1
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Zhang L, Zheng J, Liu SY, Hou LL, Zhang B, Tian SW. Acute Administration of Lactate Exerts Antidepressant-like Effect Through cAMP-dependent Protein Synthesis. Neuroscience 2024; 542:11-20. [PMID: 38336096 DOI: 10.1016/j.neuroscience.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 01/16/2024] [Accepted: 02/05/2024] [Indexed: 02/12/2024]
Abstract
Lactate acts as an important metabolic substrate and signalling molecule modulating neural activities in the brain, and recent preclinical and clinical studies have revealed its antidepressant effect after acute or chronic peripheral administration. However, the neural mechanism underlying the antidepressant effect of lactate, in particular when lactate is acutely administered remains largely unknown. In the current study, we focused on forced swimming test (FST) to elucidate the neural mechanisms through which acute intracerebroventricular (ICV) infusion of lactate exerts antidepressant-like effect. A total of 238 male Sprague Dawley rats were used as experimental subjects. Results showed lactate produced antidepressant-like effect, as indicated by reduced immobility, in a dose- and time-dependent manner. Moreover, the antidepressant-like effect of lactate was dependent of new protein synthesis but not new gene expression, lactate's metabolic effect or hydroxy-carboxylic acid receptor 1 (HCAR1) activation. Furthermore, lactate rapidly promoted dephosphorylation of eukaryotic elongation factor 2 (eEF2) and increased brain-derived neurotrophic factor (BDNF) protein synthesis in the hippocampus in a cyclic adenosine monophosphate (cAMP)-dependent manner. Finally, inhibition of cAMP production blocked the antidepressant-like effect of lactate. These findings suggest that acute administration of lactate exerts antidepressant-like effect through cAMP-dependent protein synthesis.
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Affiliation(s)
- Liang Zhang
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Faculty of Basic Medical Sciences, Guilin Medical University, Guilin, Guangxi 541199, China; Department of Anesthesiology, National Clinical Research Center for Infectious Diseases, Shenzhen Third People's Hospital, Shenzhen, Guangdong 518112, China; Department of Anesthesiology, Nanhua Affiliated Hospital, University of South China, Hengyang, Hunan 421001, China
| | - Jing Zheng
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Faculty of Basic Medical Sciences, Guilin Medical University, Guilin, Guangxi 541199, China
| | - Shi-Yan Liu
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Faculty of Basic Medical Sciences, Guilin Medical University, Guilin, Guangxi 541199, China
| | - Li-Li Hou
- Department of Anesthesiology, Nanhua Affiliated Hospital, University of South China, Hengyang, Hunan 421001, China
| | - Bo Zhang
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Faculty of Basic Medical Sciences, Guilin Medical University, Guilin, Guangxi 541199, China
| | - Shao-Wen Tian
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Faculty of Basic Medical Sciences, Guilin Medical University, Guilin, Guangxi 541199, China.
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2
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Zhong C, Zhu R, Jiang T, Tian S, Zhao X, Wan X, Jiang S, Chen Z, Gong R, He L, Yang J, Ye N, Cheng Y. Design and Characterization of a Novel eEF2K Degrader with Potent Therapeutic Efficacy Against Triple-Negative Breast Cancer. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305035. [PMID: 38084501 PMCID: PMC10837347 DOI: 10.1002/advs.202305035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 11/18/2023] [Indexed: 02/04/2024]
Abstract
Dysregulated eEF2K expression is implicated in the pathogenesis of many human cancers, including triple-negative breast cancer (TNBC), making it a plausible therapeutic target. However, specific eEF2K inhibitors with potent anti-cancer activity have not been available so far. Targeted protein degradation has emerged as a new strategy for drug discovery. In this study, a novel small molecule chemical is designed and synthesized, named as compound C1, which shows potent activity in degrading eEF2K. C1 selectively binds to F8, L10, R144, C146, E229, and Y236 of the eEF2K protein and promotes its proteasomal degradation by increasing the interaction between eEF2K and the ubiquitin E3 ligase βTRCP in the form of molecular glue. C1 significantly inhibits the proliferation and metastasis of TNBC cells both in vitro and in vivo and in TNBC patient-derived organoids, and these antitumor effects are attributed to the degradation of eEF2K by C1. Additionally, combination treatment of C1 with paclitaxel, a commonly used chemotherapeutic drug, exhibits synergistic anti-tumor effects against TNBC. This study not only generates a powerful research tool to investigate the therapeutic potential of targeting eEF2K, but also provides a promising lead compound for developing novel drugs for the treatment of TNBC and other cancers.
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Affiliation(s)
- Changxin Zhong
- Department of PharmacyThe Second Xiangya HospitalCentral South UniversityChangsha410011China
- Hunan Provincial Engineering Research Centre of Translational Medicine and Innovative DrugChangsha410011China
| | - Rongfeng Zhu
- Department of Medicinal ChemistryJiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123China
| | - Ting Jiang
- Department of PharmacyThe Second Xiangya HospitalCentral South UniversityChangsha410011China
- Hunan Provincial Engineering Research Centre of Translational Medicine and Innovative DrugChangsha410011China
| | - Sheng Tian
- Department of Medicinal ChemistryJiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123China
| | - Xiaobao Zhao
- Department of Medicinal ChemistryJiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123China
| | - Xiaoya Wan
- Department of PharmacyThe Second Xiangya HospitalCentral South UniversityChangsha410011China
- Hunan Provincial Engineering Research Centre of Translational Medicine and Innovative DrugChangsha410011China
| | - Shilong Jiang
- Department of PharmacyXiangya HospitalCentral South UniversityChangsha410011China
| | - Zonglin Chen
- Department of PharmacyThe Second Xiangya HospitalCentral South UniversityChangsha410011China
- Department of General SurgeryThe Second Xiangya HospitalCentral South UniversityChangshaHunan410011China
| | - Rong Gong
- Department of PharmacyThe Second Xiangya HospitalCentral South UniversityChangsha410011China
- Hunan Provincial Engineering Research Centre of Translational Medicine and Innovative DrugChangsha410011China
| | - Linhao He
- Department of PharmacyThe Second Xiangya HospitalCentral South UniversityChangsha410011China
- Hunan Provincial Engineering Research Centre of Translational Medicine and Innovative DrugChangsha410011China
| | - Jin‐Ming Yang
- Department of Cancer Biology and ToxicologyDepartment of PharmacologyCollege of Medicine and Markey Cancer CenterUniversity of KentuckyLexingtonKY40536USA
| | - Na Ye
- Department of Medicinal ChemistryJiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123China
| | - Yan Cheng
- Department of PharmacyThe Second Xiangya HospitalCentral South UniversityChangsha410011China
- Hunan Provincial Engineering Research Centre of Translational Medicine and Innovative DrugChangsha410011China
- Ministry of EducationKey Laboratory of Diabetes Immunology (Central South University)Changsha410011China
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3
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Lkhagva-Yondon E, Seo MS, Oh Y, Jung J, Jeon E, Na K, Yoo HS, Kim WC, Esser C, Song SU, Jeon MS. The aryl hydrocarbon receptor controls mesenchymal stromal cell-mediated immunomodulation via ubiquitination of eukaryotic elongation factor-2 kinase. Cell Death Dis 2023; 14:812. [PMID: 38071243 PMCID: PMC10710493 DOI: 10.1038/s41419-023-06341-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 11/07/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023]
Abstract
Mesenchymal stem cells (MSCs) have great therapeutic advantages due to their immunosuppressive properties. The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor whose signaling plays an important role in the immune system. AHR may be involved in the regulation of MSC-associated immunomodulatory functions. However, the mechanisms by which AHR controls the immunosuppressive functions of MSCs are not well understood. Here, we report that Ahr-deficient MSCs show decreased therapeutic efficacy against graft-versus-host disease (GVHD) compared to wild-type (WT)-MSCs. This was probably due to decreased iNOS protein expression, which is a key regulatory enzyme in MSC immunomodulation. The expression of eukaryotic elongation factor 2 kinase (eEF2K), which inhibits the elongation stage of protein synthesis, is significantly increased in the Ahr-deficient MSCs. Inhibition of eEF2K restored iNOS protein expression. AHR is known to act as an E3 ligase together with CUL4B. We observed constitutive binding of AHR to eEF2K. Consequently, ubiquitination and degradation of eEF2K were inhibited in Ahr-deficient MSCs and by the AHR antagonist CH223191 in WT-MSCs. In summary, AHR regulates the immunomodulatory functions of MSCs through ubiquitination of eEF2K, thereby controlling iNOS protein synthesis and its product, nitric oxide levels.
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Affiliation(s)
- Enkhmaa Lkhagva-Yondon
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
- Program in Biomedical Science & Engineering Inha University, Incheon, 22212, Republic of Korea
| | - Myeong Seong Seo
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
- Program in Biomedical Science & Engineering Inha University, Incheon, 22212, Republic of Korea
| | - Yena Oh
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
- Department of Molecular Biomedicine, College of Medicine Inha University, Incheon, 22212, Republic of Korea
| | - Jonghun Jung
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
- Program in Biomedical Science & Engineering Inha University, Incheon, 22212, Republic of Korea
| | - Eunhae Jeon
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
- Department of Molecular Biomedicine, College of Medicine Inha University, Incheon, 22212, Republic of Korea
| | - Kwangmin Na
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
| | - Hyun Seung Yoo
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
- Department of Molecular Biomedicine, College of Medicine Inha University, Incheon, 22212, Republic of Korea
| | - Woo Chul Kim
- Department of Radiation Oncology, Inha University Hospital, Incheon, 22332, Republic of Korea
| | - Charlotte Esser
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, 40021, Germany
| | - Sun U Song
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea
- Department of Molecular Biomedicine, College of Medicine Inha University, Incheon, 22212, Republic of Korea
- SCM Lifescience, Incheon, 21999, Republic of Korea
| | - Myung-Shin Jeon
- Translational Research Center, Inha University Hospital, Incheon, 22332, Republic of Korea.
- Program in Biomedical Science & Engineering Inha University, Incheon, 22212, Republic of Korea.
- Department of Molecular Biomedicine, College of Medicine Inha University, Incheon, 22212, Republic of Korea.
- SCM Lifescience, Incheon, 21999, Republic of Korea.
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4
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Bécsi B, Kónya Z, Boratkó A, Kovács K, Erdődi F. Epigallocatechine-3-gallate Inhibits the Adipogenesis of Human Mesenchymal Stem Cells via the Regulation of Protein Phosphatase-2A and Myosin Phosphatase. Cells 2022; 11:cells11101704. [PMID: 35626740 PMCID: PMC9140100 DOI: 10.3390/cells11101704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 02/01/2023] Open
Abstract
Epigallocatechin-3-gallate (EGCG) has widespread effects on adipocyte development. However, the molecular mechanisms of EGCG are not fully understood. We investigate the adipogenic differentiation of human-derived mesenchymal stem cells, including lipid deposition and changes in the expression and phosphorylation of key transcription factors, myosin, protein phosphatase-2A (PP2A), and myosin phosphatase (MP). On day 6 of adipogenic differentiation, EGCG (1–20 µM) suppressed lipid droplet formation, which was counteracted by an EGCG-binding peptide for the 67 kDa laminin receptor (67LR), suggesting that EGCG acts via 67LR. EGCG decreased the phosphorylation of CCAAT-enhancer-binding protein beta via the activation of PP2A in a protein kinase A (PKA)-dependent manner, leading to the partial suppression of peroxisome proliferator-activated receptor gamma (PPARγ) and adiponectin expression. Differentiated cells exhibited a rounded shape, cortical actin filaments, and lipid accumulation. The EGCG treatment induced cell elongation, stress fiber formation, and less lipid accumulation. These effects were accompanied by the degradation of the MP target subunit-1 and increased the phosphorylation of the 20 kDa myosin light chain. Our results suggest that EGCG acts as an agonist of 67LR to inhibit adipogenesis via the activation of PP2A and suppression of MP. These events are coupled with the decreased phosphorylation and expression levels of adipogenic transcription factors and changes in cell shape, culminating in curtailed adipogenesis.
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Affiliation(s)
- Bálint Bécsi
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (Z.K.); (A.B.); (K.K.)
| | - Zoltán Kónya
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (Z.K.); (A.B.); (K.K.)
- MTA-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Anita Boratkó
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (Z.K.); (A.B.); (K.K.)
| | - Katalin Kovács
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (Z.K.); (A.B.); (K.K.)
- MTA-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Ferenc Erdődi
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (Z.K.); (A.B.); (K.K.)
- MTA-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
- Correspondence: ; Tel.: +36-52-412345
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5
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Kliche J, Ivarsson Y. Orchestrating serine/threonine phosphorylation and elucidating downstream effects by short linear motifs. Biochem J 2022; 479:1-22. [PMID: 34989786 PMCID: PMC8786283 DOI: 10.1042/bcj20200714] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022]
Abstract
Cellular function is based on protein-protein interactions. A large proportion of these interactions involves the binding of short linear motifs (SLiMs) by folded globular domains. These interactions are regulated by post-translational modifications, such as phosphorylation, that create and break motif binding sites or tune the affinity of the interactions. In addition, motif-based interactions are involved in targeting serine/threonine kinases and phosphatases to their substrate and contribute to the specificity of the enzymatic actions regulating which sites are phosphorylated. Here, we review how SLiM-based interactions assist in determining the specificity of serine/threonine kinases and phosphatases, and how phosphorylation, in turn, affects motif-based interactions. We provide examples of SLiM-based interactions that are turned on/off, or are tuned by serine/threonine phosphorylation and exemplify how this affects SLiM-based protein complex formation.
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Affiliation(s)
- Johanna Kliche
- Department of Chemistry – BMC, Uppsala University, Husargatan 3, Box 576 751 23 Uppsala, Sweden
| | - Ylva Ivarsson
- Department of Chemistry – BMC, Uppsala University, Husargatan 3, Box 576 751 23 Uppsala, Sweden
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6
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Creus-Muncunill J, Badillos-Rodríguez R, Garcia-Forn M, Masana M, Garcia-Díaz Barriga G, Guisado-Corcoll A, Alberch J, Malagelada C, Delgado-García JM, Gruart A, Pérez-Navarro E. Increased translation as a novel pathogenic mechanism in Huntington's disease. Brain 2020; 142:3158-3175. [PMID: 31365052 DOI: 10.1093/brain/awz230] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 05/29/2019] [Accepted: 06/02/2019] [Indexed: 11/15/2022] Open
Abstract
Huntington's disease is a neurodegenerative disorder caused by a CAG repeat expansion in exon 1 of the huntingtin gene. Striatal projection neurons are mainly affected, leading to motor symptoms, but molecular mechanisms involved in their vulnerability are not fully characterized. Here, we show that eIF4E binding protein (4E-BP), a protein that inhibits translation, is inactivated in Huntington's disease striatum by increased phosphorylation. Accordingly, we detected aberrant de novo protein synthesis. Proteomic characterization indicates that translation specifically affects sets of proteins as we observed upregulation of ribosomal and oxidative phosphorylation proteins and downregulation of proteins related to neuronal structure and function. Interestingly, treatment with the translation inhibitor 4EGI-1 prevented R6/1 mice motor deficits, although corticostriatal long-term depression was not markedly changed in behaving animals. At the molecular level, injection of 4EGI-1 normalized protein synthesis and ribosomal content in R6/1 mouse striatum. In conclusion, our results indicate that dysregulation of protein synthesis is involved in mutant huntingtin-induced striatal neuron dysfunction.
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Affiliation(s)
- Jordi Creus-Muncunill
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Raquel Badillos-Rodríguez
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Marta Garcia-Forn
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Mercè Masana
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Gerardo Garcia-Díaz Barriga
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Anna Guisado-Corcoll
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Jordi Alberch
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Cristina Malagelada
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia
| | | | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, Seville, Spain
| | - Esther Pérez-Navarro
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, Barcelona, Catalonia.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
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7
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Im YN, Lee YD, Park JS, Kim HK, Im SY, Song HR, Lee HK, Han MK. GPCR Kinase (GRK)-2 Is a Key Negative Regulator of Itch: l-Glutamine Attenuates Itch via a Rapid Induction of GRK2 in an ERK-Dependent Way. J Invest Dermatol 2018. [PMID: 29530536 DOI: 10.1016/j.jid.2018.02.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many itch mediators activate GPCR and trigger itch via activation of GPCR-mediated signaling pathways. GPCRs are desensitized by GPCR kinases (GRKs). The aim of this study is to explore the role of GRKs in itch response and the link between GRKs and glutamine, an amino acid previously shown to be an itch reliever. Itch responses were evoked by histamine, chloroquine, and dinitrochlorobenzene-induced contact dermatitis (CD). Phosphorylation and protein expression were detected by immunofluorescent staining and Western blotting. GRK2 knockdown using small interfering RNA enhanced itch responses evoked by histamine, chloroquine, and dinitrochlorobenzene-induced CD, whereas GRK2 overexpression using GRK2-expressing adenovirus reduced the itch responses. Glutamine reduced all itch evoked by histamine, chloroquine, and dinitrochlorobenzene-induced CD. Glutamine-mediated inhibition of itch was abolished by GRK2 knockdown. Glutamine application resulted in a rapid and strong expression of GRK2 in not only dinitrochlorobenzene-induced CD (within 10 minutes) but also cultured rat dorsal root ganglion cells, F11 (within 1 minute). ERK inhibitor abrogates glutamine-mediated GRK2 expression and inhibition of itch in dinitrochlorobenzene-induced CD. Our data indicate that GRK2 is a key negative regulator of itch and that glutamine attenuates itch via a rapid induction of GRK2 in an ERK-dependent way.
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Affiliation(s)
- Yu-Na Im
- Department of Immunology and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - Yu-Dong Lee
- Department of Immunology and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - Jeong-Soo Park
- Department of Immunology and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - Hae-Kyoung Kim
- Department of Immunology and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - Suhn-Young Im
- Department of Biological Sciences, College of Natural Sciences, Chonnam National University, Gwangju, Republic of Korea
| | - Hwa-Ryung Song
- Department of Microbiology and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - Hern-Ku Lee
- Department of Microbiology and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Republic of Korea.
| | - Myung-Kwan Han
- Department of Microbiology and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Republic of Korea.
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8
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Pan Z, Chen Y, Liu J, Jiang Q, Yang S, Guo L, He G. Design, synthesis, and biological evaluation of polo-like kinase 1/eukaryotic elongation factor 2 kinase (PLK1/EEF2K) dual inhibitors for regulating breast cancer cells apoptosis and autophagy. Eur J Med Chem 2018; 144:517-528. [PMID: 29288948 DOI: 10.1016/j.ejmech.2017.12.046] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/06/2017] [Accepted: 12/13/2017] [Indexed: 01/09/2023]
Abstract
Both PLK1 and EEF2K are serine⁄threonine kinases that play important roles in the proliferation and programmed cell death of various types of cancer. They are highly expressed in breast cancer tissues. Based on the multiple-complexes generated pharmacophore models of PLK1 and homology models of EEF2K, the integrated virtual screening is performed to discover novel PLK1/EEF2K dual inhibitors. The top ten hit compounds are selected and tested in vitro, and five of them display PLK1 and EEF2K inhibition in vitro. Based on the docking modes of the most potent hit compound, a series of derivatives are synthesized, characterized and biological assayed on the PLK1, EEF2K as well as breast cancer cell proliferation models. Compound 18i with satisfied inhibitory potency are shifted to molecular mechanism studies contained molecular dynamics simulations, cell cycles, apoptosis and autophagy assays. Our results suggested that these novel PLK1/EEF2K dual inhibitors can be used as lead compounds for further development breast cancer chemotherapy.
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Affiliation(s)
- Zhaoping Pan
- Key Laboratory of Drug-Targeting of Education Ministry and Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China; State Key Laboratory of Biotherapy and Department of Breast Surgery, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Yujuan Chen
- State Key Laboratory of Biotherapy and Department of Breast Surgery, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Jingyan Liu
- State Key Laboratory of Biotherapy and Department of Breast Surgery, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Qinglin Jiang
- State Key Laboratory of Biotherapy and Department of Breast Surgery, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China; School of Pharmacy and Sichuan Province College Key Laboratory of Structure-Specific Small Molecule Drugs, Chengdu Medical College, Chengdu 610500, China.
| | - Shengyong Yang
- State Key Laboratory of Biotherapy and Department of Breast Surgery, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China
| | - Li Guo
- Key Laboratory of Drug-Targeting of Education Ministry and Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
| | - Gu He
- Key Laboratory of Drug-Targeting of Education Ministry and Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China; State Key Laboratory of Biotherapy and Department of Breast Surgery, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China.
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9
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Tavares CDJ, Giles DH, Stancu G, Chitjian CA, Ferguson SB, Wellmann RM, Kaoud TS, Ghose R, Dalby KN. Signal Integration at Elongation Factor 2 Kinase: THE ROLES OF CALCIUM, CALMODULIN, AND SER-500 PHOSPHORYLATION. J Biol Chem 2016; 292:2032-2045. [PMID: 27956550 DOI: 10.1074/jbc.m116.753277] [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: 08/11/2016] [Revised: 11/28/2016] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic elongation factor 2 kinase (eEF-2K), the only calmodulin (CaM)-dependent member of the unique α-kinase family, impedes protein synthesis by phosphorylating eEF-2. We recently identified Thr-348 and Ser-500 as two key autophosphorylation sites within eEF-2K that regulate its activity. eEF-2K is regulated by Ca2+ ions and multiple upstream signaling pathways, but how it integrates these signals into a coherent output, i.e. phosphorylation of eEF-2, is unclear. This study focuses on understanding how the post-translational phosphorylation of Ser-500 integrates with Ca2+ and CaM to regulate eEF-2K. CaM is shown to be absolutely necessary for efficient activity of eEF-2K, and Ca2+ is shown to enhance the affinity of CaM toward eEF-2K. Ser-500 is found to undergo autophosphorylation in cells treated with ionomycin and is likely also targeted by PKA. In vitro, autophosphorylation of Ser-500 is found to require Ca2+ and CaM and is inhibited by mutations that compromise binding of phosphorylated Thr-348 to an allosteric binding pocket on the kinase domain. A phosphomimetic Ser-500 to aspartic acid mutation (eEF-2K S500D) enhances the rate of activation (Thr-348 autophosphorylation) by 6-fold and lowers the EC50 for Ca2+/CaM binding to activated eEF-2K (Thr-348 phosphorylated) by 20-fold. This is predicted to result in an elevation of the cellular fraction of active eEF-2K. In support of this mechanism, eEF-2K knock-out MCF10A cells reconstituted with eEF-2K S500D display relatively high levels of phospho-eEF-2 under basal conditions. This study reports how phosphorylation of a regulatory site (Ser-500) integrates with Ca2+ and CaM to influence eEF-2K activity.
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Affiliation(s)
- Clint D J Tavares
- From the Graduate Program in Cell and Molecular Biology, University of Texas, Austin, Texas 78712; Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712.
| | - David H Giles
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712
| | - Gabriel Stancu
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712
| | - Catrina A Chitjian
- From the Graduate Program in Cell and Molecular Biology, University of Texas, Austin, Texas 78712; Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712
| | - Scarlett B Ferguson
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712
| | - Rebecca M Wellmann
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712
| | - Tamer S Kaoud
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712
| | - Ranajeet Ghose
- the Department of Chemistry, City College of New York, New York, New York 10031; the Graduate Center, City University of New York, New York, New York 10016
| | - Kevin N Dalby
- From the Graduate Program in Cell and Molecular Biology, University of Texas, Austin, Texas 78712; Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas 78712.
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10
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Bal’ NV, Balaban PM. Ubiquitin-dependent protein degradation is necessary for long-term plasticity and memory. NEUROCHEM J+ 2015. [DOI: 10.1134/s1819712415040042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Rinaldi L, Sepe M, Donne RD, Feliciello A. A dynamic interface between ubiquitylation and cAMP signaling. Front Pharmacol 2015; 6:177. [PMID: 26388770 PMCID: PMC4559665 DOI: 10.3389/fphar.2015.00177] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/06/2015] [Indexed: 01/01/2023] Open
Abstract
Phosphorylation waves drive the propagation of signals generated in response to hormones and growth factors in target cells. cAMP is an ancient second messenger implicated in key biological functions. In mammals, most of the effects elicited by cAMP are mediated by protein kinase A (PKA). Activation of the kinase by cAMP results in the phosphorylation of a variety of cellular substrates, leading to differentiation, proliferation, survival, metabolism. The identification of scaffold proteins, namely A-Kinase Anchor proteins (AKAPs), that localize PKA in specific cellular districts, provided critical cues for our understanding of the role played by cAMP in cell biology. Multivalent complexes are assembled by AKAPs and include signaling enzymes, mRNAs, adapter molecules, receptors and ion channels. A novel development derived from the molecular analysis of these complexes nucleated by AKAPs is represented by the presence of components of the ubiquitin-proteasome system (UPS). More to it, the AKAP complex can be regulated by the UPS, eliciting relevant effects on downstream cAMP signals. This represents a novel, yet previously unpredicted interface between compartmentalized signaling and the UPS. We anticipate that impairment of these regulatory mechanisms could promote cell dysfunction and disease. Here, we will focus on the reciprocal regulation between cAMP signaling and UPS, and its relevance to human degenerative and proliferative disorders.
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Affiliation(s)
- Laura Rinaldi
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Maria Sepe
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Rossella Delle Donne
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
| | - Antonio Feliciello
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II , Naples, Italy
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12
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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.
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13
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Elongation Factor 2 Kinase Is Regulated by Proline Hydroxylation and Protects Cells during Hypoxia. Mol Cell Biol 2015; 35:1788-804. [PMID: 25755286 DOI: 10.1128/mcb.01457-14] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/01/2015] [Indexed: 12/19/2022] Open
Abstract
Protein synthesis, especially translation elongation, requires large amounts of energy, which is often generated by oxidative metabolism. Elongation is controlled by phosphorylation of eukaryotic elongation factor 2 (eEF2), which inhibits its activity and is catalyzed by eEF2 kinase (eEF2K), a calcium/calmodulin-dependent α-kinase. Hypoxia causes the activation of eEF2K and induces eEF2 phosphorylation independently of previously known inputs into eEF2K. Here, we show that eEF2K is subject to hydroxylation on proline-98. Proline hydroxylation is catalyzed by proline hydroxylases, oxygen-dependent enzymes which are inactivated during hypoxia. Pharmacological inhibition of proline hydroxylases also stimulates eEF2 phosphorylation. Pro98 lies in a universally conserved linker between the calmodulin-binding and catalytic domains of eEF2K. Its hydroxylation partially impairs the binding of calmodulin to eEF2K and markedly limits the calmodulin-stimulated activity of eEF2K. Neuronal cells depend on oxygen, and eEF2K helps to protect them from hypoxia. eEF2K is the first example of a protein directly involved in a major energy-consuming process to be regulated by proline hydroxylation. Since eEF2K is cytoprotective during hypoxia and other conditions of nutrient insufficiency, it may be a valuable target for therapy of poorly vascularized solid tumors.
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14
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Kim EJ, Juhnn YS. Cyclic AMP signaling reduces sirtuin 6 expression in non-small cell lung cancer cells by promoting ubiquitin-proteasomal degradation via inhibition of the Raf-MEK-ERK (Raf/mitogen-activated extracellular signal-regulated kinase/extracellular signal-regulated kinase) pathway. J Biol Chem 2015; 290:9604-13. [PMID: 25713071 DOI: 10.1074/jbc.m114.633198] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Indexed: 12/18/2022] Open
Abstract
The cAMP signaling system regulates various cellular functions, including metabolism, gene expression, and death. Sirtuin 6 (SIRT6) removes acetyl groups from histones and regulates genomic stability and cell viability. We hypothesized that cAMP modulates SIRT6 activity to regulate apoptosis. Therefore, we examined the effects of cAMP signaling on SIRT6 expression and radiation-induced apoptosis in lung cancer cells. cAMP signaling in H1299 and A549 human non-small cell lung cancer cells was activated via the expression of constitutively active Gαs plus treatment with prostaglandin E2 (PGE2), isoproterenol, or forskolin. The expression of sirtuins and signaling molecules were analyzed by Western blotting. Activation of cAMP signaling reduced SIRT6 protein expression in lung cancer cells. cAMP signaling increased the ubiquitination of SIRT6 protein and promoted its degradation. Treatment with MG132 and inhibiting PKA with H89 or with a dominant-negative PKA abolished the cAMP-mediated reduction in SIRT6 levels. Treatment with PGE2 inhibited c-Raf activation by increasing inhibitory phosphorylation at Ser-259 in a PKA-dependent manner, thereby inhibiting downstream MEK-ERK signaling. Inhibiting ERK with inhibitors or with dominant-negative ERKs reduced SIRT6 expression, whereas activation of ERK by constitutively active MEK abolished the SIRT6-depleting effects of PGE2. cAMP signaling also augmented radiation-induced apoptosis in lung cancer cells. This effect was abolished by exogenous expression of SIRT6. It is concluded that cAMP signaling reduces SIRT6 expression by promoting its ubiquitin-proteasome-dependent degradation, a process mediated by the PKA-dependent inhibition of the Raf-MEK-ERK pathway. Reduced SIRT6 expression mediates the augmentation of radiation-induced apoptosis by cAMP signaling in lung cancer cells.
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Affiliation(s)
- Eui-Jun Kim
- From the Department of Biochemistry and Molecular Biology and Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799, Korea
| | - Yong-Sung Juhnn
- From the Department of Biochemistry and Molecular Biology and Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799, Korea
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15
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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.
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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
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16
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Tavares CDJ, Ferguson SB, Giles DH, Wang Q, Wellmann RM, O'Brien JP, Warthaka M, Brodbelt JS, Ren P, Dalby KN. The molecular mechanism of eukaryotic elongation factor 2 kinase activation. J Biol Chem 2014; 289:23901-16. [PMID: 25012662 DOI: 10.1074/jbc.m114.577148] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Calmodulin (CaM)-dependent eukaryotic elongation factor 2 kinase (eEF-2K) impedes protein synthesis through phosphorylation of eukaryotic elongation factor 2 (eEF-2). It is subject to complex regulation by multiple upstream signaling pathways, through poorly described mechanisms. Precise integration of these signals is critical for eEF-2K to appropriately regulate protein translation rates. Here, an allosteric mechanism comprising two sequential conformations is described for eEF-2K activation. First, Ca(2+)/CaM binds eEF-2K with high affinity (Kd(CaM)(app) = 24 ± 5 nm) to enhance its ability to autophosphorylate Thr-348 in the regulatory loop (R-loop) by > 10(4)-fold (k(auto) = 2.6 ± 0.3 s(-1)). Subsequent binding of phospho-Thr-348 to a conserved basic pocket in the kinase domain potentially drives a conformational transition of the R-loop, which is essential for efficient substrate phosphorylation. Ca(2+)/CaM binding activates autophosphorylated eEF-2K by allosterically enhancing k(cat)(app) for peptide substrate phosphorylation by 10(3)-fold. Thr-348 autophosphorylation results in a 25-fold increase in the specificity constant (k(cat)(app)/K(m)(Pep-S) (app)), with equal contributions from k(cat)(app) and K(m)(Pep-S)(app), suggesting that peptide substrate binding is partly impeded in the unphosphorylated enzyme. In cells, Thr-348 autophosphorylation appears to control the catalytic output of active eEF-2K, contributing more than 5-fold to its ability to promote eEF-2 phosphorylation. Fundamentally, eEF-2K activation appears to be analogous to an amplifier, where output volume may be controlled by either toggling the power switch (switching on the kinase) or altering the volume control (modulating stability of the active R-loop conformation). Because upstream signaling events have the potential to modulate either allosteric step, this mechanism allows for exquisite control of eEF-2K output.
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Affiliation(s)
- Clint D J Tavares
- From the Graduate Program in Cell and Molecular Biology, the Division of Medicinal Chemistry, College of Pharmacy,
| | | | - David H Giles
- the Division of Medicinal Chemistry, College of Pharmacy
| | - Qiantao Wang
- the Division of Medicinal Chemistry, College of Pharmacy, the Department of Biomedical Engineering, Cockrell School of Engineering, and
| | | | - John P O'Brien
- the Department of Chemistry and Biochemistry, College of Natural Sciences, University of Texas, Austin, Texas 78712
| | | | - Jennifer S Brodbelt
- the Department of Chemistry and Biochemistry, College of Natural Sciences, University of Texas, Austin, Texas 78712
| | - Pengyu Ren
- the Department of Biomedical Engineering, Cockrell School of Engineering, and
| | - Kevin N Dalby
- From the Graduate Program in Cell and Molecular Biology, the Division of Medicinal Chemistry, College of Pharmacy,
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17
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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.
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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.
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