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Schwob M, Kugler V, Wagner R. Cloning and Overexpressing Membrane Proteins Using Pichia pastoris (Komagataella phaffii). Curr Protoc 2023; 3:e936. [PMID: 37933574 DOI: 10.1002/cpz1.936] [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] [Indexed: 11/08/2023]
Abstract
Understanding the structure and function of key proteins located within biological membranes is essential for fundamental knowledge and therapeutic applications. Robust cell systems allowing their actual overexpression are required, among which stands the methylotrophic yeast Pichia pastoris. This system proves highly efficient in producing many eukaryotic membrane proteins of various functions and structures at levels and quality compatible with their subsequent isolation and molecular investigation. This article describes a set of basic guidelines and directions to clone and select recombinant P. pastoris clones overexpressing eukaryotic membrane proteins. Illustrative results obtained for a panel of mammalian membrane proteins are presented, and hints are given on a series of experimental parameters that may substantially improve the amount and/or the functionality of the expressed proteins. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Designing and cloning a P. pastoris expression vector Basic Protocol 2: Integrative transformation of P. pastoris and selection of recombinant clones Basic Protocol 3: Culturing transformed P. pastoris for membrane protein expression Basic Protocol 4: Yeast cell lysis and membrane preparation Basic Protocol 5: Immunodetection of expressed membrane proteins: western blot Alternate Protocol 1: Immunodetection of expressed membrane proteins: dot blot Alternate Protocol 2: Immunodetection of expressed membrane proteins: yeastern blot Basic Protocol 6: Activity assay: ligand-binding analysis of an expressed GPCR.
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Affiliation(s)
- Magali Schwob
- IMPReSs Facility, Biotechnology and Cell Signaling, University of Strasbourg-CNRS, Illkirch, France
- Department of Structural Biology, NovAliX, Strasbourg, France
| | - Valérie Kugler
- IMPReSs Facility, Biotechnology and Cell Signaling, University of Strasbourg-CNRS, Illkirch, France
| | - Renaud Wagner
- IMPReSs Facility, Biotechnology and Cell Signaling, University of Strasbourg-CNRS, Illkirch, France
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Beaurain M, Talmont F, Pierre D, Péran P, Boucher S, Hitzel A, Rols MP, Cuvillier O, Payoux P, Salabert AS. Pharmacological Characterization of [ 18F]-FNM and Evaluation of NMDA Receptors Activation in a Rat Brain Injury Model. Mol Imaging Biol 2023:10.1007/s11307-023-01811-y. [PMID: 36944798 DOI: 10.1007/s11307-023-01811-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/23/2023]
Abstract
PURPOSE NMDA receptors (NMDARs) dysfunction plays a central role in the physiopathology of psychiatric and neurodegenerative disorders whose mechanisms are still poorly understood. The development of a PET (positron emission tomography) tracer able to selectively bind to the NMDARs intra-channel PCP site may make it possible to visualize NMDARs in an open and active state. We describe the in vitro pharmacological characterization of [18F]-fluoroethylnormemantine ([18F]-FNM) and evaluate its ability to localize activated NMDA receptors in a rat preclinical model of excitotoxicity. PROCEDURES The affinity of the non-radioactive analog for the intra-channel PCP site was determined in a radioligand competition assay using [3H]TCP ([3H]N-(1-[thienyl]cyclohexyl)piperidine) on rat brain homogenates. Selectivity was also investigated by the displacement of specific radioligands targeting various cerebral receptors. In vivo brain lesions were performed using stereotaxic quinolinic acid (QA) injections in the left motor area (M1) of seven Sprague Dawley rats. Each rat was imaged with a microPET/CT camera, 40 min after receiving a dose of 30 MBq + / - 20 of [18F]-FNM, 24 and 72 h after injury. Nine non-injured rats were also imaged using the same protocol. RESULTS FNM displayed IC50 value of 13.0 ± 8.9 µM in rat forebrain homogenates but also showed significant bindings on opioid receptors. In the frontal and left somatosensory areas, [18F]FNM PET detected a mean of 37% and 41% increase in [18F]FNM uptake (p < 0,0001) 24 and 72 h after QA stereotaxic injection, respectively, compared to the control group. CONCLUSIONS In spite of FNM's poor affinity for NMDAR PCP site, this study supports the ability of this tracer to track massive activation of NMDARs in neurological diseases.
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Affiliation(s)
- Marie Beaurain
- Toulouse NeuroImaging Center, ToNIC, UMR1214 Inserm, Toulouse, France.
- Nuclear Medicine Department, Toulouse Purpan University Hospital, Toulouse, France.
| | - Franck Talmont
- Institut de Pharmacologie Et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31059, Toulouse, France
| | - Damien Pierre
- Toulouse NeuroImaging Center, ToNIC, UMR1214 Inserm, Toulouse, France
| | - Patrice Péran
- Toulouse NeuroImaging Center, ToNIC, UMR1214 Inserm, Toulouse, France
| | - Samuel Boucher
- Toulouse NeuroImaging Center, ToNIC, UMR1214 Inserm, Toulouse, France
| | - Anne Hitzel
- Nuclear Medicine Department, Toulouse Purpan University Hospital, Toulouse, France
| | - Marie-Pierre Rols
- Institut de Pharmacologie Et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31059, Toulouse, France
| | - Olivier Cuvillier
- Institut de Pharmacologie Et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31059, Toulouse, France
| | - Pierre Payoux
- Toulouse NeuroImaging Center, ToNIC, UMR1214 Inserm, Toulouse, France
- Nuclear Medicine Department, Toulouse Purpan University Hospital, Toulouse, France
| | - Anne-Sophie Salabert
- Toulouse NeuroImaging Center, ToNIC, UMR1214 Inserm, Toulouse, France
- Nuclear Medicine Department, Toulouse Purpan University Hospital, Toulouse, France
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Cholesterol as a modulator of cannabinoid receptor CB 2 signaling. Sci Rep 2021; 11:3706. [PMID: 33580091 PMCID: PMC7881127 DOI: 10.1038/s41598-021-83245-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/20/2021] [Indexed: 11/21/2022] Open
Abstract
Signaling through integral membrane G protein-coupled receptors (GPCRs) is influenced by lipid composition of cell membranes. By using novel high affinity ligands of human cannabinoid receptor CB2, we demonstrate that cholesterol increases basal activation levels of the receptor and alters the pharmacological categorization of these ligands. Our results revealed that (2-(6-chloro-2-((2,2,3,3-tetramethylcyclopropane-1-carbonyl)imino)benzo[d]thiazol-3(2H)-yl)ethyl acetate ligand (MRI-2646) acts as a partial agonist of CB2 in membranes devoid of cholesterol and as a neutral antagonist or a partial inverse agonist in cholesterol-containing membranes. The differential effects of a specific ligand on activation of CB2 in different types of membranes may have implications for screening of drug candidates in a search of modulators of GPCR activity. MD simulation suggests that cholesterol exerts an allosteric effect on the intracellular regions of the receptor that interact with the G-protein complex thereby altering the recruitment of G protein.
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