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Roquini D, Lemes BL, Kreutz ALB, Spoladore SC, Amaro MC, Lopes FB, Fernandes JP, de Moraes J. Antihistamines H 1 as Potential Anthelmintic Agents against the Zoonotic Parasite Angiostrongylus cantonensis. ACS OMEGA 2024; 9:31159-31165. [PMID: 39035884 PMCID: PMC11256074 DOI: 10.1021/acsomega.4c04773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/21/2024] [Accepted: 06/25/2024] [Indexed: 07/23/2024]
Abstract
Infections caused by parasitic helminths pose significant health concerns for both humans and animals. The limited efficacy of existing drugs underscores the urgent need for novel anthelmintic agents. Given the reported potential of antihistamines against various parasites, including worms, this study conducted a screening of clinically available antihistamines against Angiostrongylus cantonensis-a nematode with widespread implications for vertebrate hosts, including humans. Twenty-one anti-H1 antihistamines were screened against first-stage larvae (L1) of A. cantonensis obtained from the feces of infected rats. Standard anthelmintic drugs ivermectin and albendazole were employed for comparative analysis. The findings revealed four active compounds (promethazine, cinnarizine, desloratadine, and rupatadine), with promethazine demonstrating the highest potency (EC50 = 31.6 μM). Additionally, morphological analysis showed that antihistamines induced significant changes in larvae. To understand the mechanism of action, antimuscarinic activities were reported based on average pK i values for human muscarinic receptor (mAChR) subtypes of the evaluated compounds. Furthermore, an analysis of the physicochemical and pharmacodynamic properties of antihistamines revealed that their anthelmintic activity does not correlate with their activity at H1 receptors. This study marks the first documentation of antihistamines' activity against A. cantonensis, offering a valuable contribution to the quest for novel agents effective against zoonotic helminths.
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Affiliation(s)
- Daniel
B. Roquini
- Núcleo
de Pesquisa em Doenças Negligenciadas, Universidade Guarulhos, 07023-070 Guarulhos, SP, Brazil
| | - Bruna L. Lemes
- Núcleo
de Pesquisa em Doenças Negligenciadas, Universidade Guarulhos, 07023-070 Guarulhos, SP, Brazil
| | - Amanda L. B. Kreutz
- Núcleo
de Pesquisa em Doenças Negligenciadas, Universidade Guarulhos, 07023-070 Guarulhos, SP, Brazil
| | - Sophia C. Spoladore
- Núcleo
de Pesquisa em Doenças Negligenciadas, Universidade Guarulhos, 07023-070 Guarulhos, SP, Brazil
| | - Monique C. Amaro
- Núcleo
de Pesquisa em Doenças Negligenciadas, Universidade Guarulhos, 07023-070 Guarulhos, SP, Brazil
| | - Flavia B. Lopes
- Departamento
de Medicina, Universidade Federal de São
Paulo, 04023-062 São Paulo, SP, Brazil
- Departamento
de Ciências Farmacêuticas, Universidade Federal de São Paulo, 09913-030 Diadema, SP, Brazil
| | - João Paulo
S. Fernandes
- Departamento
de Ciências Farmacêuticas, Universidade Federal de São Paulo, 09913-030 Diadema, SP, Brazil
| | - Josué de Moraes
- Núcleo
de Pesquisa em Doenças Negligenciadas, Universidade Guarulhos, 07023-070 Guarulhos, SP, Brazil
- Núcleo
de Pesquisa em Doenças Negligenciadas, Instituto Científico e Tecnológico, Universidade Brasil, 08230-030 São
Paulo, SP, Brazil
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2
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Murphy EA, Kleiner FH, Helliwell KE, Wheeler GL. Channels of Evolution: Unveiling Evolutionary Patterns in Diatom Ca 2+ Signalling. PLANTS (BASEL, SWITZERLAND) 2024; 13:1207. [PMID: 38732422 PMCID: PMC11085791 DOI: 10.3390/plants13091207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/09/2024] [Accepted: 04/15/2024] [Indexed: 05/13/2024]
Abstract
Diatoms are important primary producers in marine and freshwater environments, but little is known about the signalling mechanisms they use to detect changes in their environment. All eukaryotic organisms use Ca2+ signalling to perceive and respond to environmental stimuli, employing a range of Ca2+-permeable ion channels to facilitate the movement of Ca2+ across cellular membranes. We investigated the distribution of different families of Ca2+ channels in diatom genomes, with comparison to other members of the stramenopile lineage. The four-domain voltage-gated Ca2+ channels (Cav) are present in some centric diatoms but almost completely absent in pennate diatoms, whereas single-domain voltage-gated EukCatA channels were found in all diatoms. Glutamate receptors (GLRs) and pentameric ligand-gated ion channels (pLGICs) also appear to have been lost in several pennate species. Transient receptor potential (TRP) channels are present in all diatoms, but have not undergone the significant expansion seen in brown algae. All diatom species analysed lacked the mitochondrial uniporter (MCU), a highly conserved channel type found in many eukaryotes, including several stramenopile lineages. These results highlight the unique Ca2+-signalling toolkit of diatoms and indicate that evolutionary gains or losses of different Ca2+ channels may contribute to differences in cellular-signalling mechanisms between species.
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Affiliation(s)
- Eleanor A. Murphy
- Marine Biological Association, Plymouth PL1 2PB, UK (K.E.H.)
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | | | - Katherine E. Helliwell
- Marine Biological Association, Plymouth PL1 2PB, UK (K.E.H.)
- Department of Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Glen L. Wheeler
- Marine Biological Association, Plymouth PL1 2PB, UK (K.E.H.)
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3
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Wolstenholme AJ, Andersen EC, Choudhary S, Ebner F, Hartmann S, Holden-Dye L, Kashyap SS, Krücken J, Martin RJ, Midha A, Nejsum P, Neveu C, Robertson AP, von Samson-Himmelstjerna G, Walker R, Wang J, Whitehead BJ, Williams PDE. Getting around the roundworms: Identifying knowledge gaps and research priorities for the ascarids. ADVANCES IN PARASITOLOGY 2024; 123:51-123. [PMID: 38448148 PMCID: PMC11143470 DOI: 10.1016/bs.apar.2023.12.002] [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] [Indexed: 03/08/2024]
Abstract
The ascarids are a large group of parasitic nematodes that infect a wide range of animal species. In humans, they cause neglected diseases of poverty; many animal parasites also cause zoonotic infections in people. Control measures include hygiene and anthelmintic treatments, but they are not always appropriate or effective and this creates a continuing need to search for better ways to reduce the human, welfare and economic costs of these infections. To this end, Le Studium Institute of Advanced Studies organized a two-day conference to identify major gaps in our understanding of ascarid parasites with a view to setting research priorities that would allow for improved control. The participants identified several key areas for future focus, comprising of advances in genomic analysis and the use of model organisms, especially Caenorhabditis elegans, a more thorough appreciation of the complexity of host-parasite (and parasite-parasite) communications, a search for novel anthelmintic drugs and the development of effective vaccines. The participants agreed to try and maintain informal links in the future that could form the basis for collaborative projects, and to co-operate to organize future meetings and workshops to promote ascarid research.
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Affiliation(s)
- Adrian J Wolstenholme
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Université de Tours, ISP, Nouzilly, France.
| | - Erik C Andersen
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Shivani Choudhary
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Friederike Ebner
- Department of Molecular Life Sciences, School of Life Sciences, Technische Universität München, Freising, Germany
| | - Susanne Hartmann
- Institute for Immunology, Freie Universität Berlin, Berlin, Germany
| | - Lindy Holden-Dye
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Sudhanva S Kashyap
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Richard J Martin
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Ankur Midha
- Institute for Immunology, Freie Universität Berlin, Berlin, Germany
| | - Peter Nejsum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Cedric Neveu
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Université de Tours, ISP, Nouzilly, France
| | - Alan P Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | | | - Robert Walker
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Jianbin Wang
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, United States
| | | | - Paul D E Williams
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
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4
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Randi F, Sharma AK, Dvali S, Leifer AM. Neural signal propagation atlas of Caenorhabditis elegans. Nature 2023; 623:406-414. [PMID: 37914938 PMCID: PMC10632145 DOI: 10.1038/s41586-023-06683-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/27/2023] [Indexed: 11/03/2023]
Abstract
Establishing how neural function emerges from network properties is a fundamental problem in neuroscience1. Here, to better understand the relationship between the structure and the function of a nervous system, we systematically measure signal propagation in 23,433 pairs of neurons across the head of the nematode Caenorhabditis elegans by direct optogenetic activation and simultaneous whole-brain calcium imaging. We measure the sign (excitatory or inhibitory), strength, temporal properties and causal direction of signal propagation between these neurons to create a functional atlas. We find that signal propagation differs from model predictions that are based on anatomy. Using mutants, we show that extrasynaptic signalling not visible from anatomy contributes to this difference. We identify many instances of dense-core-vesicle-dependent signalling, including on timescales of less than a second, that evoke acute calcium transients-often where no direct wired connection exists but where relevant neuropeptides and receptors are expressed. We propose that, in such cases, extrasynaptically released neuropeptides serve a similar function to that of classical neurotransmitters. Finally, our measured signal propagation atlas better predicts the neural dynamics of spontaneous activity than do models based on anatomy. We conclude that both synaptic and extrasynaptic signalling drive neural dynamics on short timescales, and that measurements of evoked signal propagation are crucial for interpreting neural function.
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Affiliation(s)
- Francesco Randi
- Department of Physics, Princeton University, Princeton, NJ, USA
- Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Anuj K Sharma
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Sophie Dvali
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Andrew M Leifer
- Department of Physics, Princeton University, Princeton, NJ, USA.
- Princeton Neurosciences Institute, Princeton University, Princeton, NJ, USA.
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5
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Hernando G, Turani O, Rodriguez Araujo N, Bouzat C. The diverse family of Cys-loop receptors in Caenorhabditis elegans: insights from electrophysiological studies. Biophys Rev 2023; 15:733-750. [PMID: 37681094 PMCID: PMC10480131 DOI: 10.1007/s12551-023-01080-7] [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: 03/29/2023] [Accepted: 06/18/2023] [Indexed: 09/09/2023] Open
Abstract
Cys-loop receptors integrate a large family of pentameric ligand-gated ion channels that mediate fast ionotropic responses in vertebrates and invertebrates. Their vital role in converting neurotransmitter recognition into an electrical impulse makes these receptors essential for a great variety of physiological processes. In vertebrates, the Cys-loop receptor family includes the cation-selective channels, nicotinic acetylcholine and 5-hydroxytryptamine type 3 receptors, and the anion-selective channels, GABAA and glycine receptors, whereas in invertebrates, the repertoire is significantly larger. The free-living nematode Caenorhabditis elegans has the largest known Cys-loop receptor family as well as unique receptors that are absent in vertebrates and constitute attractive targets for anthelmintic drugs. Given the large number and variety of Cys-loop receptor subunits and the multiple possible ways of subunit assembly, C. elegans offers a large diversity of receptors although only a limited number of them have been characterized to date. C. elegans has emerged as a powerful model for the study of the nervous system and human diseases as well as a model for antiparasitic drug discovery. This nematode has also shown promise in the pharmaceutical industry search for new therapeutic compounds. C. elegans is therefore a powerful model organism to explore the biology and pharmacology of Cys-loop receptors and their potential as targets for novel therapeutic interventions. In this review, we provide a comprehensive overview of what is known about the function of C. elegans Cys-loop receptors from an electrophysiological perspective.
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Affiliation(s)
- Guillermina Hernando
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
| | - Ornella Turani
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
| | - Noelia Rodriguez Araujo
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
| | - Cecilia Bouzat
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
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6
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Qian K, Jiang C, Guan D, Zhuang A, Meng X, Wang J. Characterization of Glutamate-Gated Chloride Channel in Tribolium castaneum. INSECTS 2023; 14:580. [PMID: 37504587 PMCID: PMC10380907 DOI: 10.3390/insects14070580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/21/2023] [Accepted: 06/24/2023] [Indexed: 07/29/2023]
Abstract
The glutamate-gated chloride channels (GluCls) play essential roles in signal transduction by regulating fast inhibitory synaptic transmission in the nervous system of invertebrates. While there is only one GluCl subunit in the insect, the diversity of insect GluCls is broadened by alternative splicing. In the present study, three TcGluCl variant genes were cloned from the red flour beetle Tribolium castaneum. Analysis of the characteristics of TcGluCls including sequence features, genomic structures, and alternative splicing revealed that TcGluCls had the typical structural features of GluCls and showed high homologies with the GluCls from other insect orders. The TcGluCl-encoding gene consists of nine exons and three variants (TcGluCl-3a, TcGluCl-3b, and TcGluCl-3c) were generated by the alternative splicing of exon 3, which was a highly conserved alternative splicing site in insect GluCls. Homology modeling of TcGluCl-3a showed that the exon 3 coding protein located at the N-terminal extracellular domain, and there were no steric clashes encountered between the exon 3 coding region and ivermectin/glutamate binding pocket, which indicated that the alternative splicing of exon 3 might have no impact on the binding of GluCls to glutamate and insecticide. In addition to the head tissue, TcGluCl-3a and TcGluCl-3c also had high expressions in the ovary and testis of T. castaneum, whereas TcGluCl-3b showed high expression in the midgut, suggesting the diverse physiological functions of TcGluCl variants in T. castaneum. The total TcGluCl and three variants showed the highest expression levels in the early stage larvae. The expressions of TcGluCl, TcGluCl-3b, and TcGluCl-3c were significantly increased from the late-stage larvae to the early stage pupae and indicated that the TcGluCl might be involved in the growth and development of T. castaneum. These results are helpful to further understand the molecular characteristics of insect GluCls and provide foundations for studying the specific function of the GluCl variant.
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Affiliation(s)
- Kun Qian
- College of Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Chengyun Jiang
- College of Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Daojie Guan
- College of Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Anxiang Zhuang
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
| | - Xiangkun Meng
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
| | - Jianjun Wang
- College of Plant Protection, Yangzhou University, Yangzhou 225009, China
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7
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Habibi S, Nazareth K, Nichols J, Varley S, Forrester SG. The Haemonchus contortus LGC-39 subunit is a novel subtype of an acetylcholine-gated chloride channel. Int J Parasitol Drugs Drug Resist 2023; 22:20-26. [PMID: 37054482 PMCID: PMC10122009 DOI: 10.1016/j.ijpddr.2023.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/27/2023] [Accepted: 04/02/2023] [Indexed: 04/15/2023]
Abstract
The nematode genome exhibits a vast array of Cys-loop receptors that are activated by a diverse set of neurotransmitters and anthelmintic drugs such as ivermectin and levamisole. While many Cys-loop receptors have been functionally and pharmacologically characterized, there remains a large subset of orphan receptors where the agonist remains unknown. We have identified an orphan Cys-loop receptor, LGC-39, from the parasitic nematode Haemonchus contortus that is a novel type of cholinergic-sensitive ligand-gated chloride channel. This receptor groups outside of the acetylcholine-gated chloride channel family, in the previously named GGR-1 (GABA/Glycine Receptor-1) group of Cys-loop receptors. We found that LGC-39 forms a functional homomeric receptor when expressed in Xenopus laevis oocytes and is activated by several cholinergic ligands including acetylcholine, methacholine and surprisingly, atropine with an EC50 for atropine on the low μM range. A homology model was generated which revealed some key features of the LGC-39 ligand-binding pocket that may explain some of the elements important for atropine recognition of the LGC-39 receptor. Overall these results suggest that the GGR-1 family (now called LGC-57) of Cys-loop receptors includes novel acetylcholine-gated chloride channel subtypes and may represent important future drug targets.
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Affiliation(s)
- Sarah Habibi
- Faculty of Science, Ontario Tech University, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Kristen Nazareth
- Faculty of Science, Ontario Tech University, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Jennifer Nichols
- Faculty of Science, Ontario Tech University, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Sierra Varley
- Faculty of Science, Ontario Tech University, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Sean G Forrester
- Faculty of Science, Ontario Tech University, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada.
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8
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Sun X, Hua W, Wang K, Song J, Zhu B, Gao X, Liang P. A novel V263I mutation in the glutamate-gated chloride channel of Plutella xylostella (L.) confers a high level of resistance to abamectin. Int J Biol Macromol 2023; 230:123389. [PMID: 36706876 DOI: 10.1016/j.ijbiomac.2023.123389] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/11/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023]
Abstract
The frequent and extensive use of insecticides leads to the evolution of insecticide resistance, which has become one of the constraints on global agricultural production. Avermectins are microbial-derived insecticides that target a wide number of insect pests, including the diamondback moth Plutella xylostella, an important global pest of brassicaceous vegetables. However, field populations of P. xylostella have evolved serious resistance to avermectins, including abamectin, thereby threatening the efficiency of these insecticides. In this study, a novel valine to isoleucine mutation (V263I) was identified in the glutamate-gated chloride channel (GluCl) of field P. xylostella populations, which showed different levels of resistance to abamectin. Electrophysiological analysis revealed that the V263I mutation significantly reduced the sensitivity of PxGluCl to abamectin by 6.9-fold. Genome-modified Drosophila melanogaster carrying the V263I mutation exhibited 27.1-fold resistance to abamectin. Then, a knockin strain (V263I-KI) of P. xylostella expressing the homozygous V263I mutation was successfully constructed using the CRISPR/Cas9. The V263I-KI had high resistance to abamectin (106.3-fold), but significantly reduced fecundity. In this study, the function of V263I mutation in PxGluCl was verified for the first time. These findings provide a more comprehensive understanding of abamectin resistance mechanisms and lay the foundation for providing a new molecular detection method for abamectin resistance monitoring.
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Affiliation(s)
- Xi Sun
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Wenjuan Hua
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Kunkun Wang
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Jiajia Song
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Bin Zhu
- Department of Entomology, China Agricultural University, Beijing 100193, China.
| | - Xiwu Gao
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Pei Liang
- Department of Entomology, China Agricultural University, Beijing 100193, China.
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9
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Hardege I, Morud J, Courtney A, Schafer WR. A Novel and Functionally Diverse Class of Acetylcholine-Gated Ion Channels. J Neurosci 2023; 43:1111-1124. [PMID: 36604172 PMCID: PMC9962794 DOI: 10.1523/jneurosci.1516-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/02/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023] Open
Abstract
Fast cholinergic neurotransmission is mediated by acetylcholine-gated ion channels; in particular, excitatory nicotinic acetylcholine receptors play well established roles in virtually all nervous systems. Acetylcholine-gated inhibitory channels have also been identified in some invertebrate phyla, yet their roles in the nervous system are less well understood. We report the existence of multiple new inhibitory ion channels with diverse ligand activation properties in Caenorhabditis elegans We identify three channels, LGC-40, LGC-57, and LGC-58, whose primary ligand is choline rather than acetylcholine, as well as the first evidence of a truly polymodal channel, LGC-39, which is activated by both cholinergic and aminergic ligands. Using our new ligand-receptor pairs we uncover the surprising extent to which single neurons in the hermaphrodite nervous system express both excitatory and inhibitory channels, not only for acetylcholine but also for the other major neurotransmitters. The results presented in this study offer new insight into the potential evolutionary benefit of a vast and diverse repertoire of ligand-gated ion channels to generate complexity in an anatomically compact nervous system.SIGNIFICANCE STATEMENT Here we describe the diversity of cholinergic signaling in the nematode Caenorhabditis elegans We identify and characterize a novel family of ligand-gated ion channels and show that they are preferentially gated by choline rather than acetylcholine and expressed broadly in the nervous system. Interestingly, we also identify one channel gated by chemically diverse ligands including acetylcholine and aminergic ligands. By using our new knowledge of these ligand-gated ion channels, we built a model to predict the synaptic polarity in the C. elegans connectome. This model can be used for generating hypotheses on neural circuit function.
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Affiliation(s)
- Iris Hardege
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Julia Morud
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Amy Courtney
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - William R Schafer
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
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10
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Choudhary S, Abongwa M, Kashyap SS, Verma S, Mair GR, Kulke D, Martin RJ, Robertson AP. Nodulisporic acid produces direct activation and positive allosteric modulation of AVR-14B, a glutamate-gated chloride channel from adult Brugia malayi. Proc Natl Acad Sci U S A 2022; 119:e2111932119. [PMID: 35969762 PMCID: PMC9407656 DOI: 10.1073/pnas.2111932119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 06/13/2022] [Indexed: 11/18/2022] Open
Abstract
Glutamate-gated chloride channels (GluCls) are unique to invertebrates and are targeted by macrocyclic lactones. In this study, we cloned an AVR-14B GluCl subunit from adult Brugia malayi, a causative agent of lymphatic filariasis in humans. To elucidate this channel's pharmacological properties, we used Xenopus laevis oocytes for expression and performed two-electrode voltage-clamp electrophysiology. The receptor was gated by the natural ligand L-glutamate (effective concentration, 50% [EC50] = 0.4 mM) and ivermectin (IVM; EC50 = 1.8 nM). We also characterized the effects of nodulisporic acid (NA) on Bma-AVR-14B and NA-produced dual effects on the receptor as an agonist and a type II positive allosteric modulator. Here we report characterization of the complex activity of NA on a nematode GluCl. Bma-AVR-14B demonstrated some unique pharmacological characteristics. IVM did not produce potentiation of L-glutamate-mediated responses but instead, reduced the channel's sensitivity for the ligand. Further electrophysiological exploration showed that IVM (at a moderate concentration of 0.1 nM) functioned as an inhibitor of both agonist and positive allosteric modulatory effects of NA. This suggests that IVM and NA share a complex interaction. The pharmacological properties of Bma-AVR-14B indicate that the channel is an important target of IVM and NA. In addition, the unique electrophysiological characteristics of Bma-AVR-14B could explain the observed variation in drug sensitivities of various nematode parasites. We have also shown the inhibitory effects of IVM and NA on adult worm motility using Worminator. RNA interference (RNAi) knockdown suggests that AVR-14 plays a role in influencing locomotion in B. malayi.
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Affiliation(s)
- Shivani Choudhary
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Melanie Abongwa
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Sudhanva S. Kashyap
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Saurabh Verma
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Gunnar R. Mair
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Daniel Kulke
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Richard J. Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
| | - Alan P. Robertson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011
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11
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Choudhary S, Kashyap SS, Martin RJ, Robertson AP. Advances in our understanding of nematode ion channels as potential anthelmintic targets. Int J Parasitol Drugs Drug Resist 2022; 18:52-86. [PMID: 35149380 PMCID: PMC8841521 DOI: 10.1016/j.ijpddr.2021.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 12/15/2022]
Abstract
Ion channels are specialized multimeric proteins that underlie cell excitability. These channels integrate with a variety of neuromuscular and biological functions. In nematodes, the physiological behaviors including locomotion, navigation, feeding and reproduction, are regulated by these protein entities. Majority of the antinematodal chemotherapeutics target the ion channels to disrupt essential biological functions. Here, we have summarized current advances in our understanding of nematode ion channel pharmacology. We review cys-loop ligand gated ion channels (LGICs), including nicotinic acetylcholine receptors (nAChRs), acetylcholine-chloride gated ion channels (ACCs), glutamate-gated chloride channels (GluCls), and GABA (γ-aminobutyric acid) receptors, and other ionotropic receptors (transient receptor potential (TRP) channels and potassium ion channels). We have provided an update on the pharmacological properties of these channels from various nematodes. This article catalogs the differences in ion channel composition and resulting pharmacology in the phylum Nematoda. This diversity in ion channel subunit repertoire and pharmacology emphasizes the importance of pursuing species-specific drug target research. In this review, we have provided an overview of recent advances in techniques and functional assays available for screening ion channel properties and their application.
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Affiliation(s)
- Shivani Choudhary
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Sudhanva S Kashyap
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Richard J Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Alan P Robertson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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12
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Morud J, Hardege I, Liu H, Wu T, Choi MK, Basu S, Zhang Y, Schafer WR. Deorphanization of novel biogenic amine-gated ion channels identifies a new serotonin receptor for learning. Curr Biol 2021; 31:4282-4292.e6. [PMID: 34388373 PMCID: PMC8536830 DOI: 10.1016/j.cub.2021.07.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/09/2021] [Accepted: 07/15/2021] [Indexed: 11/16/2022]
Abstract
Pentameric ligand-gated ion channels (LGICs) play conserved, critical roles in both excitatory and inhibitory synaptic transmission and can be activated by diverse neurochemical ligands. We have performed a characterization of orphan channels from the nematode C. elegans, identifying five new monoamine-gated LGICs with diverse functional properties and expression postsynaptic to aminergic neurons. These include polymodal anion channels activated by both dopamine and tyramine, which may mediate inhibitory transmission by both molecules in vivo. Intriguingly, we also find that a novel serotonin-gated cation channel, LGC-50, is essential for aversive olfactory learning of pathogenic bacteria, a process known to depend on serotonergic neurotransmission. Remarkably, the redistribution of LGC-50 to neuronal processes is modulated by olfactory conditioning, and lgc-50 point mutations that cause misregulation of receptor membrane expression interfere with olfactory learning. Thus, the intracellular trafficking and localization of these receptors at synapses may represent a molecular cornerstone of the learning mechanism.
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Affiliation(s)
- Julia Morud
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Iris Hardege
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - He Liu
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA; Centre for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Taihong Wu
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA; Centre for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Myung-Kyu Choi
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA; Centre for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Swaraj Basu
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Medicinaregatan 9A, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA; Centre for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - William R Schafer
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium.
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Huang QT, Sheng CW, Jones AK, Jiang J, Tang T, Han ZJ, Zhao CQ. Functional Characteristics of the Lepidopteran Ionotropic GABA Receptor 8916 Subunit Interacting with the LCCH3 or the RDL Subunit. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:11582-11591. [PMID: 34555899 DOI: 10.1021/acs.jafc.1c00385] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The ionotropic γ-aminobutyric acid (iGABA) receptor is commonly considered as a fast inhibitory channel and is an important insecticide target. Since 1990, RDL, LCCH3, and GRD have been successively isolated and found to be potential subunits of the insect iGABA receptor. More recently, one orphan gene named 8916 was found and considered to be another potential iGABA receptor subunit according to its amino acid sequence. However, little information about 8916 has been reported. Here, the 8916 subunit from Chilo suppressalis was studied to determine whether it can form part of a functional iGABA receptor by co-expressing this subunit with CsRDL1 or CsLCCH3 in the Xenopus oocyte system. Cs8916 or CsLCCH3 did not form functional ion channels when expressed alone. However, Cs8916 was able to form heteromeric ion channels when expressed with either CsLCCH3 or CsRDL1. The recombinant heteromeric Cs8916/LCCH3 channel was a cation-selective channel, which was sensitive to GABA or β-alanine. The current of the Cs8916/LCCH3 channel was inhibited by dieldrin, endosulfan, fipronil, or ethiprole. In contrast, fluralaner, broflanilide, and avermectin showed little effect on the Cs8916/LCCH3 channel (IC50s > 10 000 nM). The Cs8916/RDL1 channel was sensitive to GABA, but was significantly different in EC50 and Imax for GABA to those of homomeric CsRDL1. Fluralaner, fipronil, or dieldrin showed antagonistic actions on Cs8916/RDL1. In conclusion, Cs8916 is a potential iGABA receptor subunit, which can interact with CsLCCH3 to generate a cation-selective channel that is sensitive to several insecticides. Also, as Cs8916/RDL1 has a higher EC50 than homomeric CsRDL1, Cs8916 may affect the physiological functions of CsRDL1 and therefore play a role in fine-tuning GABAergic signaling.
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Affiliation(s)
- Qiu Tang Huang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Cheng Wang Sheng
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Andrew K Jones
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, U.K
| | - Jie Jiang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Tao Tang
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, P. R. China
| | - Zhao Jun Han
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Chun Qing Zhao
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
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Nomura K, Yoshizumi S, Ozoe F, Ozoe Y. Molecular cloning and pharmacology of Min-UNC-49B, a GABA receptor from the southern root-knot nematode Meloidogyne incognita. PEST MANAGEMENT SCIENCE 2021; 77:3763-3776. [PMID: 32954620 DOI: 10.1002/ps.6096] [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: 07/29/2020] [Revised: 09/11/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Root-knot nematodes are plant-parasitic nematodes that cause immense damage to a broad range of cultivated crops by forming root galls, resulting in yield losses in crops. To facilitate the development of faster-acting selective nematicides, we cloned three cDNAs encoding UNC-49B proteins from the southern root-knot nematode Meloidogyne incognita and examined their functional and pharmacological properties by two-electrode voltage clamp electrophysiology using a Xenopus oocyte expression system. RESULTS The three cloned cDNAs encoded Min-UNC-49B, Min-UNC-49B-L and Min-UNC-49B-XL; the last two proteins have longer N-terminal regions than the first protein. When expressed in Xenopus oocytes, these proteins responded to γ-aminobutyric acid (GABA) to activate currents with high-micromolar or low-millimolar half-maximal effective concentration (EC50 ) values, indicating the formation of functional homo-pentameric GABA receptors. Fipronil and picrotoxinin inhibited GABA-induced currents with high-nanomolar and low-micromolar half-maximal inhibitory concentration (IC50 ) values, respectively, in oocytes expressing Min-UNC-49B. The G2'A and T6'M mutations in the second transmembrane domain of Min-UNC-49B enhanced and reduced the sensitivity of Min-UNC-49B to these two antagonists, respectively. Samaderine B and SF-14 inhibited GABA responses in oocytes expressing Min-UNC-49B with low-micromolar and high-nanomolar IC50 values, respectively. Ivermectin, α-terpineol, thymol and methyl eugenol exerted dual effects on Min-UNC-49B by potentiating currents induced by low concentrations of GABA and inhibiting currents induced by high concentrations of GABA. CONCLUSION We have shown that structurally diverse compounds act at Min-UNC-49B GABA receptors. Our results may serve as a starting point to decipher the molecular function of native GABA receptors of plant-parasitic nematodes, which could aid in the structure-based design of novel nematicides. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Kazuki Nomura
- Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane, Japan
| | - Satoru Yoshizumi
- Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane, Japan
| | - Fumiyo Ozoe
- Interdisciplinary Institute for Science Research, Organization for Research and Academic Information, Shimane University, Matsue, Shimane, Japan
| | - Yoshihisa Ozoe
- Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane, Japan
- Interdisciplinary Institute for Science Research, Organization for Research and Academic Information, Shimane University, Matsue, Shimane, Japan
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15
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Fenyves BG, Szilágyi GS, Vassy Z, Sőti C, Csermely P. Synaptic polarity and sign-balance prediction using gene expression data in the Caenorhabditis elegans chemical synapse neuronal connectome network. PLoS Comput Biol 2020; 16:e1007974. [PMID: 33347479 PMCID: PMC7785220 DOI: 10.1371/journal.pcbi.1007974] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 01/05/2021] [Accepted: 10/19/2020] [Indexed: 12/16/2022] Open
Abstract
Graph theoretical analyses of nervous systems usually omit the aspect of connection polarity, due to data insufficiency. The chemical synapse network of Caenorhabditis elegans is a well-reconstructed directed network, but the signs of its connections are yet to be elucidated. Here, we present the gene expression-based sign prediction of the ionotropic chemical synapse connectome of C. elegans (3,638 connections and 20,589 synapses total), incorporating available presynaptic neurotransmitter and postsynaptic receptor gene expression data for three major neurotransmitter systems. We made predictions for more than two-thirds of these chemical synapses and observed an excitatory-inhibitory (E:I) ratio close to 4:1 which was found similar to that observed in many real-world networks. Our open source tool (http://EleganSign.linkgroup.hu) is simple but efficient in predicting polarities by integrating neuronal connectome and gene expression data.
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Affiliation(s)
- Bánk G. Fenyves
- Department of Molecular Biology, Semmelweis University, Budapest, Hungary
- Department of Emergency Medicine, Semmelweis University, Budapest, Hungary
| | - Gábor S. Szilágyi
- Department of Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Zsolt Vassy
- Department of Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Csaba Sőti
- Department of Molecular Biology, Semmelweis University, Budapest, Hungary
| | - Peter Csermely
- Department of Molecular Biology, Semmelweis University, Budapest, Hungary
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GABAergic motor neurons bias locomotor decision-making in C. elegans. Nat Commun 2020; 11:5076. [PMID: 33033264 PMCID: PMC7544903 DOI: 10.1038/s41467-020-18893-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 09/17/2020] [Indexed: 12/18/2022] Open
Abstract
Proper threat-reward decision-making is critical to animal survival. Emerging evidence indicates that the motor system may participate in decision-making but the neural circuit and molecular bases for these functions are little known. We found in C. elegans that GABAergic motor neurons (D-MNs) bias toward the reward behavior in threat-reward decision-making by retrogradely inhibiting a pair of premotor command interneurons, AVA, that control cholinergic motor neurons in the avoidance neural circuit. This function of D-MNs is mediated by a specific ionotropic GABA receptor (UNC-49) in AVA, and depends on electrical coupling between the two AVA interneurons. Our results suggest that AVA are hub neurons where sensory inputs from threat and reward sensory modalities and motor information from D-MNs are integrated. This study demonstrates at single-neuron resolution how motor neurons may help shape threat-reward choice behaviors through interacting with other neurons.
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17
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Crisford A, Calahorro F, Ludlow E, Marvin JMC, Hibbard JK, Lilley CJ, Kearn J, Keefe F, Johnson P, Harmer R, Urwin PE, O’Connor V, Holden-Dye L. Identification and characterisation of serotonin signalling in the potato cyst nematode Globodera pallida reveals new targets for crop protection. PLoS Pathog 2020; 16:e1008884. [PMID: 33007049 PMCID: PMC7556481 DOI: 10.1371/journal.ppat.1008884] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 10/14/2020] [Accepted: 08/14/2020] [Indexed: 11/18/2022] Open
Abstract
Plant parasitic nematodes are microscopic pathogens that invade plant roots and cause extensive damage to crops. We have used a chemical biology approach to define mechanisms underpinning their parasitic behaviour: We discovered that reserpine, a plant alkaloid that inhibits the vesicular monoamine transporter (VMAT), potently impairs the ability of the potato cyst nematode Globodera pallida to enter the host plant root. We show this is due to an inhibition of serotonergic signalling that is essential for activation of the stylet which is used to access the host root. Prompted by this we identified core molecular components of G. pallida serotonin signalling encompassing the target of reserpine, VMAT; the synthetic enzyme for serotonin, tryptophan hydroxylase; the G protein coupled receptor SER-7 and the serotonin-gated chloride channel MOD-1. We cloned each of these molecular components and confirmed their functional identity by complementation of the corresponding C. elegans mutant thus mapping out serotonergic signalling in G. pallida. Complementary approaches testing the effect of chemical inhibitors of each of these signalling elements on discrete sub-behaviours required for parasitism and root invasion reinforce the critical role of serotonin. Thus, targeting the serotonin signalling pathway presents a promising new route to control plant parasitic nematodes.
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Affiliation(s)
- Anna Crisford
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Fernando Calahorro
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Elizabeth Ludlow
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Jessica M. C. Marvin
- Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Jennifer K. Hibbard
- Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Catherine J. Lilley
- Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - James Kearn
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Francesca Keefe
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Peter Johnson
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Rachael Harmer
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Peter E. Urwin
- Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Vincent O’Connor
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Lindy Holden-Dye
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
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18
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Treinin M, Jin Y. Cholinergic transmission in C. elegans: Functions, diversity, and maturation of ACh-activated ion channels. J Neurochem 2020; 158:1274-1291. [PMID: 32869293 DOI: 10.1111/jnc.15164] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/13/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023]
Abstract
Acetylcholine is an abundant neurotransmitter in all animals. Effects of acetylcholine are excitatory, inhibitory, or modulatory depending on the receptor and cell type. Research using the nematode C. elegans has made ground-breaking contributions to the mechanistic understanding of cholinergic transmission. Powerful genetic screens for behavioral mutants or for responses to pharmacological reagents identified the core cellular machinery for synaptic transmission. Pharmacological reagents that perturb acetylcholine-mediated processes led to the discovery and also uncovered the composition and regulators of acetylcholine-activated channels and receptors. From a combination of electrophysiological and molecular cellular studies, we have gained a profound understanding of cholinergic signaling at the levels of synapses, neural circuits, and animal behaviors. This review will begin with a historical overview, then cover in-depth current knowledge on acetylcholine-activated ionotropic receptors, mechanisms regulating their functional expression and their functions in regulating locomotion.
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Affiliation(s)
- Millet Treinin
- Department of Medical Neurobiology, Hadassah Medical school - Hebrew University, Jerusalem, Israel
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
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19
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Castro MJ, Turani O, Faraoni MB, Gerbino D, Bouzat C. A New Antagonist of Caenorhabditis elegans Glutamate-Activated Chloride Channels With Anthelmintic Activity. Front Neurosci 2020; 14:879. [PMID: 32973433 PMCID: PMC7466757 DOI: 10.3389/fnins.2020.00879] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 07/28/2020] [Indexed: 12/15/2022] Open
Abstract
Nematode parasitosis causes significant mortality and morbidity in humans and considerable losses in livestock and domestic animals. The acquisition of resistance to current anthelmintic drugs has prompted the search for new compounds for which the free-living nematode Caenorhabditis elegans has emerged as a valuable platform. We have previously synthetized a small library of oxygenated tricyclic compounds and determined that dibenzo[b,e]oxepin-11(6H)-one (doxepinone) inhibits C. elegans motility. Because doxepinone shows potential anthelmintic activity, we explored its behavioral effects and deciphered its target site and mechanism of action on C. elegans. Doxepinone reduces swimming rate, induces paralysis, and decreases the rate of pharyngeal pumping required for feeding, indicating a marked anthelmintic activity. To identify the main drug targets, we performed an in vivo screening of selected strains carrying mutations in Cys-loop receptors involved in worm locomotion for determining resistance to doxepinone effects. A mutant strain that lacks subunit genes of the invertebrate glutamate-gated chloride channels (GluCl), which are targets of the widely used antiparasitic ivermectin (IVM), is resistant to doxepinone effects. To unravel the molecular mechanism, we measured whole-cell currents from GluClα1/β receptors expressed in mammalian cells. Glutamate elicits macroscopic currents whereas no responses are elicited by doxepinone, indicating that it is not an agonist of GluCls. Preincubation of the cell with doxepinone produces a statistically significant decrease of the decay time constant and net charge of glutamate-elicited currents, indicating that it inhibits GluCls, which contrasts to IVM molecular actions. Thus, we identify doxepinone as an attractive scaffold with promising anthelmintic activity and propose the inhibition of GluCls as a potential anthelmintic mechanism of action.
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Affiliation(s)
- María Julia Castro
- Departamento de Biología, Bioquímica y Farmacia, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina.,Instituto de Química del Sur (INQUISUR), Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Ornella Turani
- Departamento de Biología, Bioquímica y Farmacia, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - María Belén Faraoni
- Instituto de Química del Sur (INQUISUR), Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Darío Gerbino
- Instituto de Química del Sur (INQUISUR), Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Cecilia Bouzat
- Departamento de Biología, Bioquímica y Farmacia, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
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20
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Habibi SA, Blazie SM, Jin Y, Forrester SG. Isolation and characterization of a novel member of the ACC ligand-gated chloride channel family, Hco-LCG-46, from the parasitic nematode Haemonchus contortus. Mol Biochem Parasitol 2020; 237:111276. [DOI: 10.1016/j.molbiopara.2020.111276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 10/24/2022]
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21
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Zhou X, Bessereau JL. Molecular Architecture of Genetically-Tractable GABA Synapses in C. elegans. Front Mol Neurosci 2019; 12:304. [PMID: 31920535 PMCID: PMC6920096 DOI: 10.3389/fnmol.2019.00304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/26/2019] [Indexed: 12/18/2022] Open
Abstract
Inhibitory synapses represent a minority of the total chemical synapses in the mammalian brain, yet proper tuning of inhibition is fundamental to shape neuronal network properties. The neurotransmitter γ-aminobutyric acid (GABA) mediates rapid synaptic inhibition by the activation of the type A GABA receptor (GABAAR), a pentameric chloride channel that governs major inhibitory neuronal transduction in the nervous system. Impaired GABA transmission leads to a variety of neuropsychiatric diseases, including schizophrenia, autism, epilepsy or anxiety. From an evolutionary perspective, GABAAR shows remarkable conservations, and are found in all eukaryotic clades and even in bacteria and archaea. Specifically, bona fide GABAARs are found in the nematode Caenorhabditis elegans. Because of the anatomical simplicity of the nervous system and its amenability to genetic manipulations, C. elegans provide a powerful system to investigate the molecular and cellular biology of GABA synapses. In this mini review article, we will introduce the structure of the C. elegans GABAergic system and describe recent advances that have identified novel proteins controlling the localization of GABAARs at synapses. In particular, Ce-Punctin/MADD-4 is an evolutionarily-conserved extracellular matrix protein that behaves as an anterograde synaptic organizer to instruct the excitatory or inhibitory identity of postsynaptic domains.
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Affiliation(s)
- Xin Zhou
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, Institut NeuroMyoGène, Lyon, France
| | - Jean-Louis Bessereau
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, Institut NeuroMyoGène, Lyon, France
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22
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Meng X, Miao L, Ge H, Yang X, Dong F, Xu X, Wu Z, Qian K, Wang J. Molecular characterization of glutamate-gated chloride channel and its possible roles in development and abamectin susceptibility in the rice stem borer, Chilo suppressalis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 155:72-80. [PMID: 30857629 DOI: 10.1016/j.pestbp.2019.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/15/2019] [Accepted: 01/20/2019] [Indexed: 06/09/2023]
Abstract
Glutamate-gated chloride channels (GluCls) mediate fast inhibitory neurotransmission in invertebrate nervous systems, and are of considerable interest in insecticide discovery. The full length cDNA encoding CsGluCl was cloned from the rice stem borer Chilo suppressalis (Walker). Multiple cDNA sequence alignment revealed three variants of CsGluCl generated by alternative splicing of exon 3 and exon 9. While all the transcripts were predominantly expressed in both nerve cord and brain, the expression patterns of these three variants differed among other tissues and developmental stages. Specifically, the expression level of CsGluCl C in cuticle was similar to that in nerve cord and brain, and was the predominant variant in late pupae and early adult stages. Both injection and oral delivery of dsGluCl significantly reduced the mRNA level of CsGluCl. Increased susceptibility to abamectin and reduced larvae growth and pupation rate were observed in dsGluCl-treated larvae. Thus, our results provide the evidence that in addition to act as the target of abamectin, GluCls also play important physiological roles in the development of insects.
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Affiliation(s)
- Xiangkun Meng
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Lijun Miao
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Huichen Ge
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Xuemei Yang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Fan Dong
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Xin Xu
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Zhaolu Wu
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Kun Qian
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Jianjun Wang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China.
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Wang X, O Reilly AO, Williamson MS, Puinean AM, Yang Y, Wu S, Wu Y. Function and pharmacology of glutamate-gated chloride channel exon 9 splice variants from the diamondback moth Plutella xylostella. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 104:58-64. [PMID: 30550974 DOI: 10.1016/j.ibmb.2018.12.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/24/2018] [Accepted: 12/11/2018] [Indexed: 06/09/2023]
Abstract
Glutamate-gated chloride channels (GluCls) are found only in invertebrates and mediate fast inhibitory neurotransmission. The structural and functional diversity of GluCls are produced through assembly of multiple subunits and via posttranscriptional alternations. Alternative splicing is the most common way to achieve this in insect GluCls and splicing occurs primarily at exons 3 and 9. As expression pattern and pharmacological properties of exon 9 alternative splices in invertebrate GluCls remain poorly understood, the cDNAs encoding three alternative splice variants (9a, 9b and 9c) of the PxGluCl gene from the diamondback moth Plutella xylostella were constructed and their pharmacological characterizations were examined using electrophysiological studies. Alternative splicing of exon 9 had little to no impact on PxGluCl sensitivity towards the agonist glutamate when subunits were singly or co-expressed in Xenopus oocytes. In contrast, the allosteric modulator abamectin and the chloride channel blocker fipronil had differing effects on PxGluCl splice variants. PxGluCl9c channels were more resistant to abamectin and PxGluCl9b channels were more sensitive to fipronil than other homomeric channels. In addition, heteromeric channels containing different splice variants showed similar sensitivity to abamectin (except for 9c) and reduced sensitivity to fipronil than homomeric channels. These findings suggest that functionally indistinguishable but pharmacologically distinct GluCls could be formed in P. xylostella and that the upregulated constitutive expression of the specific variants may contribute to the evolution of insecticide resistance in P. xylostella and other arthropods.
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Affiliation(s)
- Xingliang Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
| | - Andrias O O Reilly
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK.
| | - Martin S Williamson
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, UK.
| | - Alin M Puinean
- Oxitec Limited, 71 Innovation Drive, Abingdon, Oxfordshire, UK.
| | - Yihua Yang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
| | - Shuwen Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
| | - Yidong Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
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Foster J, Cochrane E, Khatami MH, Habibi SA, de Haan H, Forrester SG. A mutational and molecular dynamics study of the cys-loop GABA receptor Hco-UNC-49 from Haemonchus contortus: Agonist recognition in the nematode GABA receptor family. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2018; 8:534-539. [PMID: 30361167 PMCID: PMC6287672 DOI: 10.1016/j.ijpddr.2018.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/01/2018] [Accepted: 10/04/2018] [Indexed: 11/04/2022]
Abstract
The UNC-49 receptor is a unique nematode γ-aminobutyric acid (GABA)-gated chloride channel that may prove to be a novel target for the development of nematocides. Here we have characterized various charged amino acid residues in and near the agonist binding site of the UNC-49 receptor from the parasitic nematode Haemonchus contorts. Utilizing the Caenorhabditis elegans GluCl crystal structure as a template, a model was generated and various charged residues [D83 (loop D), E131 (loop A), H137 (pre-loop E), R159 (Loop E), E185 (Loop B) and R241 (Loop C)] were investigated based on their location and conservation. These residues may contribute to structure, function, and molecular interactions with agonists. It was found that all residues chosen were important for receptor function to varying degrees. Results of the mutational analysis and molecular simulations suggest that R159 may be interacting with D83 by an ionic interaction that may be crucial for general GABA receptor function. We have used the results from this study as well as knowledge of residues involved in GABA receptor binding to identify sequence patterns that may assist in understanding the function of lesser known GABA receptor subunits from parasitic nematodes. Key functional residues were investigated in the Hco-UNC-49 receptor. A glutamic acid in the binding pocket (loop B) is essential for agonist recognition. Interaction between residues in different binding loops are important for function.
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Affiliation(s)
- Josh Foster
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Everett Cochrane
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Mohammad Hassan Khatami
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Sarah A Habibi
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Hendrick de Haan
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Sean G Forrester
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada.
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Molecular and pharmacological characterization of an acetylcholine-gated chloride channel (ACC-2) from the parasitic nematode Haemonchus contortus. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2018; 8:518-525. [PMID: 30266440 PMCID: PMC6287471 DOI: 10.1016/j.ijpddr.2018.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/17/2018] [Accepted: 09/17/2018] [Indexed: 12/05/2022]
Abstract
Nematode cys-loop ligand-gated ion channels (LGICs) have been shown to be attractive targets for the development of novel anti-parasitic drugs. The ACC-1 family of receptors are a unique group of acetylcholine-gated chloride channels present only in invertebrates, and sequence analysis suggests that they contain a novel binding site for acetylcholine. We have isolated a novel member of this family, Hco-ACC-2, from the parasitic nematode Haemonchus contortus and using site-directed mutagenesis, electrophysiology and molecular modelling examined how two aromatic amino acids in the binding site contributed to agonist recognition. It was found that instead of a tryptophan residue in binding loop B, which essential for ligand binding in mammalian nAChRs, there is a phenylalanine (F200) in Hco-ACC-2. Amino acid changes at F200 to either a tyrosine or tryptophan were fairly well tolerated, where a F200Y mutation resulted in a channel hypersensitive to ACh and nicotine as well as other cholinergic agonists such as carbachol and methacholine. In addition, both pyrantel and levamisole were partial agonists at the wild-type receptor and like the other agonists showed an increase in sensitivity at F200Y. On the other hand, in Hco-ACC-2 there is a tryptophan residue at position 248 in loop C that appears to be essential for receptor function, as mutations to either phenylalanine or tyrosine resulted in a marked decrease in agonist sensitivity. Moreover, mutations that swapped the residues F200 and W248 (ie. F200W/W248F) produced non-functional receptors. Overall, Hco-ACC-2 appears to have a novel cholinergic binding site that could have implications for the design of specific anthelmintics that target this family of receptors in parasitic nematodes. Isolation of an ACC-2 orthologue from Haemonchus contortus. Hco-ACC-2 responds to several cholinergic agonists including levamisole and pyrantel. W248 in loop C plays an essential role in agonist recognition.
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Kwaka A, Hassan Khatami M, Foster J, Cochrane E, Habibi SA, de Haan HW, Forrester SG. Molecular Characterization of Binding Loop E in the Nematode Cys-Loop GABA Receptor. Mol Pharmacol 2018; 94:1289-1297. [PMID: 30194106 DOI: 10.1124/mol.118.112821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/30/2018] [Indexed: 01/27/2023] Open
Abstract
Nematodes exhibit a vast array of cys-loop ligand-gated ion channels with unique pharmacologic characteristics. However, many of the structural components that govern the binding of various ligands are unknown. The nematode cys-loop GABA receptor uncoordinated 49 (UNC-49) is an important receptor found at neuromuscular junctions that plays an important role in the sinusoidal movement of worms. The unique pharmacologic features of this receptor suggest that there are structural differences in the agonist binding site when compared with mammalian receptors. In this study, we examined each amino acid in one of the main agonist binding loops (loop E) via the substituted cysteine accessibility method (SCAM) and analyzed the interaction of various residues by molecular dynamic simulations. We found that of the 18 loop E mutants analyzed, H142C, R147C, and S157C had significant changes in GABA EC50 and were accessible to modification by a methanethiosulfonate reagent (MTSET) resulting in a change in I GABA In addition, the residue H142, which is unique to nematode UNC-49 GABA receptors, appears to play a negative role in GABA sensitivity as its mutation to cysteine increased sensitivity to GABA and caused the UNC-49 receptor partial agonist 5-aminovaleric acid (DAVA) to behave as a full agonist. Overall, this study has revealed potential differences in the agonist binding pocket between nematode UNC-49 and mammalian GABA receptors that could be exploited in the design of novel anthelmintics.
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Affiliation(s)
- Ariel Kwaka
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | | | - Joshua Foster
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - Everett Cochrane
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - Sarah A Habibi
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - Hendrick W de Haan
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - Sean G Forrester
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
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Turani O, Hernando G, Corradi J, Bouzat C. Activation of Caenorhabditis elegans Levamisole-Sensitive and Mammalian Nicotinic Receptors by the Antiparasitic Bephenium. Mol Pharmacol 2018; 94:1270-1279. [PMID: 30190363 DOI: 10.1124/mol.118.113357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/29/2018] [Indexed: 11/22/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels involved in neuromuscular transmission. In nematodes, muscle nAChRs are targets of antiparasitic drugs. Bephenium is an anthelmintic compound whose molecular action in the free-living nematode Caenorhabditis elegans, which is a model for anthelmintic drug discovery, is poorly known. We explored the effect of bephenium on C. elegans locomotion and applied single-channel recordings to identify its molecular target, mechanism of action, and selectivity between mammalian and C. elegans nAChRs. As in parasites, bephenium paralyzes C. elegans A mutant strain lacking the muscle levamisole-sensitive nAChR (L-AChR) shows full resistance to bephenium, indicating that this receptor is the target site. Bephenium activates L-AChR channels from larvae muscle cells in the micromolar range. Channel activity is similar to that elicited by levamisole, appearing mainly as isolated brief openings. Our analysis revealed that bephenium is an agonist of L-AChR and an open-channel blocker at higher concentrations. It also activates mammalian muscle nAChRs. Opening events are significantly briefer than those elicited by ACh and do not appear in activation episodes at a range of concentrations, indicating that it is a very weak agonist of mammalian nAChRs. Recordings in the presence of ACh showed that bephenium acts as a voltage-dependent channel blocker and a low-affinity agonist. Molecular docking into homology-modeled binding-site interfaces represent the binding mode of bephenium that explains its partial agonism. Given the great diversity of helminth nAChRs and the overlap of their pharmacological profiles, unraveling the basis of drug receptor-selectivity will be required for rational design of anthelmintic drugs.
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Affiliation(s)
- Ornella Turani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Guillermina Hernando
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Jeremías Corradi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
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Schoville SD, Chen YH, Andersson MN, Benoit JB, Bhandari A, Bowsher JH, Brevik K, Cappelle K, Chen MJM, Childers AK, Childers C, Christiaens O, Clements J, Didion EM, Elpidina EN, Engsontia P, Friedrich M, García-Robles I, Gibbs RA, Goswami C, Grapputo A, Gruden K, Grynberg M, Henrissat B, Jennings EC, Jones JW, Kalsi M, Khan SA, Kumar A, Li F, Lombard V, Ma X, Martynov A, Miller NJ, Mitchell RF, Munoz-Torres M, Muszewska A, Oppert B, Palli SR, Panfilio KA, Pauchet Y, Perkin LC, Petek M, Poelchau MF, Record É, Rinehart JP, Robertson HM, Rosendale AJ, Ruiz-Arroyo VM, Smagghe G, Szendrei Z, Thomas GWC, Torson AS, Vargas Jentzsch IM, Weirauch MT, Yates AD, Yocum GD, Yoon JS, Richards S. A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae). Sci Rep 2018; 8:1931. [PMID: 29386578 PMCID: PMC5792627 DOI: 10.1038/s41598-018-20154-1] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/13/2018] [Indexed: 01/04/2023] Open
Abstract
The Colorado potato beetle is one of the most challenging agricultural pests to manage. It has shown a spectacular ability to adapt to a variety of solanaceaeous plants and variable climates during its global invasion, and, notably, to rapidly evolve insecticide resistance. To examine evidence of rapid evolutionary change, and to understand the genetic basis of herbivory and insecticide resistance, we tested for structural and functional genomic changes relative to other arthropod species using genome sequencing, transcriptomics, and community annotation. Two factors that might facilitate rapid evolutionary change include transposable elements, which comprise at least 17% of the genome and are rapidly evolving compared to other Coleoptera, and high levels of nucleotide diversity in rapidly growing pest populations. Adaptations to plant feeding are evident in gene expansions and differential expression of digestive enzymes in gut tissues, as well as expansions of gustatory receptors for bitter tasting. Surprisingly, the suite of genes involved in insecticide resistance is similar to other beetles. Finally, duplications in the RNAi pathway might explain why Leptinotarsa decemlineata has high sensitivity to dsRNA. The L. decemlineata genome provides opportunities to investigate a broad range of phenotypes and to develop sustainable methods to control this widely successful pest.
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Affiliation(s)
- Sean D Schoville
- Department of Entomology, University of Wisconsin-Madison, Madison, USA.
| | - Yolanda H Chen
- Department of Plant and Soil Sciences, University of Vermont, Burlington, USA
| | | | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, USA
| | - Anita Bhandari
- Department of Molecular Physiology, Christian-Albrechts-University at Kiel, Kiel, Germany
| | - Julia H Bowsher
- Department of Biological Sciences, North Dakota State University, Fargo, USA
| | - Kristian Brevik
- Department of Plant and Soil Sciences, University of Vermont, Burlington, USA
| | - Kaat Cappelle
- Department of Crop Protection, Ghent University, Ghent, Belgium
| | - Mei-Ju M Chen
- USDA-ARS National Agricultural Library, Beltsville, MD, USA
| | - Anna K Childers
- USDA-ARS Bee Research Lab, Beltsville, MD, USA
- USDA-ARS Insect Genetics and Biochemistry Research Unit, Fargo, ND, USA
| | | | | | - Justin Clements
- Department of Entomology, University of Wisconsin-Madison, Madison, USA
| | - Elise M Didion
- Department of Biological Sciences, University of Cincinnati, Cincinnati, USA
| | - Elena N Elpidina
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moskva, Russia
| | - Patamarerk Engsontia
- Department of Biology, Faculty of Science, Prince of Songkla University, Amphoe Hat Yai, Thailand
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, Detroit, USA
| | | | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Chandan Goswami
- National Institute of Science Education and Research, Bhubaneswar, India
| | | | - Kristina Gruden
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
| | - Marcin Grynberg
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, 13288, Marseille, France
- INRA, USC 1408 AFMB, F-13288, Marseille, France
- Department of Biological Sciences, King Abdulaziz University, King Abdulaziz, Saudi Arabia
| | - Emily C Jennings
- Department of Biological Sciences, University of Cincinnati, Cincinnati, USA
| | - Jeffery W Jones
- Department of Biological Sciences, Wayne State University, Detroit, USA
| | - Megha Kalsi
- Department of Entomology, University of Kentucky, Lexington, USA
| | - Sher A Khan
- Department of Entomology, Texas A&M University, College Station, USA
| | - Abhishek Kumar
- Department of Genetics & Molecular Biology in Botany, Christian-Albrechts-University at Kiel, Kiel, Germany
- Division of Molecular Genetic Epidemiology, German Cancer Research Center, Heidelberg, Germany
| | - Fei Li
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Vincent Lombard
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, 13288, Marseille, France
- INRA, USC 1408 AFMB, F-13288, Marseille, France
| | - Xingzhou Ma
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Alexander Martynov
- Center for Data-Intensive Biomedicine and Biotechnology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Nicholas J Miller
- Department of Biology, Illinois Institute of Technology, Chicago, USA
| | - Robert F Mitchell
- Department of Biology, University of Wisconsin-Oshkosh, Oshkosh, USA
| | - Monica Munoz-Torres
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, USA
| | - Anna Muszewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Brenda Oppert
- USDA-ARS Center for Grain and Animal Health Research, New York, USA
| | | | - Kristen A Panfilio
- Institute for Developmental Biology, University of Cologne, Köln, Germany
- School of Life Sciences, University of Warwick, Gibbet Hill Campus, England, UK
| | - Yannick Pauchet
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Lindsey C Perkin
- USDA-ARS Center for Grain and Animal Health Research, New York, USA
| | - Marko Petek
- Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia
| | | | - Éric Record
- INRA, Aix-Marseille Université, UMR1163, Biodiversité et Biotechnologie Fongiques, Marseille, France
| | - Joseph P Rinehart
- USDA-ARS Insect Genetics and Biochemistry Research Unit, Fargo, ND, USA
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Andrew J Rosendale
- Department of Biological Sciences, University of Cincinnati, Cincinnati, USA
| | | | - Guy Smagghe
- Department of Crop Protection, Ghent University, Ghent, Belgium
| | - Zsofia Szendrei
- Department of Entomology, Michigan State University, East Lansing, USA
| | - Gregg W C Thomas
- Department of Biology and School of Informatics and Computing, Indiana University, Bloomington, USA
| | - Alex S Torson
- Department of Biological Sciences, North Dakota State University, Fargo, USA
| | | | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology, Division of Biomedical Informatics and Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, USA
| | - Ashley D Yates
- Department of Entomology, The Ohio State University, Columbus, USA
- Center for Applied Plant Sciences, The Ohio State University, Columbus, USA
| | - George D Yocum
- USDA-ARS Insect Genetics and Biochemistry Research Unit, Fargo, ND, USA
| | - June-Sun Yoon
- Department of Entomology, University of Kentucky, Lexington, USA
| | - Stephen Richards
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
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IGDB-2, an Ig/FNIII protein, binds the ion channel LGC-34 and controls sensory compartment morphogenesis in C. elegans. Dev Biol 2017; 430:105-112. [PMID: 28803967 DOI: 10.1016/j.ydbio.2017.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/04/2017] [Accepted: 08/07/2017] [Indexed: 11/21/2022]
Abstract
Sensory organ glia surround neuronal receptive endings (NREs), forming a specialized compartment important for neuronal activity, and reminiscent of glia-ensheathed synapses in the central nervous system. We previously showed that DAF-6, a Patched-related protein, is required in glia of the C. elegans amphid sensory organ to restrict sensory compartment size. LIT-1, a Nemo-like kinase, and SNX-1, a retromer component, antagonize DAF-6 and promote compartment expansion. To further explore the machinery underlying compartment size control, we sought genes whose inactivation restores normal compartment size to daf-6 mutants. We found that mutations in igdb-2, encoding a single-pass transmembrane protein containing Ig-like and fibronectin type III domains, suppress daf-6 mutant defects. IGDB-2 acts in glia, where it localizes to glial membranes surrounding NREs, and, together with LIT-1 and SNX-1, regulates compartment morphogenesis. Immunoprecipitation followed by mass spectrometry demonstrates that IGDB-2 binds to LGC-34, a predicted ligand-gated ion channel, and lgc-34 mutations inhibit igdb-2 suppression of daf-6. Our findings reveal a novel membrane protein complex and suggest possible mechanisms for how sensory compartment size is controlled.
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Wang X, Puinean AM, O Reilly AO, Williamson MS, Smelt CLC, Millar NS, Wu Y. Mutations on M3 helix of Plutella xylostella glutamate-gated chloride channel confer unequal resistance to abamectin by two different mechanisms. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 86:50-57. [PMID: 28576654 DOI: 10.1016/j.ibmb.2017.05.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 05/29/2017] [Indexed: 06/07/2023]
Abstract
Abamectin is one of the most widely used avermectins for agricultural pests control, but the emergence of resistance around the world is proving a major threat to its sustained application. Abamectin acts by directly activating glutamate-gated chloride channels (GluCls) and modulating other Cys-loop ion channels. To date, three mutations occurring in the transmembrane domain of arthropod GluCls are associated with target-site resistance to abamectin: A309V in Plutella xylostella GluCl (PxGluCl), G323D in Tetranychus urticae GluCl1 (TuGluCl1) and G326E in TuGluCl3. To compare the effects of these mutations in a single system, A309V/I/G and G315E (corresponding to G323 in TuGluCl1 and G326 in TuGluCl3) substitutions were introduced individually into the PxGluCl channel. Functional analysis using Xenopus oocytes showed that the A309V and G315E mutations reduced the sensitivity to abamectin by 4.8- and 493-fold, respectively. In contrast, the substitutions A309I/G show no significant effects on the response to abamectin. Interestingly, the A309I substitution increased the channel sensitivity to glutamate by one order of magnitude (∼12-fold). Analysis of PxGluCl homology models indicates that the G315E mutation interferes with abamectin binding through a steric hindrance mechanism. In contrast, the structural consequences of the A309 mutations are not so clear and an allosteric modification of the binding site is the most likely mechanism. Overall the results show that both A309V and G315E mutations may contribute to target-site resistance to abamectin and may be important for the future prediction and monitoring of abamectin resistance in P. xylostella and other arthropod pests.
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Affiliation(s)
- Xingliang Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
| | - Alin M Puinean
- Rothamsted Research, Biological Chemistry and Crop Protection Department, Harpenden, UK.
| | - Andrias O O Reilly
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK.
| | - Martin S Williamson
- Rothamsted Research, Biological Chemistry and Crop Protection Department, Harpenden, UK.
| | - Charles L C Smelt
- Department of Neuroscience Physiology and Pharmacology, University College London, London, UK.
| | - Neil S Millar
- Department of Neuroscience Physiology and Pharmacology, University College London, London, UK.
| | - Yidong Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
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31
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Liu P, Chen B, Mailler R, Wang ZW. Antidromic-rectifying gap junctions amplify chemical transmission at functionally mixed electrical-chemical synapses. Nat Commun 2017; 8:14818. [PMID: 28317880 PMCID: PMC5364397 DOI: 10.1038/ncomms14818] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 02/06/2017] [Indexed: 11/09/2022] Open
Abstract
Neurons communicate through chemical synapses and electrical synapses (gap junctions). Although these two types of synapses often coexist between neurons, little is known about whether they interact, and whether any interactions between them are important to controlling synaptic strength and circuit functions. By studying chemical and electrical synapses between premotor interneurons (AVA) and downstream motor neurons (A-MNs) in the Caenorhabditis elegans escape circuit, we found that disrupting either the chemical or electrical synapses causes defective escape response. Gap junctions between AVA and A-MNs only allow antidromic current, but, curiously, disrupting them inhibits chemical transmission. In contrast, disrupting chemical synapses has no effect on the electrical coupling. These results demonstrate that gap junctions may serve as an amplifier of chemical transmission between neurons with both electrical and chemical synapses. The use of antidromic-rectifying gap junctions to amplify chemical transmission is potentially a conserved mechanism in circuit functions.
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Affiliation(s)
- Ping Liu
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Bojun Chen
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Roger Mailler
- Department of Computer Science, University of Tulsa, Tulsa, Oklahoma 74104, USA
| | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
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Wu SF, Mu XC, Dong YX, Wang LX, Wei Q, Gao CF. Expression pattern and pharmacological characterisation of two novel alternative splice variants of the glutamate-gated chloride channel in the small brown planthopper Laodelphax striatellus. PEST MANAGEMENT SCIENCE 2017; 73:590-597. [PMID: 27302648 DOI: 10.1002/ps.4340] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Glutamate-gated chloride channels (GluCl) mediate fast inhibitory neurotransmission in invertebrate nervous systems. Although only one GluCl gene was presented in insects, it showed diverse alternative splicing that was speculated could affect channel function and pharmacology. RESULTS In this study, we isolated GluCl cDNAs from adults of the small brown planthopper (SBPH) Laodelphax striatellus and showed that six L. striatellus GluCl variants (LsGluCl-AS, LsGluCl-BS, LsGluCl-CS, LsGluCl-AL, LsGluCl-BL, LsGluCl-CL) were present in the SBPH. The expression patterns of six variants differed among developmental stages (egg, first- to fifth-instar nymphs, male and female adults) and among the body parts (head, thorax, abdomen, leg) of the female adult SBPH. All the transcripts were abundant in the head of the adult. When expressed in African clawed frog, Xenopus laevis, oocytes, the two functional variants (LsGluCl-AS, LsGluCl-AL) had similar EC50 and IC50 values for L-glutamate and channel blockers picrotoxinin and fipronil. CONCLUSION This study represents a comprehensive molecular, expression and pharmacological characterisation of GluCl in the SBPH. These findings should be useful in providing more opportunities to discover novel insect control chemicals. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Shun-Fan Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- State and Local Joint Engineering Research Centre of Green Pesticide Invention and Application, Jiangsu, China
| | - Xi-Chao Mu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- State and Local Joint Engineering Research Centre of Green Pesticide Invention and Application, Jiangsu, China
| | - Yao-Xue Dong
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- State and Local Joint Engineering Research Centre of Green Pesticide Invention and Application, Jiangsu, China
| | - Li-Xiang Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- State and Local Joint Engineering Research Centre of Green Pesticide Invention and Application, Jiangsu, China
| | - Qi Wei
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- State and Local Joint Engineering Research Centre of Green Pesticide Invention and Application, Jiangsu, China
| | - Cong-Fen Gao
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- State and Local Joint Engineering Research Centre of Green Pesticide Invention and Application, Jiangsu, China
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Taylor-Wells J, Jones AK. Variations in the Insect GABA Receptor, RDL, and Their Impact on Receptor Pharmacology. ACS SYMPOSIUM SERIES 2017. [DOI: 10.1021/bk-2017-1265.ch001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jennina Taylor-Wells
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 8NZ, United Kingdom
| | - Andrew K. Jones
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford OX3 8NZ, United Kingdom
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Takayanagi-Kiya S, Zhou K, Jin Y. Release-dependent feedback inhibition by a presynaptically localized ligand-gated anion channel. eLife 2016; 5:e21734. [PMID: 27782882 PMCID: PMC5102579 DOI: 10.7554/elife.21734] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/25/2016] [Indexed: 12/16/2022] Open
Abstract
Presynaptic ligand-gated ion channels (LGICs) have long been proposed to affect neurotransmitter release and to tune the neural circuit activity. However, the understanding of their in vivo physiological action remains limited, partly due to the complexity in channel types and scarcity of genetic models. Here we report that C. elegans LGC-46, a member of the Cys-loop acetylcholine (ACh)-gated chloride (ACC) channel family, localizes to presynaptic terminals of cholinergic motor neurons and regulates synaptic vesicle (SV) release kinetics upon evoked release of acetylcholine. Loss of lgc-46 prolongs evoked release, without altering spontaneous activity. Conversely, a gain-of-function mutation of lgc-46 shortens evoked release to reduce synaptic transmission. This inhibition of presynaptic release requires the anion selectivity of LGC-46, and can ameliorate cholinergic over-excitation in a C. elegans model of excitation-inhibition imbalance. These data demonstrate a novel mechanism of presynaptic negative feedback in which an anion-selective LGIC acts as an auto-receptor to inhibit SV release.
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Affiliation(s)
- Seika Takayanagi-Kiya
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
| | - Keming Zhou
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
- Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, San Diego, United States
- Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States
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Duguet TB, Charvet CL, Forrester SG, Wever CM, Dent JA, Neveu C, Beech RN. Recent Duplication and Functional Divergence in Parasitic Nematode Levamisole-Sensitive Acetylcholine Receptors. PLoS Negl Trop Dis 2016; 10:e0004826. [PMID: 27415016 PMCID: PMC4945070 DOI: 10.1371/journal.pntd.0004826] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/16/2016] [Indexed: 01/07/2023] Open
Abstract
Helminth parasites rely on fast-synaptic transmission in their neuromusculature to experience the outside world and respond to it. Acetylcholine plays a pivotal role in this and its receptors are targeted by a wide variety of both natural and synthetic compounds used in human health and for the control of parasitic disease. The model, Caenorhabditis elegans is characterized by a large number of acetylcholine receptor subunit genes, a feature shared across the nematodes. This dynamic family is characterized by both gene duplication and loss between species. The pentameric levamisole-sensitive acetylcholine receptor has been characterized from C. elegans, comprised of five different subunits. More recently, cognate receptors have been reconstituted from multiple parasitic nematodes that are found to vary in subunit composition. In order to understand the implications of receptor composition change and the origins of potentially novel drug targets, we investigated a specific example of subunit duplication based on analysis of genome data for 25 species from the 50 helminth genome initiative. We found multiple independent duplications of the unc-29, acetylcholine receptor subunit, where codon substitution rate analysis identified positive, directional selection acting on amino acid positions associated with subunit assembly. Characterization of four gene copies from a model parasitic nematode, Haemonchus contortus, demonstrated that each copy has acquired unique functional characteristics based on phenotype rescue of transgenic C. elegans and electrophysiology of receptors reconstituted in Xenopus oocytes. We found evidence that a specific incompatibility has evolved for two subunits co-expressed in muscle. We demonstrated that functional divergence of acetylcholine receptors, driven by directional selection, can occur more rapidly than previously thought and may be mediated by alteration of receptor assembly. This phenomenon is common among the clade V parasitic nematodes and this work provides a foundation for understanding the broader context of changing anthelmintic drug targets across the parasitic nematodes.
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Affiliation(s)
- Thomas B. Duguet
- Institute of Parasitology, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Claude L. Charvet
- INRA, UMR1282 Infectiologie Animale et Santé Publique, Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie Santé Publique, Tours, France
| | - Sean G. Forrester
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - Claudia M. Wever
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Joseph A. Dent
- Department of Biology, McGill University, Montreal, Quebec, Canada
- Centre for Host-Parasite Interactions, Ste-Anne-de-Bellevue, Quebec, Canada
| | - Cedric Neveu
- INRA, UMR1282 Infectiologie Animale et Santé Publique, Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie Santé Publique, Tours, France
| | - Robin N. Beech
- Institute of Parasitology, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
- Centre for Host-Parasite Interactions, Ste-Anne-de-Bellevue, Quebec, Canada
- * E-mail:
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Evolution, Expression, and Function of Nonneuronal Ligand-Gated Chloride Channels in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2016; 6:2003-12. [PMID: 27172217 PMCID: PMC4938653 DOI: 10.1534/g3.116.029546] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ligand-gated chloride channels have established roles in inhibitory neurotransmission in the nervous systems of vertebrates and invertebrates. Paradoxically, expression databases in Drosophila melanogaster have revealed that three uncharacterized ligand-gated chloride channel subunits, CG7589, CG6927, and CG11340, are highly expressed in nonneuronal tissues. Furthermore, subunit copy number varies between insects, with some orders containing one ortholog, whereas other lineages exhibit copy number increases. Here, we show that the Dipteran lineage has undergone two gene duplications followed by expression-based functional differentiation. We used promoter-GFP expression analysis, RNA-sequencing, and in situ hybridization to examine cell type and tissue-specific localization of the three D. melanogaster subunits. CG6927 is expressed in the nurse cells of the ovaries. CG7589 is expressed in multiple tissues including the salivary gland, ejaculatory duct, malpighian tubules, and early midgut. CG11340 is found in malpighian tubules and the copper cell region of the midgut. Overexpression of CG11340 increased sensitivity to dietary copper, and RNAi and ends-out knockout of CG11340 resulted in copper tolerance, providing evidence for a specific nonneuronal role for this subunit in D. melanogaster Ligand-gated chloride channels are important insecticide targets and here we highlight copy number and functional divergence in insect lineages, raising the potential that order-specific receptors could be isolated within an effective class of insecticide targets.
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Whittaker JH, Carlson SA, Jones DE, Brewer MT. Molecular mechanisms for anthelmintic resistance in strongyle nematode parasites of veterinary importance. J Vet Pharmacol Ther 2016; 40:105-115. [PMID: 27302747 DOI: 10.1111/jvp.12330] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 05/02/2016] [Indexed: 11/26/2022]
Abstract
Veterinarians rely on a relatively limited spectrum of anthelmintic agents to control nematode parasites in domestic animals. Unfortunately, anthelmintic resistance has been an emerging problem in veterinary medicine. In particular, resistance has emerged among the strongyles, a group of gastrointestinal nematodes that infect a variety of hosts that range from large herbivores to small companion animals. Over the last several decades, a great deal of research effort has been directed toward developing an understanding of the mechanisms conferring resistance against the three major groups of anthelmintics: macrocyclic lactones, benzimidazoles, and nicotinic agonists. Our understanding of anthelmintic resistance has been largely formed by determining the mechanism of action for each drug class and then evaluating drug-resistant nematode isolates for mutations or differences in expression of target genes. More recently, drug efflux pumps have been recognized for their potential contribution to anthelmintic resistance. In this mini-review, we summarize the evidence for mechanisms of resistance in strongyle nematodes.
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Affiliation(s)
- J H Whittaker
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, USA
| | - S A Carlson
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, USA
| | - D E Jones
- Department of Veterinary Pathology, Iowa State University College of Veterinary Medicine, Ames, IA, USA
| | - M T Brewer
- Department of Veterinary Pathology, Iowa State University College of Veterinary Medicine, Ames, IA, USA
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Wang X, Wang R, Yang Y, Wu S, O'Reilly AO, Wu Y. A point mutation in the glutamate-gated chloride channel of Plutella xylostella is associated with resistance to abamectin. INSECT MOLECULAR BIOLOGY 2016; 25:116-125. [PMID: 26592158 DOI: 10.1111/imb.12204] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The diamondback moth, Plutella xylostella, is a global pest of cruciferous vegetables. Abamectin resistance in a field population of P. xylostella was introgressed into the susceptible Roth strain. The resulting introgression strain Roth-Abm showed 11 000-fold resistance to abamectin compared with Roth. An A309V substitution at the N-terminus of the third transmembrane helix (M3) of the glutamate-gated chloride channel of P. xylostella (PxGluCl) was identified in Roth-Abm. The frequency of the V309 allele of PxGluCl was 94.7% in Roth-Abm, whereas no such allele was detected in Roth. A subpopulation of Roth-Abm was kept without abamectin selection for 20 generations to produce a revertant strain, Roth-Abm-D. Abamectin resistance in Roth-Abm-D declined to 1150-fold compared with Roth, with the V309 allele frequency decreased to 9.6%. After treatment of the Roth-Abm-D strain with 80 mg/l abamectin the V309 allele frequency in the survivors increased to 55%. This demonstrates that the A309V mutation in PxGluCl is strongly associated with a 10-fold increase in abamectin resistance in Roth-Abm relative to Roth-Abm-D. Homology modelling and automated ligand docking results suggest that the A309V substitution allosterically modifies the abamectin-binding site, as opposed to directly eliminating a key binding contact. Other resistance mechanisms to abamectin in Roth-Abm are discussed besides the A309V mutation of PxGluCl.
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Affiliation(s)
- X Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - R Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Y Yang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - S Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - A O O'Reilly
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
| | - Y Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Mukherjee A. Computational analysis of a cys-loop ligand gated ion channel from the green alga Chlamydomonas reinhardtii. Mol Biol 2015. [DOI: 10.1134/s002689331505012x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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DOP-2 D2-Like Receptor Regulates UNC-7 Innexins to Attenuate Recurrent Sensory Motor Neurons during C. elegans Copulation. J Neurosci 2015; 35:9990-10004. [PMID: 26156999 DOI: 10.1523/jneurosci.0940-15.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
UNLABELLED Neuromodulation of self-amplifying circuits directs context-dependent behavioral executions. Although recurrent networks are found throughout the Caenorhabditis elegans connectome, few reports describe the mechanisms that regulate reciprocal neural activity during complex behavior. We used C. elegans male copulation to dissect how a goal-oriented motor behavior is regulated by recurrently wired sensory-motor neurons. As the male tail presses against the hermaphrodite's vulva, cholinergic and glutamatergic reciprocal innervations of post cloaca sensilla (PCS) neurons (PCA, PCB, and PCC), hook neurons (HOA, HOB), and their postsynaptic sex muscles execute rhythmic copulatory spicule thrusts. These repetitive spicule movements continue until the male shifts off the vulva or genital penetration is accomplished. However, the signaling mechanism that temporally and spatially restricts repetitive intromission attempts to vulva cues was unclear. Here, we report that confinement of spicule insertion attempts to the vulva is facilitated by D2-like receptor modulation of gap-junctions between PCB and the hook sensillum. We isolated a missense mutation in the UNC-7(L) gap-junction isoform, which perturbs DOP-2 signaling in the PCB neuron and its electrical partner, HOA. The glutamate-gated chloride channel AVR-14 is expressed in HOA. Our analysis of the unc-7 mutant allele indicates that when DOP-2 promotes UNC-7 electrical communication, AVR-14-mediated inhibitory signals pass from HOA to PCB. As a consequence, PCB is less receptive to be stimulated by its recurrent synaptic partner, PCA. Behavioral observations suggest that dopamine neuromodulation of UNC-7 ensures attenuation of recursive intromission attempts when the male disengages or is dislodged from the hermaphrodite genitalia. SIGNIFICANCE STATEMENT Using C. elegans male copulation as a model, we found that the neurotransmitter dopamine stimulates D2-like receptors in two sensory circuits to terminate futile behavioral loops. The D2-like receptors promote inhibitory electrical junction activity between a chemosensory and a mechanosensory circuit. Therefore, both systems are attenuated and the animal ceases the recursive behavior.
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Transcriptome Analysis of the Central and Peripheral Nervous Systems of the Spider Cupiennius salei Reveals Multiple Putative Cys-Loop Ligand Gated Ion Channel Subunits and an Acetylcholine Binding Protein. PLoS One 2015; 10:e0138068. [PMID: 26368804 PMCID: PMC4569296 DOI: 10.1371/journal.pone.0138068] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/25/2015] [Indexed: 11/19/2022] Open
Abstract
Invertebrates possess a diverse collection of pentameric Cys-loop ligand gated ion channel (LGIC) receptors whose molecular structures, evolution and relationships to mammalian counterparts have been intensely investigated in several clinically and agriculturally important species. These receptors are targets for a variety of control agents that may also harm beneficial species. However, little is known about Cys-loop receptors in spiders, which are important natural predators of insects. We assembled de novo transcriptomes from the central and peripheral nervous systems of the Central American wandering spider Cupiennius salei, a model species for neurophysiological, behavioral and developmental studies. We found 15 Cys-loop receptor subunits that are expected to form anion or cation permeable channels, plus a putative acetylcholine binding protein (AChBP) that has only previously been reported in molluscs and one annelid. We used phylogenetic and sequence analysis to compare the spider subunits to homologous receptors in other species and predicted the 3D structures of each protein using the I-Tasser server. The quality of homology models improved with increasing sequence identity to the available high-resolution templates. We found that C. salei has orthologous γ-aminobutyric acid (GABA), GluCl, pHCl, HisCl and nAChα LGIC subunits to other arthropods, but some subgroups are specific to arachnids, or only to spiders. C. salei sequences were phylogenetically closest to gene fragments from the social spider, Stegodyphus mimosarum, indicating high conservation within the Araneomorphae suborder of spiders. C. salei sequences had similar ligand binding and transmembrane regions to other invertebrate and vertebrate LGICs. They also had motifs associated with high sensitivity to insecticides and antiparasitic agents such as fipronil, dieldrin and ivermectin. Development of truly selective control agents for pest species will require information about the molecular structure and pharmacology of Cys-loop receptors in beneficial species.
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Jobson MA, Valdez CM, Gardner J, Garcia LR, Jorgensen EM, Beg AA. Spillover transmission is mediated by the excitatory GABA receptor LGC-35 in C. elegans. J Neurosci 2015; 35:2803-16. [PMID: 25673867 PMCID: PMC4323542 DOI: 10.1523/jneurosci.4557-14.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/10/2014] [Accepted: 12/23/2014] [Indexed: 11/21/2022] Open
Abstract
Under most circumstances, GABA activates chloride-selective channels and thereby inhibits neuronal activity. Here, we identify a GABA receptor in the nematode Caenorhabditis elegans that conducts cations and is therefore excitatory. Expression in Xenopus oocytes demonstrates that LGC-35 is a homopentameric cation-selective receptor of the cys-loop family exclusively activated by GABA. Phylogenetic analysis suggests that LGC-35 evolved from GABA-A receptors, but the pore-forming domain contains novel molecular determinants that confer cation selectivity. LGC-35 is expressed in muscles and directly mediates sphincter muscle contraction in the defecation cycle in hermaphrodites, and spicule eversion during mating in the male. In the locomotory circuit, GABA release directly activates chloride channels on the muscle to cause muscle relaxation. However, GABA spillover at these synapses activates LGC-35 on acetylcholine motor neurons, which in turn cause muscles to contract, presumably to drive wave propagation along the body. These studies demonstrate that both direct and indirect excitatory GABA signaling plays important roles in regulating neuronal circuit function and behavior in C. elegans.
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Affiliation(s)
- Meghan A Jobson
- Program in Neuroscience, University of Utah School of Medicine, Salt Lake City, Utah 84132, Department of Biology, University of Utah, Salt Lake City, Utah 84132
| | - Chris M Valdez
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, Neuroscience Program, University of Michigan, Ann Arbor, Michigan 48109
| | - Jann Gardner
- Department of Biology, University of Utah, Salt Lake City, Utah 84132
| | - L Rene Garcia
- Department of Biology, Texas A&M University, College Station, Texas 77843, Howard Hughes Medical Institute, Texas A&M University, College Station, Texas 77843
| | - Erik M Jorgensen
- Program in Neuroscience, University of Utah School of Medicine, Salt Lake City, Utah 84132, Department of Biology, University of Utah, Salt Lake City, Utah 84132, Howard Hughes Medical Institute, University of Utah, Salt Lake City, Utah 84132, and
| | - Asim A Beg
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, Neuroscience Program, University of Michigan, Ann Arbor, Michigan 48109,
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MmTX1 and MmTX2 from coral snake venom potently modulate GABAA receptor activity. Proc Natl Acad Sci U S A 2015; 112:E891-900. [PMID: 25675485 DOI: 10.1073/pnas.1415488112] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
GABAA receptors shape synaptic transmission by modulating Cl(-) conductance across the cell membrane. Remarkably, animal toxins that specifically target GABAA receptors have not been identified. Here, we report the discovery of micrurotoxin1 (MmTX1) and MmTX2, two toxins present in Costa Rican coral snake venom that tightly bind to GABAA receptors at subnanomolar concentrations. Studies with recombinant and synthetic toxin variants on hippocampal neurons and cells expressing common receptor compositions suggest that MmTX1 and MmTX2 allosterically increase GABAA receptor susceptibility to agonist, thereby potentiating receptor opening as well as desensitization, possibly by interacting with the α(+)/β(-) interface. Moreover, hippocampal neuron excitability measurements reveal toxin-induced transitory network inhibition, followed by an increase in spontaneous activity. In concert, toxin injections into mouse brain result in reduced basal activity between intense seizures. Altogether, we characterized two animal toxins that enhance GABAA receptor sensitivity to agonist, thereby establishing a previously unidentified class of tools to study this receptor family.
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The evolution of pentameric ligand-gated ion-channels and the changing family of anthelmintic drug targets. Parasitology 2014; 142:303-17. [PMID: 25354656 DOI: 10.1017/s003118201400170x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
SUMMARY Pentameric ligand-gated ion-channels rapidly transduce synaptic neurotransmitter signals to an electrical response in post-synaptic neuronal or muscle cells and control the neuromusculature of a majority of multicellular animals. A wide range of pharmaceuticals target these receptors including ethanol, nicotine, anti-depressants and other mood regulating drugs, compounds that control pain and mobility and are targeted by a majority of anthelmintic drugs used to control parasitic infection of humans and livestock. Major advances have been made in recent years to our understanding of the structure, function, activity and the profile of compounds that can activate specific receptors. It is becoming clear that these anthelmintic drug targets are not fixed, but differ in significant details from one nematode species to another. Here we review what is known about the evolution of the pentameric ligand-gated ion-channels, paying particular attention to the nematodes, how we can infer the origins of such receptors and understand the factors that determine how they change both over time and from one species to another. Using this knowledge provides a biological framework in which to understand these important drug targets and avenues to identify new receptors and aid the search for new anthelmintic drugs.
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Furutani S, Ihara M, Nishino Y, Akamatsu M, Jones AK, Sattelle DB, Matsuda K. Exon 3 splicing and mutagenesis identify residues influencing cell surface density of heterologously expressed silkworm (Bombyx mori) glutamate-gated chloride channels. Mol Pharmacol 2014; 86:686-95. [PMID: 25261427 DOI: 10.1124/mol.114.095869] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glutamate-gated chloride channels (GluCls) mediate fast inhibitory neurotransmission in invertebrate nervous systems. Insect GluCls show alternative splicing, and, to determine its impact on channel function and pharmacology, we isolated GluCl cDNAs from larvae of the silkworm (Bombyx mori). We show that six B. mori glutamate-gated chloride channel variants are generated by splicing in exons 3 and 9 and that exons 3b and 3c are common in the brain and third thoracic ganglion. When expressed in Xenopus laevis oocytes, the three functional exon 3 variants (3a, b, c) all had similar EC50 values for l-glutamate and ivermectin (IVM); however, Imax (the maximum l-glutamate- and IVM-induced response of the channels at saturating concentrations) differed strikingly between variants, with the 3c variant showing the largest l-glutamate- and IVM-induced responses. By contrast, a partial deletion detected in exon 9 had a much smaller impact on l-glutamate and IVM actions. Binding assays using [(3)H]IVM indicate that diversity in IVM responses among the GluCl variants is mainly due to the impact on channel assembly, altering receptor cell surface numbers. GluCl variants expressed in HEK293 cells show that structural differences influenced Bmax but not Kd values of [(3)H]IVM. Domain swapping and site-directed mutagenesis identified four amino acids in exon 3c as hot spots determining the highest amplitude of the l-glutamate and IVM responses. Modeling the GluCl 3a and 3c variants suggested that three of the four amino acids contribute to intersubunit contacts, whereas the other interacts with the TM2-TM3 linker, influencing the receptor response.
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Affiliation(s)
- Shogo Furutani
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, Nakamachi Nara, Japan (S.F., M.I., K.M.); Graduate School of Life Science, University of Hyogo, Koto, Kamigori-cho, Ako-gun, Hyogo, Japan (Y.N.); Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, Japan (M.A.); Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom (A.K.J.); and Department of Medicine, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom (D.B.S.)
| | - Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, Nakamachi Nara, Japan (S.F., M.I., K.M.); Graduate School of Life Science, University of Hyogo, Koto, Kamigori-cho, Ako-gun, Hyogo, Japan (Y.N.); Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, Japan (M.A.); Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom (A.K.J.); and Department of Medicine, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom (D.B.S.)
| | - Yuri Nishino
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, Nakamachi Nara, Japan (S.F., M.I., K.M.); Graduate School of Life Science, University of Hyogo, Koto, Kamigori-cho, Ako-gun, Hyogo, Japan (Y.N.); Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, Japan (M.A.); Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom (A.K.J.); and Department of Medicine, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom (D.B.S.)
| | - Miki Akamatsu
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, Nakamachi Nara, Japan (S.F., M.I., K.M.); Graduate School of Life Science, University of Hyogo, Koto, Kamigori-cho, Ako-gun, Hyogo, Japan (Y.N.); Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, Japan (M.A.); Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom (A.K.J.); and Department of Medicine, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom (D.B.S.)
| | - Andrew K Jones
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, Nakamachi Nara, Japan (S.F., M.I., K.M.); Graduate School of Life Science, University of Hyogo, Koto, Kamigori-cho, Ako-gun, Hyogo, Japan (Y.N.); Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, Japan (M.A.); Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom (A.K.J.); and Department of Medicine, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom (D.B.S.)
| | - David B Sattelle
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, Nakamachi Nara, Japan (S.F., M.I., K.M.); Graduate School of Life Science, University of Hyogo, Koto, Kamigori-cho, Ako-gun, Hyogo, Japan (Y.N.); Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, Japan (M.A.); Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom (A.K.J.); and Department of Medicine, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom (D.B.S.)
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, Nakamachi Nara, Japan (S.F., M.I., K.M.); Graduate School of Life Science, University of Hyogo, Koto, Kamigori-cho, Ako-gun, Hyogo, Japan (Y.N.); Graduate School of Agriculture, Kyoto University, Sakyo-Ku, Kyoto, Japan (M.A.); Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom (A.K.J.); and Department of Medicine, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom (D.B.S.)
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Cornejo I, Andrini O, Niemeyer MI, Marabolí V, González-Nilo FD, Teulon J, Sepúlveda FV, Cid LP. Identification and functional expression of a glutamate- and avermectin-gated chloride channel from Caligus rogercresseyi, a southern Hemisphere sea louse affecting farmed fish. PLoS Pathog 2014; 10:e1004402. [PMID: 25255455 PMCID: PMC4177951 DOI: 10.1371/journal.ppat.1004402] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 08/15/2014] [Indexed: 12/02/2022] Open
Abstract
Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs) ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl) and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC50 value of around 200 nM, being cooperative (nH = 2) for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new, more efficient drugs whilst functional expression of the receptor allows a first stage of testing of their efficacy. Sea lice are the main parasites affecting farmed salmon and trout in the world. Caligus rogercresseyi is the principal sea louse species infesting farmed fish in the southern hemisphere. Successful control of these parasites has been achieved using macrocyclic lactones (MLs), but resistance has emerged over time. In other invertebrates, MLs target membrane receptors regulating synaptic transmission in the parasite nervous system. Here we identify and study the function of such a receptor from Caligus rogercresseyi, and gain an idea about how two MLs, ivermectin and emamectin, interact with the receptor to produce their effects. Our molecular modeling of the protein in complex with the drugs suggests a novel way in which ivermectin and emamectin exert their effects on CrGluCl due to a lack of conservation at interaction sites identified in the crystal structure of the receptor from C. elegans. We believe that the identification of a ML target in sea louse will aid the study of drug-resistance mechanisms and could help in the design of new, more efficient antiparasitic drugs.
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Affiliation(s)
| | - Olga Andrini
- UPMC Université Paris 06, UMR_S 1138, Team 3, Paris, France
- INSERM, UMR_S 872, Paris, France
| | | | - Vanessa Marabolí
- Universidad Andrés Bello, Centro de Bioinformática y Biología Integrativa, Facultad de Ciencias Biológicas, Santiago, Chile
| | - F. Danilo González-Nilo
- Universidad Andrés Bello, Centro de Bioinformática y Biología Integrativa, Facultad de Ciencias Biológicas, Santiago, Chile
| | - Jacques Teulon
- UPMC Université Paris 06, UMR_S 1138, Team 3, Paris, France
- INSERM, UMR_S 872, Paris, France
| | | | - L. Pablo Cid
- Centro de Estudios Científicos (CECs), Valdivia, Chile
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47
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Démares F, Drouard F, Massou I, Crattelet C, Lœuillet A, Bettiol C, Raymond V, Armengaud C. Differential involvement of glutamate-gated chloride channel splice variants in the olfactory memory processes of the honeybee Apis mellifera. Pharmacol Biochem Behav 2014; 124:137-44. [PMID: 24911646 DOI: 10.1016/j.pbb.2014.05.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 05/27/2014] [Accepted: 05/31/2014] [Indexed: 11/16/2022]
Abstract
Glutamate-gated chloride channels (GluCl) belong to the cys-loop ligand-gated ion channel superfamily and their expression had been described in several invertebrate nervous systems. In the honeybee, a unique gene amel_glucl encodes two alternatively spliced subunits, Amel_GluCl A and Amel_GluCl B. The expression and differential localization of those variants in the honeybee brain had been previously reported. Here we characterized the involvement of each variant in olfactory learning and memory processes, using specific small-interfering RNA (siRNA) targeting each variant. Firstly, the efficacy of the two siRNAs to decrease their targets' expression was tested, both at mRNA and protein levels. The two proteins showed a decrease of their respective expression 24h after injection. Secondly, each siRNA was injected into the brain to test whether or not it affected olfactory memory by using a classical paradigm of conditioning the proboscis extension reflex (PER). Amel_GluCl A was found to be involved only in retrieval of 1-nonanol, whereas Amel_GluCl B was involved in the PER response to 2-hexanol used as a conditioned stimulus or as new odorant. Here for the first time, a differential behavioral involvement of two highly similar GluCl subunits has been characterized in an invertebrate species.
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Affiliation(s)
- Fabien Démares
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France.
| | - Florian Drouard
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
| | - Isabelle Massou
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
| | - Cindy Crattelet
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
| | - Aurore Lœuillet
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
| | - Célia Bettiol
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
| | - Valérie Raymond
- Laboratoire Récepteurs et Canaux Ioniques Membranaires (RCIM), UPRES-EA2647 USC INRA 1330 SFR 4207 QUASAV, LUNAM Université d'Angers, 2 blvd Lavoisier, F-49045 Angers Cedex 01, France
| | - Catherine Armengaud
- Centre de Recherches sur la Cognition Animale, Université Paul Sabatier Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 9, France
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48
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Romine NM, Martin RJ, Beetham JK. Transcriptomic evaluation of the nicotinic acetylcholine receptor pathway in levamisole-resistant and -sensitive Oesophagostomum dentatum. Mol Biochem Parasitol 2014; 193:66-70. [PMID: 24530453 DOI: 10.1016/j.molbiopara.2014.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 01/27/2014] [Accepted: 02/04/2014] [Indexed: 11/25/2022]
Abstract
Nematode anthelminthic resistance is widespread for the 3 major drug classes commonly used in agriculture: benzamidazoles, macrocyclic lactones, and nicotinic agonists e.g. levamisole. In parasitic nematodes the genetics of resistance is unknown other than to the benzimidazoles which primarily involve a single gene. In previous work with a levamisole resistant Oesophagostomum dentatum isolate, the nicotinic acetylcholine receptor (nAChR) exhibited decreased levamisole sensitivity. Here, using a transcriptomic approach on the same isolate, we investigate whether that decreased nAChR sensitivity is achieved via a 1-gene mechanism involving 1 of 27 nAChR pathway genes. 3 nAChR receptor subunit genes exhibited ≥2-fold change in transcript abundance: acr-21 and acr-25 increased, and unc-63 decreased. 4 SNPs having a ≥2-fold change in frequency were also identified. These data suggest that resistance is likely polygenic, involving modulated abundance of multiple subunits comprising the heteropentameric nAChR, and is not due to a simple 1-gene mechanism.
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Affiliation(s)
- Nathan M Romine
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Richard J Martin
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Jeffrey K Beetham
- Department of Veterinary Pathology, Iowa State University, Ames, IA 50011, USA.
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49
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Kita T, Ozoe F, Ozoe Y. Expression pattern and function of alternative splice variants of glutamate-gated chloride channel in the housefly Musca domestica. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 45:1-10. [PMID: 24291284 DOI: 10.1016/j.ibmb.2013.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 11/19/2013] [Accepted: 11/21/2013] [Indexed: 06/02/2023]
Abstract
Glutamate-gated chloride channels (GluCls) mediate fast inhibitory neurotransmission in invertebrate nervous systems. cDNAs encoding two alternative splice variants (MdGluClB and C) of the GluCl subunit were cloned from the housefly Musca domestica. The expression patterns of three variants, including the previously reported MdGluClA, differed among the body parts (head, thorax, abdomen, and leg) of the adult housefly and among developmental stages (embryo, larva, pupa, and adult). The MdGluClA and B transcripts were abundant in the central nervous system of the adult, whereas the MdGluClC transcript was expressed in the central nervous system and as the predominant variant in the peripheral tissues. The sensitivities to the agonist glutamate and the allosteric activator ivermectin B1a did not differ between channels containing MdGluCl variants when they were singly or co-expressed in Xenopus oocytes. By contrast, MdGluClA and B channels were more sensitive to the channel blockers fipronil and picrotoxinin than was MdGluClC channels. Heteromeric channels containing different subunit variants were more sensitive to picrotoxinin than were homomeric channels. Heteromeric channels were more sensitive to fipronil than were homomeric MdGluClC channels but not than homomeric MdGluClA and B channels. These results suggest that functionally indistinguishable but pharmacologically distinct GluCls are expressed in a spatially and temporally distinct manner in the housefly.
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Affiliation(s)
- Tomo Kita
- Division of Bioscience and Biotechnology, The United Graduate School of Agricultural Sciences, Tottori University, Tottori 680-8553, Japan
| | - Fumiyo Ozoe
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504, Japan
| | - Yoshihisa Ozoe
- Division of Bioscience and Biotechnology, The United Graduate School of Agricultural Sciences, Tottori University, Tottori 680-8553, Japan; Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504, Japan.
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50
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Beech RN, Callanan MK, Rao VTS, Dawe GB, Forrester SG. Characterization of cys-loop receptor genes involved in inhibitory amine neurotransmission in parasitic and free living nematodes. Parasitol Int 2013; 62:599-605. [PMID: 23602737 DOI: 10.1016/j.parint.2013.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 03/15/2013] [Accepted: 03/22/2013] [Indexed: 01/23/2023]
Abstract
We have isolated two genes, Hco-lgc-53 and Hco-mod-1, from the parasitic nematode Haemonchus contortus, which are orthologs of previously characterized genes that encode dopamine and serotonin-gated chloride channels, respectively, in Caenorhabditis elegans. A search of transcriptome data for the filarial nematode parasites Loa loa, Brugia malayi, and Wucheria bancrofti revealed predicted coding sequences for orthologs of acetylcholine, serotonin and dopamine-gated chloride channels, which correspond to the C. elegans clades acc-1, mod-1 and ggr-3, respectively. Genome data for the more distantly related nematode parasite, Trichinella spiralis, contain genes predicted to encode members of the acc-1 clade only, but all three clades were absent from the trematode Schistosoma mansoni. Analysis of the ratio of non-synonymous to synonymous substitutions (ω) for receptor subunit sequences revealed strong selective constraint over the entire protein, consistent with the known highly conserved 3D structure of cys-loop receptors. This constraint was significantly greater for binding loop residues that are predicted to contact bound ligand and residues of the transmembrane domains. The substitution rate for ligand binding residues was significantly higher for branches leading to the acc-1 and mod-1 clades, where the convergent evolution for binding acetylcholine and serotonin, respectively, is thought to have occurred. Homology models of both Hco-MOD-1 and Hco-LGC-53 channels revealed the presence of binding structures typical of the cys-loop receptor family, including the presence of an aromatic box that is important for the formation of the binding pocket. Both receptors contain a tryptophan in loop C that appears to be a key residue important for the binding of amines to ligand-gated chloride channels. As additional ligand-gated chloride-channel sequences become available for a wider range of species the combination of molecular modeling and analysis of sequence evolution should provide an effective tool to understand the wide diversity of neurotransmitters that bind to this unique group of receptors.
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Affiliation(s)
- Robin N Beech
- Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa ON L1H 7K4, Canada
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