1
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Wang XZ, Chen JS, Wang W, Niu DB, Wu HZ, Palli SR, Cao HQ, Sheng CW. Knockdown of the glutamate-gated chloride channel gene decreases emamectin benzoate susceptibility in the fall armyworm, Spodoptera frugiperda. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 196:105636. [PMID: 37945267 DOI: 10.1016/j.pestbp.2023.105636] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/23/2023] [Accepted: 09/30/2023] [Indexed: 11/12/2023]
Abstract
Emamectin benzoate (EB), a derivative of avermectin, is the primary insecticide used to control the fall armyworm (FAW) in China. However, the specific molecular targets of EB against FAW remain unclear. In this study, we cloned the glutamate-gated chloride channel (GluCl) gene, which is known to be a primary molecular target for avermectin. We first investigated the transcript levels of SfGluCl in FAW and found that the expression level of SfGluCl in the head and nerve cord was significantly higher than that in other tissues. Furthermore, we found that the expression level of SfGluCl was significantly higher in eggs than that in other developmental stages, including larvae, pupae, and adults. Additionally, we identified three variable splice forms of SfGluCl in exons 3 and 9 and found that their splice frequencies remained unaffected by treatment with the LC50 of EB. RNAi mediated knockdown of SfGluCl showed a significant reduction of 42% and 65% after 48 and 72 h of dsRNA feeding, respectively. Importantly, knockdown of SfGluCl sifgnificantly reduced LC50 and LC90 EB treatment induced mortality of FAW larvae by 15% and 44%, respectively, compared to the control group feeding by dsEGFP. In contrast, there were no significant changes in the mortality of FAW larvae treated with the control insecticides chlorantraniliprole and spinetoram. Finally, molecular docking simulations revealed that EB bound to the large amino-terminal extracellular domain of SfGluCl by forming five hydrogen bonds, two alkyl hydrophobic interactions and one salt bridge. These findings strongly suggest that GluCl may serve as one of the molecular targets of EB in FAW, shedding light on the mode of action of this important insecticide.
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Affiliation(s)
- Xian-Zheng Wang
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, PR China
| | - Jia-Sheng Chen
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, PR China; Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Wei Wang
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, PR China
| | - Duo-Bang Niu
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, PR China
| | - Hui-Zi Wu
- Guizhou Provincial Tobacco Company Zunyi Branch, Zunyi 563000, PR China
| | - Subba Reddy Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Hai-Qun Cao
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, PR China
| | - Cheng-Wang Sheng
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei 230036, PR China.
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2
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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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3
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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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4
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Ihara M, Tanaka K, Kai K, Hayashi H, Matsuda K. Competitive chrodrimanin B interactions with rat brain GABA A receptors revealed by radioligand binding assays. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 183:105074. [PMID: 35430068 DOI: 10.1016/j.pestbp.2022.105074] [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: 10/30/2021] [Revised: 02/25/2022] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
Meroterpenoid compounds chrodrimanins produced by Talaromyces sp. YO-2 have been shown to act as competitive antagonists of silkworm larval GABAA receptors using electrophysiology, yet no further evidence has been provided to support such an action. We have investigated the actions of chrodrimanin B on rat brain GABAA receptors by binding assays with non-competitive ligand of GABAA receptors [3H]EBOB and competitive ligands [3H]gabazine and [3H]muscimol. Chrodrimanin B did not significantly affect the binding of [3H]EBOB while reducing the binding of [3H]gabazine and [3H]muscimol to the rat membrane preparations. Chrodrimanin B increased the dissociation constant Kd of [3H]gabazine and [3H]muscimol without significantly affecting the maximum binding, pointing to competitive interactions of chrodrimanin B with rat GABAA receptors in support of our previous observation that the compound acts as a competitive antagonist on the silkworm larval GABA receptor.
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Affiliation(s)
- Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Keiji Tanaka
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Kenji Kai
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan
| | - Hideo Hayashi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University 3327-204 Nakamachi, Nara 631-8505, Japan; Agricultural Technology and Innovation Research Institute, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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5
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Cens T, Chavanieu A, Bertaud A, Mokrane N, Estaran S, Roussel J, Ménard C, De Jesus Ferreira M, Guiramand J, Thibaud J, Cohen‐Solal C, Rousset M, Rolland V, Vignes M, Charnet P. Molecular Targets of Neurotoxic Insecticides in
Apis mellifera. European J Org Chem 2022. [DOI: 10.1002/ejoc.202101531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Thierry Cens
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Alain Chavanieu
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Anaïs Bertaud
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Nawfel Mokrane
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Sébastien Estaran
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Julien Roussel
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Claudine Ménard
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | | | - Janique Guiramand
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Jean‐Baptiste Thibaud
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Catherine Cohen‐Solal
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Matthieu Rousset
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Valérie Rolland
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Michel Vignes
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
| | - Pierre Charnet
- Institut des Biomolécules Max Mousseron Université de Montpellier, CNRS, ENSCM 1919 Route de Mende 34293 Montpellier France
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6
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Matsuda K. Chemical and biological studies of natural and synthetic products for the highly selective control of pest insect species. Biosci Biotechnol Biochem 2021; 86:1-11. [PMID: 34694357 DOI: 10.1093/bbb/zbab187] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 10/17/2021] [Indexed: 11/12/2022]
Abstract
Tanacetum cinerariifolium was known to produce pyrethrins, but the mechanism of pyrethrin biosynthesis was largely unclear. The author showed that the nonmevalonate and oxylipin pathways underlie biosynthesis of the acid and alcohol moieties, respectively, and a GDSL lipase joins the products of these pathways. A blend of the green leaf volatiles and (E)-β-farnesene mediates the induction of wounding responses to neighboring intact conspecies by enhancing pyrethrin biosynthesis. Plants fight against herbivores underground as well as aboveground, and, in soy pulps, some fungi produce compounds selectively modulating ion channels in insect nervous system. The author proposed that indirect defense of plants occurs where microorganisms produce defense substances in the rhizosphere. Broad-spectrum pesticides, including neonicotinoids, may affect nontarget organisms. The author discovered cofactors enabling functional expression of insect nicotinic acetylcholine receptors (nAChRs). This led to understanding the mechanism of insect nAChR-neonicotinoid interactions, thus paving new avenues for controlling crop pests and disease vectors.
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Affiliation(s)
- Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, Nara 631-8505, Japan
- Agricultural Technology and Innovation Research Institute, Kindai University, Nara 631-8505, Japan
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7
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Wang JD, Chen LF, Lin DJ, Zhang JS, Zhao JH, Xiao D, Wang R, Wang R, Gao SJ. Molecular cloning, characterization and functional analysis of GluCl from the oriental armyworm, Mythimna separata Walker. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 156:56-62. [PMID: 31027581 DOI: 10.1016/j.pestbp.2019.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/04/2019] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
Glutamate-gated chloride channels (GluCls) mediate inhibitory synaptic transmission in invertebrate nervous systems, and only one GluCl gene has been found in insects. Therefore, insect GluCls are one of the major targets of insecticides including avermectins. In the present study, a 1347 bp full-length cDNA encoding a 449-amino acid protein (named MsGluCl, GenBank ID: MK336885) was cloned from the oriental armyworm, Mythimna separata, and characterized two alternative splicing variants of MsGluCl. The protein shares 76.9-98.6% identity with other insect GluCl isoforms. Spatial and temporal expression analysis revealed that MsGluCl was highly expressed in the 3rd instar and adult head. Dietary ingestion of dsMsGluCl significantly reduced the mRNA level of MsGluCl and decreased abamectin mortality. Thus, our results reveal that MsGluCl could be the molecular target of abamectin and provide the basis for further understanding the resistance mechanism to abamectin in arthropods.
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Affiliation(s)
- Jin-da Wang
- National Engineering Research Center of Sugarcane, Fujian Agricultural and Forestry University, Fuzhou 350002, China.
| | - Li-Fei Chen
- National Engineering Research Center of Sugarcane, Fujian Agricultural and Forestry University, Fuzhou 350002, China
| | - Dong-Jiang Lin
- National Engineering Research Center of Sugarcane, Fujian Agricultural and Forestry University, Fuzhou 350002, China
| | - Jia-Song Zhang
- National Engineering Research Center of Sugarcane, Fujian Agricultural and Forestry University, Fuzhou 350002, China
| | - Ji-Han Zhao
- National Engineering Research Center of Sugarcane, Fujian Agricultural and Forestry University, Fuzhou 350002, China
| | - Da Xiao
- Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Ran Wang
- Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
| | - Rong Wang
- College of Forestry, Fujian Agricultural and Forestry University, Fuzhou 350002, China
| | - San-Ji Gao
- National Engineering Research Center of Sugarcane, Fujian Agricultural and Forestry University, Fuzhou 350002, China
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8
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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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9
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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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10
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Matsuda K. Okaramines and other plant fungal products as new insecticide leads. CURRENT OPINION IN INSECT SCIENCE 2018; 30:67-72. [PMID: 30553487 DOI: 10.1016/j.cois.2018.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/13/2018] [Accepted: 09/19/2018] [Indexed: 06/09/2023]
Abstract
Okaramine were indole alkaloids discovered from products of Penicillium simplicissimum AK-40 in soy bean pulp 'okara'. Okaramines exhibit insecticidal activity on a broad range of insects. Hence, more insecticide leads were explored by fermenting the other fungi with okara, resulting in the isolations of meroterpenes and cyclic peptides as well as indole alkaloids with distinct skeletons. Most okaramines activate l-glutamate-gated chloride channels found only in invertebrate nervous systems and muscle cells. Other fungal products selectively modulate other invertebrate ligand-gated chloride channels. Recently, the okaramine biosynthetic pathway has been elucidated, providing new insights in structural features important for activity. Enhanced production of okaramine in okara points to the involvement of plant mediators in the production of insect modulators by plant associated microorganisms in the rhizosphere as a novel defense strategy.
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Affiliation(s)
- Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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11
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Hikida M, Shimada S, Kurata R, Shigetou S, Ihara M, Sattelle DB, Matsuda K. Combined effects of mutations in loop C and the loop D-E-G triangle on neonicotinoid interactions with Drosophila Dα1/chicken β2 hybrid nAChRs. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 151:47-52. [PMID: 30704712 DOI: 10.1016/j.pestbp.2018.03.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/01/2018] [Accepted: 03/21/2018] [Indexed: 06/09/2023]
Abstract
Neonicotinoid insecticides interact with the orthosteric sites of nicotinic acetylcholine receptors (nAChRs) formed at the interfaces of (a) two adjacent α subunits and (b) α and non-α subunits. However, little is known of the detailed contributions of these two orthosteric sites to neonicotinoid actions. We therefore applied voltage-clamp electrophysiology to the Dα1/chicken β2 hybrid nAChR expressed in Xenopus laevis oocytes to explore the agonist actions of imidacloprid and thiacloprid on wild type receptors and following binding site mutations. First, we studied the S221E mutation in loop C of the ACh binding site of the Dα1 subunit. Secondly, we explored the impact of combining this mutation in loop C with others in the loop D-E-G triangle (R57S; E78K; K140T; S221E). The S221E loop C mutation alone reduced the affinity of the neonicotinoids tested, while hardly affecting the concentration-response curve for acetylcholine. Addition of the three R57S; E78K; K140T mutations in the loop D-E-G triangle led to a further reduction in neonicotinoid sensitivity, suggesting that all four binding site loops (C, D, E, G) in the Dα1 subunit, which are located upstream of loop B in the N-terminal, extracellular domain, contribute to the selective actions of neonicotinoid insecticides.
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Affiliation(s)
- Mai Hikida
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Shota Shimada
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Ryo Kurata
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Sho Shigetou
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - David B Sattelle
- Centre for Respiratory Biology, UCL Respiratory, Rayne Building, University College London, London WC1E 6JF, United Kingdom
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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12
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Furutani S, Ihara M, Lees K, Buckingham SD, Partridge FA, David JA, Patel R, Warchal S, Mellor IR, Matsuda K, Sattelle DB. The fungal alkaloid Okaramine-B activates an L-glutamate-gated chloride channel from Ixodes scapularis, a tick vector of Lyme disease. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2018; 8:350-360. [PMID: 29957333 PMCID: PMC6039357 DOI: 10.1016/j.ijpddr.2018.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 05/31/2018] [Accepted: 06/03/2018] [Indexed: 11/29/2022]
Abstract
A novel L-glutamate-gated anion channel (IscaGluCl1) has been cloned from the black-legged tick, Ixodes scapularis, which transmits multiple pathogens including the agents of Lyme disease and human granulocytic anaplasmosis. When mRNA encoding IscaGluCl1 was expressed in Xenopus laevis oocytes, we detected robust 50-400 nA currents in response to 100 μM L-glutamate. Responses to L-glutamate were concentration-dependent (pEC50 3.64 ± 0.11). Ibotenate was a partial agonist on IscaGluCl1. We detected no response to 100 μM aspartate, quisqualate, kainate, AMPA or NMDA. Ivermectin at 1 μM activated IscaGluCl1, whereas picrotoxinin (pIC50 6.20 ± 0.04) and the phenylpyrazole fipronil (pIC50 6.90 ± 0.04) showed concentration-dependent block of the L-glutamate response. The indole alkaloid okaramine B, isolated from fermentation products of Penicillium simplicissimum (strain AK40) grown on okara pulp, activated IscaGluCl1 in a concentration-dependent manner (pEC50 5.43 ± 0.43) and may serve as a candidate lead compound for the development of new acaricides.
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Affiliation(s)
- Shogo Furutani
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Kristin Lees
- Neurosystems Section, Faculty of Life Sciences, University of Manchester, AV Hill Building, Oxford Road, Manchester M13 9PT, UK
| | - Steven D Buckingham
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, Rayne Building, 5 University Street, London WC1E 6JF, UK
| | - Frederick A Partridge
- Neurosystems Section, Faculty of Life Sciences, University of Manchester, AV Hill Building, Oxford Road, Manchester M13 9PT, UK; Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, Rayne Building, 5 University Street, London WC1E 6JF, UK
| | - Jonathan A David
- School of Biology, University of St Andrews, North Haug, St. Andrews, Fife, Scotland KY16 9ST, UK
| | - Rohit Patel
- Neurosystems Section, Faculty of Life Sciences, University of Manchester, AV Hill Building, Oxford Road, Manchester M13 9PT, UK; School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Scott Warchal
- Neurosystems Section, Faculty of Life Sciences, University of Manchester, AV Hill Building, Oxford Road, Manchester M13 9PT, UK
| | - Ian R Mellor
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - David B Sattelle
- Neurosystems Section, Faculty of Life Sciences, University of Manchester, AV Hill Building, Oxford Road, Manchester M13 9PT, UK; Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, Rayne Building, 5 University Street, London WC1E 6JF, UK.
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13
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Wei P, Che W, Wang J, Xiao D, Wang R, Luo C. RNA interference of glutamate-gated chloride channel decreases abamectin susceptibility in Bemisia tabaci. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 145:1-7. [PMID: 29482724 DOI: 10.1016/j.pestbp.2017.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 12/13/2017] [Accepted: 12/16/2017] [Indexed: 06/08/2023]
Abstract
The Bemisia tabaci (Gennadius) cryptic species complex comprises very destructive insect pests of agricultural crops worldwide and has been found to be resistant to various insecticides in China. Abamectin is one of the most widely used insecticides for insect pest control and the glutamate-gated chloride channel (GluCl) in insects was presumed to be the main target site of abamectin. In this study, a 1353bp full-length cDNA encoding GluCl (named BtGluCl, GenBank ID: MF673854) was cloned and characterized from B. tabaci. BtGluCl encodes 450 amino acids, which shares 71-81% identity with other insect GluCl isoforms. Spatial and temporal expression revealed BtGluCl was highly expressed in the 4th nymphal instar and adult head, and the least expressed in the 1st nymphal instar and adult leg. Dietary ingestion of dsBtGluCl significantly reduced the mRNA level of BtGluCl in the treated adults by 62.9% and greatly decreased abamectin-induced mortality. Thus, our results could be conducive to further understanding the mechanisms of resistance to abamectin in arthropods.
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Affiliation(s)
- Peiling Wei
- Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China; Department of Entomology, China Agricultural University, Beijing, 100193, China
| | - Wunan Che
- Department of Pesticide Sciences, Shenyang Agricultural University, Shenyang 110866, China
| | - Jinda Wang
- National Engineering Research Center of Sugarcane, Fujian Agricultural and Forestry University, Fuzhou 350002, China
| | - Da Xiao
- Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Ran Wang
- Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
| | - Chen Luo
- Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
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14
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Mermans C, Dermauw W, Geibel S, Van Leeuwen T. A G326E substitution in the glutamate-gated chloride channel 3 (GluCl3) of the two-spotted spider mite Tetranychus urticae abolishes the agonistic activity of macrocyclic lactones. PEST MANAGEMENT SCIENCE 2017; 73:2413-2418. [PMID: 28736919 DOI: 10.1002/ps.4677] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/10/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND The macrocyclic lactones abamectin and milbemectin are frequently used to control phytophagous mites such as Tetranychus urticae. Consequently, resistance has developed and was genetically linked with substitutions in the glutamate-gated chloride channel (GluCl) subunits TuGluCl1 and TuGluCl3. Here, we functionally validated a G326E substitution in TuGluCl3 by functional expression in Xenopus laevis oocytes followed by two-electrode voltage-clamp electrophysiology. RESULTS Homomeric wild-type and mutated GluCl3 were successfully expressed. l-glutamic-acid-induced currents exhibited a rapid onset equal in both channels and EC50 for l-glutamic-acid was in the micromolar range (384.2 μm and 292.7 μm, respectively). Abamectin and milbemycin A4 elicited sustained currents in wild-type GluCl3, but the G326E substitution completely abolished the agonistic activity of macrocyclic lactones. CONCLUSION A target-site mutation in Tu GluCl3 contributes to avermectin resistance in T. urticae. However, given the multitude of channel genes and the potential additive or synergistic effects of mutations, to what extent mutations determine the often extremely strong resistance phenotype in the field deserves further study. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Catherine Mermans
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Wannes Dermauw
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Sven Geibel
- Bayer AG, CropScience Division, Monheim, Germany
| | - Thomas Van Leeuwen
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Department of Evolutionary Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
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15
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Furutani S, Okuhara D, Hashimoto A, Ihara M, Kai K, Hayashi H, Sattelle DB, Matsuda K. An L319F mutation in transmembrane region 3 (TM3) selectively reduces sensitivity to okaramine B of the Bombyx mori l-glutamate-gated chloride channel. Biosci Biotechnol Biochem 2017; 81:1861-1867. [DOI: 10.1080/09168451.2017.1359487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Okaramines produced by Penicillium simplicissimum AK-40 activate l-glutamate-gated chloride channels (GluCls) and thus paralyze insects. However, the okaramine binding site on insect GluCls is poorly understood. Sequence alignment shows that the equivalent of residue Leucine319 of the okaramine B sensitive Bombyx mori (B. mori) GluCl is a phenylalanine in the okaramine B insensitive B. mori γ-aminobutyric acid-gated chloride channel of the same species. This residue is located in the third transmembrane (TM3) region, a location which in a nematode GluCl is close to the ivermectin binding site. The B. mori GluCl containing the L319F mutation retained its sensitivity to l-glutamate, but responses to ivermectin were reduced and those to okaramine B were completely blocked.
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Affiliation(s)
- Shogo Furutani
- Faculty of Agriculture, Department of Applied Biological Chemistry, Kindai University, Nara, Japan
| | - Daiki Okuhara
- Faculty of Agriculture, Department of Applied Biological Chemistry, Kindai University, Nara, Japan
| | - Anju Hashimoto
- Faculty of Agriculture, Department of Applied Biological Chemistry, Kindai University, Nara, Japan
| | - Makoto Ihara
- Faculty of Agriculture, Department of Applied Biological Chemistry, Kindai University, Nara, Japan
| | - Kenji Kai
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Japan
| | - Hideo Hayashi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Japan
| | - David B Sattelle
- Centre for Respiratory Biology, UCL Respiratory, Rayne Building, University College London, London, UK
| | - Kazuhiko Matsuda
- Faculty of Agriculture, Department of Applied Biological Chemistry, Kindai University, Nara, Japan
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16
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Okuhara D, Furutani S, Ito K, Ihara M, Matsuda K. Splice Variants of pH-Sensitive Chloride Channel Identify a Key Determinant of Ivermectin Sensitivity in the Larvae of the Silkworm Bombyx mori. Mol Pharmacol 2017; 92:491-499. [PMID: 28739571 DOI: 10.1124/mol.117.109199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/20/2017] [Indexed: 11/22/2022] Open
Abstract
The pH-sensitive chloride channels (pHCls) are broadly expressed in insects, but little is known about their physiologic role, diversity, and sensitivity to insecticides acting on relevant chloride channels. Here we have sequenced 50 transcripts of the pHCl-1 gene from the brain, third thoracic ganglion (T3G), and midgut of larvae of silkworm Bombyx mori It was found that >50 variants were expressed with distinct splicing in the T3G compared with the brain and midgut. Of the variants detected, variant 9, which was expressed most abundantly in the larvae, was reconstituted in Xenopus laevis oocytes to characterize its pH and ivermectin sensitivity. Variant 9 formed a functional pHCl with half-maximal activation at a pH of 7.87, and was activated by ivermectin irrespective of the extracellular pH. This was in contrast to variant 1, which was activated more profoundly at acidic rather than basic pH. To identify a key determinant for such differential ivermectin sensitivity, different amino acids in variants 1 and 9 were swapped, and the effects of the mutations on ivermectin sensitivity were investigated. The V275S mutation of variant 1 enhanced ivermectin sensitivity, whereas the S275V mutation of variant 9 caused a reduction in sensitivity. In homology models of the Bombyx pHCls, Val275 of variant 1 interacted more strongly with Ala273 than Ser275 of variant 9 at the channel gate. This interaction is likely to prevent ivermectin-induced opening of the channel, accounting, at least partially, for the differential macrolide action on the two variants.
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Affiliation(s)
- Daiki Okuhara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, Nara, Japan (D.O., S.F., M.I., K.M.); Department of Science of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan (K.I.)
| | - Shogo Furutani
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, Nara, Japan (D.O., S.F., M.I., K.M.); Department of Science of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan (K.I.)
| | - Katsuhiko Ito
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, Nara, Japan (D.O., S.F., M.I., K.M.); Department of Science of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan (K.I.)
| | - Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, Nara, Japan (D.O., S.F., M.I., K.M.); Department of Science of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan (K.I.)
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, Nara, Japan (D.O., S.F., M.I., K.M.); Department of Science of Biological Production, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan (K.I.)
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17
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Degani-Katzav N, Gortler R, Weissman M, Paas Y. Mutational Analysis at Intersubunit Interfaces of an Anionic Glutamate Receptor Reveals a Key Interaction Important for Channel Gating by Ivermectin. Front Mol Neurosci 2017; 10:92. [PMID: 28428744 PMCID: PMC5382172 DOI: 10.3389/fnmol.2017.00092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 03/17/2017] [Indexed: 11/13/2022] Open
Abstract
The broad-spectrum anthelmintic drug ivermectin (IVM) activates and stabilizes an open-channel conformation of invertebrate chloride-selective glutamate receptors (GluClRs), thereby causing a continuous inflow of chloride ions and sustained membrane hyperpolarization. These effects suppress nervous impulses and vital physiological processes in parasitic nematodes. The GluClRs are pentamers. Homopentameric receptors assembled from the Caenorhabditis elegans (C. elegans) GluClα (GLC-1) subunit can inherently respond to IVM but not to glutamate (the neurotransmitter). In contrast, heteromeric GluClα/β (GLC-1/GLC-2) assemblies respond to both ligands, independently of each other. Glutamate and IVM bind at the interface between adjacent subunits, far away from each other; glutamate in the extracellular ligand-binding domain, and IVM in the ion-channel pore periphery. To understand the importance of putative intersubunit contacts located outside the glutamate and IVM binding sites, we introduced mutations at intersubunit interfaces, between these two binding-site types. Then, we determined the effect of these mutations on the activation of the heteromeric mutant receptors by glutamate and IVM. Amongst these mutations, we characterized an α-subunit point mutation located close to the putative IVM-binding pocket, in the extracellular end of the first transmembrane helix (M1). This mutation (αF276A) moderately reduced the sensitivity of the heteromeric GluClαF276A/βWT receptor to glutamate, and slightly decreased the receptor subunits’ cooperativity in response to glutamate. In contrast, the αF276A mutation drastically reduced the sensitivity of the receptor to IVM and significantly increased the receptor subunits’ cooperativity in response to IVM. We suggest that this mutation reduces the efficacy of channel gating, and impairs the integrity of the IVM-binding pocket, likely by disrupting important interactions between the tip of M1 and the M2-M3 loop of an adjacent subunit. We hypothesize that this physical contact between M1 and the M2-M3 loop tunes the relative orientation of the ion-channel transmembrane helices M1, M2 and M3 to optimize pore opening. Interestingly, pre-exposure of the GluClαF276A/βWT mutant receptor to subthreshold IVM concentration recovered the receptor sensitivity to glutamate. We infer that IVM likely retained its positive modulation activity by constraining the transmembrane helices in a preopen orientation sensitive to glutamate, with no need for the aforementioned disrupted interactions between M1 and the M2-M3 loop.
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Affiliation(s)
- Nurit Degani-Katzav
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology and Advanced Materials, Bar-Ilan UniversityRamat Gan, Israel
| | - Revital Gortler
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology and Advanced Materials, Bar-Ilan UniversityRamat Gan, Israel
| | - Marina Weissman
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology and Advanced Materials, Bar-Ilan UniversityRamat Gan, Israel
| | - Yoav Paas
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology and Advanced Materials, Bar-Ilan UniversityRamat Gan, Israel
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18
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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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19
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Degani-Katzav N, Klein M, Har-Even M, Gortler R, Tobi R, Paas Y. Trapping of ivermectin by a pentameric ligand-gated ion channel upon open-to-closed isomerization. Sci Rep 2017; 7:42481. [PMID: 28218274 PMCID: PMC5317004 DOI: 10.1038/srep42481] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 01/11/2017] [Indexed: 11/09/2022] Open
Abstract
Ivermectin (IVM) is a broad-spectrum anthelmintic drug used to treat human parasitic diseases like river blindness and lymphatic filariasis. By activating invertebrate pentameric glutamate-gated chloride channels (GluCl receptors; GluClRs), IVM induces sustained chloride influx and long-lasting membrane hyperpolarization that inhibit neural excitation in nematodes. Although IVM activates the C. elegans heteromeric GluClα/β receptor, it cannot activate a homomeric receptor composed of the C. elegans GluClβ subunits. To understand this incapability, we generated a homopentameric α7-GluClβ chimeric receptor that consists of an extracellular ligand-binding domain of an α7 nicotinic acetylcholine receptor known to be potentiated by IVM, and a chloride-selective channel domain assembled from GluClβ subunits. Application of IVM prior to acetylcholine inhibited the responses of the chimeric α7-GluClβR. Adding IVM to activated α7-GluClβRs, considerably accelerated the decline of ACh-elicited currents and stabilized the receptors in a non-conducting state. Determination of IVM association and dissociation rate constants and recovery experiments suggest that, following initial IVM binding to open α7-GluClβRs, the drug induces a conformational change and locks the ion channel in a closed state for a long duration. We further found that IVM also inhibits the activation by glutamate of a homomeric receptor assembled from the C. elegans full-length GluClβ subunits.
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Affiliation(s)
- Nurit Degani-Katzav
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences and The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Moshe Klein
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences and The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Moran Har-Even
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences and The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Revital Gortler
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences and The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Ruthi Tobi
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences and The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Yoav Paas
- Laboratory of Ion Channels, The Mina and Everard Goodman Faculty of Life Sciences and The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan 52900, Israel
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20
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Meyers JI, Gray M, Kuklinski W, Johnson LB, Snow CD, Black WC, Partin KM, Foy BD. Characterization of the target of ivermectin, the glutamate-gated chloride channel, from Anopheles gambiae. ACTA ACUST UNITED AC 2016; 218:1478-86. [PMID: 25994631 DOI: 10.1242/jeb.118570] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The use of insecticide-treated nets and indoor residual insecticides targeting adult mosquito vectors is a key element in malaria control programs. However, mosquito resistance to the insecticides used in these applications threatens malaria control efforts. Recently, the mass drug administration of ivermectin (IVM) has been shown to kill Anopheles gambiae mosquitoes and disrupt Plasmodium falciparum transmission in the field. We cloned the molecular target of IVM from A. gambiae, the glutamate-gated chloride channel (AgGluCl), and characterized its transcriptional patterns, protein expression and functional responses to glutamate and IVM. AgGluCl cloning revealed an unpredicted fourth splice isoform as well as a novel exon and splice site. The predicted gene products contained heterogeneity in the N-terminal extracellular domain and the intracellular loop region. Responses to glutamate and IVM were measured using two-electrode voltage clamp on Xenopus laevis oocytes expressing AgGluCl. IVM induced non-persistent currents in AgGluCl-a1 and did not potentiate glutamate responses. In contrast, AgGluCl-b was insensitive to IVM, suggesting that the AgGluCl gene could produce IVM-sensitive and -insensitive homomultimers from alternative splicing. AgGluCl isoform-specific transcripts were measured across tissues, ages, blood feeding status and sex, and were found to be differentially transcribed across these physiological variables. Lastly, we stained adult, female A. gambiae for GluCl expression. The channel was expressed in the antenna, Johnston's organ, supraesophageal ganglion and thoracic ganglia. In summary, we have characterized the first GluCl from a mosquito, A. gambiae, and described its unique activity and expression with respect to it as the target of the insecticide IVM.
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Affiliation(s)
- Jacob I Meyers
- Department of Biomedical Sciences, Colorado State University, 1617 Campus Delivery, Fort Collins, CO 80523-1617, USA
| | - Meg Gray
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, 1692 Campus Delivery, Fort Collins, CO 80523-1692, USA
| | - Wojtek Kuklinski
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, 1692 Campus Delivery, Fort Collins, CO 80523-1692, USA
| | - Lucas B Johnson
- Department of Chemical and Biological Engineering, Colorado State University, 1370 Campus Delivery, Fort Collins, CO 80523-1370, USA
| | - Christopher D Snow
- Department of Chemical and Biological Engineering, Colorado State University, 1370 Campus Delivery, Fort Collins, CO 80523-1370, USA
| | - William C Black
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, 1692 Campus Delivery, Fort Collins, CO 80523-1692, USA
| | - Kathryn M Partin
- Department of Biomedical Sciences, Colorado State University, 1617 Campus Delivery, Fort Collins, CO 80523-1617, USA
| | - Brian D Foy
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, 1692 Campus Delivery, Fort Collins, CO 80523-1692, USA
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21
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Furutani S, Ihara M, Kai K, Tanaka K, Sattelle DB, Hayashi H, Matsuda K. Okaramine insecticidal alkaloids show similar activity on both exon 3c and exon 3b variants of glutamate-gated chloride channels of the larval silkworm, Bombyx mori. Neurotoxicology 2016; 60:240-244. [PMID: 27153748 DOI: 10.1016/j.neuro.2016.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 05/02/2016] [Accepted: 05/02/2016] [Indexed: 10/21/2022]
Abstract
The okaramine indole alkaloids were recently shown to be more selective than ivermectin in activating the glutamate-gated chloride channels of the silkworm larvae of Bombyx mori (BmGluCls). Those studies were carried out using the exon 3b variant as a representative of BmGluCls. However, it remains unknown whether okaramines are similarly effective on other silkworm GluCl variants and whether they share the same binding site as ivermectin on GluCls. To begin to address these questions, we examined the potency of four okaramines on the exon 3c variant of BmGluCls by two-electrode voltage clamp voltage recordings of glutamate-induced chloride currents. The potency of okaramines in activating the exon 3c BmGluCl agreed well with findings on the exon 3b BmGluCl and insecticidal potency. Okaramine B (10μM) reduced the maximum binding (Bmax) but not the dissociation constant (KD) of [3H]ivermectin in studies on plasma membrane fractions of HEK293 cells expressing the exon 3c variant. These findings indicate that activation of GluCls is important in the insecticidal actions of okaramines.
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Affiliation(s)
- Shogo Furutani
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Kenji Kai
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-chou, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Keiji Tanaka
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - David B Sattelle
- UCL Respiratory, Division of Medicine, University College London, The Rayne Building, 5 University Street, London WC1E 6JF, UK
| | - Hideo Hayashi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-chou, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kindai University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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22
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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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23
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Nakatani Y, Furutani S, Ihara M, Matsuda K. Ivermectin modulation of pH-sensitive chloride channels in the silkworm larvae of Bombyx mori. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2016; 126:1-5. [PMID: 26778427 DOI: 10.1016/j.pestbp.2015.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/23/2015] [Accepted: 08/24/2015] [Indexed: 05/27/2023]
Affiliation(s)
- Yuri Nakatani
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Shogo Furutani
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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