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Kulbatskii D, Shenkarev Z, Bychkov M, Loktyushov E, Shulepko M, Koshelev S, Povarov I, Popov A, Peigneur S, Chugunov A, Kozlov S, Sharonova I, Efremov R, Skrebitsky V, Tytgat J, Kirpichnikov M, Lyukmanova E. Human Three-Finger Protein Lypd6 Is a Negative Modulator of the Cholinergic System in the Brain. Front Cell Dev Biol 2021; 9:662227. [PMID: 34631692 PMCID: PMC8494132 DOI: 10.3389/fcell.2021.662227] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 08/30/2021] [Indexed: 11/19/2022] Open
Abstract
Lypd6 is a GPI-tethered protein from the Ly-6/uPAR family expressed in the brain. Lypd6 enhances the Wnt/β-catenin signaling, although its action on nicotinic acetylcholine receptors (nAChRs) have been also proposed. To investigate a cholinergic activity of Lypd6, we studied a recombinant water-soluble variant of the human protein (ws-Lypd6) containing isolated “three-finger” LU-domain. Experiments at different nAChR subtypes expressed in Xenopus oocytes revealed the negative allosteric modulatory activity of ws-Lypd6. Ws-Lypd6 inhibited ACh-evoked currents at α3β4- and α7-nAChRs with IC50 of ∼35 and 10 μM, respectively, and the maximal amplitude of inhibition of 30–50%. EC50 of ACh at α3β4-nAChRs (∼30 μM) was not changed in the presence of 35 μM ws-Lypd6, while the maximal amplitude of ACh-evoked current was reduced by ∼20%. Ws-Lypd6 did not elicit currents through nAChRs in the absence of ACh. Application of 1 μM ws-Lypd6 significantly inhibited (up to ∼28%) choline-evoked current at α7-nAChRs in rat hippocampal slices. Similar to snake neurotoxin α-bungarotoxin, ws-Lypd6 suppressed the long-term potentiation (LTP) in mouse hippocampal slices. Colocalization of endogenous GPI-tethered Lypd6 with α3β4- and α7-nAChRs was detected in primary cortical and hippocampal neurons. Ws-Lypd6 interaction with the extracellular domain of α7-nAChR was modeled using the ensemble protein-protein docking protocol. The interaction of all three Lypd6 loops (“fingers”) with the entrance to the orthosteric ligand-binding site and the loop C of the primary receptor subunit was predicted. The results obtained allow us to consider Lypd6 as the endogenous negative modulator involved in the regulation of the cholinergic system in the brain.
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Affiliation(s)
- Dmitrii Kulbatskii
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia
| | - Zakhar Shenkarev
- Structural Biology Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia.,Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Moscow, Russia
| | - Maxim Bychkov
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia
| | - Eugene Loktyushov
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia
| | - Mikhail Shulepko
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia
| | - Sergey Koshelev
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia
| | - Igor Povarov
- Brain Research Department, Research Center of Neurology, Moscow, Russia
| | - Alexander Popov
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia.,Institute of Neuroscience, Nizhny Novgorod University, Nizhny Novgorod, Russia
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Anton Chugunov
- Structural Biology Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia.,Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Moscow, Russia.,International Laboratory for Supercomputer Atomistic Modelling and Multi-Scale Analysis, National Research University Higher School of Economics, Moscow, Russia
| | - Sergey Kozlov
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia
| | - Irina Sharonova
- Brain Research Department, Research Center of Neurology, Moscow, Russia
| | - Roman Efremov
- Structural Biology Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia.,Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Moscow, Russia.,International Laboratory for Supercomputer Atomistic Modelling and Multi-Scale Analysis, National Research University Higher School of Economics, Moscow, Russia
| | | | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Mikhail Kirpichnikov
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia.,Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Ekaterina Lyukmanova
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences (RAS), Moscow, Russia.,Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Moscow, Russia.,Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
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2
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Bychkov ML, Shulepko MA, Shlepova OV, Kulbatskii DS, Chulina IA, Paramonov AS, Baidakova LK, Azev VN, Koshelev SG, Kirpichnikov MP, Shenkarev ZO, Lyukmanova EN. SLURP-1 Controls Growth and Migration of Lung Adenocarcinoma Cells, Forming a Complex With α7-nAChR and PDGFR/EGFR Heterodimer. Front Cell Dev Biol 2021; 9:739391. [PMID: 34595181 PMCID: PMC8476798 DOI: 10.3389/fcell.2021.739391] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 08/17/2021] [Indexed: 12/18/2022] Open
Abstract
Secreted Ly6/uPAR-related protein 1 (SLURP-1) is a secreted Ly6/uPAR protein that negatively modulates the nicotinic acetylcholine receptor of α7 type (α7-nAChR), participating in control of cancer cell growth. Previously we showed, that a recombinant analogue of human SLURP-1 (rSLURP-1) diminishes the lung adenocarcinoma A549 cell proliferation and abolishes the nicotine-induced growth stimulation. Here, using multiplex immunoassay, we demonstrated a decrease in PTEN and mammalian target of rapamycin (mTOR) kinase phosphorylation in A549 cells upon the rSLURP-1 treatment pointing on down-regulation of the PI3K/AKT/mTOR signaling pathway. Decreased phosphorylation of the platelet-derived growth factor receptor type β (PDGFRβ) and arrest of the A549 cell cycle in the S and G2/M phases without apoptosis induction was also observed. Using a scratch migration assay, inhibition of A549 cell migration under the rSLURP-1 treatment was found. Affinity extraction demonstrated that rSLURP-1 in A549 cells forms a complex not only with α7-nAChR, but also with PDGFRα and epidermal growth factor receptor (EGFR), which are known to be involved in regulation of cancer cell growth and migration and are able to form a heterodimer. Knock-down of the genes encoding α7-nAChR, PDGFRα, and EGFR confirmed the involvement of these receptors in the anti-migration effect of SLURP-1. Thus, SLURP-1 can target the α7-nAChR complexes with PDGFRα and EGFR in the membrane of epithelial cells. Using chimeric proteins with grafted SLURP-1 loops we demonstrated that loop I is the principal active site responsible for the SLURP-1 interaction with α7-nAChR and its antiproliferative effect. Synthetic peptide mimicking the loop I cyclized by a disulfide bond inhibited ACh-evoked current at α7-nAChR, as well as A549 cell proliferation and migration. This synthetic peptide represents a promising prototype of new antitumor drug with the properties close to that of the native SLURP-1 protein.
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Affiliation(s)
- Maxim L. Bychkov
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Mikhail A. Shulepko
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Olga V. Shlepova
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
- Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Dmitrii S. Kulbatskii
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Irina A. Chulina
- Group of Peptide Chemistry, Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Pushchino, Russia
| | - Alexander S. Paramonov
- Department of Structural Biology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Ludmila K. Baidakova
- Group of Peptide Chemistry, Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Pushchino, Russia
| | - Viatcheslav N. Azev
- Group of Peptide Chemistry, Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Pushchino, Russia
| | - Sergey G. Koshelev
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Mikhail P. Kirpichnikov
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
- Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Zakhar O. Shenkarev
- Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Department of Structural Biology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Ekaterina N. Lyukmanova
- Bioengineering Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
- Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
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Gulsevin A, Papke RL, Stokes C, Tran HNT, Jin AH, Vetter I, Meiler J. The Allosteric Activation of α7 nAChR by α-Conotoxin MrIC Is Modified by Mutations at the Vestibular Site. Toxins (Basel) 2021; 13:toxins13080555. [PMID: 34437426 PMCID: PMC8402416 DOI: 10.3390/toxins13080555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/02/2021] [Accepted: 08/09/2021] [Indexed: 12/18/2022] Open
Abstract
α-conotoxins are 13–19 amino acid toxin peptides that bind various nicotinic acetylcholine receptor (nAChR) subtypes. α-conotoxin Mr1.7c (MrIC) is a 17 amino acid peptide that targets α7 nAChR. Although MrIC has no activating effect on α7 nAChR when applied by itself, it evokes a large response when co-applied with the type II positive allosteric modulator PNU-120596, which potentiates the α7 nAChR response by recovering it from a desensitized state. A lack of standalone activity, despite activation upon co-application with a positive allosteric modulator, was previously observed for molecules that bind to an extracellular domain allosteric activation (AA) site at the vestibule of the receptor. We hypothesized that MrIC may activate α7 nAChR allosterically through this site. We ran voltage-clamp electrophysiology experiments and in silico peptide docking calculations in order to gather evidence in support of α7 nAChR activation by MrIC through the AA site. The experiments with the wild-type α7 nAChR supported an allosteric mode of action, which was confirmed by the significantly increased MrIC + PNU-120596 responses of three α7 nAChR AA site mutants that were designed in silico to improve MrIC binding. Overall, our results shed light on the allosteric activation of α7 nAChR by MrIC and suggest the involvement of the AA site.
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Affiliation(s)
- Alican Gulsevin
- Center for Structural Biology, Department of Chemistry, Vanderbilt University, Nashville, TN 37212, USA;
- Correspondence:
| | - Roger L. Papke
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (R.L.P.); (C.S.)
| | - Clare Stokes
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (R.L.P.); (C.S.)
| | - Hue N. T. Tran
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (H.N.T.T.); (A.H.J.); (I.V.)
| | - Aihua H. Jin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (H.N.T.T.); (A.H.J.); (I.V.)
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (H.N.T.T.); (A.H.J.); (I.V.)
- School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Jens Meiler
- Center for Structural Biology, Department of Chemistry, Vanderbilt University, Nashville, TN 37212, USA;
- Institute for Drug Discovery, Leipzig University Medical School, 04103 Leipzig, Germany
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Papke RL, De Biasi M, Damaj MI. Nicotine: Understanding the big picture while also studying the details. Neuropharmacology 2021; 196:108715. [PMID: 34271018 DOI: 10.1016/j.neuropharm.2021.108715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roger L Papke
- Department of Pharmacology and Therapeutics, University of Florida, P.O. Box 100267, Gainesville, FL, 32610-0267, USA.
| | - Mariella De Biasi
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - M Imad Damaj
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, Richmond, VA, 23298-0613, USA
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Abstract
The α7-type nicotinic acetylcholine receptor is one of the most unique and interesting of all the members of the cys-loop superfamily of ligand-gated ion channels. Since it was first identified initially as a binding site for α-bungarotoxin in mammalian brain and later as a functional homomeric receptor with relatively high calcium permeability, it has been pursued as a potential therapeutic target for numerous indications, from Alzheimer disease to asthma. In this review, we discuss the history and state of the art for targeting α7 receptors, beginning with subtype-selective agonists and the basic pharmacophore for the selective activation of α7 receptors. A key feature of α7 receptors is their rapid desensitization by standard "orthosteric" agonist, and we discuss insights into the conformational landscape of α7 receptors that has been gained by the development of ligands binding to allosteric sites. Some of these sites are targeted by positive allosteric modulators that have a wide range of effects on the activation profile of the receptors. Other sites are targeted by direct allosteric agonist or antagonists. We include a perspective on the potential importance of α7 receptors for metabotropic as well as ionotropic signaling. We outline the challenges that exist for future development of drugs to target this important receptor and approaches that may be considered to address those challenges. SIGNIFICANCE STATEMENT: The α7-type nicotinic acetylcholine receptor (nAChR) is acknowledged as a potentially important therapeutic target with functional properties associated with both ionotropic and metabotropic signaling. The functional properties of α7 nAChR can be regulated in diverse ways with the variety of orthosteric and allosteric ligands described in this review.
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Affiliation(s)
- Roger L Papke
- Departments of Pharmacology and Therapeutics (R.L.P) and Chemistry (N.A.H.), University of Florida, Gainesville, FL
| | - Nicole A Horenstein
- Departments of Pharmacology and Therapeutics (R.L.P) and Chemistry (N.A.H.), University of Florida, Gainesville, FL
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Sabnis RW. Novel Spiropiperidine Allosteric Modulators of Nicotinic Acetylcholine Receptors for Treating Central Nervous System Disorders. ACS Med Chem Lett 2021; 12:172-173. [PMID: 33603958 DOI: 10.1021/acsmedchemlett.0c00670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Indexed: 11/29/2022] Open
Affiliation(s)
- Ram W. Sabnis
- Smith, Gambrell & Russell LLP, 1230 Peachtree Street NE, Suite 3100, Atlanta, Georgia 30309, United States
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7
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Gulsevin A, Meiler J, Horenstein NA. A Computational Analysis of the Factors Governing the Dynamics of α7 nAChR and Its Homologs. Biophys J 2020; 119:1656-1669. [PMID: 33010233 PMCID: PMC7642335 DOI: 10.1016/j.bpj.2020.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 12/18/2022] Open
Abstract
The α7 nicotinic acetylcholine receptor is a homopentameric ion channel from the Cys-loop receptor superfamily targeted for psychiatric indications and inflammatory pain. Molecular dynamics studies of the receptor have focused on residue mobility and global conformational changes to address receptor function. However, a comparative analysis of α7 with its homologs that cannot trigger channel opening has not been made so far. To identify the residues involved in α7 activation, we ran triplicate 500-ns molecular dynamics simulations with an α7 extracellular domain homology model and two acetylcholine-binding protein homologs. We tested the effect of ligand binding and amino acid sequence on the structure and dynamics of the three proteins. We found that mobile regions identified based on root mean-square deviation and root mean-square fluctuation values are not always consistent among the individual α7 extracellular domain simulations. Comparison of the replica-average properties of the three proteins based on dynamic cross-correlation maps showed that ligand binding affects the coupling between the C-loop and the Cys-loop, vestibular loop, and β1-β2 loops. In addition, the main-immunogenic-region-like domain of α7 went through correlated motions with multiple domains of the receptor. These correlated motions were absent or diminished in α7 homologs, suggesting a unique role in α7 activation.
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Affiliation(s)
- Alican Gulsevin
- Department of Chemistry, Biochemistry Division, University of Florida, Gainesville, Florida; Department of Chemistry, Vanderbilt University, Nashville, Tennessee.
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee; Leipzig University Medical School, Institute for Drug Discovery, Leipzig, Germany
| | - Nicole A Horenstein
- Department of Chemistry, Biochemistry Division, University of Florida, Gainesville, Florida
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