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Salimi K, Alvandi M, Saberi Pirouz M, Rakhshan K, Howatson G. Regulating eEF2 and eEF2K in skeletal muscle by exercise. Arch Physiol Biochem 2024; 130:503-514. [PMID: 36633938 DOI: 10.1080/13813455.2023.2164898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 12/15/2022] [Accepted: 12/29/2022] [Indexed: 01/13/2023]
Abstract
Skeletal muscle is a flexible and adaptable tissue that strongly responds to exercise training. The skeletal muscle responds to exercise by increasing muscle protein synthesis (MPS) when energy is available. One of protein synthesis's major rate-limiting and critical regulatory steps is the translation elongation pathway. The process of translation elongation in skeletal muscle is highly regulated. It requires elongation factors that are intensely affected by various physiological stimuli such as exercise and the total available energy of cells. Studies have shown that exercise involves the elongation pathway by numerous signalling pathways. Since the elongation pathway, has been far less studied than the other translation steps, its comprehensive prospect and quantitative understanding remain in the dark. This study highlights the current understanding of the effect of exercise training on the translation elongation pathway focussing on the molecular factors affecting the pathway, including Ca2+, AMPK, PKA, mTORC1/P70S6K, MAPKs, and myostatin. We further discussed the mode and volume of exercise training intervention on the translation elongation pathway.What is the topic of this review? This review summarises the impacts of exercise training on the translation elongation pathway in skeletal muscle focussing on eEF2 and eEF2K.What advances does it highlight? This review highlights mechanisms and factors that profoundly influence the translation elongation pathway and argues that exercise might modulate the response. This review also combines the experimental observations focussing on the regulation of translation elongation during and after exercise. The findings widen our horizon to the notion of mechanisms involved in muscle protein synthesis (MPS) through translation elongation response to exercise training.
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Affiliation(s)
- Kia Salimi
- Department of Exercise Physiology, Faculty of Sport and Exercise Sciences, University of Tehran, Tehran, Iran
| | - Masoomeh Alvandi
- Department of Biological Science in Sport and Health, University of Shahid Beheshti, Tehran, Iran
| | - Mahdi Saberi Pirouz
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran
| | - Kamran Rakhshan
- Department of Medical Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Electrophysiology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Glyn Howatson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
- Water Research Group, North West University, Potchefstroom, South Africa
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2
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Acharya M, Singh N, Gupta G, Tambuwala MM, Aljabali AAA, Chellappan DK, Dua K, Goyal R. Vitamin D, Calbindin, and calcium signaling: Unraveling the Alzheimer's connection. Cell Signal 2024; 116:111043. [PMID: 38211841 DOI: 10.1016/j.cellsig.2024.111043] [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: 06/23/2023] [Revised: 12/21/2023] [Accepted: 01/08/2024] [Indexed: 01/13/2024]
Abstract
Calcium is a ubiquitous second messenger that is indispensable in regulating neurotransmission and memory formation. A precise intracellular calcium level is achieved through the concerted action of calcium channels, and calcium exerts its effect by binding to an array of calcium-binding proteins, including calmodulin (CAM), calcium-calmodulin complex-dependent protein kinase-II (CAMK-II), calbindin (CAL), and calcineurin (CAN). Calbindin orchestrates a plethora of signaling events that regulate synaptic transmission and depolarizing signals. Vitamin D, an endogenous fat-soluble metabolite, is synthesized in the skin upon exposure to ultraviolet B radiation. It modulates calcium signaling by increasing the expression of the calcium-sensing receptor (CaSR), stimulating phospholipase C activity, and regulating the expression of calcium channels such as TRPV6. Vitamin D also modulates the activity of calcium-binding proteins, including CAM and calbindin, and increases their expression. Calbindin, a high-affinity calcium-binding protein, is involved in calcium buffering and transport in neurons. It has been shown to inhibit apoptosis and caspase-3 activity stimulated by presenilin 1 and 2 in AD. Whereas CAM, another calcium-binding protein, is implicated in regulating neurotransmitter release and memory formation by phosphorylating CAN, CAMK-II, and other calcium-regulated proteins. CAMK-II and CAN regulate actin-induced spine shape changes, which are further modulated by CAM. Low levels of both calbindin and vitamin D are attributed to the pathology of Alzheimer's disease. Further research on vitamin D via calbindin-CAMK-II signaling may provide newer insights, revealing novel therapeutic targets and strategies for treatment.
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Affiliation(s)
- Manish Acharya
- Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University, Himachal Pradesh, India
| | - Nicky Singh
- Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University, Himachal Pradesh, India
| | - Gaurav Gupta
- School of Pharmacy, Suresh Gyan Vihar University, Jagatpura, Jaipur 302017, India
| | - Murtaza M Tambuwala
- Lincoln Medical School, Universities of Nottingham and Lincoln College of Science, Brayford Pool Campus, Lincoln LN6 7TS, UK.
| | - Alaa A A Aljabali
- Faculty of Pharmacy, Department of Pharmaceutical Sciences, Yarmouk University, Irbid 21163, Jordan.
| | - Dinesh Kumar Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur 57000, Malaysia.
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW 2007, Australia; Faculty of Health, Australian Research Centre in Complementary and Integrative Medicine, University of Technology Sydney, Ultimo, NSW 2007, Australia.
| | - Rohit Goyal
- Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University, Himachal Pradesh, India.
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3
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Piserchio A, Dalby KN, Ghose R. Revealing eEF-2 kinase: recent structural insights into function. Trends Biochem Sci 2024; 49:169-182. [PMID: 38103971 PMCID: PMC10950556 DOI: 10.1016/j.tibs.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023]
Abstract
The α-kinase eukaryotic elongation factor 2 kinase (eEF-2K) regulates translational elongation by phosphorylating its ribosome-associated substrate, the GTPase eEF-2. eEF-2K is activated by calmodulin (CaM) through a distinctive mechanism unlike that in other CaM-dependent kinases (CAMK). We describe recent structural insights into this unique activation process and examine the effects of specific regulatory signals on this mechanism. We also highlight key unanswered questions to guide future structure-function studies. These include structural mechanisms which enable eEF-2K to interact with upstream/downstream partners and facilitate its integration of diverse inputs, including Ca2+ transients, phosphorylation mediated by energy/nutrient-sensing pathways, pH changes, and metabolites. Answering these questions is key to establishing how eEF-2K harmonizes translation with cellular requirements within the boundaries of its molecular landscape.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, The 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; The Graduate Center of The City University of New York (CUNY), New York, NY 10016, USA.
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4
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Piserchio A, Long K, Browning L, Bohanon A, Isiorho E, Dalby K, Ghose R. ADP enhances the allosteric activation of eukaryotic elongation factor 2 kinase by calmodulin. Proc Natl Acad Sci U S A 2023; 120:e2300902120. [PMID: 37068230 PMCID: PMC10151598 DOI: 10.1073/pnas.2300902120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/06/2023] [Indexed: 04/19/2023] Open
Abstract
Protein translation, one of the most energy-consumptive processes in a eukaryotic cell, requires robust regulation, especially under energy-deprived conditions. A critical component of this regulation is the suppression of translational elongation through reduced ribosome association of the GTPase eukaryotic elongation factor 2 (eEF-2) resulting from its specific phosphorylation by the calmodulin (CaM)-activated α-kinase eEF-2 kinase (eEF-2K). It has been suggested that the eEF-2K response to reduced cellular energy levels is indirect and mediated by the universal energy sensor AMP-activated protein kinase (AMPK) through direct stimulatory phosphorylation and/or downregulation of the eEF-2K-inhibitory nutrient-sensing mTOR pathway. Here, we provide structural, biochemical, and cell-biological evidence of a direct energy-sensing role of eEF-2K through its stimulation by ADP. A crystal structure of the nucleotide-bound complex between CaM and the functional core of eEF-2K phosphorylated at its primary stimulatory site (T348) reveals ADP bound at a unique pocket located on the face opposite that housing the kinase active site. Within this basic pocket (BP), created at the CaM/eEF-2K interface upon complex formation, ADP is stabilized through numerous interactions with both interacting partners. Biochemical analyses using wild-type eEF-2K and specific BP mutants indicate that ADP stabilizes CaM within the active complex, increasing the sensitivity of the kinase to CaM. Induction of energy stress through glycolysis inhibition results in significantly reduced enhancement of phosphorylated eEF-2 levels in cells expressing ADP-binding compromised BP mutants compared to cells expressing wild-type eEF-2K. These results suggest a direct energy-sensing role for eEF-2K through its cooperative interaction with CaM and ADP.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY10031
| | - Kimberly J. Long
- Division of Chemical Biology and Medicinal Chemistry, the University of Texas, Austin, TX78712
| | - Luke S. Browning
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Amanda L. Bohanon
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Eta A. Isiorho
- Macromolecular Crystallization Facility CUNY Advanced Science Research Center, New York, NY10031
| | - Kevin N. Dalby
- Division of Chemical Biology and Medicinal Chemistry, the University of Texas, Austin, TX78712
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY10031
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY10016
- PhD Program in Chemistry, The Graduate Center of CUNY, New York, NY10016
- PhD Program in Physics, The Graduate Center of CUNY, New York, NY10016
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5
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Zheng Y, Li X, Kuang L, Wang Y. New insights into the characteristics of DRAK2 and its role in apoptosis: From molecular mechanisms to clinically applied potential. Front Pharmacol 2022; 13:1014508. [PMID: 36386181 PMCID: PMC9649744 DOI: 10.3389/fphar.2022.1014508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/12/2022] [Indexed: 11/27/2022] Open
Abstract
As a member of the death-associated protein kinase (DAPK) family, DAP kinase-associated apoptosis-inducing kinase 2 (DRAK2) performs apoptosis-related functions. Compelling evidence suggests that DRAK2 is involved in regulating the activation of T lymphocytes as well as pancreatic β-cell apoptosis in type I diabetes. In addition, DRAK2 has been shown to be involved in the development of related tumor and non-tumor diseases through a variety of mechanisms, including exacerbation of alcoholic fatty liver disease (NAFLD) through SRSF6-associated RNA selective splicing mechanism, regulation of chronic lymphocytic leukemia and acute myeloid leukemia, and progression of colorectal cancer. This review focuses on the structure, function, and upstream pathways of DRAK2 and discusses the potential and challenges associated with the clinical application of DRAK2-based small-molecule inhibitors, with the aim of advancing DRAK2 research.
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Affiliation(s)
| | | | | | - Yong Wang
- Department of General Surgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
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6
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Zhdanov AV, Golubeva AV, Yordanova MM, Andreev DE, Ventura-Silva AP, Schellekens H, Baranov PV, Cryan JF, Papkovsky DB. Ghrelin rapidly elevates protein synthesis in vitro by employing the rpS6K-eEF2K-eEF2 signalling axis. Cell Mol Life Sci 2022; 79:426. [PMID: 35841486 PMCID: PMC9288388 DOI: 10.1007/s00018-022-04446-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 06/16/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022]
Abstract
Activated ghrelin receptor GHS-R1α triggers cell signalling pathways that modulate energy homeostasis and biosynthetic processes. However, the effects of ghrelin on mRNA translation are unknown. Using various reporter assays, here we demonstrate a rapid elevation of protein synthesis in cells within 15–30 min upon stimulation of GHS-R1α by ghrelin. We further show that ghrelin-induced activation of translation is mediated, at least in part, through the de-phosphorylation (de-suppression) of elongation factor 2 (eEF2). The levels of eEF2 phosphorylation at Thr56 decrease due to the reduced activity of eEF2 kinase, which is inhibited via Ser366 phosphorylation by rpS6 kinases. Being stress-susceptible, the ghrelin-mediated decrease in eEF2 phosphorylation can be abolished by glucose deprivation and mitochondrial uncoupling. We believe that the observed burst of translation benefits rapid restocking of neuropeptides, which are released upon GHS-R1α activation, and represents the most time- and energy-efficient way of prompt recharging the orexigenic neuronal circuitry.
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Affiliation(s)
- Alexander V Zhdanov
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Anna V Golubeva
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
| | - Martina M Yordanova
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - Dmitry E Andreev
- Belozersky Research Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Ana Paula Ventura-Silva
- APC Microbiome Institute, University College Cork, Cork, Ireland.,School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Harriet Schellekens
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Pavel V Baranov
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - John F Cryan
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Dmitri B Papkovsky
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
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7
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Piserchio A, Isiorho EA, Long K, Bohanon AL, Kumar EA, Will N, Jeruzalmi D, Dalby KN, Ghose R. Structural basis for the calmodulin-mediated activation of eukaryotic elongation factor 2 kinase. SCIENCE ADVANCES 2022; 8:eabo2039. [PMID: 35857468 PMCID: PMC9258954 DOI: 10.1126/sciadv.abo2039] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/20/2022] [Indexed: 05/27/2023]
Abstract
Translation is a tightly regulated process that ensures optimal protein quality and enables adaptation to energy/nutrient availability. The α-kinase eukaryotic elongation factor 2 kinase (eEF-2K), a key regulator of translation, specifically phosphorylates the guanosine triphosphatase eEF-2, thereby reducing its affinity for the ribosome and suppressing the elongation phase of protein synthesis. eEF-2K activation requires calmodulin binding and autophosphorylation at the primary stimulatory site, T348. Biochemical studies predict a calmodulin-mediated activation mechanism for eEF-2K distinct from other calmodulin-dependent kinases. Here, we resolve the atomic details of this mechanism through a 2.3-Å crystal structure of the heterodimeric complex of calmodulin and the functional core of eEF-2K (eEF-2KTR). This structure, which represents the activated T348-phosphorylated state of eEF-2KTR, highlights an intimate association of the kinase with the calmodulin C-lobe, creating an "activation spine" that connects its amino-terminal calmodulin-targeting motif to its active site through a conserved regulatory element.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
| | - Eta A. Isiorho
- Macromolecular Crystallization Facility, CUNY ASRC, New York, NY 10031, USA
| | - Kimberly Long
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Amanda L. Bohanon
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Eric A. Kumar
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Nathan Will
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - David Jeruzalmi
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - Kevin N. Dalby
- 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
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
- PhD Program in Chemistry, The Graduate Center of CUNY, New York, NY 10016, USA
- PhD Program in Physics, The Graduate Center of CUNY, New York, NY 10016, USA
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8
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Piserchio A, Long K, Lee K, Kumar EA, Abzalimov R, Dalby KN, Ghose R. Structural dynamics of the complex of calmodulin with a minimal functional construct of eukaryotic elongation factor 2 kinase and the role of Thr348 autophosphorylation. Protein Sci 2021; 30:1221-1234. [PMID: 33890716 DOI: 10.1002/pro.4087] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 04/15/2021] [Indexed: 12/31/2022]
Abstract
The calmodulin (CaM) activated α-kinase, eukaryotic elongation factor 2 kinase (eEF-2K), plays a central role in regulating translational elongation by phosphorylating eukaryotic elongation factor 2 (eEF-2), thereby reducing its ability to associate with the ribosome and suppressing global protein synthesis. Using TR (for truncated), a minimal functional construct of eEF-2K, and utilizing hydrogen/deuterium exchange mass spectrometry (HXMS), solution-state nuclear magnetic resonance (NMR) and biochemical approaches, we investigate the conformational changes accompanying complex formation between Ca2+ -CaM and TR and the effects of autophosphorylation of the latter at Thr348, its primary regulatory site. Our results suggest that a CaM C-lobe surface, complementary to the one involved in recognizing the calmodulin-binding domain (CBD) of TR, provides a secondary TR-interaction platform. CaM helix F, which is part of this secondary surface, responds to both Thr348 phosphorylation and pH changes, indicating its integration into an allosteric network that encompasses both components of the Ca2+ -CaM•TR complex. Solution NMR data suggest that CaMH107K , which carries a helix F mutation, is compromised in its ability to drive the conformational changes in TR necessary to enable efficient Thr348 phosphorylation. Biochemical studies confirm the diminished capacity of CaMH107K to induce TR autophosphorylation compared to wild-type CaM.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York, USA
| | - Kimberly Long
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas, USA
| | - Kwangwoon Lee
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York, USA.,Graduate Programs in Biochemistry, The Graduate Center of CUNY, New York, New York, USA.,Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Eric A Kumar
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas, USA
| | - Rinat Abzalimov
- Biomolecular Mass Spectrometry Facility, CUNY ASRC, New York, New York, USA
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas, USA.,Graduate Program in Cell and Molecular Biology, University of Texas, Austin, Texas, USA
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York, USA.,Graduate Programs in Biochemistry, The Graduate Center of CUNY, New York, New York, USA.,Graduate Programs in Chemistry, The Graduate Center of CUNY, New York, New York, USA.,Graduate Programs in Physics, The Graduate Center of CUNY, New York, New York, USA
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9
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Lee K, Kumar EA, Dalby KN, Ghose R. The role of calcium in the interaction between calmodulin and a minimal functional construct of eukaryotic elongation factor 2 kinase. Protein Sci 2020; 28:2089-2098. [PMID: 31626716 DOI: 10.1002/pro.3753] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/13/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF-2K) regulates protein synthesis by phosphorylating eukaryotic elongation factor 2 (eEF-2), thereby reducing its affinity for the ribosome and suppressing global translational elongation rates. eEF-2K is regulated by calmodulin (CaM) through a mechanism that is distinct from that of other CaM-regulated kinases. We had previously identified a minimal construct of eEF-2K (TR) that is activated similarly to the wild-type enzyme by CaM in vitro and retains its ability to phosphorylate eEF-2 efficiently in cells. Here, we employ solution nuclear magnetic resonance techniques relying on Ile δ1-methyls of TR and Ile δ1- and Met ε-methyls of CaM, as probes of their mutual interaction and the influence of Ca2+ thereon. We find that in the absence of Ca2+ , CaM exclusively utilizes its C-terminal lobe (CaMC ) to engage the N-terminal CaM-binding domain (CBD) of TR in a high-affinity interaction. Avidity resulting from additional weak interactions of TR with the Ca2+ -loaded N-terminal lobe of CaM (CaMN ) at increased Ca2+ levels serves to enhance the affinity further. These latter interactions under Ca2+ saturation result in minimal perturbations in the spectra of TR in the context of its complex with CaM, suggesting that the latter is capable of driving TR to its final, presumably active conformation, in the Ca2+ -free state. Our data are consistent with a scenario in which Ca2+ enhances the affinity of the TR/CaM interactions, resulting in the increased effective concentration of the CaM-bound species without significantly modifying the conformation of TR within the final, active complex.
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Affiliation(s)
- Kwangwoon Lee
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York.,Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, New York
| | - Eric A Kumar
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, Texas.,Graduate Program in Cell and Molecular Biology, University of Texas, Austin, Texas
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York.,Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, New York.,Graduate Program in Chemistry, The Graduate Center of CUNY, New York, New York.,Graduate Program in Physics, The Graduate Center of CUNY, New York, New York
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10
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The Importance of Protein Phosphorylation for Signaling and Metabolism in Response to Diel Light Cycling and Nutrient Availability in a Marine Diatom. BIOLOGY 2020; 9:biology9070155. [PMID: 32640597 PMCID: PMC7408324 DOI: 10.3390/biology9070155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 01/23/2023]
Abstract
Diatoms are major contributors to global primary production and their populations in the modern oceans are affected by availability of iron, nitrogen, phosphate, silica, and other trace metals, vitamins, and infochemicals. However, little is known about the role of phosphorylation in diatoms and its role in regulation and signaling. We report a total of 2759 phosphorylation sites on 1502 proteins detected in Phaeodactylum tricornutum. Conditionally phosphorylated peptides were detected at low iron (n = 108), during the diel cycle (n = 149), and due to nitrogen availability (n = 137). Through a multi-omic comparison of transcript, protein, phosphorylation, and protein homology, we identify numerous proteins and key cellular processes that are likely under control of phospho-regulation. We show that phosphorylation regulates: (1) carbon retrenchment and reallocation during growth under low iron, (2) carbon flux towards lipid biosynthesis after the lights turn on, (3) coordination of transcription and translation over the diel cycle and (4) in response to nitrogen depletion. We also uncover phosphorylation sites for proteins that play major roles in diatom Fe sensing and utilization, including flavodoxin and phytotransferrin (ISIP2A), as well as identify phospho-regulated stress proteins and kinases. These findings provide much needed insight into the roles of protein phosphorylation in diel cycling and nutrient sensing in diatoms.
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11
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Suzuki K, Monteggia LM. The role of eEF2 kinase in the rapid antidepressant actions of ketamine. RAPID ACTING ANTIDEPRESSANTS 2020; 89:79-99. [DOI: 10.1016/bs.apha.2020.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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12
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Piserchio A, Will N, Giles DH, Hajredini F, Dalby KN, Ghose R. Solution Structure of the Carboxy-Terminal Tandem Repeat Domain of Eukaryotic Elongation Factor 2 Kinase and Its Role in Substrate Recognition. J Mol Biol 2019; 431:2700-2717. [PMID: 31108082 PMCID: PMC6599559 DOI: 10.1016/j.jmb.2019.05.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/15/2019] [Accepted: 05/12/2019] [Indexed: 12/31/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF-2K), an atypical calmodulin-activated protein kinase, regulates translational elongation by phosphorylating its substrate, eukaryotic elongation factor 2 (eEF-2), thereby reducing its affinity for the ribosome. The activation and activity of eEF-2K are critical for survival under energy-deprived conditions and is implicated in a variety of essential physiological processes. Previous biochemical experiments have indicated that the binding site for the substrate eEF-2 is located in the C-terminal domain of eEF-2K, a region predicted to harbor several α-helical repeats. Here, using NMR methodology, we have determined the solution structure of a C-terminal fragment of eEF-2K, eEF-2K562-725 that encodes two α-helical repeats. The structure of eEF-2K562-725 shows signatures characteristic of TPR domains and of their SEL1-like sub-family. Furthermore, using the analyses of NMR spectral perturbations and ITC measurements, we have localized the eEF-2 binding site on eEF-2K562-725. We find that eEF-2K562-725 engages eEF-2 with an affinity comparable to that of the full-length enzyme. Furthermore, eEF-2K562-725 is able to inhibit the phosphorylation of eEF-2 by full-length eEF-2K in trans. Our present studies establish that eEF-2K562-725 encodes the major elements necessary to enable the eEF-2K/eEF-2 interactions.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA
| | - Nathan Will
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - David H Giles
- Graduate Program in Cell and Molecular Biology, University of Texas, Austin, TX 78712, USA
| | - Fatlum Hajredini
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - Kevin N Dalby
- Graduate Program in Cell and Molecular Biology, University of Texas, Austin, TX 78712, USA; Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, NewYork, NY 10031, USA; Graduate Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA; Graduate Program in Chemistry, The Graduate Center of CUNY, New York, NY 10016, USA; Graduate Program in Physics, The Graduate Center of CUNY, New York, NY 10016, USA.
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13
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Will N, Lee K, Hajredini F, Giles DH, Abzalimov RR, Clarkson M, Dalby KN, Ghose R. Structural Dynamics of the Activation of Elongation Factor 2 Kinase by Ca 2+-Calmodulin. J Mol Biol 2018; 430:2802-2821. [PMID: 29800565 DOI: 10.1016/j.jmb.2018.05.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 05/16/2018] [Accepted: 05/16/2018] [Indexed: 11/18/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF-2K), the only known calmodulin (CaM)-activated α-kinase, phosphorylates eukaryotic elongation factor 2 (eEF-2) on a specific threonine (Thr-56) diminishing its affinity for the ribosome and reducing the rate of nascent chain elongation during translation. Despite its critical cellular role, the precise mechanisms underlying the CaM-mediated activation of eEF-2K remain poorly defined. Here, employing a minimal eEF-2K construct (TR) that exhibits activity comparable to the wild-type enzyme and is fully activated by CaM in vitro and in cells, and using a variety of complimentary biophysical techniques in combination with computational modeling, we provide a structural mechanism by which CaM activates eEF-2K. Native mass analysis reveals that CaM, with two bound Ca2+ ions, forms a stoichiometric 1:1 complex with TR. Chemical crosslinking mass spectrometry and small-angle X-ray scattering measurements localize CaM near the N-lobe of the TR kinase domain and the spatially proximal C-terminal helical repeat. Hydrogen/deuterium exchange mass spectrometry and methyl NMR indicate that the conformational changes induced on TR by the engagement of CaM are not localized but are transmitted to remote regions that include the catalytic site and the functionally important phosphate binding pocket. The structural insights obtained from the present analyses, together with our previously published kinetics data, suggest that TR, and by inference, wild-type eEF-2K, upon engaging CaM undergoes a conformational transition resulting in a state that is primed to efficiently auto-phosphorylate on the primary activating T348 en route to full activation.
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Affiliation(s)
- Nathan Will
- 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
| | - 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
| | - Fatlum Hajredini
- 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
| | - David H Giles
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Rinat R Abzalimov
- Biomolecular Mass Spectrometry Facility, CUNY ASRC, New York, NY 10031, USA
| | - Michael Clarkson
- Molecular Structures Core, University of Arizona, Tucson, AZ 85721, USA
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA; Graduate Program in Cell and Molecular Biology, 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.
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14
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Henry M, Power M, Kaushik P, Coleman O, Clynes M, Meleady P. Differential Phosphoproteomic Analysis of Recombinant Chinese Hamster Ovary Cells Following Temperature Shift. J Proteome Res 2017; 16:2339-2358. [DOI: 10.1021/acs.jproteome.6b00868] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Michael Henry
- National Institute for Cellular
Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Martin Power
- National Institute for Cellular
Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Prashant Kaushik
- National Institute for Cellular
Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Orla Coleman
- National Institute for Cellular
Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Martin Clynes
- National Institute for Cellular
Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Paula Meleady
- National Institute for Cellular
Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
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