with poor patient survival and promotes proliferation, invasion and tumor growth of lung cancer. Lung Cancer 2018; 124:31-39. [DOI: 10.1016/j.lungcan.2018.07.027] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/19/2018] [Accepted: 07/19/2018] [Indexed: 12/20/2022]
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45
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Muscle transcriptome resource for growth, lipid metabolism and immune system in Hilsa shad, Tenualosa ilisha. Genes Genomics 2018; 41:1-15. [PMID: 30196475 DOI: 10.1007/s13258-018-0732-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 08/22/2018] [Indexed: 12/17/2022]
Abstract
The information on the genes involved in muscle growth, lipid metabolism and immune systems would help to understand the mechanisms during the spawning migration in Hilsa shad, which in turn would be useful in its future domestication process. The primary objective of this study was to generate the transcriptome profile of its muscle through RNA seq. The total RNA was isolated and library was prepared from muscle tissue of Tenualosa ilisha, which was collected from Padma River at Farakka, India. The prepared library was then sequenced by Illumina HiSeq platform, HiSeq 2000, using paired-end strategy. A total of 8.68 GB of pair-end reads of muscle transcriptome was generated, and 43,384,267 pair-end reads were assembled into 3,04,233 contigs, of which 23.99% of assembled contigs has length ≥ 150 bp. The total GO terms were categorised into cellular component, molecular function and biological process through PANTHER database. Fifty-three genes related to muscle growth were identified and genes in different pathways were: 75 in PI3/AKT, 46 in mTOR, 76 in MAPK signalling, 24 in Janus kinase-signal transducer and activator of transcription, 45 in AMPK and 27 in cGMP pathways. This study also mined the genes involved in lipid metabolism, in which glycerophospholipid metabolism contained highest number of genes (32) and four were found to be involved in fatty acid biosynthesis. There were 58 immune related genes found, in which 31 were under innate and 27 under adaptive immunity. The present study included a large genomic resource of T. ilisha muscle generated through RNAseq, which revealed the essential dataset for our understanding of regulatory processes, specifically during the seasonal spawning migration. As Hilsa is a slow growing fish, the genes identified for muscle growth provided the basic information to study myogenesis. In addition, genes identified for lipid metabolism and immune system would provide resources for lipid synthesis and understanding of Hilsa defense mechanisms, respectively.
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46
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Abstract
Translation is a key step in the regulation of gene expression and one of the most energy-consuming processes in the cell. In response to various stimuli, multiple signaling pathways converge on the translational machinery to regulate its function. To date, the roles of phosphoinositide 3-kinase (PI3K)/AKT and the mitogen-activated protein kinase (MAPK) pathways in the regulation of translation are among the best understood. Both pathways engage the mechanistic target of rapamycin (mTOR) to regulate a variety of components of the translational machinery. While these pathways regulate protein synthesis in homeostasis, their dysregulation results in aberrant translation leading to human diseases, including diabetes, neurological disorders, and cancer. Here we review the roles of the PI3K/AKT and MAPK pathways in the regulation of mRNA translation. We also highlight additional signaling mechanisms that have recently emerged as regulators of the translational apparatus.
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47
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Suppression of eEF-2K-mediated autophagy enhances the cytotoxicity of raddeanin A against human breast cancer cells in vitro. Acta Pharmacol Sin 2018; 39:642-648. [PMID: 29239350 DOI: 10.1038/aps.2017.139] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/16/2017] [Indexed: 11/08/2022] Open
Abstract
Recent evidence shows that raddeanin A (RA), an oleanane-type triterpenoid saponin extracted from Anemone raddeana Regel, exerts remarkable cytotoxicity against cancer cells in vitro and in vivo. In addition, RA has also been found to activate autophagy in human gastric cancer cells. In this study, we investigated the molecular mechanisms underlying RA-induced autophagy as well as the relationship between RA-induced autophagy and its cytotoxicity in human breast cancer cells in vitro. Treatment with RA (2-8 μmol/L) dose-dependently enhanced autophagy, as evidenced by increased LC3 levels in breast cancer cell lines T47D, MCF-7 and MDA-MB-231. Furthermore, the Akt-mTOR-eEF-2K signaling pathway was demonstrated to be involved in RA-induced activation of autophagy in the 3 breast cancer cell lines. Treatment with RA (2-10 μmol/L) dose-dependently induced apoptosis in the 3 breast cancer cell lines. Pretreatment with the autophagy inhibitor chloroquine (CQ, 20 μmol/L) significantly enhanced RA-caused cytotoxicity via promoting apoptosis. In conclusion, our results suggest that modulating autophagy can reinforce the cytotoxicity of RA against human breast cancer cells.
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48
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Garza-Lombó C, Schroder A, Reyes-Reyes EM, Franco R. mTOR/AMPK signaling in the brain: Cell metabolism, proteostasis and survival. CURRENT OPINION IN TOXICOLOGY 2018; 8:102-110. [PMID: 30417160 PMCID: PMC6223325 DOI: 10.1016/j.cotox.2018.05.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The mechanistic (or mammalian) target of rapamycin (mTOR) and the adenosine monophosphate-activated protein kinase (AMPK) regulate cell survival and metabolism in response to diverse stimuli such as variations in amino acid content, changes in cellular bioenergetics, oxygen levels, neurotrophic factors and xenobiotics. This Opinion paper aims to discuss the current state of knowledge regarding how mTOR and AMPK regulate the metabolism and survival of brain cells and the close interrelationship between both signaling cascades. It is now clear that both mTOR and AMPK pathways regulate cellular homeostasis at multiple levels. Studies so far demonstrate that dysregulation in these two pathways is associated with neuronal injury, degeneration and neurotoxicity, but the mechanisms involved remain unclear. Most of the work so far has been focused on their antagonistic regulation of autophagy, but recent findings highlight that changes in protein synthesis, metabolism and mitochondrial function are likely to play a role in the regulatory effects of both mTOR and AMPK on neuronal health. Understanding the role and relationship between these two master regulators of cell metabolism is crucial for future therapeutic approaches to counteract alterations in cell metabolism and survival in brain injury and disease.
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Affiliation(s)
- Carla Garza-Lombó
- Redox Biology Center. University of Nebraska-Lincoln, Lincoln, NE 68588
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México City, México 04510
| | - Annika Schroder
- Redox Biology Center. University of Nebraska-Lincoln, Lincoln, NE 68588
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583
| | - Elsa M. Reyes-Reyes
- University of Arizona College of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Tucson, AZ 85724
| | - Rodrigo Franco
- Redox Biology Center. University of Nebraska-Lincoln, Lincoln, NE 68588
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583
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49
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Ji C, Xu Q, Guo L, Wang X, Ren Y, Zhang H, Zhu W, Ming Z, Yuan Y, Ren X, Song J, Cheng Y, Yang J, Zhang Y. eEF-2 Kinase-targeted miR-449b confers radiation sensitivity to cancer cells. Cancer Lett 2018; 418:64-74. [DOI: 10.1016/j.canlet.2018.01.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/27/2017] [Accepted: 01/08/2018] [Indexed: 10/18/2022]
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50
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El-Naggar AM, Sorensen PH. Translational control of aberrant stress responses as a hallmark of cancer. J Pathol 2018; 244:650-666. [PMID: 29293271 DOI: 10.1002/path.5030] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 12/21/2017] [Accepted: 12/22/2017] [Indexed: 12/12/2022]
Abstract
Altered mRNA translational control is emerging as a critical factor in cancer development and progression. Targeting specific elements of the translational machinery, such as mTORC1 or eIF4E, is emerging as a new strategy for innovative cancer therapy. While translation of most mRNAs takes place through cap-dependent mechanisms, a sub-population of cellular mRNA species, particularly stress-inducible mRNAs with highly structured 5'-UTR regions, are primarily translated through cap-independent mechanisms. Intriguingly, many of these mRNAs encode proteins that are involved in tumour cell adaptation to microenvironmental stress, and thus linked to aggressive behaviour including tumour invasion and metastasis. This necessitates a rigorous search for links between microenvironmental stress and aggressive tumour phenotypes. Under stress, cells block global protein synthesis to preserve energy while maintaining selective synthesis of proteins that support cell survival. One highly conserved mechanism to regulate protein synthesis under cell stress is to sequester mRNAs into cytosolic aggregates called stress granules (SGs), where their translation is silenced. SGs confer survival advantages and chemotherapeutic resistance to tumour cells under stress. Recently, it has been shown that genetically blocking SG formation dramatically reduces tumour invasive and metastatic capacity in vivo. Therefore, targeting SG formation might represent a potential treatment strategy to block cancer metastasis. Here, we present the critical link between selective mRNA translation, stress adaptation, SGs, and tumour progression. Further, we also explain how deciphering mechanisms of selective mRNA translation occurs under cell stress holds great promise for the identification of new targets in the treatment of cancer. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Amal M El-Naggar
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.,Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, Canada.,Department of Pathology, Faculty of Medicine, Menoufia University, Egypt
| | - Poul H Sorensen
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.,Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, Canada
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