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Dubey A, Baxter M, Hendargo KJ, Medrano-Soto A, Saier MH. The Pentameric Ligand-Gated Ion Channel Family: A New Member of the Voltage Gated Ion Channel Superfamily? Int J Mol Sci 2024; 25:5005. [PMID: 38732224 PMCID: PMC11084639 DOI: 10.3390/ijms25095005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/28/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
In this report we present seven lines of bioinformatic evidence supporting the conclusion that the Pentameric Ligand-gated Ion Channel (pLIC) Family is a member of the Voltage-gated Ion Channel (VIC) Superfamily. In our approach, we used the Transporter Classification Database (TCDB) as a reference and applied a series of bioinformatic methods to search for similarities between the pLIC family and members of the VIC superfamily. These include: (1) sequence similarity, (2) compatibility of topology and hydropathy profiles, (3) shared domains, (4) conserved motifs, (5) similarity of Hidden Markov Model profiles between families, (6) common 3D structural folds, and (7) clustering analysis of all families. Furthermore, sequence and structural comparisons as well as the identification of a 3-TMS repeat unit in the VIC superfamily suggests that the sixth transmembrane segment evolved into a re-entrant loop. This evidence suggests that the voltage-sensor domain and the channel domain have a common origin. The classification of the pLIC family within the VIC superfamily sheds light onto the topological origins of this family and its evolution, which will facilitate experimental verification and further research into this superfamily by the scientific community.
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Affiliation(s)
| | | | | | - Arturo Medrano-Soto
- Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0116, USA; (A.D.); (M.B.); (K.J.H.)
| | - Milton H. Saier
- Department of Molecular Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0116, USA; (A.D.); (M.B.); (K.J.H.)
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Van Renterghem C, Nemecz Á, Medjebeur K, Corringer P. Short-chain mono-carboxylates as negative modulators of allosteric transitions in Gloeobacter violaceus ligand-gated ion channel, and impact of a pre-β5 strand (Loop Ω) double mutation on crotonate, not butyrate effect. Physiol Rep 2024; 12:e15916. [PMID: 38343277 PMCID: PMC10859675 DOI: 10.14814/phy2.15916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/24/2023] [Accepted: 01/03/2024] [Indexed: 02/15/2024] Open
Abstract
Using the bacterial proton-activated pentameric receptor-channel Gloeobacter violaceus ligand-gated ion channel (GLIC): (1) We characterize saturated, mono-carboxylates as negative modulators of GLIC (as previously shown for crotonate; Alqazzaz et al., Biochemistry, 2016, 55, 5947). Butyrate and crotonate have indistinguishable properties regarding negative modulation of wt GLIC. (2) We identify a locus in the pre-β5 strand (Loop Ω) whose mutation inverses the effect of the mono-carboxylate crotonate from negative to positive modulation of the allosteric transitions, suggesting an involvement of the pre-β5 strand in coupling the extracellular orthotopic receptor to pore gating. (3) As an extension to the previously proposed "in series" mechanism, we suggest that a orthotopic/orthosteric site-vestibular site-Loop Ω-β5-β6 "sandwich"-Pro-Loop/Cys-Loop series may be an essential component of orthotopic/orthosteric compound-elicited gating control in this pentameric ligand-gated ion channel, on top of which compounds targeting the vestibular site may provide modulation.
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Affiliation(s)
| | - Ákos Nemecz
- Channel‐Receptors Unit, Institut Pasteur, CNRS UMR3571Université Paris CitéParisFrance
| | - Karima Medjebeur
- Channel‐Receptors Unit, Institut Pasteur, CNRS UMR3571Université Paris CitéParisFrance
| | - Pierre‐Jean Corringer
- Channel‐Receptors Unit, Institut Pasteur, CNRS UMR3571Université Paris CitéParisFrance
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3
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Hardege I, Morud J, Yu J, Wilson TS, Schroeder FC, Schafer WR. Neuronally produced betaine acts via a ligand-gated ion channel to control behavioral states. Proc Natl Acad Sci U S A 2022; 119:e2201783119. [PMID: 36413500 PMCID: PMC9860315 DOI: 10.1073/pnas.2201783119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 10/11/2022] [Indexed: 11/23/2022] Open
Abstract
Trimethylglycine, or betaine, is an amino acid derivative found in diverse organisms, from bacteria to plants and animals, with well-established functions as a methyl donor and osmolyte in all cells. In addition, betaine is found in the nervous system, though its function there is not well understood. Here, we show that betaine is synthesized in the nervous system of the nematode worm, Caenorhabditis elegans, where it functions in the control of different behavioral states. Specifically, we find that betaine can be produced in a pair of interneurons, the RIMs, and packed into synaptic vesicles by the vesicular monoamine transporter, CAT-1, expressed in these cells. Mutant animals defective in betaine synthesis are unable to control the switch from local to global foraging, a phenotype that can be rescued by restoring betaine specifically to the RIM neurons. These effects on behavior are mediated by a newly identified betaine-gated chloride channel, LGC-41, which is expressed broadly in the navigation circuit. These results implicate neuronally produced betaine as a neuromodulator in vivo and suggest a potentially similar role for betaine in nervous systems of other animals.
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Affiliation(s)
- Iris Hardege
- MRC Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Julia Morud
- MRC Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Jingfang Yu
- Boyce Thompson Institute, Cornell University, Ithaca, NY14853
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Tatiana S. Wilson
- MRC Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Frank C. Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, NY14853
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - William R. Schafer
- MRC Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
- Department of Biology, KU Leuven, Leuven3000, Belgium
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4
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Abstract
Ammonia and its amine-containing derivatives are widely found in natural decomposition byproducts. Here, we conducted biased chemoreceptor screening to investigate the mechanisms by which different concentrations of ammonium salt, urea, and putrescine in rotten fruits affect feeding and oviposition behavior. We identified three ionotropic receptors, including the two broadly required IR25a and IR76b receptors, as well as the narrowly tuned IR51b receptor. These three IRs were fundamental in eliciting avoidance against nitrogenous waste products, which is mediated by bitter-sensing gustatory receptor neurons (GRNs). The aversion of nitrogenous wastes was evaluated by the cellular requirement by expressing Kir2.1 and behavioral recoveries of the mutants in bitter-sensing GRNs. Furthermore, by conducting electrophysiology assays, we confirmed that ammonia compounds are aversive in taste as they directly activated bitter-sensing GRNs. Therefore, our findings provide insights into the ecological roles of IRs as a means to detect and avoid toxic nitrogenous waste products in nature.
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Affiliation(s)
- Subash Dhakal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Jiun Sang
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Binod Aryal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea.
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul, 02707, Republic of Korea.
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Sridhar A, Lummis SCR, Pasini D, Mehregan A, Brams M, Kambara K, Bertrand D, Lindahl E, Howard RJ, Ulens C. Regulation of a pentameric ligand-gated ion channel by a semiconserved cationic lipid-binding site. J Biol Chem 2021; 297:100899. [PMID: 34157288 PMCID: PMC8327344 DOI: 10.1016/j.jbc.2021.100899] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/10/2021] [Accepted: 06/18/2021] [Indexed: 02/08/2023] Open
Abstract
Pentameric ligand-gated ion channels (pLGICs) are crucial mediators of electrochemical signal transduction in various organisms from bacteria to humans. Lipids play an important role in regulating pLGIC function, yet the structural bases for specific pLGIC-lipid interactions remain poorly understood. The bacterial channel ELIC recapitulates several properties of eukaryotic pLGICs, including activation by the neurotransmitter GABA and binding and modulation by lipids, offering a simplified model system for structure-function relationship studies. In this study, functional effects of noncanonical amino acid substitution of a potential lipid-interacting residue (W206) at the top of the M1-helix, combined with detergent interactions observed in recent X-ray structures, are consistent with this region being the location of a lipid-binding site on the outward face of the ELIC transmembrane domain. Coarse-grained and atomistic molecular dynamics simulations revealed preferential binding of lipids containing a positive charge, particularly involving interactions with residue W206, consistent with cation-π binding. Polar contacts from other regions of the protein, particularly M3 residue Q264, further support lipid binding via headgroup ester linkages. Aromatic residues were identified at analogous sites in a handful of eukaryotic family members, including the human GABAA receptor ε subunit, suggesting conservation of relevant interactions in other evolutionary branches. Further mutagenesis experiments indicated that mutations at this site in ε-containing GABAA receptors can change the apparent affinity of the agonist response to GABA, suggesting a potential role of this site in channel gating. In conclusion, this work details type-specific lipid interactions, which adds to our growing understanding of how lipids modulate pLGICs.
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Affiliation(s)
- Akshay Sridhar
- Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Solna, Sweden
| | - Sarah C R Lummis
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Diletta Pasini
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Aujan Mehregan
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Marijke Brams
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | | | | | - Erik Lindahl
- Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Solna, Sweden; Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Rebecca J Howard
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden.
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Leuven, Belgium.
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Chen C, Zhu H, Li SY, Han YY, Chen L, Fan BQ, Zhang YF, Wang Y, Hao DJ. Insights into chemosensory genes of Pagiophloeus tsushimanus adults using transcriptome and qRT-PCR analysis. Comp Biochem Physiol Part D Genomics Proteomics 2021; 37:100785. [PMID: 33548831 DOI: 10.1016/j.cbd.2020.100785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 11/18/2022]
Abstract
Pagiophloeus tsushimanus is a new, destructive, and monophagous weevil pest that thrives on Cinnamomum camphora, found in Shanghai. The functions of chemosensory genes involved in the host location and intraspecific communication of P. tsushimanus remain unknown. The male-female transcriptomes of P. tsushimanus adults were assembled using Illumina sequencing, and we focused on all chemosensory genes in transcriptomes. In general, 58,088 unigenes with a mean length of 1018.19 bp were obtained. In total, 39 odorant binding proteins (OBPs), 10 chemosensory proteins (CSPs), 22 olfactory receptors (ORs), 16 gustatory receptors (GRs), eight ionotropic receptors (IRs), and five sensory neuron membrane proteins (SNMPs) were identified. PtsuOBPs comprised four subfamilies (20 Minus-C, one Plus-C, two Dimer, and 15 Classic). Both PtsuOBPs and PtsuCSPs contained a highly conserved sequence motif of cysteine residues. PtsuORs including one olfactory receptor co-receptors (Ptsu/Orco) comprised seven predicted transmembrane domains. Phylogenetic analysis revealed that PtsuOBPs, PtsuCSPs, and PtsuORs in P. tsushimanus exhibited low homology compared to other insect species. The results of tissue- and sex-specific expression patterns indicated that PtsuOBPs and PtsuORs were highly abundant in the antennae; whereas, PtsuCSPs were not only highly abundant in antennae, but also abdominal apexes, wings, and legs. In conclusion, these results enrich the gene database of P. tsushimanus, which may serve as a basis for identifying novel targets to disrupt olfactory key genes and may provide a reverse validation method to identify attractants for formulating potential eco-friendly control strategies for this pest.
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Affiliation(s)
- Cong Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu, China
| | - Han Zhu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu, China
| | - Shou-Yin Li
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu, China
| | | | - Liang Chen
- Shanghai Kaisheng Landscape Engineering Co., Ltd, Shanghai, China
| | - Bin-Qi Fan
- Forest Station of Shanghai, Shanghai, China
| | | | - Yan Wang
- Forest Station of Shanghai, Shanghai, China
| | - De-Jun Hao
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, China; College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu, China.
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Brams M, Govaerts C, Kambara K, Price KL, Spurny R, Gharpure A, Pardon E, Evans GL, Bertrand D, Lummis SCR, Hibbs RE, Steyaert J, Ulens C. Modulation of the Erwinia ligand-gated ion channel (ELIC) and the 5-HT 3 receptor via a common vestibule site. eLife 2020; 9:e51511. [PMID: 31990273 PMCID: PMC7015668 DOI: 10.7554/elife.51511] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/27/2020] [Indexed: 01/13/2023] Open
Abstract
Pentameric ligand-gated ion channels (pLGICs) or Cys-loop receptors are involved in fast synaptic signaling in the nervous system. Allosteric modulators bind to sites that are remote from the neurotransmitter binding site, but modify coupling of ligand binding to channel opening. In this study, we developed nanobodies (single domain antibodies), which are functionally active as allosteric modulators, and solved co-crystal structures of the prokaryote (Erwinia) channel ELIC bound either to a positive or a negative allosteric modulator. The allosteric nanobody binding sites partially overlap with those of small molecule modulators, including a vestibule binding site that is not accessible in some pLGICs. Using mutagenesis, we extrapolate the functional importance of the vestibule binding site to the human 5-HT3 receptor, suggesting a common mechanism of modulation in this protein and ELIC. Thus we identify key elements of allosteric binding sites, and extend drug design possibilities in pLGICs with an accessible vestibule site.
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Affiliation(s)
- Marijke Brams
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU LeuvenLeuvenBelgium
| | - Cedric Govaerts
- Laboratory for the Structure and Function of Biological Membranes, Center for Structural Biology and Bioinformatics, Université libre de BruxellesBrusselsBelgium
| | | | - Kerry L Price
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Radovan Spurny
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU LeuvenLeuvenBelgium
| | - Anant Gharpure
- Department of Neuroscience, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit BrusselBrusselsBelgium
- VIB-VUB Center for Structural Biology, VIBBrusselsBelgium
| | - Genevieve L Evans
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU LeuvenLeuvenBelgium
| | | | - Sarah CR Lummis
- Department of Biochemistry, University of CambridgeCambridgeUnited Kingdom
| | - Ryan E Hibbs
- Department of Neuroscience, University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biophysics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit BrusselBrusselsBelgium
- VIB-VUB Center for Structural Biology, VIBBrusselsBelgium
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU LeuvenLeuvenBelgium
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He Z, Luo Y, Shang X, Sun JS, Carlson JR. Chemosensory sensilla of the Drosophila wing express a candidate ionotropic pheromone receptor. PLoS Biol 2019; 17:e2006619. [PMID: 31112532 PMCID: PMC6528970 DOI: 10.1371/journal.pbio.2006619] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 04/05/2019] [Indexed: 12/01/2022] Open
Abstract
The Drosophila wing was proposed to be a taste organ more than 35 years ago, but there has been remarkably little study of its role in chemoreception. We carry out a differential RNA-seq analysis of a row of sensilla on the anterior wing margin and find expression of many genes associated with pheromone and chemical perception. To ask whether these sensilla might receive pheromonal input, we devised a dye-transfer paradigm and found that large, hydrophobic molecules comparable to pheromones can be transferred from one fly to the wing margin of another. One gene, Ionotropic receptor (IR)52a, is coexpressed in neurons of these sensilla with fruitless, a marker of sexual circuitry; IR52a is also expressed in legs. Mutation of IR52a and optogenetic silencing of IR52a+ neurons decrease levels of male sexual behavior. Optogenetic activation of IR52a+ neurons induces males to show courtship toward other males and, remarkably, toward females of another species. Surprisingly, IR52a is also required in females for normal sexual behavior. Optogenetic activation of IR52a+ neurons in mated females induces copulation, which normally occurs at very low levels. Unlike other chemoreceptors that act in males to inhibit male–male interactions and promote male–female interactions, IR52a acts in both males and females, and can promote male–male as well as male–female interactions. Moreover, IR52a+ neurons can override the circuitry that normally suppresses sexual behavior toward unproductive targets. Circuit mapping and Ca2+ imaging using the trans-Tango system reveals second-order projections of IR52a+ neurons in the subesophageal zone (SEZ), some of which are sexually dimorphic. Optogenetic activation of IR52a+ neurons in the wing activates second-order projections in the SEZ. Taken together, this study provides a molecular description of the chemosensory sensilla of a greatly understudied taste organ and defines a gene that regulates the sexual circuitry of the fly.
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Affiliation(s)
- Zhe He
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Yichen Luo
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Xueying Shang
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Jennifer S. Sun
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - John R. Carlson
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
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Callanan MK, Habibi SA, Law WJ, Nazareth K, Komuniecki RL, Forrester SG. Investigating the function and possible biological role of an acetylcholine-gated chloride channel subunit (ACC-1) from the parasitic nematode Haemonchus contortus. Int J Parasitol Drugs Drug Resist 2018; 8:526-533. [PMID: 30401619 PMCID: PMC6287539 DOI: 10.1016/j.ijpddr.2018.10.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/25/2018] [Accepted: 10/26/2018] [Indexed: 01/30/2023]
Abstract
The cys-loop superfamily of ligand-gated ion channels are well recognized as important drug targets for many invertebrate specific compounds. With the rise in resistance seen worldwide to existing anthelmintics, novel drug targets must be identified so new treatments can be developed. The acetylcholine-gated chloride channel (ACC) family is a unique family of cholinergic receptors that have been shown, using Caenorhabditis elegans as a model, to have potential as anti-parasitic drug targets. However, there is little known about the function of these receptors in parasitic nematodes. Here, we have identified an acc gene (hco-acc-1) from the sheep parasitic nematode Haemonchus contortus. While similar in sequence to the previously characterized C. elegans ACC-1 receptor, Hco-ACC-1 does not form a functional homomeric channel in Xenopus oocytes. Instead, co-expression of Hco-ACC-1 with a previously characterized subunit Hco-ACC-2 produced a functional heteromeric channel which was 3x more sensitive to acetylcholine compared to the Hco-ACC-2 homomeric channel. We have also found that Hco-ACC-1 can be functionally expressed in C. elegans. Overexpression of both cel-acc-1 and hco-acc-1 in both C. elegans N2 and acc-1 null mutants decreased the time for worms to initiate reversal avoidance to octanol. Moreover, antibodies were generated against the Hco-ACC-1 protein for use in immunolocalization studies. Hco-ACC-1 consistently localized to the anterior half of the pharynx, specifically in pharyngeal muscle tissue in H. contortus. On the other hand, expression of Hco-ACC-1 in C. elegans was restricted to neuronal tissue. Overall, this research has provided new insight into the potential role of ACC receptors in parasitic nematodes. Isolation of an ACC-1 orthologue from Haemonchus contortus. Hco-ACC-1 may play a role in pharyngeal pumping. Hco-ACC-1 forms a sensitive ACh heteromeric channel when co-expressed with Hco-ACC-2.
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Affiliation(s)
- Micah K Callanan
- 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
| | - Wen Jing Law
- Department of Biological Sciences, University of Toledo, Toledo, OH, 43606, USA
| | - Kristen Nazareth
- 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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10
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Abstract
X-ray crystallography is a powerful tool in structural biology and can offer insight into structured-based understanding of general anesthetic action on various relevant molecular targets, including pentameric ligand-gated ion channels (pLGICs). In this chapter, we outline the procedures for expression and purification of pLGICs. Optimization of crystallization conditions, especially to achieve high-resolution structures of pLGICs bound with general anesthetics, is also presented. Case studies of pLGICs bound with the volatile general anesthetic isoflurane, 2-bromoethanol, and the intravenous general anesthetic ketamine are revisited.
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Affiliation(s)
- Qiang Chen
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Yan Xu
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Pei Tang
- University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
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11
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Abdelmassih SA, Cochrane E, Forrester SG. Evaluating the longevity of surgically extracted Xenopus laevis oocytes for the study of nematode ligand-gated ion channels. Invert Neurosci 2017; 18:1. [PMID: 29185074 DOI: 10.1007/s10158-017-0205-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 11/18/2017] [Indexed: 11/26/2022]
Abstract
Xenopus laevis oocytes have been extensively used as a heterologous expression system for the study of ion channels. While used successfully worldwide as tool for expressing and characterizing ion channels from a wide range of species, the limited longevity of oocytes once removed from the animal can pose significant challenges. In this study, we evaluate a simple and useful method that extends the longevity of Xenopus oocytes after removal from the animal and quantitatively assessed the reliability of the electrophysiological date obtained. The receptor used for this study was the UNC-49 receptor originally isolated from the sheep parasite, Haemonchus contortus. Overall, we found that immediate storage of the ovary in supplemented ND96 storage buffer at 4 °C could extend their use for up to 17 days with almost 80% providing reliable electrophysiological data. This means that a single extraction can provide at least 3 weeks of experiments. In addition, we examined 24-day-old oocytes (week 4) extracted from a single frog and also obtained reliable data using the same approach. However, 50% of these oocytes were usable for full dose-response experiments. Overall, we did find that this method has the potential to significantly extend the use of single oocyte extractions for two-electrode voltage clamp electrophysiology.
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Affiliation(s)
- Sarah A Abdelmassih
- Applied Bioscience Graduate Program, Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Everett Cochrane
- Applied Bioscience Graduate Program, Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada
| | - Sean G Forrester
- Applied Bioscience Graduate Program, Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada.
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12
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Ghosh B, Tsao TW, Czajkowski C. A chimeric prokaryotic-eukaryotic pentameric ligand gated ion channel reveals interactions between the extracellular and transmembrane domains shape neurosteroid modulation. Neuropharmacology 2017; 125:343-352. [PMID: 28803966 PMCID: PMC5600277 DOI: 10.1016/j.neuropharm.2017.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/30/2017] [Accepted: 08/08/2017] [Indexed: 10/19/2022]
Abstract
Pentameric ligand-gated ion channels (pLGICs) are the targets of several clinical and endogenous allosteric modulators including anesthetics and neurosteroids. Molecular mechanisms underlying allosteric drug modulation are poorly understood. Here, we constructed a chimeric pLGIC by fusing the extracellular domain (ECD) of the proton-activated, cation-selective bacterial channel GLIC to the transmembrane domain (TMD) of the human ρ1 chloride-selective GABAAR, and tested the hypothesis that drug actions are regulated locally in the domain that houses its binding site. The chimeric channels were proton-gated and chloride-selective demonstrating the GLIC ECD was functionally coupled to the GABAρ TMD. Channels were blocked by picrotoxin and inhibited by pentobarbital, etomidate and propofol. The point mutation, ρ TMD W328M, conferred positive modulation and direct gating by pentobarbital. The data suggest that the structural machinery mediating general anesthetic modulation resides in the TMD. Proton-activation and neurosteroid modulation of the GLIC-ρ chimeric channels, however, did not simply mimic their respective actions on GLIC and GABAρ revealing that across domain interactions between the ECD and TMD play important roles in determining their actions. Proton-induced current responses were biphasic suggesting that the chimeric channels contain an additional proton sensor. Neurosteroid modulation of the GLIC-ρ chimeric channels by the stereoisomers, 5α-THDOC and 5β-THDOC, were swapped compared to their actions on GABAρ indicating that positive versus negative neurosteroid modulation is not encoded solely in the TMD nor by neurosteroid isomer structure but is dependent on specific interdomain connections between the ECD and TMD. Our data reveal a new mechanism for shaping neurosteroid modulation.
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Affiliation(s)
- Borna Ghosh
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI 53705, USA; Eli Lilly and Company, 1220 W Morris St, Indianapolis, IN 46221, USA
| | - Tzu-Wei Tsao
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI 53705, USA; Physiology Training Program, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI 53705, USA
| | - Cynthia Czajkowski
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI 53705, USA.
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13
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Chen Q, Wells MM, Tillman TS, Kinde MN, Cohen A, Xu Y, Tang P. Structural Basis of Alcohol Inhibition of the Pentameric Ligand-Gated Ion Channel ELIC. Structure 2016; 25:180-187. [PMID: 27916519 DOI: 10.1016/j.str.2016.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 09/30/2016] [Accepted: 11/07/2016] [Indexed: 11/18/2022]
Abstract
The structural basis for alcohol modulation of neuronal pentameric ligand-gated ion channels (pLGICs) remains elusive. We determined an inhibitory mechanism of alcohol on the pLGIC Erwinia chrysanthemi (ELIC) through direct binding to the pore. X-ray structures of ELIC co-crystallized with 2-bromoethanol, in both the absence and presence of agonist, reveal 2-bromoethanol binding in the pore near T237(6') and the extracellular domain (ECD) of each subunit at three different locations. Binding to the ECD does not appear to contribute to the inhibitory action of 2-bromoethanol and ethanol as indicated by the same functional responses of wild-type ELIC and mutants. In contrast, the ELIC-α1β3GABAAR chimera, replacing the ELIC transmembrane domain (TMD) with the TMD of α1β3GABAAR, is potentiated by 2-bromoethanol and ethanol. The results suggest a dominant role of the TMD in modulating alcohol effects. The X-ray structures and functional measurements support a pore-blocking mechanism for inhibitory action of short-chain alcohols.
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Affiliation(s)
- Qiang Chen
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Marta M Wells
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Department of Computational and System Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Tommy S Tillman
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Monica N Kinde
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Aina Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Yan Xu
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA; Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Pei Tang
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA; Department of Computational and System Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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14
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Abstract
Pentameric ligand-gated ion channels (pLGICs) are ubiquitous neurotransmitter receptors in Bilateria, with a small number of known prokaryotic homologues. Here we describe a new inventory and phylogenetic analysis of pLGIC genes across all kingdoms of life. Our main finding is a set of pLGIC genes in unicellular eukaryotes, some of which are metazoan-like Cys-loop receptors, and others devoid of Cys-loop cysteines, like their prokaryotic relatives. A number of such “Cys-less” receptors also appears in invertebrate metazoans. Together, those findings draw a new distribution of pLGICs in eukaryotes. A broader distribution of prokaryotic channels also emerges, including a major new archaeal taxon, Thaumarchaeota. More generally, pLGICs now appear nearly ubiquitous in major taxonomic groups except multicellular plants and fungi. However, pLGICs are sparsely present in unicellular taxa, suggesting a high rate of gene loss and a non-essential character, contrasting with their essential role as synaptic receptors of the bilaterian nervous system. Multiple alignments of these highly divergent sequences reveal a small number of conserved residues clustered at the interface between the extracellular and transmembrane domains. Only the “Cys-loop” proline is absolutely conserved, suggesting the more fitting name “Pro loop” for that motif, and “Pro-loop receptors” for the superfamily. The infered molecular phylogeny shows a Cys-loop and a Cys-less clade in eukaryotes, both containing metazoans and unicellular members. This suggests new hypotheses on the evolutionary history of the superfamily, such as a possible origin of the Cys-loop cysteines in an ancient unicellular eukaryote. Deeper phylogenetic relationships remain uncertain, particularly around the split between bacteria, archaea, and eukaryotes.
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Affiliation(s)
- Mariama Jaiteh
- Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, CNRS and Université Paris Diderot, Paris, France
| | - Antoine Taly
- Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, CNRS and Université Paris Diderot, Paris, France
| | - Jérôme Hénin
- Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, CNRS and Université Paris Diderot, Paris, France
- * E-mail:
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15
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Gulia-Nuss M, Nuss AB, Meyer JM, Sonenshine DE, Roe RM, Waterhouse RM, Sattelle DB, de la Fuente J, Ribeiro JM, Megy K, Thimmapuram J, Miller JR, Walenz BP, Koren S, Hostetler JB, Thiagarajan M, Joardar VS, Hannick LI, Bidwell S, Hammond MP, Young S, Zeng Q, Abrudan JL, Almeida FC, Ayllón N, Bhide K, Bissinger BW, Bonzon-Kulichenko E, Buckingham SD, Caffrey DR, Caimano MJ, Croset V, Driscoll T, Gilbert D, Gillespie JJ, Giraldo-Calderón GI, Grabowski JM, Jiang D, Khalil SMS, Kim D, Kocan KM, Koči J, Kuhn RJ, Kurtti TJ, Lees K, Lang EG, Kennedy RC, Kwon H, Perera R, Qi Y, Radolf JD, Sakamoto JM, Sánchez-Gracia A, Severo MS, Silverman N, Šimo L, Tojo M, Tornador C, Van Zee JP, Vázquez J, Vieira FG, Villar M, Wespiser AR, Yang Y, Zhu J, Arensburger P, Pietrantonio PV, Barker SC, Shao R, Zdobnov EM, Hauser F, Grimmelikhuijzen CJP, Park Y, Rozas J, Benton R, Pedra JHF, Nelson DR, Unger MF, Tubio JMC, Tu Z, Robertson HM, Shumway M, Sutton G, Wortman JR, Lawson D, Wikel SK, Nene VM, Fraser CM, Collins FH, Birren B, Nelson KE, Caler E, Hill CA. Genomic insights into the Ixodes scapularis tick vector of Lyme disease. Nat Commun 2016; 7:10507. [PMID: 26856261 PMCID: PMC4748124 DOI: 10.1038/ncomms10507] [Citation(s) in RCA: 328] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 12/12/2015] [Indexed: 01/06/2023] Open
Abstract
Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick-host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host 'questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent.
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Affiliation(s)
- Monika Gulia-Nuss
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Andrew B. Nuss
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Jason M. Meyer
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Daniel E. Sonenshine
- Department of Biological Sciences, Old Dominion University, Norfolk, Virginina 23529, USA
| | - R. Michael Roe
- Department of Entomology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Robert M. Waterhouse
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva 1211, Switzerland
- Swiss Institute of Bioinformatics, Geneva 1211, Switzerland
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - David B. Sattelle
- Centre for Respiratory Biology, UCL Respiratory Department, Division of Medicine, University College London, Rayne Building, 5 University Street, London WC1E 6JF, UK
| | - José de la Fuente
- SaBio, Instituto de Investigación en Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM, Ronda de Toledo sn, Ciudad Real 13005, Spain
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall, Stillwater, Oklahama 74078, USA
| | - Jose M. Ribeiro
- Laboratory of Malaria and Vector Research, NIAID, Rockville, Maryland 20852, USA
| | - Karine Megy
- VectorBase/EMBL-EBI, Wellcome Trust Genome Campus, Cambridge CB10 1SD, UK
| | - Jyothi Thimmapuram
- Bioinformatics Core, Purdue University, West Lafayette, Indiana 47907, USA
| | | | | | - Sergey Koren
- J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | | | | | | | | | - Shelby Bidwell
- J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Martin P. Hammond
- VectorBase/EMBL-EBI, Wellcome Trust Genome Campus, Cambridge CB10 1SD, UK
| | - Sarah Young
- Genome Sequencing and Analysis Program, Broad Institute, Cambridge, Massachusetts 02142, USA
| | - Qiandong Zeng
- Genome Sequencing and Analysis Program, Broad Institute, Cambridge, Massachusetts 02142, USA
| | - Jenica L. Abrudan
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Francisca C. Almeida
- Departament de Genètica & Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona E-08028, Spain
| | - Nieves Ayllón
- SaBio, Instituto de Investigación en Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM, Ronda de Toledo sn, Ciudad Real 13005, Spain
| | - Ketaki Bhide
- Bioinformatics Core, Purdue University, West Lafayette, Indiana 47907, USA
| | - Brooke W. Bissinger
- Department of Entomology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Elena Bonzon-Kulichenko
- Vascular Physiopathology, Centro Nacional de Investigaciones Cardiovasculares, Madrid 28029, Spain
| | - Steven D. Buckingham
- Centre for Respiratory Biology, UCL Respiratory Department, Division of Medicine, University College London, Rayne Building, 5 University Street, London WC1E 6JF, UK
| | - Daniel R. Caffrey
- Department of Medicine, Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Melissa J. Caimano
- Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Vincent Croset
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH-1015, Switzerland
| | - Timothy Driscoll
- Genetics, Bioinformatics, and Computational Biology Program, Virginia Bioinformatics Institute at Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Don Gilbert
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
| | - Joseph J. Gillespie
- Genetics, Bioinformatics, and Computational Biology Program, Virginia Bioinformatics Institute at Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Gloria I. Giraldo-Calderón
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Jeffrey M. Grabowski
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
- Department Biological Sciences, Markey Center for Structural Biology, Purdue University, West Lafayette, Indiana 47907, USA
| | - David Jiang
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Sayed M. S. Khalil
- Department of Microbial Molecular Biology, Agricultural Genetic Engineering Research Institute, Giza 12619, Egypt
| | - Donghun Kim
- Department of Entomology, Texas A&M University, College Station, Texas 77843, USA
| | - Katherine M. Kocan
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall, Stillwater, Oklahama 74078, USA
| | - Juraj Koči
- Department of Entomology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Richard J. Kuhn
- Department Biological Sciences, Markey Center for Structural Biology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Timothy J. Kurtti
- Department of Entomology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Kristin Lees
- Department of Neurosystems, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Emma G. Lang
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Ryan C. Kennedy
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94143, USA
| | - Hyeogsun Kwon
- Department of Entomology, Texas A&M University, College Station, Texas 77843, USA
| | - Rushika Perera
- Department Biological Sciences, Markey Center for Structural Biology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Yumin Qi
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Justin D. Radolf
- Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Joyce M. Sakamoto
- Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Alejandro Sánchez-Gracia
- Departament de Genètica & Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona E-08028, Spain
| | - Maiara S. Severo
- Department of Entomology, Center for Disease Vector Research, University of California, Riverside, California 92506, USA
| | - Neal Silverman
- Department of Medicine, Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Ladislav Šimo
- Department of Entomology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Marta Tojo
- Department of Pathology, Cambridge Genomic Services, University of Cambridge, Cambridge CB2 1QP, UK
- Department of Physiology, School of Medicine-CIMUS-Instituto de Investigaciones Sanitarias, University of Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Cristian Tornador
- Department of Experimental and Health Sciences, Universidad Pompeu Fabra, Barcelona 08003, Spain
| | - Janice P. Van Zee
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Jesús Vázquez
- Vascular Physiopathology, Centro Nacional de Investigaciones Cardiovasculares, Madrid 28029, Spain
| | - Filipe G. Vieira
- Departament de Genètica & Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona E-08028, Spain
| | - Margarita Villar
- SaBio, Instituto de Investigación en Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM, Ronda de Toledo sn, Ciudad Real 13005, Spain
| | - Adam R. Wespiser
- Department of Medicine, Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Yunlong Yang
- Department of Entomology, Texas A&M University, College Station, Texas 77843, USA
| | - Jiwei Zhu
- Department of Entomology, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Peter Arensburger
- Department of Biological Sciences, California State Polytechnic University, Pomona, California 91768, USA
| | | | - Stephen C. Barker
- Parasitology Section, School of Chemistry & Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Renfu Shao
- GeneCology Research Centre, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4556, Australia
| | - Evgeny M. Zdobnov
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva 1211, Switzerland
- Swiss Institute of Bioinformatics, Geneva 1211, Switzerland
| | - Frank Hauser
- Department of Biology, Center for Functional and Comparative Insect Genomics, University of Copenhagen, Copenhagen DK-2100, Denmark
| | - Cornelis J. P. Grimmelikhuijzen
- Department of Biology, Center for Functional and Comparative Insect Genomics, University of Copenhagen, Copenhagen DK-2100, Denmark
| | - Yoonseong Park
- Department of Entomology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Julio Rozas
- Departament de Genètica & Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona E-08028, Spain
| | - Richard Benton
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH-1015, Switzerland
| | - Joao H. F. Pedra
- Department of Entomology, Center for Disease Vector Research, University of California, Riverside, California 92506, USA
| | - David R. Nelson
- Department of Microbiology, Immunology & Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Maria F. Unger
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Jose M. C. Tubio
- Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK
- Department of Biochemistry, Genetics and Immunology, University of Vigo, Vigo 36310, Spain
| | - Zhijian Tu
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Hugh M. Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Martin Shumway
- J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Granger Sutton
- J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | | | - Daniel Lawson
- VectorBase/EMBL-EBI, Wellcome Trust Genome Campus, Cambridge CB10 1SD, UK
| | - Stephen K. Wikel
- Department of Medical Sciences, Frank H. Netter MD School of Medicine at Quinnipiac University, Hamden, Connecticut 06518, USA
| | | | - Claire M. Fraser
- Institute for Genome Sciences, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
| | - Frank H. Collins
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Bruce Birren
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | | | - Elisabet Caler
- J. Craig Venter Institute, Rockville, Maryland 20850, USA
| | - Catherine A. Hill
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907, USA
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16
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Rienzo M, Lummis SCR, Dougherty DA. Structural requirements in the transmembrane domain of GLIC revealed by incorporation of noncanonical histidine analogs. ACTA ACUST UNITED AC 2015; 21:1700-6. [PMID: 25525989 DOI: 10.1016/j.chembiol.2014.10.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/23/2014] [Accepted: 10/13/2014] [Indexed: 12/21/2022]
Abstract
The cyanobacterial pentameric ligand-gated ion channel GLIC, a homolog of the Cys-loop receptor superfamily, has provided useful structural and functional information about its eukaryotic counterparts. X-ray diffraction data and site-directed mutagenesis have previously implicated a transmembrane histidine residue (His234) as essential for channel function. Here, we investigated the role of His234 via synthesis and incorporation of histidine analogs and α-hydroxy acids using in vivo nonsense suppression. Receptors were expressed heterologously in Xenopus laevis oocytes, and whole-cell voltage-clamp electrophysiology was used to monitor channel activity. We show that an interhelix hydrogen bond involving His234 is important for stabilization of the open state, and that the shape and basicity of its side chain are highly sensitive to perturbations. In contrast, our data show that two other His residues are not involved in the acid-sensing mechanism.
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Affiliation(s)
- Matthew Rienzo
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Sarah C R Lummis
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Dennis A Dougherty
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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17
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Ghosh B, Satyshur KA, Czajkowski C. Propofol binding to the resting state of the gloeobacter violaceus ligand-gated ion channel (GLIC) induces structural changes in the inter- and intrasubunit transmembrane domain (TMD) cavities. J Biol Chem 2013; 288:17420-31. [PMID: 23640880 PMCID: PMC3682542 DOI: 10.1074/jbc.m113.464040] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/06/2013] [Indexed: 11/06/2022] Open
Abstract
General anesthetics exert many of their CNS actions by binding to and modulating membrane-embedded pentameric ligand-gated ion channels (pLGICs). The structural mechanisms underlying how anesthetics modulate pLGIC function remain largely unknown. GLIC, a prokaryotic pLGIC homologue, is inhibited by general anesthetics, suggesting anesthetics stabilize a closed channel state, but in anesthetic-bound GLIC crystal structures the channel appears open. Here, using functional GLIC channels expressed in oocytes, we examined whether propofol induces structural rearrangements in the GLIC transmembrane domain (TMD). Residues in the GLIC TMD that frame intrasubunit and intersubunit water-accessible cavities were individually mutated to cysteine. We measured and compared the rates of modification of the introduced cysteines by sulfhydryl-reactive reagents in the absence and presence of propofol. Propofol slowed the rate of modification of L240C (intersubunit) and increased the rate of modification of T254C (intrasubunit), indicating that propofol binding induces structural rearrangements in these cavities that alter the local environment near these residues. Propofol acceleration of T254C modification suggests that in the resting state propofol does not bind in the TMD intrasubunit cavity as observed in the crystal structure of GLIC with bound propofol (Nury, H., Van Renterghem, C., Weng, Y., Tran, A., Baaden, M., Dufresne, V., Changeux, J. P., Sonner, J. M., Delarue, M., and Corringer, P. J. (2011) Nature 469, 428-431). In silico docking using a GLIC closed channel homology model suggests propofol binds to intersubunit sites in the TMD in the resting state. Propofol-induced motions in the intersubunit cavity were distinct from motions associated with channel activation, indicating propofol stabilizes a novel closed state.
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Affiliation(s)
| | - Kenneth A. Satyshur
- Department of Neuroscience, University of Wisconsin, Madison, Wisconsin 53711
| | - Cynthia Czajkowski
- From the Molecular Biophysics Program and
- Department of Neuroscience, University of Wisconsin, Madison, Wisconsin 53711
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18
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Tillman T, Cheng MH, Chen Q, Tang P, Xu Y. Reversal of ion-charge selectivity renders the pentameric ligand-gated ion channel GLIC insensitive to anaesthetics. Biochem J 2013; 449:61-8. [PMID: 22978431 PMCID: PMC3992983 DOI: 10.1042/bj20121072] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
pLGICs (pentameric ligand-gated ion channels) are a family of structurally homologous cation and anion channels involved in neurotransmission. Cation-selective members of the pLGIC family are typically inhibited by general anaesthetics, whereas anion-selective members are potentiated. GLIC is a prokaryotic cation pLGIC and can be inhibited by clinical concentrations of general anaesthetics. The introduction of three mutations, Y221A (Y-3'A), E222P (E-2'P) and N224R (N0'R), at the selectivity filter and one, A237T (A13'T), at the hydrophobic gate, converted GLIC into an anion channel. The mutated GLIC (GLIC4) became insensitive to the anaesthetics propofol and etomidate, as well as the channel blocker picrotoxin. MD (molecular dynamics) simulations revealed changes in the structure and dynamics of GLIC4 in comparison with GLIC, particularly in the tilting angles of the pore-lining helix [TM2 (transmembrane helix 2)] that consequently resulted in different pore radius and hydration profiles. Propofol binding to an intra-subunit site of GLIC shifted the tilting angles of TM2 towards closure at the hydrophobic gate region, consistent with propofol inhibition of GLIC. In contrast, the pore of GLIC4 was much more resilient to perturbation from propofol binding. The present study underscores the importance of pore dynamics and conformation to anaesthetic effects on channel functions.
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Affiliation(s)
- Tommy Tillman
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Mary H. Cheng
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Computational and System Biology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Qiang Chen
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Pei Tang
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Computational and System Biology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Yan Xu
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15261
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Chorna T, Hasan G. The genetics of calcium signaling in Drosophila melanogaster. Biochim Biophys Acta Gen Subj 2011; 1820:1269-82. [PMID: 22100727 DOI: 10.1016/j.bbagen.2011.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 10/31/2011] [Accepted: 11/02/2011] [Indexed: 01/13/2023]
Abstract
BACKGROUND Genetic screens for behavioral and physiological defects in Drosophila melanogaster, helped identify several components of calcium signaling of which some, like the Trps, were novel. For genes initially identified in vertebrates, reverse genetic methods have allowed functional studies at the cellular and systemic levels. SCOPE OF REVIEW The aim of this review is to explain how various genetic methods available in Drosophila have been used to place different arms of Ca2+ signaling in the context of organismal development, physiology and behavior. MAJOR CONCLUSION Mutants generated in genes encoding a range of Ca2+ transport systems, binding proteins and enzymes affect multiple aspects of neuronal and muscle physiology. Some also affect the maintenance of ionic balance and excretion from malpighian tubules and innate immune responses in macrophages. Aspects of neuronal physiology affected include synaptic growth and plasticity, sensory transduction, flight circuit development and function. Genetic interaction screens have shown that mechanisms of maintaining Ca2+ homeostasis in Drosophila are cell specific and require a synergistic interplay between different intracellular and plasma membrane Ca2+ signaling molecules. GENERAL SIGNIFICANCE Insights gained through genetic studies of conserved Ca2+ signaling pathways have helped understand multiple aspects of fly physiology. The similarities between mutant phenotypes of Ca2+ signaling genes in Drosophila with certain human disease conditions, especially where homologous genes are causative factors, are likely to aid in the discovery of underlying disease mechanisms and help develop novel therapeutic strategies. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signalling.
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Affiliation(s)
- Tetyana Chorna
- National Center for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
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Abstract
Ionic flux mediates essential physiological and behavioral functions in defined cell populations. Cell type-specific activators of diverse ionic conductances are needed for probing these effects. We combined chemistry and protein engineering to enable the systematic creation of a toolbox of ligand-gated ion channels (LGICs) with orthogonal pharmacologic selectivity and divergent functional properties. The LGICs and their small-molecule effectors were able to activate a range of ionic conductances in genetically specified cell types. LGICs constructed for neuronal perturbation could be used to selectively manipulate neuron activity in mammalian brains in vivo. The diversity of ion channel tools accessible from this approach will be useful for examining the relationship between neuronal activity and animal behavior, as well as for cell biological and physiological applications requiring chemical control of ion conductance.
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MESH Headings
- Animals
- Benzamides/chemistry
- Benzamides/metabolism
- Benzamides/pharmacology
- Brain/cytology
- Brain/physiology
- Bridged Bicyclo Compounds/chemistry
- Bridged Bicyclo Compounds/metabolism
- Bridged Bicyclo Compounds/pharmacology
- Feeding Behavior
- Female
- HEK293 Cells
- Humans
- Ion Channel Gating
- Ligand-Gated Ion Channels/chemistry
- Ligand-Gated Ion Channels/genetics
- Ligand-Gated Ion Channels/metabolism
- Ligands
- Membrane Potentials
- Mice
- Mice, Inbred C57BL
- Mutagenesis
- Neurons/physiology
- Patch-Clamp Techniques
- Protein Binding
- Protein Engineering
- Protein Structure, Tertiary
- Quinuclidines/chemistry
- Quinuclidines/metabolism
- Quinuclidines/pharmacology
- Receptors, Glycine/genetics
- Receptors, Glycine/metabolism
- Receptors, Nicotinic/chemistry
- Receptors, Nicotinic/genetics
- Receptors, Nicotinic/metabolism
- Receptors, Serotonin, 5-HT3/genetics
- Receptors, Serotonin, 5-HT3/metabolism
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/metabolism
- Small Molecule Libraries
- Stereoisomerism
- alpha7 Nicotinic Acetylcholine Receptor
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Affiliation(s)
| | | | | | - Helen H. Su
- Janelia Farm Research Campus, HHMI, 19700 Helix Dr. Ashburn, VA 20147 USA
| | - Loren L. Looger
- Janelia Farm Research Campus, HHMI, 19700 Helix Dr. Ashburn, VA 20147 USA
| | - Scott M. Sternson
- Janelia Farm Research Campus, HHMI, 19700 Helix Dr. Ashburn, VA 20147 USA
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Rivetta A, Kuroda T, Slayman C. Anion currents in yeast K+ transporters (TRK) characterize a structural homologue of ligand-gated ion channels. Pflugers Arch 2011; 462:315-30. [PMID: 21556692 DOI: 10.1007/s00424-011-0959-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 03/13/2011] [Accepted: 03/14/2011] [Indexed: 11/26/2022]
Abstract
Patch clamp studies of the potassium-transport proteins TRK1,2 in Saccharomyces cerevisiae have revealed large chloride efflux currents: at clamp voltages negative to -100 mV, and intracellular chloride concentrations >10 mM (J. Membr. Biol. 198:177, 2004). Stationary-state current-voltage analysis led to an in-series two-barrier model for chloride activation: the lower barrier (α) being 10-13 kcal/mol located ~30% into the membrane from the cytoplasmic surface; and the higher one (β) being 12-16 kcal/mol located at the outer surface. Measurements carried out with lyotrophic anions and osmoprotective solutes have now demonstrated the following new properties: (1) selectivity for highly permeant anions changes with extracellular pH; at pH(o)= 5.5: I(-)≈ Br(-) >Cl(-) >SCN(-) >NO (3)(-) , and at pH(o) 7.5: I(-)≈ Br(-) > SCN(-) > NO(3)(-) >Cl(-). (2) NO(2)(-) acts like "superchoride", possibly enhancing the channel's intrinsic permeability to Cl(-). (3) SCN(-) and NO(3)(-) block chloride permeability. (4) The order of selectivity for several slightly permeant anions (at pH(o)= 5.5 only) is formate>gluconate>acetate>>phosphate(-1). (5) All anion conductances are modulated (choked) by osmoprotective solutes. (6) The data and descriptive two-barrier model evoke a hypothetical structure (Biophys. J. 77:789, 1999) consisting of an intramembrane homotetramer of fungal TRK molecules, arrayed radially around a central cluster of four single helices (TM7) from each monomer. (7) That tetrameric cluster would resemble the hydrophobic core of (pentameric) ligand-gated ion channels, and would suggest voltage-modulated hydrophobic gating to underlie anion permeation.
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Affiliation(s)
- Alberto Rivetta
- Department of Cellular and Molecular Physiology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
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Abstract
GluK2 is a kainate receptor subunit that is alternatively spliced at the C-terminus. Previous studies implicated GluK2 in autism. In particular, the methionine-to-isoleucine replacement at amino acid residue 867 (M867I) that can only occur in the longest isoform of the human GluK2 (hGluK2), as the disease (autism) mutation, is thought to cause gain-of-function. However, the kinetic properties of the wild-type hGluK2 and the functional consequence of this gain-of-function mutation at the molecular level are not well understood. To investigate whether the M867I mutation affects the channel properties of the human GluK2 kainate receptor, we have systematically characterized the rate and the equilibrium constants pertinent to channel opening and channel desensitization for this mutant and the wild-type hGluK2 receptor, along with the wild-type rat GluK2 kainate receptor (rGluK2) as the control. Our results show that the M867I mutation does not affect either the rate or the equilibrium constants of the channel opening but does slow down the channel desensitization rate by ~1.6-fold at saturating glutamate concentrations. It is possible that a consequence of this mutation on the desensitization rate is linked to facilitating the receptor trafficking and membrane expression, given the close proximity of M867 to the forward trafficking motif in the C-terminal sequence. By comparing the kinetic data of the wild-type human and rat GluK2 receptors, we also find that the human GluK2 has a ~3-fold smaller channel-opening rate constant but an identical channel-closing rate constant and thus a channel-opening probability of 0.85 vs 0.96 for rGluK2. Furthermore, the intrinsic equilibrium dissociation constant K(1) for hGluK2, like the EC(50) value, is ~2-fold lower than rGluK2. Our results therefore suggest that the human GluK2 is relatively a slowly activating channel but more sensitive to glutamate, as compared to the rat ortholog, despite the fact that the human and rat forms share 99% sequence homology.
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Affiliation(s)
- Yan Han
- Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Congzhou Wang
- Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Jae Seon Park
- Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
| | - Li Niu
- Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222
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Rufener L, Keiser J, Kaminsky R, Mäser P, Nilsson D. Phylogenomics of ligand-gated ion channels predicts monepantel effect. PLoS Pathog 2010; 6:e1001091. [PMID: 20838602 PMCID: PMC2936538 DOI: 10.1371/journal.ppat.1001091] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Accepted: 08/06/2010] [Indexed: 01/24/2023] Open
Abstract
The recently launched veterinary anthelmintic drench for sheep (Novartis Animal Health Inc., Switzerland) containing the nematocide monepantel represents a new class of anthelmintics: the amino-acetonitrile derivatives (AADs), much needed in view of widespread resistance to the classical drugs. Recently, it was shown that the ACR-23 protein in Caenorhabditis elegans and a homologous protein, MPTL-1 in Haemonchus contortus, are potential targets for AAD action. Both proteins belong to the DEG-3 subfamily of acetylcholine receptors, which are thought to be nematode-specific, and different from those targeted by the imidazothiazoles (e.g. levamisole). Here we provide further evidence that Cel-ACR-23 and Hco-MPTL-1-like subunits are involved in the monepantel-sensitive phenotype. We performed comparative genomics of ligand-gated ion channel genes from several nematodes and subsequently assessed their sensitivity to anthelmintics. The nematode species in the Caenorhabditis genus, equipped with ACR-23/MPTL-1-like receptor subunits, are sensitive to monepantel (EC50<1.25 µM), whereas the related nematodes Pristionchus pacificus and Strongyloides ratti, which lack an ACR-23/MPTL-1 homolog, are insensitive (EC50>43 µM). Genome sequence information has long been used to identify putative targets for therapeutic intervention. We show how comparative genomics can be applied to predict drug sensitivity when molecular targets of a compound are known or suspected. Increased use of anthelmintics has contributed to the emergence of drug-resistant nematodes, causing serious problems for more than one billion sheep worldwide. The last class of compounds indicated for livestock was introduced 28 years ago. Recently, however, Novartis AH developed a new anthelmintic active against drug-resistant nematodes of sheep, the amino-acetonitrile derivative (AAD) monepantel. We have previously indirectly shown that the AADs have a novel mode of action involving acetylcholine receptor subunits: the ACR-23 protein in Caenorhabditis elegans and a homologous protein, MPTL-1 in Haemonchus contortus. To better understand the mode of action of the AADs, we performed comparative genomics of all ligand-gated ion channel genes from a range of organisms, including members from all nematode clades. We confirmed that MPTL-1 belongs to a unique, nematode-specific sub-family of receptor subunits. We also found that some nematode species lack ACR-23/MPTL-1 and predicted them to be monepantel insensitive. We challenged this hypothesis in a panel of drug tests: several species of Caenorhabditis nematodes equipped with ACR-23/MPTL-1-like receptor subunits were found susceptible to monepantel, whereas Pristionchus pacificus, closely related to these worms but lacking an ACR-23/MPTL-1 homolog, was tolerant. The parasitic nematode Strongyloides ratti, which has only a remote homolog of DES-2 and ACR-23/MPTL-1, was also tolerant to monepantel. This confirms our prediction and highlights how comparative genomic data can be used to predict a drug effect.
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Affiliation(s)
- Lucien Rufener
- Novartis Centre de Recherche Santé Animale, St. Aubin, Switzerland
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ronald Kaminsky
- Novartis Centre de Recherche Santé Animale, St. Aubin, Switzerland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Daniel Nilsson
- Institute of Cell Biology, University of Bern, Bern, Switzerland
- * E-mail:
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