1
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Liu X, Wang W. Gating mechanism of the human α1β GlyR by glycine. Structure 2024:S0969-2126(24)00275-2. [PMID: 39146932 DOI: 10.1016/j.str.2024.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 06/20/2024] [Accepted: 07/19/2024] [Indexed: 08/17/2024]
Abstract
Glycine receptors (GlyRs) are members of the Cys-loop receptors that constitute a major portion of mammalian neurotransmitter receptors. Recent resolution of heteromeric GlyR structures in multiple functional states raised fundamental questions regarding the gating mechanism of GlyR, and generally the Cys-loop family receptors. Here, we characterized in detail equilibrium properties as well as the transition kinetics between functional states. We show that, while all allosteric sites bind cooperatively to glycine, occupation of 2 sites at the α-α interfaces is sufficient for activation and necessary for high-efficacy gating. Differential glycine concentration dependence of desensitization rate, extent, and its recovery suggests separate but concerted roles of ligand-binding and ionophore reorganization. Based on these observations and available structural information, we developed a quantitative gating model that accurately predicts both equilibrium and kinetical properties throughout the glycine gating cycle. This model likely applies generally to the Cys-loop receptors and informs on pharmaceutical endeavors.
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Affiliation(s)
- Xiaofen Liu
- Departments of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weiwei Wang
- Departments of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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2
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Wang W, Liu X. Mechanism of human ⍺3β GlyR modulation in inflammatory pain and 2, 6-DTBP interaction. RESEARCH SQUARE 2024:rs.3.rs-4402878. [PMID: 39149480 PMCID: PMC11326354 DOI: 10.21203/rs.3.rs-4402878/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
α3β glycine receptor (GlyR) is a subtype of the GlyRs that belongs to the Cys-loop receptor superfamily. It is a target for non-psychoactive pain control drug development due to its high expression in the spinal dorsal horn and indispensable roles in pain sensation. α3β GlyR activity is inhibited by a phosphorylation in the large internal M3/M4 loop of α3 through the prostaglandin E2 (PGE 2 ) pathway, which can be reverted by a small molecule analgesic, 2, 6-DTBP. However, the mechanism of regulation by phosphorylation or 2, 6-DTBP is unknown. Here we show M3/M4 loop compaction through phosphorylation and 2, 6-DTBP binding, which in turn changes the local environment and rearranges ion conduction pore conformation to modulate α3β GlyR activity. We resolved glycine-bound structures of α3β GlyR with and without phosphorylation, as well as in the presence of 2, 6-DTBP and found no change in functional states upon phosphorylation, but transition to an asymmetric super open pore by 2, 6-DTBP binding. Single-molecule Förster resonance energy transfer (smFRET) experiment shows compaction of M3/M4 loop towards the pore upon phosphorylation, and further compaction by 2, 6-DTBP. Our results reveal a localized interaction model where M3/M4 loop modulate GlyR function through physical proximation. This regulation mechanism should inform on pain medication development targeting GlyRs. Our strategy allowed investigation of how post-translational modification of an unstructured loop modulate channel conduction, which we anticipate will be applicable to intrinsically disordered loops ubiquitously found in ion channels.
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3
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López-Sánchez U, Munro LJ, Ladefoged LK, Pedersen AJ, Brun CC, Lyngby SM, Baud D, Juillan-Binard C, Pedersen MG, Lummis SCR, Bang-Andersen B, Schiøtt B, Chipot C, Schoehn G, Neyton J, Dehez F, Nury H, Kristensen AS. Structural determinants for activity of the antidepressant vortioxetine at human and rodent 5-HT 3 receptors. Nat Struct Mol Biol 2024; 31:1232-1242. [PMID: 38698207 DOI: 10.1038/s41594-024-01282-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/19/2024] [Indexed: 05/05/2024]
Abstract
Vortioxetine (VTX) is a recently approved antidepressant that targets a variety of serotonin receptors. Here, we investigate the drug's molecular mechanism of operation at the serotonin 5-HT3 receptor (5-HT3R), which features two properties: VTX acts differently on rodent and human 5-HT3R, and VTX appears to suppress any subsequent response to agonists. Using a combination of cryo-EM, electrophysiology, voltage-clamp fluorometry and molecular dynamics, we show that VTX stabilizes a resting inhibited state of the mouse 5-HT3R and an agonist-bound-like state of human 5-HT3R, in line with the functional profile of the drug. We report four human 5-HT3R structures and show that the human receptor transmembrane domain is intrinsically fragile. We also explain the lack of recovery after VTX administration via a membrane partition mechanism.
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Affiliation(s)
- Uriel López-Sánchez
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
- Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Lachlan Jake Munro
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | | | - Anders Juel Pedersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Christian Colding Brun
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Signe Meisner Lyngby
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Delphine Baud
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | | | | | - Sarah C R Lummis
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Christophe Chipot
- Université de Lorraine, CNRS, LPCT, Nancy, France
- Laboratoire International Associé CNRS and University of Illinois at Urbana-Champaign, Vandoeuvre-les-Nancy, France
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Guy Schoehn
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Jacques Neyton
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Francois Dehez
- Université de Lorraine, CNRS, LPCT, Nancy, France
- Laboratoire International Associé CNRS and University of Illinois at Urbana-Champaign, Vandoeuvre-les-Nancy, France
| | - Hugues Nury
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France.
| | - Anders S Kristensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
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4
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Nors JW, Endres Z, Goldschen-Ohm MP. GABA A receptor subunit M2-M3 linkers have asymmetric roles in pore gating and diazepam modulation. Biophys J 2024; 123:2085-2096. [PMID: 38400541 PMCID: PMC11309982 DOI: 10.1016/j.bpj.2024.02.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/19/2024] [Accepted: 02/20/2024] [Indexed: 02/25/2024] Open
Abstract
GABAA receptors (GABAARs) are neurotransmitter-gated ion channels critical for inhibitory synaptic transmission as well as the molecular target for benzodiazepines (BZDs), one of the most widely prescribed class of psychotropic drugs today. Despite structural insight into the conformations underlying functional channel states, the detailed molecular interactions involved in conformational transitions and the physical basis for their modulation by BZDs are not fully understood. We previously identified that alanine substitution at the central residue in the α1 subunit M2-M3 linker (V279A) enhances the efficiency of linkage between the BZD site and the pore gate. Here, we expand on this work by investigating the effect of alanine substitutions at the analogous positions in the M2-M3 linkers of β2 (I275A) and γ2 (V290A) subunits, which together with α1 comprise typical heteromeric α1β2γ2 synaptic GABAARs. We find that these mutations confer subunit-specific effects on the intrinsic pore closed-open equilibrium and its modulation by the BZD diazepam (DZ). The mutations α1(V279A) or γ2(V290A) bias the channel toward a closed conformation, whereas β2(I275A) biases the channel toward an open conformation to the extent that the channel becomes leaky and opens spontaneously in the absence of agonist. In contrast, only α1(V279A) enhances the efficiency of DZ-to-pore linkage, whereas mutations in the other two subunits have no effect. These observations show that the central residue in the M2-M3 linkers of distinct subunits in synaptic α1β2γ2 GABAARs contribute asymmetrically to the intrinsic closed-open equilibrium and its modulation by DZ.
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Affiliation(s)
- Joseph W Nors
- Department of Neuroscience, University of Texas at Austin, Austin, Texas; Department of Molecular and Cellular Physiology, Stanford University, Stanford, California
| | - Zachary Endres
- Department of Neuroscience, University of Texas at Austin, Austin, Texas
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5
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Wang YJ, Di XJ, Zhang PP, Chen X, Williams MP, Han DY, Nashmi R, Henderson BJ, Moss FJ, Mu TW. Hsp47 promotes biogenesis of multi-subunit neuroreceptors in the endoplasmic reticulum. eLife 2024; 13:e84798. [PMID: 38963323 PMCID: PMC11257679 DOI: 10.7554/elife.84798] [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: 11/18/2022] [Accepted: 05/21/2024] [Indexed: 07/05/2024] Open
Abstract
Protein homeostasis (proteostasis) deficiency is an important contributing factor to neurological and metabolic diseases. However, how the proteostasis network orchestrates the folding and assembly of multi-subunit membrane proteins is poorly understood. Previous proteomics studies identified Hsp47 (Gene: SERPINH1), a heat shock protein in the endoplasmic reticulum lumen, as the most enriched interacting chaperone for gamma-aminobutyric acid type A (GABAA) receptors. Here, we show that Hsp47 enhances the functional surface expression of GABAA receptors in rat neurons and human HEK293T cells. Furthermore, molecular mechanism study demonstrates that Hsp47 acts after BiP (Gene: HSPA5) and preferentially binds the folded conformation of GABAA receptors without inducing the unfolded protein response in HEK293T cells. Therefore, Hsp47 promotes the subunit-subunit interaction, the receptor assembly process, and the anterograde trafficking of GABAA receptors. Overexpressing Hsp47 is sufficient to correct the surface expression and function of epilepsy-associated GABAA receptor variants in HEK293T cells. Hsp47 also promotes the surface trafficking of other Cys-loop receptors, including nicotinic acetylcholine receptors and serotonin type 3 receptors in HEK293T cells. Therefore, in addition to its known function as a collagen chaperone, this work establishes that Hsp47 plays a critical and general role in the maturation of multi-subunit Cys-loop neuroreceptors.
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Affiliation(s)
- Ya-Juan Wang
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
| | - Xiao-Jing Di
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
| | - Pei-Pei Zhang
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
| | - Xi Chen
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
| | - Marnie P Williams
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
| | - Dong-Yun Han
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
| | - Raad Nashmi
- Department of Biology, University of VictoriaVictoriaCanada
| | - Brandon J Henderson
- Department of Biomedical Sciences, Marshall UniversityHuntingtonUnited States
| | - Fraser J Moss
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
| | - Ting-Wei Mu
- Department of Physiology and Biophysics, Case Western Reserve UniversityClevelandUnited States
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6
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Peverini L, Shi S, Medjebeur K, Corringer PJ. Mapping the molecular motions of 5-HT 3 serotonin-gated channel by voltage-clamp fluorometry. eLife 2024; 12:RP93174. [PMID: 38913422 PMCID: PMC11196107 DOI: 10.7554/elife.93174] [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] [Indexed: 06/25/2024] Open
Abstract
The serotonin-gated ion channel (5-HT3R) mediates excitatory neuronal communication in the gut and the brain. It is the target for setrons, a class of competitive antagonists widely used as antiemetics, and is involved in several neurological diseases. Cryo-electron microscopy (cryo-EM) of the 5-HT3R in complex with serotonin or setrons revealed that the protein has access to a wide conformational landscape. However, assigning known high-resolution structures to actual states contributing to the physiological response remains a challenge. In the present study, we used voltage-clamp fluorometry (VCF) to measure simultaneously, for 5-HT3R expressed at a cell membrane, conformational changes by fluorescence and channel opening by electrophysiology. Four positions identified by mutational screening report motions around and outside the serotonin-binding site through incorporation of cysteine-tethered rhodamine dyes with or without a nearby quenching tryptophan. VCF recordings show that the 5-HT3R has access to four families of conformations endowed with distinct fluorescence signatures: 'resting-like' without ligand, 'inhibited-like' with setrons, 'pre-active-like' with partial agonists, and 'active-like' (open channel) with partial and strong agonists. Data are remarkably consistent with cryo-EM structures, the fluorescence partners matching respectively apo, setron-bound, 5-HT bound-closed, and 5-HT-bound-open conformations. Data show that strong agonists promote a concerted motion of all fluorescently labeled sensors during activation, while partial agonists, especially when loss-of-function mutations are engineered, stabilize both active and pre-active conformations. In conclusion, VCF, though the monitoring of electrophysiologically silent conformational changes, illuminates allosteric mechanisms contributing to signal transduction and their differential regulation by important classes of physiological and clinical effectors.
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Affiliation(s)
- Laurie Peverini
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors UnitParisFrance
| | - Sophie Shi
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors UnitParisFrance
| | - Karima Medjebeur
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors UnitParisFrance
| | - Pierre-Jean Corringer
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors UnitParisFrance
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7
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Nemecz D, Nowak WA, Nemecz Á. VHH Nanobody Versatility against Pentameric Ligand-Gated Ion Channels. J Med Chem 2024; 67:8502-8518. [PMID: 38829690 PMCID: PMC11181324 DOI: 10.1021/acs.jmedchem.4c00231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/17/2024] [Accepted: 05/20/2024] [Indexed: 06/05/2024]
Abstract
Pentameric ligand-gated ion channels provide rapid chemical-electrical signal transmission between cells in the central and peripheral nervous system. Their dysfunction is associated with many nervous system disorders. They are composed of five identical (homomeric receptors) or homologous (heteromeric receptors) subunits. VHH nanobodies, or single-chain antibodies, are the variable domain, VHH, of antibodies that are composed of the heavy chain only from camelids. Their unique structure results in many specific biochemical and biophysical properties that make them an excellent alternative to conventional antibodies. This Perspective explores the published VHH nanobodies which have been isolated against pentameric ligand-gated ion channel subfamilies. It outlines the genetic and chemical modifications available to alter nanobody function. An assessment of the available functional and structural data indicate that it is feasible to create therapeutic agents and impart, through their modification, a given desired modulatory effect of its target receptor for current stoichiometric-specific VHH nanobodies.
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Affiliation(s)
- Dorota Nemecz
- Biochemistry
Department, Nicolaus Copernicus University
in Torun, 87-100 Torun, Poland
| | - Weronika A. Nowak
- Biochemistry
Department, Nicolaus Copernicus University
in Torun, 87-100 Torun, Poland
| | - Ákos Nemecz
- Biochemistry
Department, Nicolaus Copernicus University
in Torun, 87-100 Torun, Poland
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8
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Jalalypour F, Howard RJ, Lindahl E. Allosteric Cholesterol Site in Glycine Receptors Characterized through Molecular Simulations. J Phys Chem B 2024; 128:4996-5007. [PMID: 38747451 PMCID: PMC11129184 DOI: 10.1021/acs.jpcb.4c01703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/29/2024] [Accepted: 05/06/2024] [Indexed: 05/24/2024]
Abstract
Glycine receptors are pentameric ligand-gated ion channels that conduct chloride ions across postsynaptic membranes to facilitate fast inhibitory neurotransmission. In addition to gating by the glycine agonist, interactions with lipids and other compounds in the surrounding membrane environment modulate their function, but molecular details of these interactions remain unclear, in particular, for cholesterol. Here, we report coarse-grained simulations in a model neuronal membrane for three zebrafish glycine receptor structures representing apparent resting, open, and desensitized states. We then converted the systems to all-atom models to examine detailed lipid interactions. Cholesterol bound to the receptor at an outer-leaflet intersubunit site, with a preference for the open and desensitized versus resting states, indicating that it can bias receptor function. Finally, we used short atomistic simulations and iterative amino acid perturbations to identify residues that may mediate allosteric gating transitions. Frequent cholesterol contacts in atomistic simulations clustered with residues identified by perturbation analysis and overlapped with mutations influencing channel function and pathology. Cholesterol binding at this site was also observed in a recently reported pig heteromeric glycine receptor. These results indicate state-dependent lipid interactions relevant to allosteric transitions of glycine receptors, including specific amino acid contacts applicable to biophysical modeling and pharmaceutical design.
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Affiliation(s)
- Farzaneh Jalalypour
- Science
for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 17121 Solna, Sweden
| | - Rebecca J. Howard
- Science
for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 17121 Solna, Sweden
- Science
for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17121 Solna, Sweden
| | - Erik Lindahl
- Science
for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 17121 Solna, Sweden
- Science
for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17121 Solna, Sweden
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9
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Wang J, Zhang Z, Yu N, Wu X, Guo Z, Yan Y, Liu Z. Cys-loop ligand-gated ion channel superfamily of Pardosa pseudoannulata: Implication for natural enemy safety. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2024; 49:101190. [PMID: 38278045 DOI: 10.1016/j.cbd.2024.101190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/21/2023] [Accepted: 01/06/2024] [Indexed: 01/28/2024]
Abstract
Cys-loop ligand-gated channels mediate neurotransmission in insects and are receptors for many insecticides. Some insecticides acting on cysLGIC also have lethal effects on non-targeting organisms, but the mechanism of this negative effect is unclear due to information absence. The identification and analysis of cysLGIC family in Pardosa pseudoannulata, a pond wolf spider, can deepen the understanding of insecticides for natural enemy safety. Thirty-four cysLGIC genes were identified in P. pseudoannulata genome, including nicotinic acetylcholine receptors, γ-aminobutyric acid gated chloride channels, glutamate-gated chloride channels, histamine-gated chloride channels, and pH-sensitive chloride channels. The expansion of GABACls and HisCls accounts for the large number of cysLGICs in P. pseudoannulata, and the alternative splicing events in nAChR and RDL subunits enriched the diversity of the superfamily. Most cysLGIC genes show the highest expression in brain and lowest expression in the early-egg sac stage. Variable residues (R81, V83, R135, N137, F190, and W197) in P. pseudoannulata nAChR β subunits and critical differences in α6 subunit TM4 region compared with insects would apply for the insensitivity to neonicotinoids and spinosyn. In contrast, avermectin and dieldrin may be lethal to P. pseudoannulata due to the similar drugs binding sites in GluCls compared with insects. These findings will provide a valuable clue for natural enemy protection and environmentally friendly insecticide development.
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Affiliation(s)
- Jingting Wang
- Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Zhen Zhang
- Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Na Yu
- Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Xun Wu
- Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Zonglei Guo
- Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Yangyang Yan
- Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Zewen Liu
- Key laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
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10
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Taujale R, Gravel N, Zhou Z, Yeung W, Kochut K, Kannan N. Informatic challenges and advances in illuminating the druggable proteome. Drug Discov Today 2024; 29:103894. [PMID: 38266979 DOI: 10.1016/j.drudis.2024.103894] [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: 10/15/2023] [Revised: 01/08/2024] [Accepted: 01/17/2024] [Indexed: 01/26/2024]
Abstract
The understudied members of the druggable proteomes offer promising prospects for drug discovery efforts. While large-scale initiatives have generated valuable functional information on understudied members of the druggable gene families, translating this information into actionable knowledge for drug discovery requires specialized informatics tools and resources. Here, we review the unique informatics challenges and advances in annotating understudied members of the druggable proteome. We demonstrate the application of statistical evolutionary inference tools, knowledge graph mining approaches, and protein language models in illuminating understudied protein kinases, pseudokinases, and ion channels.
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Affiliation(s)
- Rahil Taujale
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Nathan Gravel
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | | | - Wayland Yeung
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Krystof Kochut
- School of Computing, University of Georgia, Athens, GA, USA
| | - Natarajan Kannan
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA; Institute of Bioinformatics, University of Georgia, Athens, GA, USA.
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11
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Burke SM, Avstrikova M, Noviello CM, Mukhtasimova N, Changeux JP, Thakur GA, Sine SM, Cecchini M, Hibbs RE. Structural mechanisms of α7 nicotinic receptor allosteric modulation and activation. Cell 2024; 187:1160-1176.e21. [PMID: 38382524 PMCID: PMC10950261 DOI: 10.1016/j.cell.2024.01.032] [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: 08/31/2023] [Revised: 12/05/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024]
Abstract
The α7 nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel that plays an important role in cholinergic signaling throughout the nervous system. Its unique physiological characteristics and implications in neurological disorders and inflammation make it a promising but challenging therapeutic target. Positive allosteric modulators overcome limitations of traditional α7 agonists, but their potentiation mechanisms remain unclear. Here, we present high-resolution structures of α7-modulator complexes, revealing partially overlapping binding sites but varying conformational states. Structure-guided functional and computational tests suggest that differences in modulator activity arise from the stable rotation of a channel gating residue out of the pore. We extend the study using a time-resolved cryoelectron microscopy (cryo-EM) approach to reveal asymmetric state transitions for this homomeric channel and also find that a modulator with allosteric agonist activity exploits a distinct channel-gating mechanism. These results define mechanisms of α7 allosteric modulation and activation with implications across the pentameric receptor superfamily.
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Affiliation(s)
- Sean M Burke
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mariia Avstrikova
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, 67081 Strasbourg Cedex, France
| | - Colleen M Noviello
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nuriya Mukhtasimova
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55902, USA
| | - Jean-Pierre Changeux
- Neuroscience Department, Institut Pasteur, Collège de France, 75015 Paris, France
| | - Ganesh A Thakur
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Steven M Sine
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN 55902, USA; Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN 55902, USA.
| | - Marco Cecchini
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, 67081 Strasbourg Cedex, France.
| | - Ryan E Hibbs
- Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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12
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Yang Y, Arai T, Sasaki D, Kuramochi M, Inagaki H, Ohashi S, Sekiguchi H, Mio K, Kubo T, Sasaki YC. Real-time tilting and twisting motions of ligand-bound states of α7 nicotinic acetylcholine receptor. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2024; 53:15-25. [PMID: 38233601 PMCID: PMC10853312 DOI: 10.1007/s00249-023-01693-6] [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: 06/21/2023] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 01/19/2024]
Abstract
The α7 nicotinic acetylcholine receptor is a member of the nicotinic acetylcholine receptor family and is composed of five α7 subunits arranged symmetrically around a central pore. It is localized in the central nervous system and immune cells and could be a target for treating Alzheimer's disease and schizophrenia. Acetylcholine is a ligand that opens the channel, although prolonged application rapidly decreases the response. Ivermectin was reported as one of the positive allosteric modulators, since the binding of Ivermectin to the channel enhances acetylcholine-evoked α7 currents. One research has suggested that tilting motions of the nicotinic acetylcholine receptor are responsible for channel opening and activation. To verify this hypothesis applies to α7 nicotinic acetylcholine receptor, we utilized a diffracted X-ray tracking method to monitor the stable twisting and tilting motion of nAChR α7 without a ligand, with acetylcholine, with Ivermectin, and with both of them. The results show that the α7 nicotinic acetylcholine receptor twists counterclockwise with the channel transiently opening, transitioning to a desensitized state in the presence of acetylcholine and clockwise without the channel opening in the presence of Ivermectin. We propose that the conformational transition of ACh-bound nAChR α7 may be due to the collective twisting of the five α7 subunits, resulting in the compression and movement, either downward or upward, of one or more subunits, thus manifesting tilting motions. These tilting motions possibly represent the transition from the resting state to channel opening and potentially to the desensitized state.
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Affiliation(s)
- Yue Yang
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Tatsuya Arai
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan
| | - Daisuke Sasaki
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan
| | - Masahiro Kuramochi
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, 316-8511, Japan
| | - Hidetoshi Inagaki
- Biomedical Research Insitute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan
| | - Sumiko Ohashi
- Biomedical Research Insitute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan
| | - Hiroshi Sekiguchi
- Center for Synchrotron Radiation Research, Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | - Kazuhiro Mio
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan
| | - Tai Kubo
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan
| | - Yuji C Sasaki
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan.
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan.
- Center for Synchrotron Radiation Research, Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan.
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13
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Pitman C, Santiago-McRae E, Lohia R, Bassi K, Joseph TT, Hansen MEB, Brannigan G. The blobulator: a webtool for identification and visual exploration of hydrophobic modularity in protein sequences. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.15.575761. [PMID: 38293114 PMCID: PMC10827107 DOI: 10.1101/2024.01.15.575761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Motivation Clusters of hydrophobic residues are known to promote structured protein stability and drive protein aggregation. Recent work has shown that identifying contiguous hydrophobic residue clusters (termed "blobs") has proven useful in both intrinsically disordered protein (IDP) simulation and human genome studies. However, a graphical interface was unavailable. Results Here, we present the blobulator: an interactive and intuitive web interface to detect intrinsic modularity in any protein sequence based on hydrophobicity. We demonstrate three use cases of the blobulator and show how identifying blobs with biologically relevant parameters provides useful information about a globular protein, two orthologous membrane proteins, and an IDP. Other potential applications are discussed, including: predicting protein segments with critical roles in tertiary interactions, providing a definition of local order and disorder with clear edges, and aiding in predicting protein features from sequence. Availability The blobulator GUI can be found at www.blobulator.branniganlab.org, and the source code with pip installable command line tool can be found on GitHub at www.GitHub.com/BranniganLab/blobulator.
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Affiliation(s)
- Connor Pitman
- Center for Computational and Integrative Biology, Rutgers University-Camden, 201 Broadway, 08103, NJ, USA
| | - Ezry Santiago-McRae
- Center for Computational and Integrative Biology, Rutgers University-Camden, 201 Broadway, 08103, NJ, USA
| | - Ruchi Lohia
- Department of Physiology, University of Toronto, 1 King's College Circle, M5S 1A8, Toronto, Ontario, Canada
| | - Kaitlin Bassi
- Center for Computational and Integrative Biology, Rutgers University-Camden, 201 Broadway, 08103, NJ, USA
| | - Thomas T Joseph
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, JMB 305, 3620 Hamilton Walk, 19104, PA, USA
| | - Matthew E B Hansen
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd, 19104, PA, USA
| | - Grace Brannigan
- Center for Computational and Integrative Biology, Rutgers University-Camden, 201 Broadway, 08103, NJ, USA
- Department of Physics, Rutgers University-Camden, 201 Broadway, 08103, NJ, USA
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14
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Daboe M, Parlak C, Direm A, Alver Ö, Ramasami P. Interaction between escitalopram and ibuprofen or paracetamol: DFT and molecular docking on the drug-drug interactions. J Biomol Struct Dyn 2024; 42:672-686. [PMID: 37042928 DOI: 10.1080/07391102.2023.2195004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 03/17/2023] [Indexed: 04/13/2023]
Abstract
A large number of drugs are introduced each year to treat different diseases. Most of the time, patients suffer from more than one health problem which makes it necessary to take multiple drugs. When drugs are combined, the problem of drug-drug interaction becomes relevant. In this work, we studied the drug-drug interaction between escitalopram and ibuprofen or paracetamol using density functional theory and quantum theory of atoms in molecules. The results suggest that following the interactions, the activity of drugs changes according to site of interaction. Most reactive and most stable interactions would be preferable for the purpose of use. The in silico drug-likeness studies show that escitalopram and paracetamol couple is more bioavailable than escitalopram and ibuprofen couple. Moreover, in order to gain additional insights into the mentioned drugs' interactions, the drugs were docked separately and jointly against the potential targets for antidepressants and NSAIDs, namely 6HIS and 2PXX. The molecular docking results showed a potential improvement of the effectiveness of the drugs after combining by forming hydrogen bonds, hydrophobic contacts and π…π stacking.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Musa Daboe
- Department of Physics, Science Faculty, Ege University, Izmir, Turkey
| | - Cemal Parlak
- Department of Physics, Science Faculty, Ege University, Izmir, Turkey
| | - Amani Direm
- Department of Matter Sciences, Faculty of Sciences and Technology, Abbes Laghrour University, Khenchela, Algeria
- Laboratory of Structures, Properties and Interatomic Interactions LASPI2A, Faculty of Sciences and Technology, Abbes Laghrour University, Khenchela, Algeria
| | - Özgür Alver
- Department of Physics, Science Faculty, Eskişehir Technical University, Eskişehir, Turkey
| | - Ponnadurai Ramasami
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit, Mauritius
- Department of Chemistry College of Science, Engineering and Technology, University of South Africa, Pretoria, South Africa
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15
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Kasaragod VB, Malinauskas T, Wahid AA, Lengyel J, Knoflach F, Hardwick SW, Jones CF, Chen WN, Lucas X, El Omari K, Chirgadze DY, Aricescu AR, Cecere G, Hernandez MC, Miller PS. The molecular basis of drug selectivity for α5 subunit-containing GABA A receptors. Nat Struct Mol Biol 2023; 30:1936-1946. [PMID: 37903907 PMCID: PMC10716045 DOI: 10.1038/s41594-023-01133-1] [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: 02/28/2023] [Accepted: 09/20/2023] [Indexed: 11/01/2023]
Abstract
α5 subunit-containing γ-aminobutyric acid type A (GABAA) receptors represent a promising drug target for neurological and neuropsychiatric disorders. Altered expression and function contributes to neurodevelopmental disorders such as Dup15q and Angelman syndromes, developmental epilepsy and autism. Effective drug action without side effects is dependent on both α5-subtype selectivity and the strength of the positive or negative allosteric modulation (PAM or NAM). Here we solve structures of drugs bound to the α5 subunit. These define the molecular basis of binding and α5 selectivity of the β-carboline, methyl 6,7-dimethoxy-4-ethyl-β-carboline-3-carboxylate (DMCM), type II benzodiazepine NAMs, and a series of isoxazole NAMs and PAMs. For the isoxazole series, each molecule appears as an 'upper' and 'lower' moiety in the pocket. Structural data and radioligand binding data reveal a positional displacement of the upper moiety containing the isoxazole between the NAMs and PAMs. Using a hybrid molecule we directly measure the functional contribution of the upper moiety to NAM versus PAM activity. Overall, these structures provide a framework by which to understand distinct modulator binding modes and their basis of α5-subtype selectivity, appreciate structure-activity relationships, and empower future structure-based drug design campaigns.
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Affiliation(s)
- Vikram Babu Kasaragod
- Department of Pharmacology, University of Cambridge, Cambridge, UK
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Ayla A Wahid
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Judith Lengyel
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center, Basel, Switzerland
| | - Frederic Knoflach
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center, Basel, Switzerland
| | - Steven W Hardwick
- CryoEM Facility, Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | - Wan-Na Chen
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Xavier Lucas
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center, Basel, Switzerland
| | - Kamel El Omari
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Dimitri Y Chirgadze
- CryoEM Facility, Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - A Radu Aricescu
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Giuseppe Cecere
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center, Basel, Switzerland
| | - Maria-Clemencia Hernandez
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center, Basel, Switzerland.
| | - Paul S Miller
- Department of Pharmacology, University of Cambridge, Cambridge, UK.
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16
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Li C, Gao D, Gao Y, Zhang R, Qu X, Li S, Xing C. NIR-II Regulation of Mitochondrial Potassium Channel with Dual-Targeted Conjugated Oligomer Nanoparticles for Efficient Cancer Theranostics In Vivo. Adv Healthc Mater 2023; 12:e2301954. [PMID: 37722719 DOI: 10.1002/adhm.202301954] [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: 06/21/2023] [Revised: 09/13/2023] [Indexed: 09/20/2023]
Abstract
Cell fate can be efficiently modulated by switching ion channels. However, the precise regulation of ion channels in cells, especially in specific organelles, remains challenging. Herein, biomimetic second near-infrared (NIR-II) responsive conjugated oligomer nanoparticles with dual-targeted properties are designed and prepared to modulate the ion channels of mitochondria to selectively kill malignant cells in vivo. Upon 1060 nm laser irradiation, the mitochondria-located nanoparticles photothermally release a specific ion inhibitor of the potassium channel via a temperature-sensitive liposome, thus altering the redox balance and pathways of mitochondria. NIR-II responsive nanoparticles can effectively regulate the potassium channels of mitochondria and fully suppress tumor growth. This work provides a new modality based on the NIR-II nanoplatform to regulate ion channels in specific organelles and proposes an effective therapeutic mechanism for malignant tumors.
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Affiliation(s)
- Chaoqun Li
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300130, P. R. China
| | - Dong Gao
- School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Tianjin, 300130, P. R. China
| | - Yijian Gao
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, P. R. China
| | - Ran Zhang
- School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Tianjin, 300130, P. R. China
| | - Xiongwei Qu
- School of Chemical Engineering, Hebei University of Technology, Tianjin, 300130, P. R. China
| | - Shengliang Li
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, P. R. China
| | - Chengfen Xing
- School of Materials Science and Engineering, Hebei University of Technology, Tianjin, 300130, P. R. China
- School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Tianjin, 300130, P. R. China
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17
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Fricska DI, Mesoy SM, Lummis SCR. The MA Helix Is Important for Receptor Assembly and Function in the α4β2 nACh Receptor. MEMBRANES 2023; 13:891. [PMID: 38132895 PMCID: PMC10744633 DOI: 10.3390/membranes13120891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 11/22/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023]
Abstract
Pentameric ligand-gated ion channels (pLGICs) are expressed throughout the central and peripheral nervous systems of vertebrates and modulate many aspects of human health and disease. Recent structural and computational data indicate that cation-selective pLGICs contain a long helical extension (MA) of one of the transmembrane helices. The MA helix has been shown to affect both the membrane expression of, and ion conductance levels through, these pLGICs. Here we probe the functional effects of 68 mutations in the MA region of the α4β2 nicotinic acetylcholine receptor (nAChR), using a voltage-sensitive membrane dye and radioligand binding to measure receptor function and expression/assembly. We found seven alanine mutations in a stretch of the MA helix that prevent correct receptor folding and/or assembly, as evidenced by the lack of both function and ligand binding. A further two alanine mutations resulted in receptors that were capable of binding ligand but showed no functional response, and we propose that, in these mutants, ligand binding is insufficient to trigger channel opening. The data clarify the effect of the MA helix, and as the effects of some of our mutations in the α4β2 nAChR differ from the effects of equivalent mutations in other cation-selective pLGICs, we suggest that residues in the MA helix may play subtly different roles in different receptors.
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Affiliation(s)
| | | | - Sarah C. R. Lummis
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK; (D.I.F.); (S.M.M.)
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18
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Pohl F, Germann AL, Mao J, Hou S, Bakare B, Kong Thoo Lin P, Yates K, Nonet ML, Akk G, Kornfeld K, Held JM. UNC-49 is a redox-sensitive GABA A receptor that regulates the mitochondrial unfolded protein response cell nonautonomously. SCIENCE ADVANCES 2023; 9:eadh2584. [PMID: 37910615 PMCID: PMC10619936 DOI: 10.1126/sciadv.adh2584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 09/29/2023] [Indexed: 11/03/2023]
Abstract
The γ-aminobutyric acid-mediated (GABAergic) system participates in many aspects of organismal physiology and disease, including proteostasis, neuronal dysfunction, and life-span extension. Many of these phenotypes are also regulated by reactive oxygen species (ROS), but the redox mechanisms linking the GABAergic system to these phenotypes are not well defined. Here, we report that GABAergic redox signaling cell nonautonomously activates many stress response pathways in Caenorhabditis elegans and enhances vulnerability to proteostasis disease in the absence of oxidative stress. Cell nonautonomous redox activation of the mitochondrial unfolded protein response (mitoUPR) proteostasis network requires UNC-49, a GABAA receptor that we show is activated by hydrogen peroxide. MitoUPR induction by a spinocerebellar ataxia type 3 (SCA3) C. elegans neurodegenerative disease model was similarly dependent on UNC-49 in C. elegans. These results demonstrate a multi-tissue paradigm for redox signaling in the GABAergic system that is transduced via a GABAA receptor to function in cell nonautonomous regulation of health, proteostasis, and disease.
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Affiliation(s)
- Franziska Pohl
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Allison L. Germann
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Jack Mao
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Sydney Hou
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Bayode Bakare
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK
| | - Paul Kong Thoo Lin
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK
| | - Kyari Yates
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK
| | - Michael L. Nonet
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Gustav Akk
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Jason M. Held
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
- Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, USA
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19
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Sinclair P, Kabbani N. Ionotropic and metabotropic responses by alpha 7 nicotinic acetylcholine receptors. Pharmacol Res 2023; 197:106975. [PMID: 38032294 DOI: 10.1016/j.phrs.2023.106975] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/12/2023] [Accepted: 10/26/2023] [Indexed: 12/01/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) belong to a superfamily of cys-loop receptors characterized by the assembly of five subunits into a multi-protein channel complex. Ligand binding to nAChRs activates rapid allosteric transitions of the receptor leading to channel opening and ion flux in neuronal and non-neuronal cell. Thus, while ionotropic properties of nAChRs are well recognized, less is known about ligand-mediated intracellular metabotropic signaling responses. Studies in neural and non-neural cells confirm ionotropic and metabotropic channel responses following ligand binding. In this review we summarize evidence on the existence of ionotropic and metabotropic signaling responses by homopentameric α7 nAChRs in various cell types. We explore how coordinated calcium entry through the ion channel and calcium release from nearby stores gives rise to signaling important for the modulation of cytoskeletal motility and cell growth. Amino acid residues for intracellular protein binding within the α7 nAChR support engagement in metabotropic responses including signaling through heterotrimeric G proteins in neural and immune cells. Understanding the dual properties of ionotropic and metabotropic nAChR responses is essential in advancing drug development for the treatment of various human disease.
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Affiliation(s)
| | - Nadine Kabbani
- Interdisciplinary Program in Neuroscience, Fairfax, VA, USA; School of Systems Biology, George Mason University, Fairfax, VA, USA.
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20
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Liu X, Wang W. Asymmetric gating of a human hetero-pentameric glycine receptor. Nat Commun 2023; 14:6377. [PMID: 37821459 PMCID: PMC10567788 DOI: 10.1038/s41467-023-42051-6] [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: 12/16/2022] [Accepted: 09/28/2023] [Indexed: 10/13/2023] Open
Abstract
Hetero-pentameric Cys-loop receptors constitute a major type of neurotransmitter receptors that enable signal transmission and processing in the nervous system. Despite intense investigations into their working mechanism and pharmaceutical potentials, how neurotransmitters activate these receptors remains unclear due to the lack of high-resolution structural information in the activated open state. Here we report near-atomic resolution structures resolved in digitonin consistent with all principle functional states of the human α1β GlyR, which is a major Cys-loop receptor that mediates inhibitory neurotransmission in the central nervous system of adults. Glycine binding induces cooperative and symmetric structural rearrangements in the neurotransmitter-binding extracellular domain but asymmetrical pore dilation in the transmembrane domain. Symmetric response in the extracellular domain is consistent with electrophysiological data showing cooperative glycine activation and contribution from both α1 and β subunits. A set of functionally essential but differentially charged amino acid residues in the transmembrane domain of the α1 and β subunits explains asymmetric activation. These findings provide a foundation for understanding how the gating of the Cys-loop receptor family members diverges to accommodate specific physiological environments.
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Affiliation(s)
- Xiaofen Liu
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weiwei Wang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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21
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Raisch T, Raunser S. The modes of action of ion-channel-targeting neurotoxic insecticides: lessons from structural biology. Nat Struct Mol Biol 2023; 30:1411-1427. [PMID: 37845413 DOI: 10.1038/s41594-023-01113-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 08/31/2023] [Indexed: 10/18/2023]
Abstract
Insecticides are indispensable tools for plant protection in modern agriculture. Despite having highly heterogeneous structures, many neurotoxic insecticides use similar principles to inhibit or deregulate neuronal ion channels. Insecticides targeting pentameric ligand-gated channels are structural mimetics of neurotransmitters or manipulate and deregulate the proteins. Those binding to (pseudo-)tetrameric voltage-gated(-like) channels, on the other hand, are natural or synthetic compounds that directly block the ion-conducting pore or prevent conformational changes in the transmembrane domain necessary for opening and closing the pore. The use of a limited number of inhibition mechanisms can be problematic when resistances arise and become more widespread. Therefore, there is a rising interest in the development of insecticides with novel mechanisms that evade resistance and are pest-insect-specific. During the last decade, most known insecticide targets, many with bound compounds, have been structurally characterized, bringing the rational design of novel classes of agrochemicals within closer reach than ever before.
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Affiliation(s)
- Tobias Raisch
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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22
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Prevost MS, Barilone N, Dejean de la Bâtie G, Pons S, Ayme G, England P, Gielen M, Bontems F, Pehau-Arnaudet G, Maskos U, Lafaye P, Corringer PJ. An original potentiating mechanism revealed by the cryo-EM structures of the human α7 nicotinic receptor in complex with nanobodies. Nat Commun 2023; 14:5964. [PMID: 37749098 PMCID: PMC10520083 DOI: 10.1038/s41467-023-41734-4] [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: 01/05/2023] [Accepted: 09/15/2023] [Indexed: 09/27/2023] Open
Abstract
The human α7 nicotinic receptor is a pentameric channel mediating cellular and neuronal communication. It has attracted considerable interest in designing ligands for the treatment of neurological and psychiatric disorders. To develop a novel class of α7 ligands, we recently generated two nanobodies named E3 and C4, acting as positive allosteric modulator and silent allosteric ligand, respectively. Here, we solved the cryo-electron microscopy structures of the nanobody-receptor complexes. E3 and C4 bind to a common epitope involving two subunits at the apex of the receptor. They form by themselves a symmetric pentameric assembly that extends the extracellular domain. Unlike C4, the binding of E3 drives an agonist-bound conformation of the extracellular domain in the absence of an orthosteric agonist, and mutational analysis shows a key contribution of an N-linked sugar moiety in mediating E3 potentiation. The nanobody E3, by remotely controlling the global allosteric conformation of the receptor, implements an original mechanism of regulation that opens new avenues for drug design.
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Affiliation(s)
- Marie S Prevost
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France.
| | - Nathalie Barilone
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
| | | | - Stéphanie Pons
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Integrative Neurobiology of Cholinergic Systems Unit, Paris, France
| | - Gabriel Ayme
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Antibody Engineering Platform, Paris, France
| | - Patrick England
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Molecular Biophysics Platform, Paris, France
| | - Marc Gielen
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
- Sorbonne Université, Paris, France
| | - François Bontems
- Institut Pasteur, Université Paris Cité, CNRS UMR 3569, Structural Virology Unit, Paris, France
- Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, Université Paris Saclay, Gif-sur-Yvette, France
| | - Gérard Pehau-Arnaudet
- Institut Pasteur, Université Paris Cité, Ultrastructural Bioimaging Core Facility, Paris, France
| | - Uwe Maskos
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Integrative Neurobiology of Cholinergic Systems Unit, Paris, France
| | - Pierre Lafaye
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Antibody Engineering Platform, Paris, France
| | - Pierre-Jean Corringer
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France.
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23
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Legesse DH, Fan C, Teng J, Zhuang Y, Howard RJ, Noviello CM, Lindahl E, Hibbs RE. Structural insights into opposing actions of neurosteroids on GABA A receptors. Nat Commun 2023; 14:5091. [PMID: 37607940 PMCID: PMC10444788 DOI: 10.1038/s41467-023-40800-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/10/2023] [Indexed: 08/24/2023] Open
Abstract
γ-Aminobutyric acid type A (GABAA) receptors mediate fast inhibitory signaling in the brain and are targets of numerous drugs and endogenous neurosteroids. A subset of neurosteroids are GABAA receptor positive allosteric modulators; one of these, allopregnanolone, is the only drug approved specifically for treating postpartum depression. There is a consensus emerging from structural, physiological and photolabeling studies as to where positive modulators bind, but how they potentiate GABA activation remains unclear. Other neurosteroids are negative modulators of GABAA receptors, but their binding sites remain debated. Here we present structures of a synaptic GABAA receptor bound to allopregnanolone and two inhibitory sulfated neurosteroids. Allopregnanolone binds at the receptor-bilayer interface, in the consensus potentiator site. In contrast, inhibitory neurosteroids bind in the pore. MD simulations and electrophysiology support a mechanism by which allopregnanolone potentiates channel activity and suggest the dominant mechanism for sulfated neurosteroid inhibition is through pore block.
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Affiliation(s)
| | - Chen Fan
- Dept. of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Jinfeng Teng
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
| | - Yuxuan Zhuang
- Dept. of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Rebecca J Howard
- Dept. of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Colleen M Noviello
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
| | - Erik Lindahl
- Dept. of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden.
- Dept. of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Solna, Sweden.
| | - Ryan E Hibbs
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, USA.
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA.
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24
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Papapostolou I, Ross-Kaschitza D, Bochen F, Peinelt C, Maldifassi MC. Contribution of the α5 nAChR Subunit and α5SNP to Nicotine-Induced Proliferation and Migration of Human Cancer Cells. Cells 2023; 12:2000. [PMID: 37566079 PMCID: PMC10417634 DOI: 10.3390/cells12152000] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/12/2023] Open
Abstract
Nicotine in tobacco is known to induce tumor-promoting effects and cause chemotherapy resistance through the activation of nicotinic acetylcholine receptors (nAChRs). Many studies have associated the α5 nicotinic receptor subunit (α5), and a specific polymorphism in this subunit, with (i) nicotine administration, (ii) nicotine dependence, and (iii) lung cancer. The α5 gene CHRNA5 mRNA is upregulated in several types of cancer, including lung, prostate, colorectal, and stomach cancer, and cancer severity is correlated with smoking. In this study, we investigate the contribution of α5 in the nicotine-induced cancer hallmark functions proliferation and migration, in breast, colon, and prostate cancer cells. Nine human cell lines from different origins were used to determine nAChR subunit expression levels. Then, selected breast (MCF7), colon (SW480), and prostate (DU145) cancer cell lines were used to investigate the nicotine-induced effects mediated by α5. Using pharmacological and siRNA-based experiments, we show that α5 is essential for nicotine-induced proliferation and migration. Additionally, upon downregulation of α5, nicotine-promoted expression of EMT markers and immune regulatory proteins was impaired. Moreover, the α5 polymorphism D398N (α5SNP) caused a basal increase in proliferation and migration in the DU145 cell line, and the effect was mediated through G-protein signaling. Taken together, our results indicate that nicotine-induced cancer cell proliferation and migration are mediated via α5, adding to the characterization of α5 as a putative therapeutical target.
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Affiliation(s)
| | | | | | | | - Maria Constanza Maldifassi
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012 Bern, Switzerland; (I.P.); (D.R.-K.); (F.B.); (C.P.)
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25
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Xu P, Zhang P, Zhu X, Wu Y, Harvey PJ, Kaas Q, Zhangsun D, Craik DJ, Luo S. Structure-Activity Relationships of Alanine Scan Mutants αO-Conotoxins GeXIVA[1,2] and GeXIVA[1,4]. J Med Chem 2023. [PMID: 37464764 DOI: 10.1021/acs.jmedchem.3c01023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
αO-Conotoxin GeXIVA is a selective α9α10 nicotinic acetylcholine receptor (nAChR) inhibitor displaying two disulfide bonds that can form three isomers. The bead (GeXIVA[1,2]) and ribbon (GeXIVA[1,4]) isomers possess the highest activity on rat and human α9α10 nAChRs. However, the molecular mechanism by which they inhibit the α9α10 nAChR is unknown. Here, an alanine scan of GeXIVA was used to elucidate key interactions between the peptides and the α9α10 nAChR. The majority of GeXIVA[1,2] analogues preserved affinity at α9α10 nAChR, but [R17A]GeXIVA[1,2] enhanced selectivity on the α9α10 nAChR. The I23A replacement of GeXIVA[1,4] increased activity at both rat and human α9α10 nAChRs by 10-fold. Surprisingly, these results do not support the molecular model of an interaction in the orthosteric binding site proposed previously, but rather may involve allosteric coupling with the voltage-sensitive domain of the α9α10 nAChR. These results could help to guide further development of GeXIVA analogues as analgesics.
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Affiliation(s)
- Pan Xu
- School of Medicine, Guangxi University, Nanning 530004, China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, China
| | - Panpan Zhang
- School of Medicine, Guangxi University, Nanning 530004, China
| | - Xiaopeng Zhu
- School of Medicine, Guangxi University, Nanning 530004, China
| | - Yong Wu
- School of Medicine, Guangxi University, Nanning 530004, China
| | - Peta J Harvey
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Dongting Zhangsun
- School of Medicine, Guangxi University, Nanning 530004, China
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sulan Luo
- School of Medicine, Guangxi University, Nanning 530004, China
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
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26
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Goswami U, Rahman MM, Teng J, Hibbs RE. Structural interplay of anesthetics and paralytics on muscle nicotinic receptors. Nat Commun 2023; 14:3169. [PMID: 37264005 DOI: 10.1038/s41467-023-38827-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/17/2023] [Indexed: 06/03/2023] Open
Abstract
General anesthetics and neuromuscular blockers are used together during surgery to stabilize patients in an unconscious state. Anesthetics act mainly by potentiating inhibitory ion channels and inhibiting excitatory ion channels, with the net effect of dampening nervous system excitability. Neuromuscular blockers act by antagonizing nicotinic acetylcholine receptors at the motor endplate; these excitatory ligand-gated ion channels are also inhibited by general anesthetics. The mechanisms by which anesthetics and neuromuscular blockers inhibit nicotinic receptors are poorly understood but underlie safe and effective surgeries. Here we took a direct structural approach to define how a commonly used anesthetic and two neuromuscular blockers act on a muscle-type nicotinic receptor. We discover that the intravenous anesthetic etomidate binds at an intrasubunit site in the transmembrane domain and stabilizes a non-conducting, desensitized-like state of the channel. The depolarizing neuromuscular blocker succinylcholine also stabilizes a desensitized channel but does so through binding to the classical neurotransmitter site. Rocuronium binds in this same neurotransmitter site but locks the receptor in a resting, non-conducting state. Together, this study reveals a structural mechanism for how general anesthetics work on excitatory nicotinic receptors and further rationalizes clinical observations in how general anesthetics and neuromuscular blockers interact.
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Affiliation(s)
- Umang Goswami
- Department of Neuroscience and O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Md Mahfuzur Rahman
- Department of Neuroscience and O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Thermo Fisher Scientific, Rockford, IL, 61101, USA
| | - Jinfeng Teng
- Department of Neurobiology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ryan E Hibbs
- Department of Neuroscience and O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Department of Neurobiology, University of California, San Diego, La Jolla, CA, 92093, USA.
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27
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Li Q, Nemecz Á, Aymé G, Dejean de la Bâtie G, Prevost MS, Pons S, Barilone N, Baachaoui R, Maskos U, Lafaye P, Corringer PJ. Generation of nanobodies acting as silent and positive allosteric modulators of the α7 nicotinic acetylcholine receptor. Cell Mol Life Sci 2023; 80:164. [PMID: 37231269 DOI: 10.1007/s00018-023-04779-8] [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: 12/15/2022] [Revised: 03/28/2023] [Accepted: 04/07/2023] [Indexed: 05/27/2023]
Abstract
The α7 nicotinic acetylcholine receptor (nAChR), a potential drug target for treating cognitive disorders, mediates communication between neuronal and non-neuronal cells. Although many competitive antagonists, agonists, and partial-agonists have been found and synthesized, they have not led to effective therapeutic treatments. In this context, small molecules acting as positive allosteric modulators binding outside the orthosteric, acetylcholine, site have attracted considerable interest. Two single-domain antibody fragments, C4 and E3, against the extracellular domain of the human α7-nAChR were generated through alpaca immunization with cells expressing a human α7-nAChR/mouse 5-HT3A chimera, and are herein described. They bind to the α7-nAChR but not to the other major nAChR subtypes, α4β2 and α3β4. E3 acts as a slowly associating positive allosteric modulator, strongly potentiating the acetylcholine-elicited currents, while not precluding the desensitization of the receptor. An E3-E3 bivalent construct shows similar potentiating properties but displays very slow dissociation kinetics conferring quasi-irreversible properties. Whereas, C4 does not alter the receptor function, but fully inhibits the E3-evoked potentiation, showing it is a silent allosteric modulator competing with E3 binding. Both nanobodies do not compete with α-bungarotoxin, localizing at an allosteric extracellular binding site away from the orthosteric site. The functional differences of each nanobody, as well as the alteration of functional properties through nanobody modifications indicate the importance of this extracellular site. The nanobodies will be useful for pharmacological and structural investigations; moreover, they, along with the extracellular site, have a direct potential for clinical applications.
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Affiliation(s)
- Qimeng Li
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Antibody Engineering Platform, Paris, France
- Lanzhou Institute of Biological Product Co., Lanzhou, China
- Sorbonne Université, Collège Doctoral, Paris, France
| | - Ákos Nemecz
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France.
| | - Gabriel Aymé
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Antibody Engineering Platform, Paris, France.
| | | | - Marie S Prevost
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
| | - Stéphanie Pons
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Integrative Neurobiology of Cholinergic Systems Unit, Paris, France
| | - Nathalie Barilone
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
| | - Rayen Baachaoui
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Antibody Engineering Platform, Paris, France
| | - Uwe Maskos
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Integrative Neurobiology of Cholinergic Systems Unit, Paris, France
| | - Pierre Lafaye
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Antibody Engineering Platform, Paris, France
| | - Pierre-Jean Corringer
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France.
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28
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Conners R, León-Quezada RI, McLaren M, Bennett NJ, Daum B, Rakonjac J, Gold VAM. Cryo-electron microscopy of the f1 filamentous phage reveals insights into viral infection and assembly. Nat Commun 2023; 14:2724. [PMID: 37169795 PMCID: PMC10175506 DOI: 10.1038/s41467-023-37915-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 04/04/2023] [Indexed: 05/13/2023] Open
Abstract
Phages are viruses that infect bacteria and dominate every ecosystem on our planet. As well as impacting microbial ecology, physiology and evolution, phages are exploited as tools in molecular biology and biotechnology. This is particularly true for the Ff (f1, fd or M13) phages, which represent a widely distributed group of filamentous viruses. Over nearly five decades, Ffs have seen an extraordinary range of applications, yet the complete structure of the phage capsid and consequently the mechanisms of infection and assembly remain largely mysterious. In this work, we use cryo-electron microscopy and a highly efficient system for production of short Ff-derived nanorods to determine a structure of a filamentous virus including the tips. We show that structure combined with mutagenesis can identify phage domains that are important in bacterial attack and for release of new progeny, allowing new models to be proposed for the phage lifecycle.
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Affiliation(s)
- Rebecca Conners
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Rayén Ignacia León-Quezada
- School of Natural Sciences, Massey University, Palmerston North, New Zealand
- Nanophage Technologies, Palmerston North, New Zealand
| | - Mathew McLaren
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Nicholas J Bennett
- School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Bertram Daum
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Jasna Rakonjac
- School of Natural Sciences, Massey University, Palmerston North, New Zealand.
- Nanophage Technologies, Palmerston North, New Zealand.
| | - Vicki A M Gold
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
- Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4QD, UK.
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29
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Zhan E, Jiang J, Wang Y, Zhang K, Tang T, Chen Y, Jia Z, Wang Q, Zhao C. Shisa reduces the sensitivity of homomeric RDL channel to GABA in the two-spotted spider mite, Tetranychus urticae Koch. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 192:105414. [PMID: 37105623 DOI: 10.1016/j.pestbp.2023.105414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 06/19/2023]
Abstract
The γ-aminobutyric acid receptors (GABARs) mediate fast inhibitory transmission in central nervous system of insects and are important targets of insecticides. An auxiliary subunit, Shisa7, was identified in mammals as a single-passing transmembrane protein. However, the homology gene(s) of Shisa in invertebrates has not been reported to date. In the present study, a homolog Shisa gene was identified from the two-spotted spider mite, Tetranychus urticae Koch. Its open reading frame had 927 base pairs and encoded 308 amino acid residues, which has a typical Shisa domain at 13th-181st amino acid residues. According to the phylogenetic tree, the invertebrate Shisa was categorized apart with those of vertebrate, and TuShisa showed closest relationship with the Shisa9 of velvet mite, Dinothrombium tinctorium (L.). In the electrophysiological assay with two-electrode voltage clamp, the GABA-activated TuRDL channel was functionally formed in the Africa clawed frog Xenopus laevis (Daudin) oocytes (EC50 = 53.34 μM). No GABA-activated current could be observed in TuShisa-expressed oocytes, whereas TuShisa could reduce the sensitivity of TuRDL/TuShisa (mass ratio of 1: 4) channel to GABA. The homology structural models of TuRDL and TuShisa were built by the SWISS-MODEL server, their interaction was predicted using Z-DOCK and three predicted hydrogen bonds and interface residues were analysed by PyMOL. Meanwhile, the key interface residues of TuShisa affected the stability of complex were calculated by Discovery Studio 2019. In conclusion, the TuShisa, as the first reported invertebrate Shisa, was explored and functionally examined as the GABARs auxiliary subunit. Our findings provide a basis for research of invertebrate Shisa.
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Affiliation(s)
- Enling Zhan
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Jie Jiang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Ying Wang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Kexin Zhang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Tao Tang
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, PR China.
| | - Yiqu Chen
- College of Plant Science, Tibet Agricultural and Animal Husbandry University, Nyingchi 860000, PR China.
| | - Zhongqiang Jia
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Qiuxia Wang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Chunqing Zhao
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China.
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30
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Gao Y, Amon JD, Artzi L, Ramírez-Guadiana FH, Brock KP, Cofsky JC, Marks DS, Kruse AC, Rudner DZ. Bacterial spore germination receptors are nutrient-gated ion channels. Science 2023; 380:387-391. [PMID: 37104613 PMCID: PMC11154005 DOI: 10.1126/science.adg9829] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/29/2023] [Indexed: 04/29/2023]
Abstract
Bacterial spores resist antibiotics and sterilization and can remain metabolically inactive for decades, but they can rapidly germinate and resume growth in response to nutrients. Broadly conserved receptors embedded in the spore membrane detect nutrients, but how spores transduce these signals remains unclear. Here, we found that these receptors form oligomeric membrane channels. Mutations predicted to widen the channel initiated germination in the absence of nutrients, whereas those that narrow it prevented ion release and germination in response to nutrients. Expressing receptors with widened channels during vegetative growth caused loss of membrane potential and cell death, whereas the addition of germinants to cells expressing wild-type receptors triggered membrane depolarization. Therefore, germinant receptors act as nutrient-gated ion channels such that ion release initiates exit from dormancy.
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Affiliation(s)
- Yongqiang Gao
- Department of Microbiology, Harvard Medical ScF(2hool, 77 Avenue Louis Pasteur, Boston MA 02115
| | - Jeremy D. Amon
- Department of Microbiology, Harvard Medical ScF(2hool, 77 Avenue Louis Pasteur, Boston MA 02115
- Present Address: Moderna Genomics, 200 Technology Square, Cambridge MA 02139
| | - Lior Artzi
- Department of Microbiology, Harvard Medical ScF(2hool, 77 Avenue Louis Pasteur, Boston MA 02115
- Present Address: Evolved By Nature, 196 Boston Ave, Medford MA 02155
| | | | - Kelly P. Brock
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston MA 02115
- Present Address: Kernal Biologics, 238 Main Street, Cambrdige MA 02142
| | - Joshua C. Cofsky
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston MA 02115
| | - Deborah S. Marks
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston MA 02115
| | - Andrew C. Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston MA 02115
| | - David Z. Rudner
- Department of Microbiology, Harvard Medical ScF(2hool, 77 Avenue Louis Pasteur, Boston MA 02115
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31
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Bye LJ, Finol-Urdaneta RK, Tae HS, Adams DJ. Nicotinic acetylcholine receptors: Key targets for attenuating neurodegenerative diseases. Int J Biochem Cell Biol 2023; 157:106387. [PMID: 36754161 DOI: 10.1016/j.biocel.2023.106387] [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: 12/18/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/08/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are master regulators of immune functions via the cholinergic anti-inflammatory pathway and are expressed in microglia, the brain's resident immune cells. There is an extensive dialogue between the neurons and the glial cells around them from which microglia are tasked with monitoring, nurturing, and defending their microenvironment. Dysregulation of any of these processes can have devastating and long-lasting consequences involving microglia-mediated neuroinflammation associated with neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, amongst others. Disease-associated microglia acquire a distinguishing phenotype that emphasizes scavenging and defence functions while nurturing and repairing functions become muted. Attempts to resolve this critical imbalance remain a key focus of research. Furthermore, cholinergic modulation of neuroinflammation represents a promising avenue for treatment.
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Affiliation(s)
- Lydia J Bye
- Illawarra Health and Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, NSW 2522 Australia
| | - Rocio K Finol-Urdaneta
- Illawarra Health and Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, NSW 2522 Australia
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, NSW 2522 Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), Faculty of Science, Medicine and Health, University of Wollongong, NSW 2522 Australia.
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32
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Huang Q, Zhu W, Gao X, Liu X, Zhang Z, Xing B. Nanoparticles-mediated ion channels manipulation: From their membrane interactions to bioapplications. Adv Drug Deliv Rev 2023; 195:114763. [PMID: 36841331 DOI: 10.1016/j.addr.2023.114763] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/14/2023] [Accepted: 02/18/2023] [Indexed: 02/26/2023]
Abstract
Ion channels are transmembrane proteins ubiquitously expressed in all cells that control various ions (e.g. Na+, K+, Ca2+ and Cl- etc) crossing cellular plasma membrane, which play critical roles in physiological processes including regulating signal transduction, cell proliferation as well as excitatory cell excitation and conduction. Abnormal ion channel function is usually associated with dysfunctions and many diseases, such as neurodegenerative disorders, ophthalmic diseases, pulmonary diseases and even cancers. The precise regulation of ion channels not only helps to decipher physiological and pathological processes, but also is expected to become cutting-edge means for disease treatment. Recently, nanoparticles-mediated ion channel manipulation emerges as a highly promising way to meet the increasing requirements with respect to their simple, efficient, precise, spatiotemporally controllable and non-invasive regulation in biomedicine and other research frontiers. Thanks the advantages of their unique properties, nanoparticles can not only directly block the pore sites or kinetics of ion channels through their tiny size effect, and perturb active voltage-gated ion channel by their charged surface, but they can also act as antennas to conduct or enhance external physical stimuli to achieve spatiotemporal, precise and efficient regulation of various ion channel activities (e.g. light-, mechanical-, and temperature-gated ion channels etc). So far, nanoparticles-mediated ion channel regulation has shown potential prospects in many biomedical fields at the interfaces of neuro- and cardiovascular modulation, physiological function regeneration and tumor therapy et al. Towards such important fields, in this typical review, we specifically outline the latest studies of different types of ion channels and their activities relevant to the diseases. In addition, the different types of stimulation responsive nanoparticles, their interaction modes and targeting strategies towards the plasma membrane ion channels will be systematically summarized. More importantly, the ion channel regulatory methods mediated by functional nanoparticles and their bioapplications associated with physiological modulation and therapeutic development will be discussed. Last but not least, current challenges and future perspectives in this field will be covered as well.
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Affiliation(s)
- Qiwen Huang
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Weisheng Zhu
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xiaoyin Gao
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xinping Liu
- School of Pharmaceutical Science, University of South China, Hengyang 421001, China
| | - Zhijun Zhang
- Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China.
| | - Bengang Xing
- School of Chemistry, Chemical Engineering & Biotechnology, Nanyang Technological University, Singapore, 637371, Singapore.
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33
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Chrestia JF, Turani O, Araujo NR, Hernando G, Esandi MDC, Bouzat C. Regulation of nicotinic acetylcholine receptors by post-translational modifications. Pharmacol Res 2023; 190:106712. [PMID: 36863428 DOI: 10.1016/j.phrs.2023.106712] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 03/04/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) comprise a family of pentameric ligand-gated ion channels widely distributed in the central and peripheric nervous system and in non-neuronal cells. nAChRs are involved in chemical synapses and are key actors in vital physiological processes throughout the animal kingdom. They mediate skeletal muscle contraction, autonomic responses, contribute to cognitive processes, and regulate behaviors. Dysregulation of nAChRs is associated with neurological, neurodegenerative, inflammatory and motor disorders. In spite of the great advances in the elucidation of nAChR structure and function, our knowledge about the impact of post-translational modifications (PTMs) on nAChR functional activity and cholinergic signaling has lagged behind. PTMs occur at different steps of protein life cycle, modulating in time and space protein folding, localization, function, and protein-protein interactions, and allow fine-tuned responses to changes in the environment. A large body of evidence demonstrates that PTMs regulate all levels of nAChR life cycle, with key roles in receptor expression, membrane stability and function. However, our knowledge is still limited, restricted to a few PTMs, and many important aspects remain largely unknown. There is thus a long way to go to decipher the association of aberrant PTMs with disorders of cholinergic signaling and to target PTM regulation for novel therapeutic interventions. In this review we provide a comprehensive overview of what is known about how different PTMs regulate nAChR.
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Affiliation(s)
- Juan Facundo Chrestia
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Ornella Turani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Noelia Rodriguez Araujo
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Guillermina Hernando
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - María Del Carmen Esandi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca 8000, Argentina.
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Illumination of a progressive allosteric mechanism mediating the glycine receptor activation. Nat Commun 2023; 14:795. [PMID: 36781912 PMCID: PMC9925812 DOI: 10.1038/s41467-023-36471-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 02/02/2023] [Indexed: 02/15/2023] Open
Abstract
Pentameric ligand-gated ion channel mediate signal transduction at chemical synapses by transiting between resting and open states upon neurotransmitter binding. Here, we investigate the gating mechanism of the glycine receptor fluorescently labeled at the extracellular-transmembrane interface by voltage-clamp fluorometry (VCF). Fluorescence reports a glycine-elicited conformational change that precedes pore opening. Low concentrations of glycine, partial agonists or specific mixtures of glycine and strychnine trigger the full fluorescence signal while weakly activating the channel. Molecular dynamic simulations of a partial agonist bound-closed Cryo-EM structure show a highly dynamic nature: a marked structural flexibility at both the extracellular-transmembrane interface and the orthosteric site, generating docking properties that recapitulate VCF data. This work illuminates a progressive propagating transition towards channel opening, highlighting structural plasticity within the mechanism of action of allosteric effectors.
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Kumar L, Brenner N, Sledzieski S, Olaosebikan M, Roger LM, Lynn-Goin M, Klein-Seetharaman R, Berger B, Putnam H, Yang J, Lewinski NA, Singh R, Daniels NM, Cowen L, Klein-Seetharaman J. Transfer of knowledge from model organisms to evolutionarily distant non-model organisms: The coral Pocillopora damicornis membrane signaling receptome. PLoS One 2023; 18:e0270965. [PMID: 36735673 PMCID: PMC9897584 DOI: 10.1371/journal.pone.0270965] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 06/21/2022] [Indexed: 02/04/2023] Open
Abstract
With the ease of gene sequencing and the technology available to study and manipulate non-model organisms, the extension of the methodological toolbox required to translate our understanding of model organisms to non-model organisms has become an urgent problem. For example, mining of large coral and their symbiont sequence data is a challenge, but also provides an opportunity for understanding functionality and evolution of these and other non-model organisms. Much more information than for any other eukaryotic species is available for humans, especially related to signal transduction and diseases. However, the coral cnidarian host and human have diverged over 700 million years ago and homologies between proteins in the two species are therefore often in the gray zone, or at least often undetectable with traditional BLAST searches. We introduce a two-stage approach to identifying putative coral homologues of human proteins. First, through remote homology detection using Hidden Markov Models, we identify candidate human homologues in the cnidarian genome. However, for many proteins, the human genome alone contains multiple family members with similar or even more divergence in sequence. In the second stage, therefore, we filter the remote homology results based on the functional and structural plausibility of each coral candidate, shortlisting the coral proteins likely to have conserved some of the functions of the human proteins. We demonstrate our approach with a pipeline for mapping membrane receptors in humans to membrane receptors in corals, with specific focus on the stony coral, P. damicornis. More than 1000 human membrane receptors mapped to 335 coral receptors, including 151 G protein coupled receptors (GPCRs). To validate specific sub-families, we chose opsin proteins, representative GPCRs that confer light sensitivity, and Toll-like receptors, representative non-GPCRs, which function in the immune response, and their ability to communicate with microorganisms. Through detailed structure-function analysis of their ligand-binding pockets and downstream signaling cascades, we selected those candidate remote homologues likely to carry out related functions in the corals. This pipeline may prove generally useful for other non-model organisms, such as to support the growing field of synthetic biology.
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Affiliation(s)
- Lokender Kumar
- Department of Chemistry, Colorado School of Mines, Golden, CO, United States of America
| | - Nathanael Brenner
- Department of Chemistry, Colorado School of Mines, Golden, CO, United States of America
| | - Samuel Sledzieski
- MIT Computer Science & Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Monsurat Olaosebikan
- Department of Computer Science, Tufts University, Medford, MA, United States of America
| | - Liza M. Roger
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Matthew Lynn-Goin
- Department of Chemistry, Colorado School of Mines, Golden, CO, United States of America
| | | | - Bonnie Berger
- MIT Computer Science & Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Hollie Putnam
- Department of Biological Sciences, University of Rhode Island, South Kingstown, RI, United States of America
| | - Jinkyu Yang
- Department of Department of Aeronautics & Astronautics, University of Washington, Seattle, WA, United States of America
| | - Nastassja A. Lewinski
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, United States of America
| | - Rohit Singh
- MIT Computer Science & Artificial Intelligence Lab, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Noah M. Daniels
- Department of Computer Science and Statistics, University of Rhode Island, South Kingstown, RI, United States of America
| | - Lenore Cowen
- Department of Computer Science, Tufts University, Medford, MA, United States of America
| | - Judith Klein-Seetharaman
- Department of Chemistry, Colorado School of Mines, Golden, CO, United States of America
- * E-mail:
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Wordom update 2: A user-friendly program for the analysis of molecular structures and conformational ensembles. Comput Struct Biotechnol J 2023; 21:1390-1402. [PMID: 36817953 PMCID: PMC9929209 DOI: 10.1016/j.csbj.2023.01.026] [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: 12/14/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/29/2023] Open
Abstract
We present the second update of Wordom, a user-friendly and efficient program for manipulation and analysis of conformational ensembles from molecular simulations. The actual update expands some of the existing modules and adds 21 new modules to the update 1 published in 2011. The new adds can be divided into three sets that: 1) analyze atomic fluctuations and structural communication; 2) explore ion-channel conformational dynamics and ionic translocation; and 3) compute geometrical indices of structural deformation. Set 1 serves to compute correlations of motions, find geometrically stable domains, identify a dynamically invariant core, find changes in domain-domain separation and mutual orientation, perform wavelet analysis of large-scale simulations, process the output of principal component analysis of atomic fluctuations, perform functional mode analysis, infer regions of mechanical rigidity, analyze overall fluctuations, and perform the perturbation response scanning. Set 2 includes modules specific for ion channels, which serve to monitor the pore radius as well as water or ion fluxes, and measure functional collective motions like receptor twisting or tilting angles. Finally, set 3 includes tools to monitor structural deformations by computing angles, perimeter, area, volume, β-sheet curvature, radial distribution function, and center of mass. The ring perception module is also included, helpful to monitor supramolecular self-assemblies. This update places Wordom among the most suitable, complete, user-friendly, and efficient software for the analysis of biomolecular simulations. The source code of Wordom and the relative documentation are available under the GNU general public license at http://wordom.sf.net.
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Liu X, Wang W. Asymmetric gating of a human hetero-pentameric glycine receptor. RESEARCH SQUARE 2023:rs.3.rs-2386831. [PMID: 36711971 PMCID: PMC9882600 DOI: 10.21203/rs.3.rs-2386831/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hetero-pentameric Cys-loop receptors constitute a major type of neurotransmitter receptors that enable signal transmission and processing in the nervous system. Despite intense investigations in their working mechanism and pharmaceutical potentials, how neurotransmitters activate these receptors remain unclear due to the lack of high-resolution structural information in the activated open state. Here we report near-atomic resolution structures in all principle functional states of the human α1β GlyR, which is a major Cys-loop receptor that mediates inhibitory neurotransmission in the central nervous system of adults. Glycine binding induced cooperative and symmetric structural rearrangements in the neurotransmitter-binding extracellular domain, but asymmetrical pore dilation in the transmembrane domain. Symmetric response in the extracellular domain is consistent with electrophysiological data showing similar contribution to activation from all the α1 and β subunits. A set of functionally essential but differentially charged amino-acid residues in the transmembrane domain of the α1 and β subunits explains asymmetric activation. These findings point to a gating mechanism that is distinct from homomeric receptors but more compatible with heteromeric GlyRs being clustered at synapses through β subunit-scaffolding protein interactions. Such mechanism provides foundation for understanding how gating of the Cys-loop receptor members diverge to accommodate specific physiological environment.
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Affiliation(s)
- Xiaofen Liu
- University of Texas Southwestern Medical Center
| | - Weiwei Wang
- University of Texas Southwestern Medical Center
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38
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Goldschen-Ohm MP. Benzodiazepine Modulation of GABA A Receptors: A Mechanistic Perspective. Biomolecules 2022; 12:biom12121784. [PMID: 36551212 PMCID: PMC9775625 DOI: 10.3390/biom12121784] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/05/2022] Open
Abstract
Benzodiazepines (BZDs) are a class of widely prescribed psychotropic drugs that target GABAA receptors (GABAARs) to tune inhibitory synaptic signaling throughout the central nervous system. Despite knowing their molecular target for over 40 years, we still do not fully understand the mechanism of modulation at the level of the channel protein. Nonetheless, functional studies, together with recent cryo-EM structures of GABAA(α1)2(βX)2(γ2)1 receptors in complex with BZDs, provide a wealth of information to aid in addressing this gap in knowledge. Here, mechanistic interpretations of functional and structural evidence for the action of BZDs at GABAA(α1)2(βX)2(γ2)1 receptors are reviewed. The goal is not to describe each of the many studies that are relevant to this discussion nor to dissect in detail all the effects of individual mutations or perturbations but rather to highlight general mechanistic principles in the context of recent structural information.
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Zhuang Y, Noviello CM, Hibbs RE, Howard RJ, Lindahl E. Differential interactions of resting, activated, and desensitized states of the α7 nicotinic acetylcholine receptor with lipidic modulators. Proc Natl Acad Sci U S A 2022; 119:e2208081119. [PMID: 36251999 PMCID: PMC9618078 DOI: 10.1073/pnas.2208081119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 09/08/2022] [Indexed: 11/18/2022] Open
Abstract
The α7 nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel that modulates neuronal excitability, largely by allowing Ca2+ permeation. Agonist binding promotes transition from a resting state to an activated state, and then rapidly to a desensitized state. Recently, cryogenic electron microscopy (cryo-EM) structures of the human α7 receptor in nanodiscs were reported in multiple conformations. These were selectively stabilized by inhibitory, activating, or potentiating compounds. However, the functional annotation of these structures and their differential interactions with unresolved lipids and ligands remain incomplete. Here, we characterized their ion permeation, membrane interactions, and ligand binding using computational electrophysiology, free-energy calculations, and coarse-grained molecular dynamics. In contrast to nonconductive structures in apparent resting and desensitized states, the structure determined in the presence of the potentiator PNU-120596 was consistent with an activated state permeable to Ca2+. Transition to this state was associated with compression and rearrangement of the membrane, particularly in the vicinity of the peripheral MX helix. An intersubunit transmembrane site was implicated in selective binding of either PNU-120596 in the activated state or cholesterol in the desensitized state. This substantiates functional assignment of all three lipid-embedded α7-receptor structures with ion-permeation simulations. It also proposes testable models of their state-dependent interactions with lipophilic ligands, including a mechanism for allosteric modulation at the transmembrane subunit interface.
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Affiliation(s)
- Yuxuan Zhuang
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, PO Box 1031, Solna, 171 21 Sweden
| | - Colleen M. Noviello
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ryan E. Hibbs
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Rebecca J. Howard
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, PO Box 1031, Solna, 171 21 Sweden
| | - Erik Lindahl
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, PO Box 1031, Solna, 171 21 Sweden
- Department of Applied Physics, Swedish e-Science Research Center, KTH Royal Institute of Technology, PO Box 1031, Solna, 171 21 Sweden
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Cerdan AH, Peverini L, Changeux JP, Corringer PJ, Cecchini M. Lateral fenestrations in the extracellular domain of the glycine receptor contribute to the main chloride permeation pathway. SCIENCE ADVANCES 2022; 8:eadc9340. [PMID: 36240268 PMCID: PMC9565810 DOI: 10.1126/sciadv.adc9340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Glycine receptors (GlyRs) are ligand-gated ion channels mediating signal transduction at chemical synapses. Since the early patch-clamp electrophysiology studies, the details of the ion permeation mechanism have remained elusive. Here, we combine molecular dynamics simulations of a zebrafish GlyR-α1 model devoid of the intracellular domain with mutagenesis and single-channel electrophysiology of the full-length human GlyR-α1. We show that lateral fenestrations between subunits in the extracellular domain provide the main translocation pathway for chloride ions to enter/exit a central water-filled vestibule at the entrance of the transmembrane channel. In addition, we provide evidence that these fenestrations are at the origin of current rectification in known anomalous mutants and design de novo two inward-rectifying channels by introducing mutations within them. These results demonstrate the central role of lateral fenestrations on synaptic neurotransmission.
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Affiliation(s)
- Adrien H. Cerdan
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, F-67083 Strasbourg Cedex, France
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
| | - Laurie Peverini
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
| | - Jean-Pierre Changeux
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
- Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, CA, USA
- Collège de France, Paris, France
| | - Pierre-Jean Corringer
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Channel-Receptors Unit, Paris, France
| | - Marco Cecchini
- Institut de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, F-67083 Strasbourg Cedex, France
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41
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Residues in the 1st Transmembrane-Spanning Helix Are Important for GABAAρ Receptor Function. Biomolecules 2022; 12:biom12091251. [PMID: 36139090 PMCID: PMC9496367 DOI: 10.3390/biom12091251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/22/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
GABAAρ receptors are a subfamily of the GABAA receptor family of pentameric ligand-gated ion channels (pLGICs). Each subunit has a common structure, including a transmembrane domain of four α-helices (M1–M4). The aim of this study was to identify important M1 residues in the GABAAρ receptor (GABAAρR), using mutagenesis and functional assays combined with bioinformatic approaches. Alanine substitution of 12 of the 23 M1 residues yielded receptors with altered functional parameters, indicating these residues contribute to GABAAρR function. Further mutations reveal the properties that are important for function in critical residues, and, using a GABAAρR homology model, we suggest amino acid interactions that could be important. Phylogenetic analysis comparing GABAAR and other pLGICs subunits reveals most M1 residue properties linked to GABAAρR function are ancestrally ancient, but some are more recent acquisitions. Multiple sequence alignment of M1 residues across GABAAR subunits reveal three residues are well conserved except in GABAAR α subunits. Substitution of ρ1 subunit residues to their α1 subunit equivalents showed one alters functional parameters. Overall, the data provide a comprehensive picture of M1 residues that contribute to GABAAρR function, and illustrate how they might do so.
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Structural and dynamic mechanisms of GABA A receptor modulators with opposing activities. Nat Commun 2022; 13:4582. [PMID: 35933426 PMCID: PMC9357065 DOI: 10.1038/s41467-022-32212-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 07/21/2022] [Indexed: 12/02/2022] Open
Abstract
γ-Aminobutyric acid type A (GABAA) receptors are pentameric ligand-gated ion channels abundant in the central nervous system and are prolific drug targets for treating anxiety, sleep disorders and epilepsy. Diverse small molecules exert a spectrum of effects on γ-aminobutyric acid type A (GABAA) receptors by acting at the classical benzodiazepine site. They can potentiate the response to GABA, attenuate channel activity, or counteract modulation by other ligands. Structural mechanisms underlying the actions of these drugs are not fully understood. Here we present two high-resolution structures of GABAA receptors in complex with zolpidem, a positive allosteric modulator and heavily prescribed hypnotic, and DMCM, a negative allosteric modulator with convulsant and anxiogenic properties. These two drugs share the extracellular benzodiazepine site at the α/γ subunit interface and two transmembrane sites at β/α interfaces. Structural analyses reveal a basis for the subtype selectivity of zolpidem that underlies its clinical success. Molecular dynamics simulations provide insight into how DMCM switches from a negative to a positive modulator as a function of binding site occupancy. Together, these findings expand our understanding of how GABAA receptor allosteric modulators acting through a common site can have diverging activities. GABAA receptors are important targets for anxiety, sedation and anesthesia. Here, the authors present structures bound by zolpidem (Ambien), the most prescribed hypnotic in the US, and DMCM, a negative modulator, providing insights into receptor modulation.
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Structural Insights into the Role of β3 nAChR Subunit in the Activation of Nicotinic Receptors. Molecules 2022; 27:molecules27144642. [PMID: 35889515 PMCID: PMC9319688 DOI: 10.3390/molecules27144642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 02/06/2023] Open
Abstract
The β3 subunit of nicotinic acetylcholine receptors (nAChRs) participates in heteropentameric assemblies with some α and other β neuronal subunits forming a plethora of various subtypes, differing in their electrophysiological and pharmacological properties. While β3 has for several years been considered an accessory subunit without direct participation in the formation of functional binding sites, recent electrophysiology data have disputed this notion and indicated the presence of a functional (+) side on the extracellular domain (ECD) of β3. In this study, we present the 2.4 Å resolution crystal structure of the monomeric β3 ECD, which revealed rather distinctive loop C features as compared to those of α nAChR subunits, leading to intramolecular stereochemical hindrance of the binding site cavity. Vigorous molecular dynamics simulations in the context of full length pentameric β3-containing nAChRs, while not excluding the possibility of a β3 (+) binding site, demonstrate that this site cannot efficiently accommodate the agonist nicotine. From the structural perspective, our results endorse the accessory rather than functional role of the β3 nAChR subunit, in accordance with earlier functional studies on β3-containing nAChRs.
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Noviello CM, Kreye J, Teng J, Prüss H, Hibbs RE. Structural mechanisms of GABA A receptor autoimmune encephalitis. Cell 2022; 185:2469-2477.e13. [PMID: 35803245 DOI: 10.1016/j.cell.2022.06.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/22/2022] [Accepted: 06/13/2022] [Indexed: 11/26/2022]
Abstract
Autoantibodies targeting neuronal membrane proteins can cause encephalitis, seizures, and severe behavioral abnormalities. While antibodies for several neuronal targets have been identified, structural details on how they regulate function are unknown. Here we determined cryo-electron microscopy structures of antibodies derived from an encephalitis patient bound to the γ-aminobutyric acid type A (GABAA) receptor. These antibodies induced severe encephalitis by directly inhibiting GABAA function, resulting in nervous-system hyperexcitability. The structures reveal mechanisms of GABAA inhibition and pathology. One antibody directly competes with a neurotransmitter and locks the receptor in a resting-like state. The second antibody targets the subunit interface involved in binding benzodiazepines and antagonizes diazepam potentiation. We identify key residues in these antibodies involved in specificity and affinity and confirm structure-based hypotheses for functional effects using electrophysiology. Together these studies define mechanisms of direct functional antagonism of neurotransmission underlying autoimmune encephalitis in a human patient.
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Affiliation(s)
- Colleen M Noviello
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jakob Kreye
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Department of Pediatric Neurology and Berlin Institute of Health, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jinfeng Teng
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Harald Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany; Department of Neurology and Experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Ryan E Hibbs
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Mhashal AR, Yoluk O, Orellana L. Exploring the Conformational Impact of Glycine Receptor TM1-2 Mutations Through Coarse-Grained Analysis and Atomistic Simulations. Front Mol Biosci 2022; 9:890851. [PMID: 35836931 PMCID: PMC9275627 DOI: 10.3389/fmolb.2022.890851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Pentameric ligand-gated ion channels (PLGICs) are a family of proteins that convert chemical signals into ion fluxes through cellular membranes. Their structures are highly conserved across all kingdoms from bacteria to eukaryotes. Beyond their classical roles in neurotransmission and neurological disorders, PLGICs have been recently related to cell proliferation and cancer. Here, we focus on the best characterized eukaryotic channel, the glycine receptor (GlyR), to investigate its mutational patterns in genomic-wide tumor screens and compare them with mutations linked to hyperekplexia (HPX), a Mendelian neuromotor disease that disrupts glycinergic currents. Our analysis highlights that cancer mutations significantly accumulate across TM1 and TM2, partially overlapping with HPX changes. Based on 3D-clustering, conservation, and phenotypic data, we select three mutations near the pore, expected to impact GlyR conformation, for further study by molecular dynamics (MD). Using principal components from experimental GlyR ensembles as framework, we explore the motions involved in transitions from the human closed and desensitized structures and how they are perturbed by mutations. Our MD simulations show that WT GlyR spontaneously explores opening and re-sensitization transitions that are significantly impaired by mutations, resulting in receptors with altered permeability and desensitization properties in agreement with HPX functional data.
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46
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Recent Insight into Lipid Binding and Lipid Modulation of Pentameric Ligand-Gated Ion Channels. Biomolecules 2022; 12:biom12060814. [PMID: 35740939 PMCID: PMC9221113 DOI: 10.3390/biom12060814] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/03/2022] [Accepted: 06/08/2022] [Indexed: 02/04/2023] Open
Abstract
Pentameric ligand-gated ion channels (pLGICs) play a leading role in synaptic communication, are implicated in a variety of neurological processes, and are important targets for the treatment of neurological and neuromuscular disorders. Endogenous lipids and lipophilic compounds are potent modulators of pLGIC function and may help shape synaptic communication. Increasing structural and biophysical data reveal sites for lipid binding to pLGICs. Here, we update our evolving understanding of pLGIC–lipid interactions highlighting newly identified modes of lipid binding along with the mechanistic understanding derived from the new structural data.
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Sivakumar D, Ramli R. GABAergic signalling in modulation of dental pain. Eur J Pharmacol 2022; 924:174958. [DOI: 10.1016/j.ejphar.2022.174958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 11/30/2022]
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Mesoy SM, Bridgland-Taylor M, Lummis SCR. Mutations of the nACh Receptor M4 Helix Reveal Different Phenotypes in Different Expression Systems: Could Lipids be Responsible? Front Physiol 2022; 13:850782. [PMID: 35600303 PMCID: PMC9116227 DOI: 10.3389/fphys.2022.850782] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 03/31/2022] [Indexed: 11/18/2022] Open
Abstract
The role of the outermost helix (M4) in the pentameric ligand-gated ion channel (pLGIC) family is currently not fully understood. It is known that M4 is important for receptor assembly, possibly via interactions with neighboring M1 and M3 helices. M4 can also transmit information on the lipid content of the membrane to the gating mechanism, and it may form a link to the extracellular domain via the Cys-loop. Our previous study examining the α4β2 nACh receptor M4 helix using HEK cells indicated M4 here is more sensitive to change than those of other pLGIC. Many of these other studies, however, were performed in Xenopus oocytes. Here we examine the nine previously identified nonfunctional α4β2 nACh receptor M4 mutant receptors using this system. The data reveal that seven of these mutant receptors do function when expressed in oocytes, with only 2, the conserved Asp at the intracellular end of M4 and a Phe in the center, having a similar phenotype (nonfunctional) in both HEK cells and oocytes. The oocyte data are more consistent with studies in other pLGIC and demonstrate the importance of the expression system used. Of the many differences between these two expression systems, we suggest that the different lipid content of the plasma membrane is a possible candidate for explaining these discrepancies.
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Affiliation(s)
- Susanne M. Mesoy
- Department of Biochemistry, University of Cambridge, University of Cambridge, Cambridge, United Kingdom
| | - Matthew Bridgland-Taylor
- Clinical Pharmacology and Safety Sciences, Biopharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Sarah C. R. Lummis
- Department of Biochemistry, University of Cambridge, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Sarah C. R. Lummis,
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Matsuo Y. Introducing Thioredoxin-Related Transmembrane Proteins: Emerging Roles of Human TMX and Clinical Implications. Antioxid Redox Signal 2022; 36:984-1000. [PMID: 34465218 PMCID: PMC9127828 DOI: 10.1089/ars.2021.0187] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Significance: The presence of a large number of thioredoxin superfamily members suggests a complex mechanism of redox-based regulation in mammalian cells. However, whether these members are functionally redundant or play separate and distinct roles in each cellular compartment remains to be elucidated. Recent Advances: In the mammalian endoplasmic reticulum (ER), ∼20 thioredoxin-like proteins have been identified. Most ER oxidoreductases are soluble proteins located in the luminal compartment, whereas a small family of five thioredoxin-related transmembrane proteins (TMX) also reside in the ER membrane and play crucial roles with specialized functions. Critical Issues: In addition to the predicted function of ER protein quality control, several independent studies have suggested the diverse roles of TMX family proteins in the regulation of cellular processes, including calcium homeostasis, bioenergetics, and thiol-disulfide exchange in the extracellular space. Moreover, recent studies have provided evidence of their involvement in the pathogenesis of various diseases. Future Directions: Extensive research is required to unravel the physiological roles of TMX family proteins. Given that membrane-associated proteins are prime targets for drug discovery in a variety of human diseases, expanding our knowledge on the mechanistic details of TMX action on the cell membrane will provide the molecular basis for developing novel diagnostic and therapeutic approaches as a potent molecular target in a clinical setting. Antioxid. Redox Signal. 36, 984-1000.
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Affiliation(s)
- Yoshiyuki Matsuo
- Department of Human Stress Response Science, Institute of Biomedical Science, Kansai Medical University, Hirakata, Osaka, Japan
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Carlos DH, Bibiana Roselly CR, Angel UL, Laura MA, Kenya Karina SR, Jose Manuel CB, Alejandra CS, Gabriela CCE, Estefanía OR, Aracely SM. Cognitive improvements in a rat model with polyunsaturated fatty acids EPA and DHA through α7-nicotinic acetylcholine receptors. Nutr Neurosci 2022; 25:791-800. [DOI: 10.1080/1028415x.2020.1809878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | | | - Ugalde Lizárraga Angel
- Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Tijuana, Mexico
| | - Martínez Ana Laura
- Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Tijuana, Mexico
| | | | - Cornejo-Bravo Jose Manuel
- Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Tijuana, Mexico
| | | | | | - Ochoa-Ruíz Estefanía
- Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Tijuana, Mexico
| | - Serrano-Medina Aracely
- Facultad de Medicina y Psicología, Universidad Autónoma de Baja California, Tijuana, Mexico
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