1
|
Klupt KA, Jia Z. eEF2K Inhibitor Design: The Progression of Exemplary Structure-Based Drug Design. Molecules 2023; 28:molecules28031095. [PMID: 36770760 PMCID: PMC9921739 DOI: 10.3390/molecules28031095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/05/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023] Open
Abstract
The α-kinase, eEF2K, phosphorylates the threonine 56 residue of eEF2 to inhibit global peptide elongation (protein translation). As a master regulator of protein synthesis, in combination with its unique atypical kinase active site, investigations into the targeting of eEF2K represents a case of intense structure-based drug design that includes the use of modern computational techniques. The role of eEF2K is incredibly diverse and has been scrutinized in several different diseases including cancer and neurological disorders-with numerous studies inhibiting eEF2K as a potential treatment option, as described in this paper. Using available crystal structures of related α-kinases, particularly MHCKA, we report how homology modeling has been used to improve inhibitor design and efficacy. This review presents an overview of eEF2K related drug discovery efforts predating from the 1990's, to more recent in vivo studies in rat models. We also provide the reader with a basic introduction to several approaches and software programs used to undertake such drug discovery campaigns. With the recent exciting publication of an eEF2K crystal structure, we present our view regarding the future of eEF2K drug discovery.
Collapse
|
2
|
Knight JRP, Proud CG, Mallucci G, von der Haar T, Smales CM, Willis AE, Sansom OJ. Eukaryotic Elongation Factor 2 Kinase Activity Is Required for the Phenotypes of the Rpl24 Bst Mouse. J Invest Dermatol 2022; 142:3346-3348.e1. [PMID: 35850210 PMCID: PMC9708116 DOI: 10.1016/j.jid.2022.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 01/27/2023]
Affiliation(s)
- John R P Knight
- Beatson Institute, Cancer Research UK, Glasgow, United Kingdom; Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Christopher G Proud
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, Australia; Department of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Giovanna Mallucci
- UK Dementia Research Institute at The University of Cambridge, Cambridge, United Kingdom; Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
| | | | - C Mark Smales
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Owen J Sansom
- Beatson Institute, Cancer Research UK, Glasgow, United Kingdom; Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom.
| |
Collapse
|
3
|
Beiser T, Lisniansky E, Weitz M, Bingor A, Grad E, Rosenblum K, Thornton C, Yaka R. A functional eEF2K-eEF2 pathway in the NAc is critical for the expression of cocaine-induced psychomotor sensitisation and conditioned place preference. Transl Psychiatry 2022; 12:460. [PMID: 36319619 PMCID: PMC9626485 DOI: 10.1038/s41398-022-02232-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 01/24/2023] Open
Abstract
Recent evidence links synaptic plasticity and mRNA translation, via the eukaryotic elongation factor 2 kinase (eEF2K) and its only known substrate, eEF2. However, the involvement of the eEF2 pathway in cocaine-induced neuroadaptations and cocaine-induced behaviours is not known. Knock-in (KI) mice and shRNA were used to globally and specifically reduce eEF2K expression. Cocaine psychomotor sensitization and conditioned place preference were used to evaluate behavioural outcome. Changes in eEF2 phosphorylation were determined by western blot analyses. No effect was observed on the AMPA/NMDA receptor current ratio in the ventral tegmental area, 24 h after cocaine injection in eEF2K-KI mice compared with WT. However, development and expression of cocaine psychomotor sensitization were decreased in KI mice. Phosphorylated eEF2 was decreased one day after psychomotor sensitization and returned to baseline at seven days in the nucleus accumbens (NAc) of WT mice, but not in eEF2K-KI mice. However, one day following cocaine challenge, phosphorylated eEF2 decreased in WT but not KI mice. Importantly, specific targeting of eEF2K expression by shRNA in the NAc decreased cocaine condition place preference. These results suggest that the eEF2 pathway play a role in cocaine-induced locomotor sensitization and conditioned place preference.
Collapse
Affiliation(s)
- Tehila Beiser
- grid.9619.70000 0004 1937 0538Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Elvira Lisniansky
- grid.9619.70000 0004 1937 0538Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Moriya Weitz
- grid.9619.70000 0004 1937 0538Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alexey Bingor
- grid.9619.70000 0004 1937 0538Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Etty Grad
- grid.9619.70000 0004 1937 0538Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Kobi Rosenblum
- grid.18098.380000 0004 1937 0562Sagol Department of Neuroscience, University of Haifa, Haifa, Israel
| | - Claire Thornton
- grid.20931.390000 0004 0425 573XDepartment of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - Rami Yaka
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
| |
Collapse
|
4
|
Pérez-Ramírez Ú, López-Madrona VJ, Pérez-Segura A, Pallarés V, Moreno A, Ciccocioppo R, Hyytiä P, Sommer WH, Moratal D, Canals S. Brain Network Allostasis after Chronic Alcohol Drinking Is Characterized by Functional Dedifferentiation and Narrowing. J Neurosci 2022; 42:4401-4413. [PMID: 35437279 PMCID: PMC9145238 DOI: 10.1523/jneurosci.0389-21.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/25/2022] [Accepted: 03/30/2022] [Indexed: 11/21/2022] Open
Abstract
Alcohol use disorder (AUD) causes complex alterations in the brain that are poorly understood. The heterogeneity of drinking patterns and the high incidence of comorbid factors compromise mechanistic investigations in AUD patients. Here we used male Marchigian Sardinian alcohol-preferring (msP) rats, a well established animal model of chronic alcohol drinking, and a combination of longitudinal resting-state fMRI and manganese-enhanced MRI to provide objective measurements of brain connectivity and activity, respectively. We found that 1 month of chronic alcohol drinking changed the correlation between resting-state networks. The change was not homogeneous, resulting in the reorganization of pairwise interactions and a shift in the equilibrium of functional connections. We identified two fundamentally different forms of network reorganization. First is functional dedifferentiation, which is defined as a regional increase in neuronal activity and overall correlation, with a concomitant decrease in preferential connectivity between specific networks. Through this mechanism, occipital cortical areas lost their specific interaction with sensory-insular cortex, striatal, and sensorimotor networks. Second is functional narrowing, which is defined as an increase in neuronal activity and preferential connectivity between specific brain networks. Functional narrowing strengthened the interaction between striatal and prefrontocortical networks, involving the anterior insular, cingulate, orbitofrontal, prelimbic, and infralimbic cortices. Importantly, these two types of alterations persisted after alcohol discontinuation, suggesting that dedifferentiation and functional narrowing rendered persistent network states. Our results support the idea that chronic alcohol drinking, albeit at moderate intoxicating levels, induces an allostatic change in the brain functional connectivity that propagates into early abstinence.SIGNIFICANCE STATEMENT Excessive consumption of alcohol is positioned among the top five risk factors for disease and disability. Despite this priority, the transformations that the nervous system undergoes from an alcohol-naive state to a pathologic alcohol drinking are not well understood. In our study, we use an animal model with proven translational validity to study this transformation longitudinally. The results show that shortly after chronic alcohol consumption there is an increase in redundant activity shared by brain structures, and the specific communication shrinks to a set of pathways. This functional dedifferentiation and narrowing are not reversed immediately after alcohol withdrawal but persist during early abstinence. We causally link chronic alcohol drinking with an early and abstinence-persistent retuning of the functional equilibrium of the brain.
Collapse
Affiliation(s)
- Úrsula Pérez-Ramírez
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, E-46022 Valencia, Spain
| | - Víctor J López-Madrona
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain
| | - Andrés Pérez-Segura
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain
| | - Vicente Pallarés
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain
| | - Andrea Moreno
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain
| | | | - Petri Hyytiä
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Wolfgang H Sommer
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, 68159 Mannheim, Germany
| | - David Moratal
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, E-46022 Valencia, Spain
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain
| |
Collapse
|
5
|
Sommer WH, Canals S, Bifone A, Heilig M, Hyytiä P. From a systems view to spotting a hidden island: A narrative review implicating insula function in alcoholism. Neuropharmacology 2022; 209:108989. [PMID: 35217032 DOI: 10.1016/j.neuropharm.2022.108989] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/30/2022] [Accepted: 02/07/2022] [Indexed: 12/31/2022]
Abstract
Excessive use of alcohol promotes the development of alcohol addiction, but the understanding of how alcohol-induced brain alterations lead to addiction remains limited. To further this understanding, we adopted an unbiased discovery strategy based on the principles of systems medicine. We used functional magnetic resonance imaging data from patients and animal models of alcohol addiction-like behaviors, and developed mathematical models of the 'relapse-prone' network states to identify brain sites and functional networks that can be selectively targeted by therapeutic interventions. Our systems level, non-local, and largely unbiased analyses converged on a few well-defined brain regions, with the insula emerging as one of the most consistent finding across studies. In proof-of-concept experiments we were able to demonstrate that it is possible to guide network dynamics towards increased resilience in animals but an initial translation into a clinical trial targeting the insula failed. Here, in a narrative review, we summarize the key experiments, methodological developments and knowledge gained from this completed round of a discovery cycle moving from identification of 'relapse-prone' network states in humans and animals to target validation and intervention trial. Future concerted efforts are necessary to gain a deeper understanding of insula function a in a state-dependent, circuit-specific and cell population perspective, and to develop the means for insula-directed interventions, before therapeutic targeting of this structure may become possible.
Collapse
Affiliation(s)
- Wolfgang H Sommer
- Institute of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, Medical Faculty Mannheim, Bethania Hospital for Psychiatry, Psychosomatics, and Psychotherapy, Greifswald, Germany.
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, 03550, Sant Joan d'Alacant, Spain
| | - Angelo Bifone
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Istituto Italiano di Tecnologia, Center for Sustainable Future Technologies, Torino, Italy
| | - Markus Heilig
- Center for Social and Affective Neuroscience, Linköping University and Dept. of Psychiatry, Linköping Univ. Hospital, S-581 85, Linköping, Sweden
| | - Petri Hyytiä
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Finland
| |
Collapse
|
6
|
Shrestha P, Klann E. Spatiotemporally resolved protein synthesis as a molecular framework for memory consolidation. Trends Neurosci 2022; 45:297-311. [PMID: 35184897 PMCID: PMC8930706 DOI: 10.1016/j.tins.2022.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 01/25/2023]
Abstract
De novo protein synthesis is required for long-term memory consolidation. Dynamic regulation of protein synthesis occurs via a complex interplay of translation factors and modulators. Many components of the protein synthesis machinery have been targeted either pharmacologically or genetically to establish its requirement for memory. The combination of ligand/light-gating and genetic strategies, that is, chemogenetics and optogenetics, has begun to reveal the spatiotemporal resolution of protein synthesis in specific cell types during memory consolidation. This review summarizes current knowledge of the macroscopic and microscopic neural substrates for protein synthesis in memory consolidation. In addition, we highlight future directions for determining the localization and timing of de novo protein synthesis for memory consolidation with tools that permit unprecedented spatiotemporal precision.
Collapse
Affiliation(s)
- Prerana Shrestha
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY 10012, USA; NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
| |
Collapse
|
7
|
Knight JRP, Vlahov N, Gay DM, Ridgway RA, Faller WJ, Proud C, Mallucci GR, von der Haar T, Smales CM, Willis AE, Sansom OJ. Rpl24Bst mutation suppresses colorectal cancer by promoting eEF2 phosphorylation via eEF2K. eLife 2021; 10:e69729. [PMID: 34895463 PMCID: PMC8668188 DOI: 10.7554/elife.69729] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 11/26/2021] [Indexed: 12/15/2022] Open
Abstract
Increased protein synthesis supports the rapid cell proliferation associated with cancer. The Rpl24Bst mutant mouse reduces the expression of the ribosomal protein RPL24 and has been used to suppress translation and limit tumorigenesis in multiple mouse models of cancer. Here, we show that Rpl24Bst also suppresses tumorigenesis and proliferation in a model of colorectal cancer (CRC) with two common patient mutations, Apc and Kras. In contrast to previous reports, Rpl24Bst mutation has no effect on ribosomal subunit abundance but suppresses translation elongation through phosphorylation of eEF2, reducing protein synthesis by 40% in tumour cells. Ablating eEF2 phosphorylation in Rpl24Bst mutant mice by inactivating its kinase, eEF2K, completely restores the rates of elongation and protein synthesis. Furthermore, eEF2K activity is required for the Rpl24Bst mutant to suppress tumorigenesis. This work demonstrates that elevation of eEF2 phosphorylation is an effective means to suppress colorectal tumorigenesis with two driver mutations. This positions translation elongation as a therapeutic target in CRC, as well as in other cancers where the Rpl24Bst mutation has a tumour suppressive effect in mouse models.
Collapse
Affiliation(s)
- John RP Knight
- CRUK Beatson Institute, Garscube EstateGlasgowUnited Kingdom
| | - Nikola Vlahov
- CRUK Beatson Institute, Garscube EstateGlasgowUnited Kingdom
| | - David M Gay
- CRUK Beatson Institute, Garscube EstateGlasgowUnited Kingdom
- Institute of Cancer Sciences, University of GlasgowGlasgowUnited Kingdom
| | | | | | - Christopher Proud
- Department of Biological Sciences, University of AdelaideAdelaideAustralia
- Lifelong Health, South Australian Health and Medical Research InstituteAdelaideAustralia
| | - Giovanna R Mallucci
- UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of CambridgeCambridgeUnited Kingdom
| | - Tobias von der Haar
- School of Biosciences, Division of Natural Sciences, University of KentKentUnited Kingdom
| | | | - Anne E Willis
- MRC Toxicology Unit, University of CambridgeCambridgeUnited Kingdom
| | - Owen J Sansom
- CRUK Beatson Institute, Garscube EstateGlasgowUnited Kingdom
- Institute of Cancer Sciences, University of GlasgowGlasgowUnited Kingdom
| |
Collapse
|
8
|
Smith PR, Loerch S, Kunder N, Stanowick AD, Lou TF, Campbell ZT. Functionally distinct roles for eEF2K in the control of ribosome availability and p-body abundance. Nat Commun 2021; 12:6789. [PMID: 34815424 PMCID: PMC8611098 DOI: 10.1038/s41467-021-27160-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 11/07/2021] [Indexed: 11/09/2022] Open
Abstract
Processing bodies (p-bodies) are a prototypical phase-separated RNA-containing granule. Their abundance is highly dynamic and has been linked to translation. Yet, the molecular mechanisms responsible for coordinate control of the two processes are unclear. Here, we uncover key roles for eEF2 kinase (eEF2K) in the control of ribosome availability and p-body abundance. eEF2K acts on a sole known substrate, eEF2, to inhibit translation. We find that the eEF2K agonist nelfinavir abolishes p-bodies in sensory neurons and impairs translation. To probe the latter, we used cryo-electron microscopy. Nelfinavir stabilizes vacant 80S ribosomes. They contain SERBP1 in place of mRNA and eEF2 in the acceptor site. Phosphorylated eEF2 associates with inactive ribosomes that resist splitting in vitro. Collectively, the data suggest that eEF2K defines a population of inactive ribosomes resistant to recycling and protected from degradation. Thus, eEF2K activity is central to both p-body abundance and ribosome availability in sensory neurons.
Collapse
Affiliation(s)
- Patrick R. Smith
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Sarah Loerch
- grid.443970.dJanelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA USA ,grid.205975.c0000 0001 0740 6917University of California, Santa Cruz, Department of Chemistry and Biochemistry, Santa Cruz, CA USA
| | - Nikesh Kunder
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Alexander D. Stanowick
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Tzu-Fang Lou
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA
| | - Zachary T. Campbell
- grid.267323.10000 0001 2151 7939The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX USA ,grid.267323.10000 0001 2151 7939The Center for Advanced Pain Studies (CAPS), University of Texas at Dallas, Richardson, TX USA
| |
Collapse
|
9
|
Ma T. Roles of eukaryotic elongation factor 2 kinase (eEF2K) in neuronal plasticity, cognition, and Alzheimer disease. J Neurochem 2021. [PMID: 34796967 DOI: 10.1111/jnc.15541] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/19/2021] [Accepted: 11/15/2021] [Indexed: 01/04/2023]
Abstract
Understanding the molecular signaling mechanisms underlying cognition and neuronal plasticity would provide insights into the pathogenesis of neuronal disorders characterized by cognitive syndromes such as Alzheimer disease (AD). Phosphorylation of the mRNA translational factor eukaryotic elongation factor 2 (eEF2) by its specific kinase eEF2K is critically involved in protein synthesis regulation. In this review, we discussed recent studies on the roles of eEF2K/eEF2 signaling in the context of regulation/dysregulation of cognitive function and synaptic plasticity. We specifically focus on the discussion of recent evidence indicating suppression of eEF2K signaling as a potential novel therapeutic avenue for AD and related dementias (ADRDs).
Collapse
Affiliation(s)
- Tao Ma
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.,Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.,Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Knight JRP, Alexandrou C, Skalka GL, Vlahov N, Pennel K, Officer L, Teodosio A, Kanellos G, Gay DM, May-Wilson S, Smith EM, Najumudeen AK, Gilroy K, Ridgway RA, Flanagan DJ, Smith RCL, McDonald L, MacKay C, Cheasty A, McArthur K, Stanway E, Leach JD, Jackstadt R, Waldron JA, Campbell AD, Vlachogiannis G, Valeri N, Haigis KM, Sonenberg N, Proud CG, Jones NP, Swarbrick ME, McKinnon HJ, Faller WJ, Le Quesne J, Edwards J, Willis AE, Bushell M, Sansom OJ. MNK Inhibition Sensitizes KRAS-Mutant Colorectal Cancer to mTORC1 Inhibition by Reducing eIF4E Phosphorylation and c-MYC Expression. Cancer Discov 2021; 11:1228-1247. [PMID: 33328217 PMCID: PMC7611341 DOI: 10.1158/2159-8290.cd-20-0652] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 10/21/2020] [Accepted: 12/11/2020] [Indexed: 12/16/2022]
Abstract
KRAS-mutant colorectal cancers are resistant to therapeutics, presenting a significant problem for ∼40% of cases. Rapalogs, which inhibit mTORC1 and thus protein synthesis, are significantly less potent in KRAS-mutant colorectal cancer. Using Kras-mutant mouse models and mouse- and patient-derived organoids, we demonstrate that KRAS with G12D mutation fundamentally rewires translation to increase both bulk and mRNA-specific translation initiation. This occurs via the MNK/eIF4E pathway culminating in sustained expression of c-MYC. By genetic and small-molecule targeting of this pathway, we acutely sensitize KRASG12D models to rapamycin via suppression of c-MYC. We show that 45% of colorectal cancers have high signaling through mTORC1 and the MNKs, with this signature correlating with a 3.5-year shorter cancer-specific survival in a subset of patients. This work provides a c-MYC-dependent cotargeting strategy with remarkable potency in multiple Kras-mutant mouse models and metastatic human organoids and identifies a patient population that may benefit from its clinical application. SIGNIFICANCE: KRAS mutation and elevated c-MYC are widespread in many tumors but remain predominantly untargetable. We find that mutant KRAS modulates translation, culminating in increased expression of c-MYC. We describe an effective strategy targeting mTORC1 and MNK in KRAS-mutant mouse and human models, pathways that are also commonly co-upregulated in colorectal cancer.This article is highlighted in the In This Issue feature, p. 995.
Collapse
Affiliation(s)
| | | | - George L Skalka
- CRUK Beatson Institute, Glasgow, United Kingdom
- MRC Toxicology Unit, University of Cambridge, Cambridge, United Kingdom
| | | | - Kathryn Pennel
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Leah Officer
- MRC Toxicology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Ana Teodosio
- MRC Toxicology Unit, University of Cambridge, Cambridge, United Kingdom
| | | | - David M Gay
- CRUK Beatson Institute, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | | | | | | | | | | | - Rachael C L Smith
- CRUK Beatson Institute, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Laura McDonald
- Drug Discovery Unit, CRUK Beatson Institute, Glasgow, United Kingdom
| | - Craig MacKay
- Drug Discovery Unit, CRUK Beatson Institute, Glasgow, United Kingdom
| | - Anne Cheasty
- CRUK Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, United Kingdom
| | - Kerri McArthur
- CRUK Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, United Kingdom
| | - Emma Stanway
- CRUK Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, United Kingdom
| | - Joshua D Leach
- CRUK Beatson Institute, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | | | | | - Georgios Vlachogiannis
- Division of Molecular Pathology, The Institute of Cancer Research, London, United Kingdom
| | - Nicola Valeri
- Division of Molecular Pathology, The Institute of Cancer Research, London, United Kingdom
- Department of Medicine, The Royal Marsden NHS Foundation Trust, London, United Kingdom
| | - Kevin M Haigis
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
| | - Christopher G Proud
- Lifelong Health, South Australian Health and Medical Research Institute, North Terrace, Adelaide, South Australia, Australia
- Department of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Neil P Jones
- CRUK Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, United Kingdom
| | - Martin E Swarbrick
- CRUK Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, United Kingdom
| | | | | | - John Le Quesne
- MRC Toxicology Unit, University of Cambridge, Cambridge, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
- Leicester Cancer Research Centre, University of Leicester, Leicester, United Kingdom
- Glenfield Hospital, Leicester University Hospitals NHS Trust, Leicester, United Kingdom
| | - Joanne Edwards
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Martin Bushell
- CRUK Beatson Institute, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Owen J Sansom
- CRUK Beatson Institute, Glasgow, United Kingdom.
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
12
|
Pizzo L, Lasser M, Yusuff T, Jensen M, Ingraham P, Huber E, Singh MD, Monahan C, Iyer J, Desai I, Karthikeyan S, Gould DJ, Yennawar S, Weiner AT, Pounraja VK, Krishnan A, Rolls MM, Lowery LA, Girirajan S. Functional assessment of the "two-hit" model for neurodevelopmental defects in Drosophila and X. laevis. PLoS Genet 2021; 17:e1009112. [PMID: 33819264 PMCID: PMC8049494 DOI: 10.1371/journal.pgen.1009112] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 04/15/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022] Open
Abstract
We previously identified a deletion on chromosome 16p12.1 that is mostly inherited and associated with multiple neurodevelopmental outcomes, where severely affected probands carried an excess of rare pathogenic variants compared to mildly affected carrier parents. We hypothesized that the 16p12.1 deletion sensitizes the genome for disease, while "second-hits" in the genetic background modulate the phenotypic trajectory. To test this model, we examined how neurodevelopmental defects conferred by knockdown of individual 16p12.1 homologs are modulated by simultaneous knockdown of homologs of "second-hit" genes in Drosophila melanogaster and Xenopus laevis. We observed that knockdown of 16p12.1 homologs affect multiple phenotypic domains, leading to delayed developmental timing, seizure susceptibility, brain alterations, abnormal dendrite and axonal morphology, and cellular proliferation defects. Compared to genes within the 16p11.2 deletion, which has higher de novo occurrence, 16p12.1 homologs were less likely to interact with each other in Drosophila models or a human brain-specific interaction network, suggesting that interactions with "second-hit" genes may confer higher impact towards neurodevelopmental phenotypes. Assessment of 212 pairwise interactions in Drosophila between 16p12.1 homologs and 76 homologs of patient-specific "second-hit" genes (such as ARID1B and CACNA1A), genes within neurodevelopmental pathways (such as PTEN and UBE3A), and transcriptomic targets (such as DSCAM and TRRAP) identified genetic interactions in 63% of the tested pairs. In 11 out of 15 families, patient-specific "second-hits" enhanced or suppressed the phenotypic effects of one or many 16p12.1 homologs in 32/96 pairwise combinations tested. In fact, homologs of SETD5 synergistically interacted with homologs of MOSMO in both Drosophila and X. laevis, leading to modified cellular and brain phenotypes, as well as axon outgrowth defects that were not observed with knockdown of either individual homolog. Our results suggest that several 16p12.1 genes sensitize the genome towards neurodevelopmental defects, and complex interactions with "second-hit" genes determine the ultimate phenotypic manifestation.
Collapse
Affiliation(s)
- Lucilla Pizzo
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Micaela Lasser
- Department of Biology, Boston College, Chestnut Hill, MA, United States of America
| | - Tanzeen Yusuff
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Matthew Jensen
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Phoebe Ingraham
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Emily Huber
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Mayanglambam Dhruba Singh
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Connor Monahan
- Department of Biology, Boston College, Chestnut Hill, MA, United States of America
| | - Janani Iyer
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Inshya Desai
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Siddharth Karthikeyan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Dagny J. Gould
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Sneha Yennawar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Alexis T. Weiner
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Vijay Kumar Pounraja
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Arjun Krishnan
- Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI, United States of America
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States of America
| | - Melissa M. Rolls
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Laura Anne Lowery
- Department of Medicine, Boston University Medical Center, Boston, MA, United States of America
| | - Santhosh Girirajan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
- Department of Anthropology, The Pennsylvania State University, University Park, PA, United States of America
| |
Collapse
|
13
|
Neuroimaging reveals functionally distinct neuronal networks associated with high-level alcohol consumption in two genetic rat models. Behav Pharmacol 2020; 32:229-238. [PMID: 32925226 DOI: 10.1097/fbp.0000000000000582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Human imaging data suggest that the motivational processes associated with alcohol reward are reflected in the patterns of neural activation after alcohol or alcohol-related cues. In animal models of alcohol drinking, however, the changes in brain activation during voluntary alcohol ingestion are poorly known. In order to improve the translational utility of animal models, we examined alcohol-induced functional brain activation in Alko Alcohol (AA) and Marchigian-Sardinian alcohol-preferring (msP) rats that drink voluntarily high levels of alcohol, but exhibit widely different neurochemical and behavioral traits cosegregated with alcohol preference. Brain imaging was performed using manganese-enhanced MRI (MEMRI), which is based on accumulation of Mn2+ ions in activated neurons, allowing the identification of functional neuronal networks recruited during specific behaviors in awake animals during a subsequent imaging session under anesthesia. MEMRI was performed following 4 weeks of voluntary alcohol drinking, using water drinking as the control. Despite similar levels of alcohol drinking, strikingly different alcohol-induced neuronal activity patterns were observed in AA and msP rats. Overall, functional activation in the AA rats was more widespread, involving large cortical areas and subcortical structures, such as the bed nucleus of the stria terminalis, preoptic area, hypothalamus, periaqueductal grey, and substantia nigra. In the msP rats, however, alcohol-related activation was largely confined to prefrontal cortical regions and insular cortex, and olfactory areas. Overlapping areas of activation found in both rat lines included the nucleus accumbens, prelimbic, orbital, and insular cortex. In conclusion, our data reveal strikingly different brain circuits associated with alcohol drinking in two genetically different rat lines and suggest innately different motivational and behavioral processes driving alcohol drinking. These findings have important implications for the use of these lines in translational alcohol research.
Collapse
|
14
|
Licznerski P, Park HA, Rolyan H, Chen R, Mnatsakanyan N, Miranda P, Graham M, Wu J, Cruz-Reyes N, Mehta N, Sohail S, Salcedo J, Song E, Effman C, Effman S, Brandao L, Xu GN, Braker A, Gribkoff VK, Levy RJ, Jonas EA. ATP Synthase c-Subunit Leak Causes Aberrant Cellular Metabolism in Fragile X Syndrome. Cell 2020; 182:1170-1185.e9. [PMID: 32795412 DOI: 10.1016/j.cell.2020.07.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/04/2020] [Accepted: 07/10/2020] [Indexed: 12/26/2022]
Abstract
Loss of the gene (Fmr1) encoding Fragile X mental retardation protein (FMRP) causes increased mRNA translation and aberrant synaptic development. We find neurons of the Fmr1-/y mouse have a mitochondrial inner membrane leak contributing to a "leak metabolism." In human Fragile X syndrome (FXS) fibroblasts and in Fmr1-/y mouse neurons, closure of the ATP synthase leak channel by mild depletion of its c-subunit or pharmacological inhibition normalizes stimulus-induced and constitutive mRNA translation rate, decreases lactate and key glycolytic and tricarboxylic acid (TCA) cycle enzyme levels, and triggers synapse maturation. FMRP regulates leak closure in wild-type (WT), but not FX synapses, by stimulus-dependent ATP synthase β subunit translation; this increases the ratio of ATP synthase enzyme to its c-subunit, enhancing ATP production efficiency and synaptic growth. In contrast, in FXS, inability to close developmental c-subunit leak prevents stimulus-dependent synaptic maturation. Therefore, ATP synthase c-subunit leak closure encourages development and attenuates autistic behaviors.
Collapse
Affiliation(s)
- Pawel Licznerski
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Han-A Park
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA; Department of Human Nutrition and Hospitality Management, College of Human Environmental Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Harshvardhan Rolyan
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Rongmin Chen
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Nelli Mnatsakanyan
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Paige Miranda
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Morven Graham
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jing Wu
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | | | - Nikita Mehta
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Sana Sohail
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Jorge Salcedo
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Erin Song
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | | | - Samuel Effman
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Lucas Brandao
- Department of Biology, Clark University, Worcester, MA 01610, USA
| | - Gulan N Xu
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Amber Braker
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Valentin K Gribkoff
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Richard J Levy
- Department of Anesthesiology, Columbia University Medical Center, New York, NY 10032, USA
| | - Elizabeth A Jonas
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, CT 06511, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA.
| |
Collapse
|
15
|
Taha E, Patil S, Barrera I, Panov J, Khamaisy M, Proud CG, Bramham CR, Rosenblum K. eEF2/eEF2K Pathway in the Mature Dentate Gyrus Determines Neurogenesis Level and Cognition. Curr Biol 2020; 30:3507-3521.e7. [PMID: 32707059 DOI: 10.1016/j.cub.2020.06.061] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 05/08/2020] [Accepted: 06/18/2020] [Indexed: 12/13/2022]
Abstract
Levels of adult neurogenesis in the dentate gyrus (DG) of the hippocampus are correlated with unique cognitive functions. However, the molecular pathways controlling it are poorly understood. Here, we found that the known physiological ways to enhance neurogenesis converged on the eEF2/eEF2K pathway via AMPK in the DG. Enhancing the elongation phase of mRNA translation in eEF2K-knockout (eEF2K-KO) mice induced the expression of neurogenesis-related proteins in the hippocampus. We thus tested the hypothesis that inducing eEF2K-KO in mature neurons of the DG controls neurogenesis. Indeed, both general eEF2K-KO and targeted KO in DG excitatory mature neurons resulted in enhanced neurogenesis levels and upregulation of neurogenesis-related proteins. Increased neurogenesis was correlated with enhanced performance in DG-dependent learning. Moreover, general and local eEF2K-KO in old mice rejuvenated the DG, paving the way for better mechanistic understanding of how neurogenesis is controlled in the mature DG and possible treatments for incurable aging-associated diseases.
Collapse
Affiliation(s)
- Elham Taha
- Sagol Department of Neurobiology, 199 Aba Khoushy Avenue Mount Carmel, University of Haifa, 3498838 Haifa, Israel
| | - Sudarshan Patil
- Department of Biomedicine and KG Jebsen Centre for Research on Neuropsychiatric Disorders, Jonas Lies vei 91, University of Bergen, 5009 Bergen, Norway
| | - Iliana Barrera
- Sagol Department of Neurobiology, 199 Aba Khoushy Avenue Mount Carmel, University of Haifa, 3498838 Haifa, Israel
| | - Julia Panov
- Sagol Department of Neurobiology, 199 Aba Khoushy Avenue Mount Carmel, University of Haifa, 3498838 Haifa, Israel
| | - Mohammad Khamaisy
- Sagol Department of Neurobiology, 199 Aba Khoushy Avenue Mount Carmel, University of Haifa, 3498838 Haifa, Israel
| | - Christopher G Proud
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia; Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute, PO Box 11060, 5001 Adelaide, SA, Australia
| | - Clive R Bramham
- Department of Biomedicine and KG Jebsen Centre for Research on Neuropsychiatric Disorders, Jonas Lies vei 91, University of Bergen, 5009 Bergen, Norway
| | - Kobi Rosenblum
- Sagol Department of Neurobiology, 199 Aba Khoushy Avenue Mount Carmel, University of Haifa, 3498838 Haifa, Israel; Center for Gene Manipulation in the Brain, 199 Aba Khoushy Avenue Mount Carmel, University of Haifa, 3498838 Haifa, Israel.
| |
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|
17
|
David O, Barrera I, Gould N, Gal-Ben-Ari S, Rosenblum K. D1 Dopamine Receptor Activation Induces Neuronal eEF2 Pathway-Dependent Protein Synthesis. Front Mol Neurosci 2020; 13:67. [PMID: 32499677 PMCID: PMC7242790 DOI: 10.3389/fnmol.2020.00067] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/07/2020] [Indexed: 12/31/2022] Open
Abstract
Dopamine, alongside other neuromodulators, defines brain and neuronal states, inter alia through regulation of global and local mRNA translation. Yet, the signaling pathways underlying the effects of dopamine on mRNA translation and psychiatric disorders are not clear. In order to examine the molecular pathways downstream of dopamine receptors, we used genetic, pharmacologic, biochemical, and imaging methods, and found that activation of dopamine receptor D1 but not D2 leads to rapid dephosphorylation of eEF2 at Thr56 but not eIF2α in cortical primary neuronal culture in a time-dependent manner. NMDA receptor, mTOR, and ERK pathways are upstream of the D1 receptor-dependent eEF2 dephosphorylation and essential for it. Furthermore, D1 receptor activation resulted in a major reduction in dendritic eEF2 phosphorylation levels. D1-dependent eEF2 dephosphorylation results in an increase of BDNF and synapsin2b expression which was followed by a small yet significant increase in general protein synthesis. These results reveal the role of dopamine D1 receptor in the regulation of eEF2 pathway translation in neurons and present eEF2 as a promising therapeutic target for addiction and depression as well as other psychiatric disorders.
Collapse
Affiliation(s)
- Orit David
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Iliana Barrera
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Nathaniel Gould
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | | | - Kobi Rosenblum
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,Center for Gene Manipulation in the Brain, University of Haifa, Haifa, Israel
| |
Collapse
|
18
|
Shi Y, Cai EL, Yang C, Ye CY, Zeng P, Wang XM, Fang YY, Cheng ZK, Wang Q, Cao FY, Zhou XW, Tian Q. Protection of melatonin against acidosis-induced neuronal injuries. J Cell Mol Med 2020; 24:6928-6942. [PMID: 32364678 PMCID: PMC7299701 DOI: 10.1111/jcmm.15351] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 01/13/2020] [Accepted: 04/12/2020] [Indexed: 12/23/2022] Open
Abstract
Acidosis, a common feature of cerebral ischaemia and hypoxia, plays a key role in these pathological processes by aggravating the ischaemic and hypoxic injuries. To explore the mechanisms, in this research, we cultured primary neurons in an acidic environment (potential of hydrogen [pH]6.2, 24 hours) to mimic the acidosis. By proteomic analysis, 69 differentially expressed proteins in the acidic neurons were found, mainly related to stress and cell death, synaptic plasticity and gene transcription. And, the acidotic neurons developed obvious alterations including increased neuronal death, reduced dendritic length and complexity, reduced synaptic proteins, tau hyperphosphorylation, endoplasmic reticulum (ER) stress activation, abnormal lysosome‐related signals, imbalanced oxidative stress/anti‐oxidative stress and decreased Golgi matrix proteins. Then, melatonin (1 × 10−4 mol/L) was used to pre‐treat the cultured primary neurons before acidic treatment (pH6.2). The results showed that melatonin partially reversed the acidosis‐induced neuronal death, abnormal dendritic complexity, reductions of synaptic proteins, tau hyperphosphorylation and imbalance of kinase/phosphatase. In addition, acidosis related the activations of glycogen synthase kinase‐3β and nuclear factor‐κB signals, ER stress and Golgi stress, and the abnormal autophagy‐lysosome signals were completely reversed by melatonin. These data indicate that melatonin is beneficial for neurons against acidosis‐induced injuries.
Collapse
Affiliation(s)
- Yan Shi
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China.,School of Medicine, Hunan Normal University, Changsha, China
| | - Er-Li Cai
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Can Yang
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China.,Department of Emergency Surgery, Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Chao-Yuan Ye
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Peng Zeng
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Ming Wang
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Ying-Yan Fang
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi-Kang Cheng
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Qun Wang
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Fu-Yuan Cao
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Xin-Wen Zhou
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Tian
- Department of Pathology and Pathophysiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Laboratory of Neurological Disease of National Education Ministry, Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
19
|
Knight JRP, Garland G, Pöyry T, Mead E, Vlahov N, Sfakianos A, Grosso S, De-Lima-Hedayioglu F, Mallucci GR, von der Haar T, Smales CM, Sansom OJ, Willis AE. Control of translation elongation in health and disease. Dis Model Mech 2020; 13:dmm043208. [PMID: 32298235 PMCID: PMC7104864 DOI: 10.1242/dmm.043208] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Regulation of protein synthesis makes a major contribution to post-transcriptional control pathways. During disease, or under stress, cells initiate processes to reprogramme protein synthesis and thus orchestrate the appropriate cellular response. Recent data show that the elongation stage of protein synthesis is a key regulatory node for translational control in health and disease. There is a complex set of factors that individually affect the overall rate of elongation and, for the most part, these influence either transfer RNA (tRNA)- and eukaryotic elongation factor 1A (eEF1A)-dependent codon decoding, and/or elongation factor 2 (eEF2)-dependent ribosome translocation along the mRNA. Decoding speeds depend on the relative abundance of each tRNA, the cognate:near-cognate tRNA ratios and the degree of tRNA modification, whereas eEF2-dependent ribosome translocation is negatively regulated by phosphorylation on threonine-56 by eEF2 kinase. Additional factors that contribute to the control of the elongation rate include epigenetic modification of the mRNA, coding sequence variation and the expression of eIF5A, which stimulates peptide bond formation between proline residues. Importantly, dysregulation of elongation control is central to disease mechanisms in both tumorigenesis and neurodegeneration, making the individual key steps in this process attractive therapeutic targets. Here, we discuss the relative contribution of individual components of the translational apparatus (e.g. tRNAs, elongation factors and their modifiers) to the overall control of translation elongation and how their dysregulation contributes towards disease processes.
Collapse
Affiliation(s)
| | - Gavin Garland
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | - Tuija Pöyry
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | - Emma Mead
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Nikola Vlahov
- Beatson Institute for Cancer Research, Glasgow G61 1BD, UK
| | - Aristeidis Sfakianos
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | - Stefano Grosso
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | | | - Giovanna R Mallucci
- UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0XY, UK
| | | | - C Mark Smales
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Owen J Sansom
- Beatson Institute for Cancer Research, Glasgow G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, UK
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| |
Collapse
|
20
|
Beretta S, Gritti L, Verpelli C, Sala C. Eukaryotic Elongation Factor 2 Kinase a Pharmacological Target to Regulate Protein Translation Dysfunction in Neurological Diseases. Neuroscience 2020; 445:42-49. [PMID: 32088293 DOI: 10.1016/j.neuroscience.2020.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 02/02/2023]
Abstract
Two major processes tightly regulate protein synthesis, the initiation of mRNA translation and elongation phase that mediates the movement of ribosomes along the mRNA. The elongation phase is a high energy-consuming process, and is mainly regulated by the eukaryotic elongation factor 2 kinase (eEF2K) activity that phosphorylates and inhibits eEF2, the only known substrate of the kinase. eEF2K activity is closely regulated by several signaling pathways because the translation elongation phase strongly influences the cellular energy demand and can change the expression of specific proteins in different tissues. An increasing number of recent findings link eEF2k over activation to an array of human diseases, such as atherosclerosis, pulmonary arterial hypertension, progression of solid tumors, and some major neurological disorders. Several neurological studies suggest that eEF2K is a valuable target in treating epilepsy, depression and major neurodegenerative diseases. Despite eEF2k is an ubiquitous and conserved protein, it has been proved that its deletion does not affect development in animal models and in general cell viability. Therefore, it is possible to postulate that inhibiting its function may not cause serious side effects. In addition, eEF2K is a peculiar kinase molecularly different from most of other mammalian kinases and new compounds that inhibit eEF2K should not necessarily interfere with other important protein kinases. In this review we will critically summarize the evidence supporting the role of the altered eEF2K/eEF2 pathway in defined neurological diseases and its implications in curing these diseases in animal models, and possibly in humans, by targeting eEF2K activity.
Collapse
Affiliation(s)
| | | | | | - Carlo Sala
- CNR Neuroscience Institute, Milano, Italy.
| |
Collapse
|
21
|
Zimmermann HR, Yang W, Beckelman BC, Kasica NP, Zhou X, Galli LD, Ryazanov AG, Ma T. Genetic removal of eIF2α kinase PERK in mice enables hippocampal L-LTP independent of mTORC1 activity. J Neurochem 2019; 146:133-144. [PMID: 29337352 DOI: 10.1111/jnc.14306] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/02/2018] [Accepted: 01/03/2018] [Indexed: 01/27/2023]
Abstract
Characterization of the molecular signaling pathways underlying protein synthesis-dependent forms of synaptic plasticity, such as late long-term potentiation (L-LTP), can provide insights not only into memory expression/maintenance under physiological conditions but also potential mechanisms associated with the pathogenesis of memory disorders. Here, we report in mice that L-LTP failure induced by the mammalian (mechanistic) target of rapamycin complex 1 (mTORC1) inhibitor rapamycin is reversed by brain-specific genetic deletion of PKR-like ER kinase, PERK (PERK KO), a kinase for eukaryotic initiation factor 2α (eIF2α). In contrast, genetic removal of general control non-derepressible-2, GCN2 (GCN2 KO), another eIF2α kinase, or treatment of hippocampal slices with the PERK inhibitor GSK2606414, does not rescue rapamycin-induced L-LTP failure, suggesting mechanisms independent of eIF2α phosphorylation. Moreover, we demonstrate that phosphorylation of eukaryotic elongation factor 2 (eEF2) is significantly decreased in PERK KO mice but unaltered in GCN2 KO mice or slices treated with the PERK inhibitor. Reduction in eEF2 phosphorylation results in increased general protein synthesis, and thus could contribute to the mTORC1-independent L-LTP in PERK KO mice. We further performed experiments on mutant mice with genetic removal of eEF2K (eEF2K KO), the only known kinase for eEF2, and found that L-LTP in eEF2K KO mice is insensitive to rapamycin. These data, for the first time, connect reduction in PERK activity with the regulation of translation elongation in enabling L-LTP independent of mTORC1. Thus, our findings indicate previously unrecognized levels of complexity in the regulation of protein synthesis-dependent synaptic plasticity. Read the Editorial Highlight for this article on page 119. Cover Image for this issue: doi: 10.1111/jnc.14185.
Collapse
Affiliation(s)
- Helena R Zimmermann
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Wenzhong Yang
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Brenna C Beckelman
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Nicole P Kasica
- 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
| | - Lucas Dufresne Galli
- Department of Internal Medicine-Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, 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 Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.,Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| |
Collapse
|
22
|
Ponzoni L, Sala C, Verpelli C, Sala M, Braida D. Different attentional dysfunctions in
eEF2K
−/−
, IL1RAPL1
−/−
and
SHANK3Δ11
−/−
mice. GENES BRAIN AND BEHAVIOR 2019; 18:e12563. [DOI: 10.1111/gbb.12563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 02/22/2019] [Accepted: 03/04/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Luisa Ponzoni
- CNR, Neuroscience Institute Milan Italy
- Department of Medical Biotechnology and Translational MedicineUniversità degli Studi di Milano Milan Italy
| | | | | | | | - Daniela Braida
- Department of Medical Biotechnology and Translational MedicineUniversità degli Studi di Milano Milan Italy
| |
Collapse
|
23
|
Local Inhibition of PERK Enhances Memory and Reverses Age-Related Deterioration of Cognitive and Neuronal Properties. J Neurosci 2017; 38:648-658. [PMID: 29196323 DOI: 10.1523/jneurosci.0628-17.2017] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 10/25/2017] [Accepted: 11/10/2017] [Indexed: 01/08/2023] Open
Abstract
Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) is one of four known kinases that respond to cellular stress by deactivating the eukaryotic initiation factor 2 α (eIF2α) or other signal transduction cascades. Recently, both eIF2α and its kinases were found to play a role in normal and pathological brain function. Here, we show that reduction of either the amount or the activity of PERK, specifically in the CA1 region of the hippocampus in young adult male mice, enhances neuronal excitability and improves cognitive function. In addition, this manipulation rescues the age-dependent cellular phenotype of reduced excitability and memory decline. Specifically, the reduction of PERK expression in the CA1 region of the hippocampus of middle-aged male mice using a viral vector rejuvenates hippocampal function and improves hippocampal-dependent learning. These results delineate a mechanism for behavior and neuronal aging and position PERK as a promising therapeutic target for age-dependent brain malfunction.SIGNIFICANCE STATEMENT We found that local reduced protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) expression or activity in the hippocampus enhances neuronal excitability and cognitive function in young normal mice, that old CA1 pyramidal cells have reduced excitability and increased PERK expression that can be rescued by reducing PERK expression in the hippocampus, and that reducing PERK expression in the hippocampus of middle-aged mice enhances hippocampal-dependent learning and memory and restores it to normal performance levels of young mice. These findings uncover an entirely new biological link among PERK, neuronal intrinsic properties, aging, and cognitive function. Moreover, our findings propose a new way to fight mild cognitive impairment and aging-related cognitive deterioration.
Collapse
|
24
|
Heise C, Taha E, Murru L, Ponzoni L, Cattaneo A, Guarnieri FC, Montani C, Mossa A, Vezzoli E, Ippolito G, Zapata J, Barrera I, Ryazanov AG, Cook J, Poe M, Stephen MR, Kopanitsa M, Benfante R, Rusconi F, Braida D, Francolini M, Proud CG, Valtorta F, Passafaro M, Sala M, Bachi A, Verpelli C, Rosenblum K, Sala C. eEF2K/eEF2 Pathway Controls the Excitation/Inhibition Balance and Susceptibility to Epileptic Seizures. Cereb Cortex 2017; 27:2226-2248. [PMID: 27005990 DOI: 10.1093/cercor/bhw075] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Alterations in the balance of inhibitory and excitatory synaptic transmission have been implicated in the pathogenesis of neurological disorders such as epilepsy. Eukaryotic elongation factor 2 kinase (eEF2K) is a highly regulated, ubiquitous kinase involved in the control of protein translation. Here, we show that eEF2K activity negatively regulates GABAergic synaptic transmission. Indeed, loss of eEF2K increases GABAergic synaptic transmission by upregulating the presynaptic protein Synapsin 2b and α5-containing GABAA receptors and thus interferes with the excitation/inhibition balance. This cellular phenotype is accompanied by an increased resistance to epilepsy and an impairment of only a specific hippocampal-dependent fear conditioning. From a clinical perspective, our results identify eEF2K as a potential novel target for antiepileptic drugs, since pharmacological and genetic inhibition of eEF2K can revert the epileptic phenotype in a mouse model of human epilepsy.
Collapse
Affiliation(s)
| | - Elham Taha
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Luca Murru
- CNR Neuroscience Institute, Milan, Italy
| | - Luisa Ponzoni
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | | | - Fabrizia C Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | | | | | - Elena Vezzoli
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | | | | | - Iliana Barrera
- Sagol Department of Neurobiology and.,Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Alexey G Ryazanov
- The Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - James Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Michael Poe
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Michael Rajesh Stephen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Maksym Kopanitsa
- Synome, Babraham Research Campus, Cambridge CB22 3AT, UK.,Charles River Discovery Research Services, 70210 Kuopio, Finland
| | - Roberta Benfante
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Francesco Rusconi
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Daniela Braida
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Maura Francolini
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Christopher G Proud
- University of Southampton, Centre for Biological Sciences, Southampton SO17 1BJ, UK.,South Australian Health and Medical Research Institute and University of Adelaide, Adelaide, Australia
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | - Maria Passafaro
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Mariaelvina Sala
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Angela Bachi
- IFOM-FIRC Institute of Molecular Oncology, Milan, Italy
| | - Chiara Verpelli
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Kobi Rosenblum
- Sagol Department of Neurobiology and.,Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Carlo Sala
- CNR Neuroscience Institute, Milan, Italy, Università degli Studi di Milano, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| |
Collapse
|
25
|
McCamphill PK, Ferguson L, Sossin WS. A decrease in eukaryotic elongation factor 2 phosphorylation is required for local translation of sensorin and long-term facilitation in Aplysia. J Neurochem 2017; 142:246-259. [PMID: 28345161 DOI: 10.1111/jnc.14030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/15/2017] [Accepted: 03/17/2017] [Indexed: 12/20/2022]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1)-dependent protein synthesis is required for many forms of synaptic plasticity and memory, but the downstream pathways important for synaptic plasticity are poorly understood. Long-term facilitation (LTF) in Aplysia is a form of synaptic plasticity that is closely linked to behavioral memory and an attractive model system for examining the important downstream targets for mTORC1 in regulating synaptic plasticity. Although mTORC1-regulated protein synthesis has been strongly linked to translation initiation, translation elongation is also regulated by mTORC1 and LTF leads to an mTORC1-dependent decrease in eukaryotic elongation factor 2 (eEF2) phosphorylation. The purpose of this study is to test the hypothesis that the decrease in eEF2 phosphorylation is required for mTORC1-dependent translation and plasticity. We show that the LTF-induced decrease in eEF2 phosphorylation is blocked by expression of an eEF2 kinase (eEF2K) modified to be resistant to mTORC1 regulation. We found that expression of this modified kinase blocked LTF. LTF requires local protein synthesis of the neuropeptide sensorin and importantly, local sensorin synthesis can be measured using a dendra fluorescent protein containing the 5' and 3' untranslated regions (UTRs) of sensorin. Using this construct, we show that blocking eEF2 dephosphorylation also blocks the increase in local sensorin synthesis. These results identify decreases in eEF2 phosphorylation as a critical downstream effector of mTOR required for long-term plasticity and identify an important translational target regulated by decreases in eEF2 phosphorylation.
Collapse
Affiliation(s)
- Patrick K McCamphill
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Larissa Ferguson
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Wayne S Sossin
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
26
|
Papale A, d'Isa R, Menna E, Cerovic M, Solari N, Hardingham N, Cambiaghi M, Cursi M, Barbacid M, Leocani L, Fasano S, Matteoli M, Brambilla R. Severe Intellectual Disability and Enhanced Gamma-Aminobutyric Acidergic Synaptogenesis in a Novel Model of Rare RASopathies. Biol Psychiatry 2017; 81:179-192. [PMID: 27587266 DOI: 10.1016/j.biopsych.2016.06.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/16/2016] [Accepted: 06/14/2016] [Indexed: 11/16/2022]
Abstract
BACKGROUND Dysregulation of Ras-extracellular signal-related kinase (ERK) signaling gives rise to RASopathies, a class of neurodevelopmental syndromes associated with intellectual disability. Recently, much attention has been directed at models bearing mild forms of RASopathies whose behavioral impairments can be attenuated by inhibiting the Ras-ERK cascade in the adult. Little is known about the brain mechanisms in severe forms of these disorders. METHODS We performed an extensive characterization of a new brain-specific model of severe forms of RASopathies, the KRAS12V mutant mouse. RESULTS The KRAS12V mutation results in a severe form of intellectual disability, which parallels mental deficits found in patients bearing mutations in this gene. KRAS12V mice show a severe impairment of both short- and long-term memory in a number of behavioral tasks. At the cellular level, an upregulation of ERK signaling during early phases of postnatal development, but not in the adult state, results in a selective enhancement of synaptogenesis in gamma-aminobutyric acidergic interneurons. The enhancement of ERK activity in interneurons at this critical postnatal time leads to a permanent increase in the inhibitory tone throughout the brain, manifesting in reduced synaptic transmission and long-term plasticity in the hippocampus. In the adult, the behavioral and electrophysiological phenotypes in KRAS12V mice can be temporarily reverted by inhibiting gamma-aminobutyric acid signaling but not by a Ras-ERK blockade. Importantly, the synaptogenesis phenotype can be rescued by a treatment at the developmental stage with Ras-ERK inhibitors. CONCLUSIONS These data demonstrate a novel mechanism underlying inhibitory synaptogenesis and provide new insights in understanding mental dysfunctions associated to RASopathies.
Collapse
Affiliation(s)
- Alessandro Papale
- Neuroscience and Mental Health Research Institute, Division of Neuroscience, School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Raffaele d'Isa
- Institute of Experimental Neurology, Division of Neuroscience, IRCCS-San Raffaele Scientific Institute, Milano
| | - Elisabetta Menna
- National Research Council (CNR), Neuroscience Institute, Milano; Humanitas Clinical and Research Center, Rozzano, Italy
| | - Milica Cerovic
- Neuroscience and Mental Health Research Institute, Division of Neuroscience, School of Biosciences, Cardiff University, Cardiff, United Kingdom; Department of Neuroscience, IRCCS Mario Negri Institute for Pharmacological Research, Milano
| | - Nicola Solari
- Institute of Experimental Neurology, Division of Neuroscience, IRCCS-San Raffaele Scientific Institute, Milano; Department of Neuroscience, IRCCS Mario Negri Institute for Pharmacological Research, Milano
| | - Neil Hardingham
- Neuroscience and Mental Health Research Institute, Division of Neuroscience, School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Marco Cambiaghi
- Institute of Experimental Neurology, Division of Neuroscience, IRCCS-San Raffaele Scientific Institute, Milano
| | - Marco Cursi
- Institute of Experimental Neurology, Division of Neuroscience, IRCCS-San Raffaele Scientific Institute, Milano
| | - Mariano Barbacid
- Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - Letizia Leocani
- Institute of Experimental Neurology, Division of Neuroscience, IRCCS-San Raffaele Scientific Institute, Milano
| | - Stefania Fasano
- Neuroscience and Mental Health Research Institute, Division of Neuroscience, School of Biosciences, Cardiff University, Cardiff, United Kingdom; Institute of Experimental Neurology, Division of Neuroscience, IRCCS-San Raffaele Scientific Institute, Milano
| | - Michela Matteoli
- National Research Council (CNR), Neuroscience Institute, Milano; Humanitas Clinical and Research Center, Rozzano, Italy
| | - Riccardo Brambilla
- Neuroscience and Mental Health Research Institute, Division of Neuroscience, School of Biosciences, Cardiff University, Cardiff, United Kingdom; Institute of Experimental Neurology, Division of Neuroscience, IRCCS-San Raffaele Scientific Institute, Milano.
| |
Collapse
|
27
|
Pizzo L, Andrieux J, Amor DJ, Girirajan S. Clinical utility gene card for: 16p12.2 microdeletion. Eur J Hum Genet 2016; 25:ejhg2016158. [PMID: 27848943 DOI: 10.1038/ejhg.2016.158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/20/2016] [Accepted: 10/11/2016] [Indexed: 11/09/2022] Open
Affiliation(s)
- Lucilla Pizzo
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Joris Andrieux
- Institut de Génétique Médicale, CHRU de Lille, Lille, France
| | - David J Amor
- Department of Paediatrics, Murdoch Childrens Research Institute, University of Melbourne, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Santhosh Girirajan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.,Department of Anthropology, The Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
28
|
Continuous infusion of manganese improves contrast and reduces side effects in manganese-enhanced magnetic resonance imaging studies. Neuroimage 2016; 147:1-9. [PMID: 27777173 DOI: 10.1016/j.neuroimage.2016.09.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 09/04/2016] [Accepted: 09/13/2016] [Indexed: 01/04/2023] Open
Abstract
The ability to administer systemically high doses of manganese as contrast agent while circumventing its toxicity is of particular interest for exploratory MRI studies of the brain. Administering low doses either repeatedly or continuously over time has been shown to enable the acquisition of satisfactory MRI images of the mouse brain without apparent side effects. Here we have systematically compared the obtained MRI contrast and recorded potential systemic side effects such as stress response and muscle strength impairment in relation to the achieved contrast. We show in mice that administering MnCl2 via osmotic infusion pumps allows for a side-effect free delivery of a high cumulative dose of manganese chloride (480mg/kg bodyweight in 8 days). High contrast in MRI was achieved while we did not observe the weight loss or distress seen in other studies where mice received manganese via fractionated intraperitoneal injections of lower doses of manganese. As the normal daily conduct of the mice was not affected, this new manganese delivery method might be of particular use to study brain activity over several days. This may facilitate the phenotyping of new transgenic mouse models, the study of chronic disease models and the monitoring of changes in brain activity in long-term behavioral studies.
Collapse
|
29
|
Will N, Piserchio A, Snyder I, Ferguson SB, Giles DH, Dalby KN, Ghose R. Structure of the C-Terminal Helical Repeat Domain of Eukaryotic Elongation Factor 2 Kinase. Biochemistry 2016; 55:5377-86. [PMID: 27571275 DOI: 10.1021/acs.biochem.6b00711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF-2K) phosphorylates its only known physiological substrate, elongation factor 2 (eEF-2), which reduces the affinity of eEF-2 for the ribosome and results in an overall reduction in protein translation rates. The C-terminal region of eEF-2K, which is predicted to contain several SEL-1-like helical repeats (SLRs), is required for the phosphorylation of eEF-2. Using solution nuclear magnetic resonance methodology, we have determined the structure of a 99-residue fragment from the extreme C-terminus of eEF-2K (eEF-2K627-725) that encompasses a region previously suggested to be essential for eEF-2 phosphorylation. eEF-2K627-725 contains four helices, of which the first (αI) is flexible, and does not pack stably against the ordered helical core formed by the last three helices (αII-αIV). The helical core is structurally similar to members of the tetratricopeptide repeat (TPR) family that includes SLRs. The two penultimate helices, αII and αIII, comprise the TPR, and the last helix, αIV, appears to have a capping function. The eEF-2K627-725 structure illustrates that the C-terminal deletion that was shown to abolish eEF-2 phosphorylation does so by destabilizing αIV and, therefore, the helical core. Indeed, mutation of two conserved C-terminal tyrosines (Y712A/Y713A) in eEF-2K previously shown to abolish eEF-2 phosphorylation leads to the unfolding of eEF-2K627-725. Preliminary functional analyses indicate that neither a peptide encoding a region deemed crucial for eEF-2 binding nor isolated eEF-2K627-725 inhibits eEF-2 phosphorylation by full-length eEF-2K. Taken together, our data suggest that the extreme C-terminal region of eEF-2K, in isolation, does not provide a primary docking site for eEF-2.
Collapse
Affiliation(s)
- Nathan Will
- Department of Chemistry and Biochemistry, The City College of New York , New York, New York 10031, United States
| | - Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York , New York, New York 10031, United States
| | - Isaac Snyder
- Department of Chemistry and Biochemistry, The City College of New York , New York, New York 10031, United States
| | - Scarlet B Ferguson
- Division of Chemical Biology and Medicinal Chemistry, University of Texas , Austin, Texas 78712, United States
| | - David H Giles
- Division of Chemical Biology and Medicinal Chemistry, University of Texas , Austin, Texas 78712, United States
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas , Austin, Texas 78712, United States.,Graduate Program in Cell and Molecular Biology, University of Texas , Austin, Texas 78712, United States
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York , New York, New York 10031, United States
| |
Collapse
|
30
|
Lee K, Alphonse S, Piserchio A, Tavares CDJ, Giles DH, Wellmann RM, Dalby KN, Ghose R. Structural Basis for the Recognition of Eukaryotic Elongation Factor 2 Kinase by Calmodulin. Structure 2016; 24:1441-51. [PMID: 27499441 DOI: 10.1016/j.str.2016.06.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/06/2016] [Accepted: 06/10/2016] [Indexed: 12/25/2022]
Abstract
Binding of Ca(2+)-loaded calmodulin (CaM) activates eukaryotic elongation factor 2 kinase (eEF-2K) that phosphorylates eEF-2, its only known cellular target, leading to a decrease in global protein synthesis. Here, using an eEF-2K-derived peptide (eEF-2KCBD) that encodes the region necessary for its CaM-mediated activation, we provide a structural basis for their interaction. The striking feature of this association is the absence of Ca(2+) from the CaM C-lobe sites, even under high Ca(2+) conditions. eEF-2KCBD engages CaM largely through the C lobe of the latter in an anti-parallel 1-5-8 hydrophobic mode reinforced by a pair of unique electrostatic contacts. Sparse interactions of eEF-2KCBD with the CaM N lobe results in persisting inter-lobe mobility. A conserved eEF-2K residue (W85) anchors it to CaM by inserting into a deep hydrophobic cavity within the CaM C lobe. Mutation of this residue (W85S) substantially weakens interactions between full-length eEF-2K and CaM in vitro and reduces eEF-2 phosphorylation in cells.
Collapse
Affiliation(s)
- Kwangwoon Lee
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - Sébastien Alphonse
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
| | - Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
| | - Clint D J Tavares
- Graduate Program in Cell and Molecular Biology, University of Texas, Austin, TX 78712, USA
| | - David H Giles
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Rebecca M Wellmann
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, 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, New York, 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.
| |
Collapse
|
31
|
mAChR-dependent decrease in proteasome activity in the gustatory cortex is necessary for novel taste learning. Neurobiol Learn Mem 2016; 135:115-124. [PMID: 27481223 DOI: 10.1016/j.nlm.2016.07.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 07/24/2016] [Accepted: 07/28/2016] [Indexed: 11/20/2022]
Abstract
Regulation of protein degradation via the ubiquitin proteasome system is crucial for normal learning and synaptic plasticity processes. While some studies reveal that increased proteasome degradation is necessary for different types of learning, others suggest the proteasome to be a negative regulator of plasticity. We aim to understand the molecular and cellular processes taking place in the gustatory cortex (GC), which underlie appetitive and aversive forms of taste learning. Previously, we have shown that N-methyl d-aspartic acid receptor (NMDAR)-dependent upregulation of proteasome activity 4h after novel taste learning is necessary for the association of novel taste with malaise and formation of conditioned taste aversion (CTA). Here, we first identify a correlative increase in proteasome activity in the GC immediately after novel taste learning and study the upstream and downstream effectors of this modulated proteasome activity. Interestingly, proteasome-mediated degradation was reduced in the GC, 20min after novel taste consumption in a muscarinic acetylcholine receptor (mAChR)-dependent and NMDAR-independent manner. This reduction in protein degradation led to an increased amount of p70 S6 kinase (p70S6k), which was abolished in the presence of mAChR antagonist scopolamine. Infusion of lactacystin, a proteasome inhibitor, to the GC precluded the amnestic effect of scopolamine. This study shows for the first time that following novel taste learning there is a cortical, mAChR-dependent reduced proteasome activity that enables the memory of taste familiarity. Moreover, inhibition of degradation in the GC attenuates novel taste learning and of p70 S6 kinase correlative increased expression. These results shed light on the complex regulation of protein synthesis and degradation machineries in the cortex following novel taste experience.
Collapse
|
32
|
Fritzen AM, Frøsig C, Jeppesen J, Jensen TE, Lundsgaard AM, Serup AK, Schjerling P, Proud CG, Richter EA, Kiens B. Role of AMPK in regulation of LC3 lipidation as a marker of autophagy in skeletal muscle. Cell Signal 2016; 28:663-74. [DOI: 10.1016/j.cellsig.2016.03.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/03/2016] [Accepted: 03/09/2016] [Indexed: 12/26/2022]
|
33
|
Eukaryotic elongation factor 2 kinase as a drug target in cancer, and in cardiovascular and neurodegenerative diseases. Acta Pharmacol Sin 2016; 37:285-94. [PMID: 26806303 DOI: 10.1038/aps.2015.123] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/26/2015] [Indexed: 01/06/2023] Open
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) is an unusual protein kinase that regulates the elongation stage of protein synthesis by phosphorylating and inhibiting its only known substrate, eEF2. Elongation is a highly energy-consuming process, and eEF2K activity is tightly regulated by several signaling pathways. Regulating translation elongation can modulate the cellular energy demand and may also control the expression of specific proteins. Growing evidence links eEF2K to a range of human diseases, including cardiovascular conditions (atherosclerosis, via macrophage survival) and pulmonary arterial hypertension, as well as solid tumors, where eEF2K appears to play contrasting roles depending on tumor type and stage. eEF2K is also involved in neurological disorders and may be a valuable target in treating depression and certain neurodegenerative diseases. Because eEF2K is not required for mammalian development or cell viability, inhibiting its function may not elicit serious side effects, while the fact that it is an atypical kinase and quite distinct from the vast majority of other mammalian kinases suggests the possibility to develop it into compounds that inhibit eEF2K without affecting other important protein kinases. Further research is needed to explore these possibilities and there is an urgent need to identify and characterize potent and specific small-molecule inhibitors of eEF2K. In this article we review the recent evidence concerning the role of eEF2K in human diseases as well as the progress in developing small-molecule inhibitors of this enzyme.
Collapse
|
34
|
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) belongs to the small family of atypical protein kinases termed α-kinases, and is the only calcium/calmodulin (Ca/CaM)-dependent member of that group. It phosphorylates and inactivates eEF2, to slow down the rate of elongation, the stage in mRNA translation that consumes almost all the energy and amino acids consumed by protein synthesis. In addition to activation by Ca/CaM, eEF2K is also regulated by an array of other regulatory inputs, which include inhibition by the nutrient- and growth-factor activated signalling pathways. Recent evidence shows that eEF2K plays an important role in learning and memory, processes that require the synthesis of new proteins and involve Ca-mediated signalling. eEF2K is activated under conditions of nutrient and energy depletion. In cancer cells, or certain tumours, eEF2K exerts cytoprotective effects, which probably reflect its ability to inhibit protein synthesis, and nutrient consumption, under starvation conditions. eEF2K is being evaluated as a potential therapeutic target in cancer.
Collapse
|
35
|
Inberg S, Jacob E, Elkobi A, Edry E, Rappaport A, Simpson TI, Armstrong JD, Shomron N, Pasmanik-Chor M, Rosenblum K. Fluid consumption and taste novelty determines transcription temporal dynamics in the gustatory cortex. Mol Brain 2016; 9:13. [PMID: 26856319 PMCID: PMC4746785 DOI: 10.1186/s13041-016-0188-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 01/07/2016] [Indexed: 12/31/2022] Open
Abstract
Background Novel taste memories, critical for animal survival, are consolidated to form long term memories which are dependent on translation regulation in the gustatory cortex (GC) hours following acquisition. However, the role of transcription regulation in the process is unknown. Results Here, we report that transcription in the GC is necessary for taste learning in rats, and that drinking and its consequences, as well as the novel taste experience, affect transcription in the GC during taste memory consolidation. We show differential effects of learning on temporal dynamics in set of genes in the GC, including Arc/Arg3.1, known to regulate the homeostasis of excitatory synapses. Conclusions We demonstrate that in taste learning, transcription programs were activated following the physiological responses (i.e., fluid consumption following a water restriction regime, reward, arousal of the animal, etc.) and the specific information about a given taste (i.e., taste novelty). Moreover, the cortical differential prolonged kinetics of mRNA following novel versus familiar taste learning may represent additional novelty related molecular response, where not only the total amount, but also the temporal dynamics of transcription is modulated by sensory experience of novel information. Electronic supplementary material The online version of this article (doi:10.1186/s13041-016-0188-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sharon Inberg
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel
| | - Eyal Jacob
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel
| | - Alina Elkobi
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel
| | - Efrat Edry
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel.,Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel
| | - Akiva Rappaport
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel
| | - T Ian Simpson
- Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, UK.,Biomathematics and Statistics Scotland, James Clerk Maxwell Building, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JZ, UK
| | - J Douglas Armstrong
- Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, UK
| | - Noam Shomron
- Sackler Faculty of Medicine, Bioinformatics Unit, George Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Metsada Pasmanik-Chor
- Sackler Faculty of Medicine, Bioinformatics Unit, George Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Kobi Rosenblum
- Sagol Department of Neurobiology, Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel. .,Center for Gene Manipulation in the Brain, University of Haifa, Haifa, 3498838, Israel.
| |
Collapse
|
36
|
Rosenberg T, Elkobi A, Dieterich DC, Rosenblum K. NMDAR-dependent proteasome activity in the gustatory cortex is necessary for conditioned taste aversion. Neurobiol Learn Mem 2016; 130:7-16. [PMID: 26785229 DOI: 10.1016/j.nlm.2016.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/06/2016] [Accepted: 01/09/2016] [Indexed: 11/15/2022]
Abstract
Taste information is processed in different brain structures in the mammalian brain, including the gustatory cortex (GC), which resides within the insular cortex. N-methyl-d-aspartate receptor (NMDAR) activity in the GC is necessary for the acquisition of conditioned taste aversion (CTA) but not positive novel taste learning. Previous studies have shown that taste memory consolidation requires intact protein synthesis in the GC. In addition, the direct involvement of translation initiation and elongation factors was documented in the GC during taste learning. However, protein expression is defined by protein synthesis, degradation, and localization. Protein degradation is critical for the consolidation and reconsolidation of other forms of learning, such as fear learning and addiction behavior, but its role in cortical-dependent learning is not clear. Here, we show for the first time that proteasome activity is specifically increased in the GC 4h following experiencing of a novel taste. This increase in proteasome activity was abolished by local administration to the GC of the NMDA antagonist, APV, as well as a CaMKII inhibitor, at the time of acquisition. In addition, local application of lactacystin, a proteasome inhibitor, resulted in impaired CTA, but not novel taste learning. These results suggest that NMDAR-dependent proteasome activity in the GC participates in the association process between novel taste experience and negative visceral sensation.
Collapse
Affiliation(s)
- Tali Rosenberg
- Sagol Dept. of Neurobiology, University of Haifa, Haifa 3498838, Israel
| | - Alina Elkobi
- Sagol Dept. of Neurobiology, University of Haifa, Haifa 3498838, Israel
| | - Daniela C Dieterich
- Institute for Pharmacology and Toxicology, Medical Faculty, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, Magdeburg 39120, Germany
| | - Kobi Rosenblum
- Sagol Dept. of Neurobiology, University of Haifa, Haifa 3498838, Israel; Center for Gene Manipulation in the Brain, University of Haifa, Haifa 3498838, Israel.
| |
Collapse
|
37
|
Kenney JW, Genheden M, Moon KM, Wang X, Foster LJ, Proud CG. Eukaryotic elongation factor 2 kinase regulates the synthesis of microtubule-related proteins in neurons. J Neurochem 2015; 136:276-84. [PMID: 26485687 PMCID: PMC4843953 DOI: 10.1111/jnc.13407] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 09/10/2015] [Accepted: 10/14/2015] [Indexed: 12/11/2022]
Abstract
Modulation of the elongation phase of protein synthesis is important for numerous physiological processes in both neurons and other cell types. Elongation is primarily regulated via eukaryotic elongation factor 2 kinase (eEF2K). However, the consequence of altering eEF2K activity on the synthesis of specific proteins is largely unknown. Using both pharmacological and genetic manipulations of eEF2K combined with two protein‐labeling techniques, stable isotope labeling of amino acids in cell culture and bio‐orthogonal non‐canonical amino acid tagging, we identified a subset of proteins whose synthesis is sensitive to inhibition of eEF2K in murine primary cortical neurons. Gene ontology (GO) analyses indicated that processes related to microtubules are particularly sensitive to eEF2K inhibition. Our findings suggest that eEF2K likely contributes to neuronal function by regulating the synthesis of microtubule‐related proteins.
Modulation of the elongation phase of protein synthesis is important for numerous physiological processes in neurons. Here, using labeling of new proteins coupled with proteomic techniques in primary cortical neurons, we find that the synthesis of microtubule‐related proteins is up‐regulated by inhibition of elongation. This suggests that translation elongation is a key regulator of cytoskeletal dynamics in neurons.
Collapse
Affiliation(s)
- Justin W Kenney
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - Maja Genheden
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - Kyung-Mee Moon
- Centre for High-throughput Biology and Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Xuemin Wang
- Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - Leonard J Foster
- Centre for High-throughput Biology and Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | | |
Collapse
|
38
|
Bidirectional regulation of eEF2 phosphorylation controls synaptic plasticity by decoding neuronal activity patterns. J Neurosci 2015; 35:4403-17. [PMID: 25762683 DOI: 10.1523/jneurosci.2376-14.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
At the sensory-motor neuron synapse of Aplysia, either spaced or continuous (massed) exposure to serotonin (5-HT) induces a form of intermediate-term facilitation (ITF) that requires new protein synthesis but not gene transcription. However, spaced and massed ITF use distinct molecular mechanisms to maintain increased synaptic strength. Synapses activated by spaced applications of 5-HT generate an ITF that depends on persistent protein kinase A (PKA) activity, whereas an ITF produced by massed 5-HT depends on persistent protein kinase C (PKC) activity. In this study, we demonstrate that eukaryotic elongation factor 2 (eEF2), which catalyzes the GTP-dependent translocation of the ribosome during protein synthesis, acts as a biochemical sensor that is tuned to the pattern of neuronal stimulation. Specifically, we find that massed training leads to a PKC-dependent increase in phosphorylation of eEF2, whereas spaced training results in a PKA-dependent decrease in phosphorylation of eEF2. Importantly, by using either pharmacological or dominant-negative strategies to inhibit eEF2 kinase (eEF2K), we were able to block massed 5-HT-dependent increases in eEF2 phosphorylation and subsequent PKC-dependent ITF. In contrast, pharmacological inhibition of eEF2K during the longer period of time required for spaced training was sufficient to reduce eEF2 phosphorylation and induce ITF. Finally, we find that the massed 5-HT-dependent increase in synaptic strength requires translation elongation, but not translation initiation, whereas the spaced 5-HT-dependent increase in synaptic strength is partially dependent on translation initiation. Thus, bidirectional regulation of eEF2 is critical for decoding distinct activity patterns at synapses by activating distinct modes of translation regulation.
Collapse
|
39
|
Dynamics of elongation factor 2 kinase regulation in cortical neurons in response to synaptic activity. J Neurosci 2015; 35:3034-47. [PMID: 25698741 DOI: 10.1523/jneurosci.2866-14.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The rapid regulation of cell signaling in response to calcium in neurons is essential for real-time processing of large amounts of information in the brain. A vital regulatory component, and one of the most energy-intensive biochemical processes in cells, is the elongation phase of mRNA translation, which is controlled by the Ca(2+)/CaM-dependent elongation factor 2 kinase (eEF2K). However, little is known about the dynamics of eEF2K regulation in neurons despite its established role in learning and synaptic plasticity. To explore eEF2K dynamics in depth, we stimulated synaptic activity in mouse primary cortical neurons. We find that synaptic activity results in a rapid, but transient, increase in eEF2K activity that is regulated by a combination of AMPA and NMDA-type glutamate receptors and the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin complex 1 (mTORC1) pathways. We then used computational modeling to test the hypothesis that considering Ca(2+)-coordinated MEK/ERK, mTORC1, and eEF2k activation is sufficient to describe the observed eEF2K dynamics. Although such a model could partially fit the empirical findings, it also suggested that a crucial positive regulator of eEF2K was also necessary. Through additional modeling and empirical evidence, we demonstrate that AMP kinase (AMPK) is also an important regulator of synaptic activity-driven eEF2K dynamics in neurons. Our combined modeling and experimental findings provide the first evidence that it is necessary to consider the combined interactions of Ca(2+) with MEK/ERK, mTORC1, and AMPK to adequately explain eEF2K regulation in neurons.
Collapse
|
40
|
Regulated stability of eukaryotic elongation factor 2 kinase requires intrinsic but not ongoing activity. Biochem J 2015; 467:321-31. [DOI: 10.1042/bj20150089] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) is an atypical protein kinase which negatively regulates protein synthesis, is activated under stress conditions and plays a role in cytoprotection, e.g. in cancer cells. It is regarded as a possible target for therapeutic intervention in solid tumours. Earlier studies showed that eEF2K is degraded by a proteasome-dependent pathway in response to genotoxic stress and that this requires a phosphodegron that includes an autophosphorylation site. Thus, application of eEF2K inhibitors would stabilize eEF2K, partially negating the effects of inhibiting its activity. In the present study, we show that under a range of other stress conditions, including acidosis or treatment of cells with 2-deoxyglucose, eEF2K is also degraded. However, in these settings, the previously identified phosphodegron is not required for its degradation. Nevertheless, kinase-dead and other activity-deficient mutants of eEF2K are stabilized, as is a mutant lacking a critical autophosphorylation site (Thr348 in eEF2K), which is thought to be required for eEF2K and other α-kinases to achieve their active conformations. In contrast, application of small-molecule eEF2K inhibitors does not stabilize the protein. Our data suggest that achieving an active conformation, rather than eEF2K activity per se, is required for its susceptibility to degradation. Additional degrons and E3 ligases beyond those already identified are probably involved in regulating eEF2K levels. Our findings have significant implications for therapeutic targeting of eEF2K, e.g. in oncology.
Collapse
|
41
|
Buffington SA, Huang W, Costa-Mattioli M. Translational control in synaptic plasticity and cognitive dysfunction. Annu Rev Neurosci 2015; 37:17-38. [PMID: 25032491 DOI: 10.1146/annurev-neuro-071013-014100] [Citation(s) in RCA: 243] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Activity-dependent changes in the strength of synaptic connections are fundamental to the formation and maintenance of memory. The mechanisms underlying persistent changes in synaptic strength in the hippocampus, specifically long-term potentiation and depression, depend on new protein synthesis. Such changes are thought to be orchestrated by engaging the signaling pathways that regulate mRNA translation in neurons. In this review, we discuss the key regulatory pathways that govern translational control in response to synaptic activity and the mRNA populations that are specifically targeted by these pathways. The critical contribution of regulatory control over new protein synthesis to proper cognitive function is underscored by human disorders associated with either silencing or mutation of genes encoding proteins that directly regulate translation. In light of these clinical implications, we also consider the therapeutic potential of targeting dysregulated translational control to treat cognitive disorders of synaptic dysfunction.
Collapse
Affiliation(s)
- Shelly A Buffington
- Department of Neuroscience, Memory and Brain Research Center, Baylor College of Medicine, Houston, Texas 77030; , ,
| | | | | |
Collapse
|
42
|
Identifying a kinase network regulating FGF14:Nav1.6 complex assembly using split-luciferase complementation. PLoS One 2015; 10:e0117246. [PMID: 25659151 PMCID: PMC4319734 DOI: 10.1371/journal.pone.0117246] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/22/2014] [Indexed: 12/31/2022] Open
Abstract
Kinases play fundamental roles in the brain. Through complex signaling pathways, kinases regulate the strength of protein:protein interactions (PPI) influencing cell cycle, signal transduction, and electrical activity of neurons. Changes induced by kinases on neuronal excitability, synaptic plasticity and brain connectivity are linked to complex brain disorders, but the molecular mechanisms underlying these cellular events remain for the most part elusive. To further our understanding of brain disease, new methods for rapidly surveying kinase pathways in the cellular context are needed. The bioluminescence-based luciferase complementation assay (LCA) is a powerful, versatile toolkit for the exploration of PPI. LCA relies on the complementation of two firefly luciferase protein fragments that are functionally reconstituted into the full luciferase enzyme by two interacting binding partners. Here, we applied LCA in live cells to assay 12 kinase pathways as regulators of the PPI complex formed by the voltage-gated sodium channel, Nav1.6, a transmembrane ion channel that elicits the action potential in neurons and mediates synaptic transmission, and its multivalent accessory protein, the fibroblast growth factor 14 (FGF14). Through extensive dose-dependent validations of structurally-diverse kinase inhibitors and hierarchical clustering, we identified the PI3K/Akt pathway, the cell-cycle regulator Wee1 kinase, and protein kinase C (PKC) as prospective regulatory nodes of neuronal excitability through modulation of the FGF14:Nav1.6 complex. Ingenuity Pathway Analysis shows convergence of these pathways on glycogen synthase kinase 3 (GSK3) and functional assays demonstrate that inhibition of GSK3 impairs excitability of hippocampal neurons. This combined approach provides a versatile toolkit for rapidly surveying PPI signaling, allowing the discovery of new modular pathways centered on GSK3 that might be the basis for functional alterations between the normal and diseased brain.
Collapse
|
43
|
Abstract
Protein translation initiation is controlled by levels of eIF2α phosphorylation (p-eIF2α) on Ser51. In addition, increased p-eIF2α levels impair long-term synaptic plasticity and memory consolidation, whereas decreased levels enhance them. Levels of p-eIF2α are determined by four kinases, of which protein kinase RNA-activated (PKR), PKR-like endoplastic reticulum kinase (PERK), and general control nonderepressible 2 are extensively expressed in the mammalian mature brain. Following identification of PERK as the major kinase to determine basal levels of p-eIF2α in primary neuronal cultures, we tested its function as a physiological constraint of memory consolidation in the cortex, the brain structure suggested to store, at least in part, long-term memories in the mammalian brain. To that aim, insular cortex (IC)-dependent positive and negative forms of taste learning were used. Genetic reduction of PERK expression was accomplished by local microinfusion of a lentivirus harboring PERK Short hairpin RNA, and pharmacological inhibition was achieved by local microinfusion of a PERK-specific inhibitor (GSK2606414) to the rat IC. Both genetic reduction of PERK expression and pharmacological inhibition of its activity reduced p-eIF2α levels and enhanced novel taste learning and conditioned taste aversion, but not memory retrieval. Moreover, enhanced extinction was observed together with enhanced associative memory, suggesting increased cortical-dependent behavioral plasticity. The results suggest that, by phosphorylating eIF2α, PERK functions in the cortex as a physiological constraint of memory consolidation, and its downregulation serves as cognitive enhancement.
Collapse
|
44
|
Differential contribution of hippocampal subfields to components of associative taste learning. J Neurosci 2014; 34:11007-15. [PMID: 25122900 DOI: 10.1523/jneurosci.0956-14.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The ability to associate the consumption of a taste with its positive or negative consequences is fundamental to survival and influences the behavior of species ranging from invertebrate to human. As a result, for both research and clinical reasons, there has been a great effort to understand the neuronal circuits, as well as the cellular and molecular mechanisms, underlying taste learning. From a neuroanatomical perspective, the contributions of the cortex and amygdala are well documented; however, the literature is riddled with conflicting results regarding the role of the hippocampus in different facets of taste learning. Here, we use conditional genetics in mice to block NMDA receptor-dependent plasticity individually in each of the three major hippocampal subfields, CA1, CA3, and the dentate gyrus, via deletion of the NR1 subunit. Across the CA1, CA3, and dentate gyrus NR1 knock-out lines, we uncover a pattern of differential deficits that establish the dispensability of hippocampal plasticity in incidental taste learning, the requirement of CA1 plasticity for associative taste learning, and a specific requirement for plasticity in the dentate gyrus when there is a long temporal gap between the taste and its outcome. Together, these data establish that the hippocampus is involved in associative taste learning and suggest an episodic component to this type of memory.
Collapse
|
45
|
Rosenberg T, Gal-Ben-Ari S, Dieterich DC, Kreutz MR, Ziv NE, Gundelfinger ED, Rosenblum K. The roles of protein expression in synaptic plasticity and memory consolidation. Front Mol Neurosci 2014; 7:86. [PMID: 25429258 PMCID: PMC4228929 DOI: 10.3389/fnmol.2014.00086] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 10/24/2014] [Indexed: 01/07/2023] Open
Abstract
The amount and availability of proteins are regulated by their synthesis, degradation, and transport. These processes can specifically, locally, and temporally regulate a protein or a population of proteins, thus affecting numerous biological processes in health and disease states. Accordingly, malfunction in the processes of protein turnover and localization underlies different neuronal diseases. However, as early as a century ago, it was recognized that there is a specific need for normal macromolecular synthesis in a specific fragment of the learning process, memory consolidation, which takes place minutes to hours following acquisition. Memory consolidation is the process by which fragile short-term memory is converted into stable long-term memory. It is accepted today that synaptic plasticity is a cellular mechanism of learning and memory processes. Interestingly, similar molecular mechanisms subserve both memory and synaptic plasticity consolidation. In this review, we survey the current view on the connection between memory consolidation processes and proteostasis, i.e., maintaining the protein contents at the neuron and the synapse. In addition, we describe the technical obstacles and possible new methods to determine neuronal proteostasis of synaptic function and better explain the process of memory and synaptic plasticity consolidation.
Collapse
Affiliation(s)
- Tali Rosenberg
- Sagol Department of Neurobiology, University of Haifa Haifa, Israel
| | | | - Daniela C Dieterich
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University Magdeburg, Germany ; Research Group Neuralomics, Leibniz Institute for Neurobiology Magdeburg, Germany ; Center for Behavioral Brain Sciences Magdeburg, Germany
| | - Michael R Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology Magdeburg, Germany
| | - Noam E Ziv
- Network Biology Research Laboratories and Faculty of Medicine, Technion - Israel Institute of Technology Haifa, Israel
| | - Eckart D Gundelfinger
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology Magdeburg, Germany ; Center for Behavioral Brain Sciences Magdeburg, Germany ; Medical School, Otto von Guericke University Magdeburg, Germany
| | - Kobi Rosenblum
- Sagol Department of Neurobiology, University of Haifa Haifa, Israel ; Center for Gene Manipulation in the Brain, University of Haifa Haifa, Israel
| |
Collapse
|
46
|
Zhang P, Riazy M, Gold M, Tsai SH, McNagny K, Proud C, Duronio V. Impairing eukaryotic elongation factor 2 kinase activity decreases atherosclerotic plaque formation. Can J Cardiol 2014; 30:1684-8. [PMID: 25475470 PMCID: PMC4424975 DOI: 10.1016/j.cjca.2014.09.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 09/23/2014] [Accepted: 09/23/2014] [Indexed: 01/16/2023] Open
Abstract
We tested whether loss of eukaryotic elongation factor 2 kinase (eEF2K) activity in macrophages suppresses development of atherosclerosis by transplanting bone marrow from mice with mutant eEF2K into ldlr−/− mice. Sixteen weeks after high-fat diet feeding, mutant eEF2K hematopoietic chimeras had a dramatically reduced level of atherosclerotic plaque formation. M1-skewed macrophages from eEF2K knock-in mice have less tumour necrosis factor-α release and a lesser ability to induce expression of endothelial cell markers, providing a potential explanation for the role of eEF2K. Because eEF2K activity in cells of the hematopoietic compartment contributes to atherosclerosis development, drugs inhibiting eEF2K might have a beneficial effect in treatment of atherosclerosis.
Collapse
Affiliation(s)
- Peng Zhang
- Department of Medicine, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Maziar Riazy
- Department of Medicine, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Matthew Gold
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shu-Huei Tsai
- Department of Medicine, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Kelly McNagny
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Christopher Proud
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Vincent Duronio
- Department of Medicine, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada.
| |
Collapse
|
47
|
Kenney JW, Moore CE, Wang X, Proud CG. Eukaryotic elongation factor 2 kinase, an unusual enzyme with multiple roles. Adv Biol Regul 2014; 55:15-27. [PMID: 24853390 DOI: 10.1016/j.jbior.2014.04.003] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 04/15/2014] [Indexed: 12/27/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) is a member of the small group of atypical 'α-kinases'. It phosphorylates and inhibits eukaryotic elongation factor 2, to slow down the elongation stage of protein synthesis, which normally consumes a great deal of energy and amino acids. The activity of eEF2K is normally dependent on calcium ions and calmodulin. eEF2K is also regulated by a plethora of other inputs, including inhibition by signalling downstream of anabolic signalling pathways such as the mammalian target of rapamycin complex 1. Recent data show that eEF2K helps to protect cancer cells against nutrient starvation and is also cytoprotective in other settings, including hypoxia. Growing evidence points to roles for eEF2K in neurological processes such as learning and memory and perhaps in depression.
Collapse
Affiliation(s)
- Justin W Kenney
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK
| | - Claire E Moore
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK
| | - Xuemin Wang
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK
| | - Christopher G Proud
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK.
| |
Collapse
|
48
|
The role of eEF2 pathway in learning and synaptic plasticity. Neurobiol Learn Mem 2013; 105:100-6. [DOI: 10.1016/j.nlm.2013.04.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/15/2013] [Accepted: 04/17/2013] [Indexed: 11/19/2022]
|
49
|
Graber TE, McCamphill PK, Sossin WS. A recollection of mTOR signaling in learning and memory. Learn Mem 2013; 20:518-30. [PMID: 24042848 DOI: 10.1101/lm.027664.112] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mechanistic target of rapamcyin (mTOR) is a central player in cell growth throughout the organism. However, mTOR takes on an additional, more specialized role in the developed neuron, where it regulates the protein synthesis-dependent, plastic changes underlying learning and memory. mTOR is sequestered in two multiprotein complexes (mTORC1 and mTORC2) that have different substrate specificities, thus allowing for distinct functions at synapses. We will examine how learning activates the mTOR complexes, survey the critical effectors of this pathway in the context of synaptic plasticity, and assess whether mTOR plays an instructive or permissive role in generating molecular memory traces.
Collapse
Affiliation(s)
- Tyson E Graber
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A-2B4, Canada
| | | | | |
Collapse
|
50
|
Blocking the eIF2α kinase (PKR) enhances positive and negative forms of cortex-dependent taste memory. J Neurosci 2013; 33:2517-25. [PMID: 23392680 DOI: 10.1523/jneurosci.2322-12.2013] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Age-associated memory deterioration (and the decline in ability to acquire new information) is one of the major diseases of our era. Cognitive enhancement can be achieved by using psycho-stimulants, such as caffeine or nicotine, but very little is known about drugs that can enhance the consolidation phase of memories in the cortex, the brain structure considered to store, at least partially, long-term memories. We used cortex-dependent taste-learning paradigms to test the hypothesis that pharmacological manipulation of the translation initiation eIF2α, which plays a role in hippocampus-dependent memory, can enhance positive or negative forms of taste memories. We found that dephosphorylation (Ser51) of eIF2α, specifically in the cortex, is both correlated with and necessary for normal memory consolidation. To reduce eIF2α phosphorylation and improve memory consolidation, we pharmacologically inhibited one of the eIF2α kinases, PKR, which is known to be involved in brain aging and Alzheimer's disease. Systemic or local microinjection of PKR inhibitor to the gustatory cortex enhanced both positive and negative forms of taste memory in rats and mice. Our results provide clear evidence that PKR plays a major role in cortex-dependent memory consolidation and, therefore, that pharmacological inhibition of PKR is a potential target for drugs to enhance cognition.
Collapse
|