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Zhang K, Chen L, Chen J, Huang H, Liu K, Zhang Y, Yang J, Wu S. Mutation V65I in the β1 Subunit of the Nicotinic Acetylcholine Receptor Confers Neonicotinoid and Sulfoxaflor Resistance in Insects. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:5671-5681. [PMID: 38442746 DOI: 10.1021/acs.jafc.3c09456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Neonicotinoids have been widely used to control pests with remarkable effectiveness. Excessive insecticides have led to serious insect resistance. Mutations of the nicotinic acetylcholine receptor (nAChR) are one of the reasons for neonicotinoid resistance conferred in various agricultural pests. Two mutations, V65I and V104I, were found in the nAChR β1 subunit of two neonicotinoid-resistant aphid populations. However, the specific functions of the two mutations remain unclear. In this study, we cloned and identified four nAChR subunits (α1, α2, α8, and β1) of thrips and found them to be highly homologous to the nAChR subunits of other insects. Subsequently, we successfully expressed two subtypes nAChR (α1/α2/α8/β1 and α1/α8/β1) by coinjecting three cofactors for the first time in thrips, and α1/α8/β1 showed abundant current rapidly. Acetylcholine, neonicotinoids, and sulfoxaflor exhibited different activation capacities for the two subtypes of nAChRs. Finally, V65I was found to significantly reduce the binding ability of nAChR to neonicotinoids and sulfoxaflor through electrophysiology and computer simulations. V104I caused a decrease in agonist affinity (pEC50) but an increase in the efficacy (Imax) of nAChR against neonicotinoids and reduced the binding ability of nAChR to sulfoxaflor. This study provides theoretical and technical support for studying the molecular mechanisms of neonicotinoid resistance in pests.
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Affiliation(s)
- Kun Zhang
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572024, China
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Danzhou 571700, China
| | - Longwei Chen
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572024, China
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Danzhou 571700, China
| | - Jianwen Chen
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572024, China
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Danzhou 571700, China
| | - Huixiu Huang
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572024, China
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Danzhou 571700, China
| | - Kaiyang Liu
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572024, China
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Danzhou 571700, China
| | - Yi Zhang
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572024, China
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Danzhou 571700, China
| | - Jingfang Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya 572024, China
| | - Shaoying Wu
- School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572024, China
- School of Tropical Agriculture and Forestry (School of Agricultural and Rural Affairs, School of Rural Revitalization), Hainan University, Danzhou 571700, China
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2
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Kang WK, Florman JT, Araya A, Fox BW, Thackeray A, Schroeder FC, Walhout AJM, Alkema MJ. Vitamin B 12 produced by gut bacteria modulates cholinergic signalling. Nat Cell Biol 2024; 26:72-85. [PMID: 38168768 DOI: 10.1038/s41556-023-01299-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/26/2023] [Indexed: 01/05/2024]
Abstract
A growing body of evidence indicates that gut microbiota influence brain function and behaviour. However, the molecular basis of how gut bacteria modulate host nervous system function is largely unknown. Here we show that vitamin B12-producing bacteria that colonize the intestine can modulate excitatory cholinergic signalling and behaviour in the host Caenorhabditis elegans. Here we demonstrate that vitamin B12 reduces cholinergic signalling in the nervous system through rewiring of the methionine (Met)/S-adenosylmethionine cycle in the intestine. We identify a conserved metabolic crosstalk between the methionine/S-adenosylmethionine cycle and the choline-oxidation pathway. In addition, we show that metabolic rewiring of these pathways by vitamin B12 reduces cholinergic signalling by limiting the availability of free choline required by neurons to synthesize acetylcholine. Our study reveals a gut-brain communication pathway by which enteric bacteria modulate host behaviour and may affect neurological health.
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Affiliation(s)
- Woo Kyu Kang
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Jeremy T Florman
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Antonia Araya
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Bennett W Fox
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Andrea Thackeray
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Albertha J M Walhout
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Mark J Alkema
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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3
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Fricska DI, Mesoy SM, Lummis SCR. The MA Helix Is Important for Receptor Assembly and Function in the α4β2 nACh Receptor. MEMBRANES 2023; 13:891. [PMID: 38132895 PMCID: PMC10744633 DOI: 10.3390/membranes13120891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 11/22/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023]
Abstract
Pentameric ligand-gated ion channels (pLGICs) are expressed throughout the central and peripheral nervous systems of vertebrates and modulate many aspects of human health and disease. Recent structural and computational data indicate that cation-selective pLGICs contain a long helical extension (MA) of one of the transmembrane helices. The MA helix has been shown to affect both the membrane expression of, and ion conductance levels through, these pLGICs. Here we probe the functional effects of 68 mutations in the MA region of the α4β2 nicotinic acetylcholine receptor (nAChR), using a voltage-sensitive membrane dye and radioligand binding to measure receptor function and expression/assembly. We found seven alanine mutations in a stretch of the MA helix that prevent correct receptor folding and/or assembly, as evidenced by the lack of both function and ligand binding. A further two alanine mutations resulted in receptors that were capable of binding ligand but showed no functional response, and we propose that, in these mutants, ligand binding is insufficient to trigger channel opening. The data clarify the effect of the MA helix, and as the effects of some of our mutations in the α4β2 nAChR differ from the effects of equivalent mutations in other cation-selective pLGICs, we suggest that residues in the MA helix may play subtly different roles in different receptors.
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Affiliation(s)
| | | | - Sarah C. R. Lummis
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK; (D.I.F.); (S.M.M.)
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4
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Alexander KD, Ramachandran S, Biswas K, Lambert CM, Russell J, Oliver DB, Armstrong W, Rettler M, Liu S, Doitsidou M, Bénard C, Walker AK, Francis MM. The homeodomain transcriptional regulator DVE-1 directs a program for synapse elimination during circuit remodeling. Nat Commun 2023; 14:7520. [PMID: 37980357 PMCID: PMC10657367 DOI: 10.1038/s41467-023-43281-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 11/02/2023] [Indexed: 11/20/2023] Open
Abstract
The elimination of synapses during circuit remodeling is critical for brain maturation; however, the molecular mechanisms directing synapse elimination and its timing remain elusive. We show that the transcriptional regulator DVE-1, which shares homology with special AT-rich sequence-binding (SATB) family members previously implicated in human neurodevelopmental disorders, directs the elimination of juvenile synaptic inputs onto remodeling C. elegans GABAergic neurons. Juvenile acetylcholine receptor clusters and apposing presynaptic sites are eliminated during the maturation of wild-type GABAergic neurons but persist into adulthood in dve-1 mutants, producing heightened motor connectivity. DVE-1 localization to GABAergic nuclei is required for synapse elimination, consistent with DVE-1 regulation of transcription. Pathway analysis of putative DVE-1 target genes, proteasome inhibitor, and genetic experiments implicate the ubiquitin-proteasome system in synapse elimination. Together, our findings define a previously unappreciated role for a SATB family member in directing synapse elimination during circuit remodeling, likely through transcriptional regulation of protein degradation processes.
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Affiliation(s)
- Kellianne D Alexander
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Shankar Ramachandran
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Kasturi Biswas
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Christopher M Lambert
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Julia Russell
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Devyn B Oliver
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - William Armstrong
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Monika Rettler
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Samuel Liu
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Maria Doitsidou
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland
| | - Claire Bénard
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Biological Sciences, Université du Québec à Montréal, Quebec, Canada
| | - Amy K Walker
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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5
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Huang M, Wang Y, Chow CH, Stepien KP, Indrawinata K, Xu J, Argiropoulos P, Xie X, Sugita K, Tien CW, Lee S, Monnier PP, Rizo J, Gao S, Sugita S. Double mutation of open syntaxin and UNC-18 P334A leads to excitatory-inhibitory imbalance and impairs multiple aspects of C. elegans behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.18.553709. [PMID: 37645974 PMCID: PMC10462135 DOI: 10.1101/2023.08.18.553709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
SNARE and Sec/Munc18 proteins are essential in synaptic vesicle exocytosis. Open form t-SNARE syntaxin and UNC-18 P334A are well-studied exocytosis-enhancing mutants. Here we investigate the interrelationship between the two mutations by generating double mutants in various genetic backgrounds in C. elegans. While each single mutation rescued the motility of CAPS/unc-31 and synaptotagmin/snt-1 mutants significantly, double mutations unexpectedly worsened motility or lost their rescuing effects. Electrophysiological analyses revealed that simultaneous mutations of open syntaxin and gain-of-function P334A UNC-18 induces a strong imbalance of excitatory over inhibitory transmission. In liposome fusion assays performed with mammalian proteins, the enhancement of fusion caused by the two mutations individually was abolished when the two mutations were introduced simultaneously, consistent with what we observed in C. elegans. We conclude that open syntaxin and P334A UNC-18 do not have additive beneficial effects, and this extends to C. elegans' characteristics such as motility, growth, offspring bared, body size, and exocytosis, as well as liposome fusion in vitro. Our results also reveal unexpected differences between the regulation of exocytosis in excitatory versus inhibitory synapses.
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Affiliation(s)
- Mengjia Huang
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Ya Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Chun Hin Chow
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Karolina P. Stepien
- Departments of Biophysics, Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Karen Indrawinata
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Junjie Xu
- Departments of Biophysics, Biochemistry and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Peter Argiropoulos
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Xiaoyu Xie
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Anesthesiology, Dalian Municipal Friendship Hospital, Dalian Medical University, Dalian, Liaoning, China
| | - Kyoko Sugita
- Donald K. Johnson Eye Institute, University Health Network, Ontario, M5T 0S8, Canada; Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Chi-Wei Tien
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Soomin Lee
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
| | - Philippe P. Monnier
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Ontario, M5T 0S8, Canada; Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Josep Rizo
- Department of Anesthesiology, Dalian Municipal Friendship Hospital, Dalian Medical University, Dalian, Liaoning, China
| | - Shangbang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
- Key Laboratory of Vascular Aging of the Ministry of Education, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Shuzo Sugita
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Ontario, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
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6
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Harrington S, Pyche J, Burns AR, Spalholz T, Ryan KT, Baker RJ, Ching J, Rufener L, Lautens M, Kulke D, Vernudachi A, Zamanian M, Deuther-Conrad W, Brust P, Roy PJ. Nemacol is a small molecule inhibitor of C. elegans vesicular acetylcholine transporter with anthelmintic potential. Nat Commun 2023; 14:1816. [PMID: 37002199 PMCID: PMC10066365 DOI: 10.1038/s41467-023-37452-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 03/17/2023] [Indexed: 04/03/2023] Open
Abstract
Nematode parasites of humans and livestock pose a significant burden to human health, economic development, and food security. Anthelmintic drug resistance is widespread among parasites of livestock and many nematode parasites of humans lack effective treatments. Here, we present a nitrophenyl-piperazine scaffold that induces motor defects rapidly in the model nematode Caenorhabditis elegans. We call this scaffold Nemacol and show that it inhibits the vesicular acetylcholine transporter (VAChT), a target recognized by commercial animal and crop health groups as a viable anthelmintic target. We demonstrate that it is possible to create Nemacol analogs that maintain potent in vivo activity whilst lowering their affinity to the mammalian VAChT 10-fold. We also show that Nemacol enhances the ability of the anthelmintic Ivermectin to paralyze C. elegans and the ruminant nematode parasite Haemonchus contortus. Hence, Nemacol represents a promising new anthelmintic scaffold that acts through a validated anthelmintic target.
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Affiliation(s)
- Sean Harrington
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Jacob Pyche
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Andrew R Burns
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Tina Spalholz
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318, Leipzig, Germany
| | - Kaetlyn T Ryan
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Rachel J Baker
- The Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Justin Ching
- The Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Lucien Rufener
- INVENesis Sàrl, Route de Neuchâtel 15A, 2072, St Blaise (NE), Switzerland
| | - Mark Lautens
- The Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Daniel Kulke
- Research Parasiticides, Bayer Animal Health GmbH, Monheim, Germany
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
- Global Innovation, Boehringer Ingelheim Vetmedica GmbH, Binger Str. 173, 55218, Ingelheim am Rhein, Germany
| | | | - Mostafa Zamanian
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Winnie Deuther-Conrad
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318, Leipzig, Germany
| | - Peter Brust
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318, Leipzig, Germany
- The Lübeck Institute of Experimental Dermatology, University Medical Center Schleswig-Holstein, 23562, Lübeck, Germany
| | - Peter J Roy
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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7
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Son S, Choi MK, Lim DS, Shim J, Lee J. A genetic screen for aldicarb resistance of Caenorhabditiselegans dauer larvae uncovers 2 alleles of dach-1, a cytochrome P450 gene. G3 (BETHESDA, MD.) 2022; 12:6747961. [PMID: 36194018 PMCID: PMC9713407 DOI: 10.1093/g3journal/jkac266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 09/26/2022] [Indexed: 12/05/2022]
Abstract
Animals exhibit phenotypic plasticity through the interaction of genes with the environment, and little is known about the genetic factors that change synaptic function at different developmental stages. Here, we investigated the genetic determinants of how animal's sensitivity to drugs that alter synaptic activity is regulated at a specific developmental stage using the free-living nematode Caenorhabditis elegans. C. elegans enters the stress-resistant dauer larval stage under harsh conditions. Although dauer is known to have reduced permeability and increased resistance to most known exogenous chemicals, we discovered that dauer is hypersensitive to a cholinesterase inhibitor, aldicarb. To investigate genes regulating dauer-specific acetylcholine transduction, we first screened for aldicarb-resistant mutations in dauer and then performed a secondary screen to rule out aldicarb-resistant mutations that also affect adults. We isolated 2 different mutations of a single gene called cyp-34A4 or dach-1 encoding a cytochrome P450. In the nondauer stages, dach-1 is mainly expressed in the intestine, but its expression is robustly increased in the epidermis of dauers. By tissue-specific rescue experiments, we found that dach-1 modulates aldicarb sensitivity in a cell nonautonomous manner. In addition, dach-1 plays pleiotropic functions in dauers by regulating quiescence and surviving heat shock and hyperosmolar stress. Our study reveals novel functions of the cytochrome P450 in synaptic and physiological changes during the developmental plasticity.
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Affiliation(s)
| | | | - Daisy S Lim
- Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea
| | - Jaegal Shim
- Research Institute, National Cancer Center, Goyang 10408, Korea
| | - Junho Lee
- Corresponding author: Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea.
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8
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Harrington S, Knox JJ, Burns AR, Choo KL, Au A, Kitner M, Haeberli C, Pyche J, D'Amata C, Kim YH, Volpatti JR, Guiliani M, Snider J, Wong V, Palmeira BM, Redman EM, Vaidya AS, Gilleard JS, Stagljar I, Cutler SR, Kulke D, Dowling JJ, Yip CM, Keiser J, Zasada I, Lautens M, Roy PJ. Egg-laying and locomotory screens with C. elegans yield a nematode-selective small molecule stimulator of neurotransmitter release. Commun Biol 2022; 5:865. [PMID: 36002479 PMCID: PMC9402605 DOI: 10.1038/s42003-022-03819-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/08/2022] [Indexed: 12/05/2022] Open
Abstract
Nematode parasites of humans, livestock and crops dramatically impact human health and welfare. Alarmingly, parasitic nematodes of animals have rapidly evolved resistance to anthelmintic drugs, and traditional nematicides that protect crops are facing increasing restrictions because of poor phylogenetic selectivity. Here, we exploit multiple motor outputs of the model nematode C. elegans towards nematicide discovery. This work yielded multiple compounds that selectively kill and/or immobilize diverse nematode parasites. We focus on one compound that induces violent convulsions and paralysis that we call nementin. We find that nementin stimulates neuronal dense core vesicle release, which in turn enhances cholinergic signaling. Consequently, nementin synergistically enhances the potency of widely-used non-selective acetylcholinesterase (AChE) inhibitors, but in a nematode-selective manner. Nementin therefore has the potential to reduce the environmental impact of toxic AChE inhibitors that are used to control nematode infections and infestations. A C. elegans-based screening approach identifies nementin as a nematode-selective nematicide that can be used synergistically with acetylcholinesterase inhibitors
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Affiliation(s)
- Sean Harrington
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | - Jessica J Knox
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Andrew R Burns
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Ken-Loon Choo
- The Department of Chemistry, University of Toronto, Toronto, Canada
| | - Aaron Au
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Megan Kitner
- USDA-ARS Horticultural Crops Research Laboratory, Corvallis, OR, USA
| | - Cecile Haeberli
- Department of Medical Parasitology and Infection Biology, Swiss-Tropical and Public Health Institute, (Swiss TPH), Basel, Switzerland.,Faculty of Science, University of Basel, Basel, Switzerland
| | - Jacob Pyche
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada.,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | - Cassandra D'Amata
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | - Yong-Hyun Kim
- The Department of Chemistry, University of Toronto, Toronto, Canada
| | - Jonathan R Volpatti
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Canada.,Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Maximillano Guiliani
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Jamie Snider
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | - Victoria Wong
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | - Bruna M Palmeira
- Department of Comparative Biology and Experimental Medicine, Host-Parasite Interactions (HPI) Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Elizabeth M Redman
- Department of Comparative Biology and Experimental Medicine, Host-Parasite Interactions (HPI) Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Aditya S Vaidya
- Institute for Integrative Genome Biology, University of California, Riverside, CA, USA.,Department of Botany and Plant Sciences, University of California, Riverside, CA, USA
| | - John S Gilleard
- Department of Comparative Biology and Experimental Medicine, Host-Parasite Interactions (HPI) Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Igor Stagljar
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada.,Mediterranean Institute for Life Sciences, Split, Croatia.,School of Medicine, University of Split, Split, Croatia
| | - Sean R Cutler
- Institute for Integrative Genome Biology, University of California, Riverside, CA, USA.,Department of Botany and Plant Sciences, University of California, Riverside, CA, USA
| | - Daniel Kulke
- Research Parasiticides, Bayer Animal Health GmbH, Monheim, Germany.,Department of Biomedical Sciences, Iowa State University, Ames, IA, USA.,Global Innovation, Boehringer Ingelheim Vetmedica GmbH, Ingelheim am Rhein, Germany
| | - James J Dowling
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Canada.,Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada
| | - Christopher M Yip
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss-Tropical and Public Health Institute, (Swiss TPH), Basel, Switzerland.,Faculty of Science, University of Basel, Basel, Switzerland
| | - Inga Zasada
- USDA-ARS Horticultural Crops Research Laboratory, Corvallis, OR, USA
| | - Mark Lautens
- The Department of Chemistry, University of Toronto, Toronto, Canada
| | - Peter J Roy
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada. .,The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, Canada.
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9
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Speculation on How RIC-3 and Other Chaperones Facilitate α7 Nicotinic Receptor Folding and Assembly. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27144527. [PMID: 35889400 PMCID: PMC9318448 DOI: 10.3390/molecules27144527] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/07/2022] [Accepted: 07/09/2022] [Indexed: 11/17/2022]
Abstract
The process of how multimeric transmembrane proteins fold and assemble in the endoplasmic reticulum is not well understood. The alpha7 nicotinic receptor (α7 nAChR) is a good model for multimeric protein assembly since it has at least two independent and specialized chaperones: Resistance to Inhibitors of Cholinesterase 3 (RIC-3) and Nicotinic Acetylcholine Receptor Regulator (NACHO). Recent cryo-EM and NMR data revealed structural features of α7 nAChRs. A ser-ala-pro (SAP) motif precedes a structurally important but unique "latch" helix in α7 nAChRs. A sampling of α7 sequences suggests the SAP motif is conserved from C. elegans to humans, but the latch sequence is only conserved in vertebrates. How RIC-3 and NACHO facilitate receptor subunits folding into their final pentameric configuration is not known. The artificial intelligence program AlphaFold2 recently predicted structures for NACHO and RIC-3. NACHO is highly conserved in sequence and structure across species, but RIC-3 is not. This review ponders how different intrinsically disordered RIC-3 isoforms from C. elegans to humans interact with α7 nAChR subunits despite having little sequence homology across RIC-3 species. Two models from the literature about how RIC-3 assists α7 nAChR assembly are evaluated considering recent structural information about the receptor and its chaperones.
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10
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Invited review: Unearthing the mechanisms of age-related neurodegenerative disease using Caenorhabditis elegans. Comp Biochem Physiol A Mol Integr Physiol 2022; 267:111166. [PMID: 35176489 DOI: 10.1016/j.cbpa.2022.111166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 12/11/2022]
Abstract
As human life expectancy increases, neurodegenerative diseases present a growing public health threat, for which there are currently few effective treatments. There is an urgent need to understand the molecular and genetic underpinnings of these disorders so new therapeutic targets can be identified. Here we present the argument that the simple nematode worm Caenorhabditis elegans is a powerful tool to rapidly study neurodegenerative disorders due to their short lifespan and vast array of genetic tools, which can be combined with characterization of conserved neuronal processes and behavior orthologous to those disrupted in human disease. We review how pre-existing C. elegans models provide insight into human neurological disease as well as an overview of current tools available to study neurodegenerative diseases in the worm, with an emphasis on genetics and behavior. We also discuss open questions that C. elegans may be particularly well suited for in future studies and how worms will be a valuable preclinical model to better understand these devastating neurological disorders.
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11
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Goncalves J, Wan Y, Garcia LR. Stearoyl-CoA desaturases sustain cholinergic excitation and copulatory robustness in metabolically aging C. elegansmales. iScience 2022; 25:104082. [PMID: 35372802 PMCID: PMC8968053 DOI: 10.1016/j.isci.2022.104082] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 02/02/2022] [Accepted: 03/14/2022] [Indexed: 01/22/2023] Open
Abstract
Regulated metabolism is required for behaviors as adults age. To understand how lipid usage affects motor coordination, we studied male Caenorhabditis elegans copulation as a model of energy-intensive behavior. Copulation performance drops after 48 h of adulthood. We found that 12–24 h before behavioral decline, males prioritize exploring and copulation behavior over feeding, suggesting that catabolizing stored metabolites, such as lipids, occurs during this period. Because fat-6/7-encoded stearoyl-CoA desaturases are essential for converting the ingested fatty acids to lipid storage, we examined the copulation behavior and neural calcium transients of fat-6(lf); fat-7(lf) mutants. In wild-type males, intestinal and epithelial fat-6/7 expression increases during the first 48 h of adulthood. The fat-6(lf); fat-7(lf) behavioral and metabolic defects indicate that in aging wild-type males, the increased expression of stearoyl-CoA desaturases in the epidermis may indirectly modulate the levels of EAG-family K+ channels in the reproductive cholinergic neurons and muscles. Tissue distribution of fat-6-encoded stearoyl-CoA desaturase changes in adulthood Markov modeling shows reduced feeding linked with more exploring in day 2 males fat-6(lf); fat-7(lf) disrupted behavior can be rescued by epidermal FAT-6 fat-6(lf); fat-7(lf) alters neural and muscular ERG and EAG K+ channel expression
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Affiliation(s)
- Jimmy Goncalves
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Yufeng Wan
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - L René Garcia
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
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12
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Leyva-Díaz E, Hobert O. Robust regulatory architecture of pan-neuronal gene expression. Curr Biol 2022; 32:1715-1727.e8. [PMID: 35259341 PMCID: PMC9050922 DOI: 10.1016/j.cub.2022.02.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/04/2022] [Accepted: 02/10/2022] [Indexed: 12/17/2022]
Abstract
Pan-neuronally expressed genes, such as genes involved in the synaptic vesicle cycle or in neuropeptide maturation, are critical for proper function of all neurons, but the transcriptional control mechanisms that direct such genes to all neurons of a nervous system remain poorly understood. We show here that six members of the CUT family of homeobox genes control pan-neuronal identity specification in Caenorhabditis elegans. Single CUT mutants show barely any effects on pan-neuronal gene expression or global nervous system function, but such effects become apparent and progressively worsen upon removal of additional CUT family members, indicating a critical role of gene dosage. Overexpression of each individual CUT gene rescued the phenotype of compound mutants, corroborating that gene dosage, rather than the activity of specific members of the gene family, is critical for CUT gene family function. Genome-wide binding profiles, as well as mutation of CUT homeodomain binding sites by CRISPR/Cas9 genome engineering show that CUT genes directly control the expression of pan-neuronal features. Moreover, CUT genes act in conjunction with neuron-type-specific transcription factors to control pan-neuronal gene expression. Our study, therefore, provides a previously missing key insight into how neuronal gene expression programs are specified and reveals a highly buffered and robust mechanism that controls the most critical functional features of all neuronal cell types.
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13
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Sadananda G, Velmurugan JD, Subramaniam JR. DMSO Delays Alzheimer Disease Causing Aβ-induced Paralysis in C. elegans Through Modulation of Glutamate/Acetylcholine Neurotransmission. Ann Neurosci 2021; 28:55-64. [PMID: 34733055 PMCID: PMC8558977 DOI: 10.1177/09727531211046369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 08/03/2021] [Indexed: 11/17/2022] Open
Abstract
Background: Alzheimer’s disease (AD), a prevalent neurodegenerative disease with
progressive dementia and neurotransmission (NT)-dysfunction-related
complications in older adults, is known to be caused by abnormal Amyloid-β
(Aβ) peptide and associated amyloid plaques in the brain. Drugs to cure AD
are not in sight. Two major excitatory neurotransmitters, glutamate (Glu)
and acetylcholine (ACh), and their signaling systems are implicated in
AD. Objective: To determine the effect of various NT-altering compounds including fenobam,
quisqualic acid, and dimethyl sulfoxide (DMSO) in the protection against Aβ
toxicity. Further, to identify the potential mechanism through which the
protection happens. Methods: The well-known C. elegans AD model, CL4176, in which human
Aβ expression is turned on upon a temperature shift to 25 °C that leads to
paralysis, was screened for protection/delay in paralysis because of Αβ
toxicity. While screening the compounds, dimethyl sulfoxide (DMSO), a
universal solvent used to solubilize compounds, was identified to provide
protection. Aldicarb and levamisole assays were performed to identify the
contribution of ACh neurotransmission in Αβ toxicity protection by DMSO. Results: One percent and two percent DMSO delayed paralysis by 48% and 90%,
respectively. DMSO was dominant over one of the Glu-NT pathway-related
compounds, Fenobam-Group I mGluR antagonist. But DMSO provided only 30% to
50% protection against Quisqualic acid, the Glu-agonist. DMSO (2%) delayed
ACh-NT, both presynaptic acetylcholine esterase inhibitor (AchEi)-aldicarb
and postsynaptic-iAChR-agonst-levamisole induced paralysis, by ∼70% in
CL4176. DMSO seems to be altering Ca2+ ion permeability essential
for NT as EthyleneDiamine Tetra-Acetic acid (EDTA) and DMSO provided similar
aldicarb resistance either combined or alone in wildtype worms. But
postsynaptic Ca2+ depletion by EDTA could reverse DMSO-induced
levamisole hypersensitivity. Surprisingly, the absence of FOrkhead boXO
(FOXO) transcription factor homolog, daf-16
(loss-of-function mutant), a critical transcription factor in the reduced
IIS-mediated longevity in C. elegans, abolished
DMSO-mediated AldR. Conclusion: DMSO and Fenobam protect against Aβ toxicity through modulation of NT.
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Affiliation(s)
- Girish Sadananda
- Center for Preclinical and Translational Medicine Research, Central Research Facility, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Janaki Devi Velmurugan
- Center for Preclinical and Translational Medicine Research, Central Research Facility, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Jamuna R Subramaniam
- Center for Preclinical and Translational Medicine Research, Central Research Facility, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
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14
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Sauvola CW, Littleton JT. SNARE Regulatory Proteins in Synaptic Vesicle Fusion and Recycling. Front Mol Neurosci 2021; 14:733138. [PMID: 34421538 PMCID: PMC8377282 DOI: 10.3389/fnmol.2021.733138] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/20/2021] [Indexed: 01/01/2023] Open
Abstract
Membrane fusion is a universal feature of eukaryotic protein trafficking and is mediated by the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) family. SNARE proteins embedded in opposing membranes spontaneously assemble to drive membrane fusion and cargo exchange in vitro. Evolution has generated a diverse complement of SNARE regulatory proteins (SRPs) that ensure membrane fusion occurs at the right time and place in vivo. While a core set of SNAREs and SRPs are common to all eukaryotic cells, a specialized set of SRPs within neurons confer additional regulation to synaptic vesicle (SV) fusion. Neuronal communication is characterized by precise spatial and temporal control of SNARE dynamics within presynaptic subdomains specialized for neurotransmitter release. Action potential-elicited Ca2+ influx at these release sites triggers zippering of SNAREs embedded in the SV and plasma membrane to drive bilayer fusion and release of neurotransmitters that activate downstream targets. Here we discuss current models for how SRPs regulate SNARE dynamics and presynaptic output, emphasizing invertebrate genetic findings that advanced our understanding of SRP regulation of SV cycling.
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Affiliation(s)
- Chad W Sauvola
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - J Troy Littleton
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States
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15
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Yu W, Long H, Gao J, Wang Y, Tu Y, Sun L, Chen N. Study on Caenorhabditis Elegans as a Combined Model of Microdosimetry and Biology. Dose Response 2021; 19:1559325821990125. [PMID: 33628153 PMCID: PMC7883169 DOI: 10.1177/1559325821990125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/05/2021] [Accepted: 01/05/2021] [Indexed: 11/16/2022] Open
Abstract
Microdosimetry is a tool for the investigation of microscopic energy deposition of ionizing radiation. This work used Caenorhabditis elegans as a model to estimate the microdosimetric deposition level at the 60Co gamma radiation. Monte Carlo software PHITS was employed to establish irradiated nematodes model. The dose deposition of the entire body and gonad irradiated to 100 Gy was calculated. The injury levels of radiation were evaluated by the detection of biological indicators. The result of microdosimetric experiment suggested that the dose of whole body of nematodes was estimated to be 99.9 ± 57.8 Gy, ranging from 19.6 to 332.2 Gy. The dose of gonad was predicted to be 129.4 ± 558.8 Gy (9.5-6597 Gy). The result of biological experiment suggested that there were little changes in the length of nematodes after irradiation. However, times of head thrash per minute and the spawning yield in 3 consecutive days decreased 27.1% and 94.7%, respectively. Nematodes in the irradiated group displayed heterogeneity. Through contour analysis, trends of behavior kinematics and reproductive capacity of irradiated nematodes proved to be consistent with the dose distribution levels estimated by microdosimetric model. Finally, C. elegans presented a suitable combined model of microdosimetry and biology for studying radiation.
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Affiliation(s)
- Wentao Yu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Huiqiang Long
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Jin Gao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Yidi Wang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Yu Tu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Liang Sun
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
| | - Na Chen
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, China
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16
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Luth ES, Hodul M, Rennich BJ, Riccio C, Hofer J, Markoja K, Juo P. VER/VEGF receptors regulate AMPA receptor surface levels and glutamatergic behavior. PLoS Genet 2021; 17:e1009375. [PMID: 33561120 PMCID: PMC7899335 DOI: 10.1371/journal.pgen.1009375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 02/22/2021] [Accepted: 01/22/2021] [Indexed: 01/09/2023] Open
Abstract
Several intracellular trafficking pathways contribute to the regulation of AMPA receptor (AMPAR) levels at synapses and the control of synaptic strength. While much has been learned about these intracellular trafficking pathways, a major challenge is to understand how extracellular factors, such as growth factors, neuropeptides and hormones, impinge on specific AMPAR trafficking pathways to alter synaptic function and behavior. Here, we identify the secreted ligand PVF-1 and its cognate VEGF receptor homologs, VER-1 and VER-4, as regulators of glutamate signaling in C. elegans. Loss of function mutations in ver-1, ver-4, or pvf-1, result in decreased cell surface levels of the AMPAR GLR-1 and defects in glutamatergic behavior. Rescue experiments indicate that PVF-1 is expressed and released from muscle, whereas the VERs function in GLR-1-expressing neurons to regulate surface levels of GLR-1 and glutamatergic behavior. Additionally, ver-4 is unable to rescue glutamatergic behavior in the absence of pvf-1, suggesting that VER function requires endogenous PVF-1. Inducible expression of a pvf-1 rescuing transgene suggests that PVF-1 can function in the mature nervous system to regulate GLR-1 signaling. Genetic double mutant analysis suggests that the VERs act together with the VPS-35/retromer recycling complex to promote cell surface levels of GLR-1. Our data support a genetic model whereby PVF-1/VER signaling acts with retromer to promote recycling and cell surface levels of GLR-1 to control behavior. Sensation, behavior, and cognition all depend on the proper function of neuronal connections called synapses. Synapses that use the neurotransmitter glutamate to signal between nerve cells are the most abundant type in our brain. Presynaptic neurons release glutamate, which activates glutamate receptors on postsynaptic neurons. Dysfunction of glutamate synapses leads to several neurological disorders, and changing their strength–in part by altering glutamate receptors numbers on the surface of the postsynaptic cell—provides the cellular basis of learning and memory. Much remains to be learned about how factors released from other cell types affects synaptic communication. We took advantage of light-activated molecular switches engineered into specific sensory neurons of C. elegans worms to trigger a behavioral reflex that depends on glutamate synapses. Using this behavior, we identified proteins called VER-1 and VER-4 as important for glutamate synapse function. We found that worms missing these VER proteins or their activator PVF-1 have reduced levels of glutamate receptors at the postsynaptic surface and defects in glutamate-dependent behaviors. Our results suggest that inter-tissue cross-talk between muscle PVF-1 and neuronal VERs is important for controlling the number of glutamate receptors at the cell surface, robust neuronal communication and behavioral responses.
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Affiliation(s)
- Eric S. Luth
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Department of Biology, Simmons University, Boston, Massachusetts, United States of America
| | - Molly Hodul
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Bethany J. Rennich
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Carmino Riccio
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Julia Hofer
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Kaitlin Markoja
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Peter Juo
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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17
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Park L, Luth ES, Jones K, Hofer J, Nguyen I, Watters KE, Juo P. The Snail transcription factor CES-1 regulates glutamatergic behavior in C. elegans. PLoS One 2021; 16:e0245587. [PMID: 33529210 PMCID: PMC7853468 DOI: 10.1371/journal.pone.0245587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/04/2021] [Indexed: 11/18/2022] Open
Abstract
Regulation of AMPA-type glutamate receptor (AMPAR) expression and function alters synaptic strength and is a major mechanism underlying synaptic plasticity. Although transcription is required for some forms of synaptic plasticity, the transcription factors that regulate AMPA receptor expression and signaling are incompletely understood. Here, we identify the Snail family transcription factor ces-1 in an RNAi screen for conserved transcription factors that regulate glutamatergic behavior in C. elegans. ces-1 was originally discovered as a selective cell death regulator of neuro-secretory motor neuron (NSM) and I2 interneuron sister cells in C. elegans, and has almost exclusively been studied in the NSM cell lineage. We found that ces-1 loss-of-function mutants have defects in two glutamatergic behaviors dependent on the C. elegans AMPA receptor GLR-1, the mechanosensory nose-touch response and spontaneous locomotion reversals. In contrast, ces-1 gain-of-function mutants exhibit increased spontaneous reversals, and these are dependent on glr-1 consistent with these genes acting in the same pathway. ces-1 mutants have wild type cholinergic neuromuscular junction function, suggesting that they do not have a general defect in synaptic transmission or muscle function. The effect of ces-1 mutation on glutamatergic behaviors is not due to ectopic cell death of ASH sensory neurons or GLR-1-expressing neurons that mediate one or both of these behaviors, nor due to an indirect effect on NSM sister cell deaths. Rescue experiments suggest that ces-1 may act, in part, in GLR-1-expressing neurons to regulate glutamatergic behaviors. Interestingly, ces-1 mutants suppress the increased reversal frequencies stimulated by a constitutively-active form of GLR-1. However, expression of glr-1 mRNA or GFP-tagged GLR-1 was not decreased in ces-1 mutants suggesting that ces-1 likely promotes GLR-1 function. This study identifies a novel role for ces-1 in regulating glutamatergic behavior that appears to be independent of its canonical role in regulating cell death in the NSM cell lineage.
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Affiliation(s)
- Lidia Park
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Graduate Program in Cell, Developmental and Molecular Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Eric S. Luth
- Department of Biology, Simmons University, Boston, Massachusetts, United States of America
| | - Kelsey Jones
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Julia Hofer
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Irene Nguyen
- Department of Biology, Simmons University, Boston, Massachusetts, United States of America
| | - Katherine E. Watters
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Peter Juo
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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18
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Sadananda G, Subramaniam JR. Absence of metabotropic glutamate receptor homolog(s) accelerates acetylcholine neurotransmission in Caenorhabditis elegans. Neurosci Lett 2021; 746:135666. [PMID: 33493646 DOI: 10.1016/j.neulet.2021.135666] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 11/30/2022]
Abstract
Glutamate (Glu) and Acetylcholine (ACh), are excitatory neurotransmitters, acting through ionotropic (iR) and metabotropic receptors (mR). Importantly, both neurotransmitters and their signalling are impaired in the prevalent neurodegenerative disease-Alzheimer disease (AD). Glu and its signalling cascade's influence on ACh-neurotransmission (NT) are sparsely understood. The mGluRs coupled to G-protein signalling acting through PI3K cascade (GrpI) or inhibition of adenylate cyclase-cAMP cascade (GrpII and GrpIII) brings about long-lasting structural/functional changes. These complexities are challenging to decipher. Here, we report that human/mouse mGluRs when compared with their Caenorhabditis elegans homologs, MGL-1-3 showed overall of homology of ∼31-39 %. Phylogeneitc analysis revealed homology of MGL-2 to GrpI, MGL-3 with Grp1 &II and GRM6 of GrpIII and MGL-1, a low homology that falls between GrpI & GrpII. Then, alteration of ACh-NT in C. elegans loss-of-function mutants of mgl-1, mgl-2, mgl-3, PI3K (age-1) and iGluR (NMDA)(nmr-1) was estimated by well-established acute aldicarb (Ald), that increases ACh at synapse, and levamisole (Lev) (postsynaptic activation of levamisole sensitive iAChR) induced time-dependent paralysis assays. Surprisingly, all of them were hypersensitive to Ald and Lev compared to wildtype (in percentage), namely, mgl-1 -17, 54; mgl-2 - 7.2, 24; mgl-3 -52, 64; age-1 - 27, 32; nmr-1- 24, 48; respectively. Of the three, mgl-3 contributes to maximal overall acceleration of ACh-NT. Adenylate cyclase, acy-1 gain-of-function mutant showed less hypersensitivity, Ald - 7% and Lev- 25 %. Together, Glu receptors and signalling cascades are altering ACh-NT permanently, thus establishing the interplay between them thereby provide potential drug targets to be considered for AD.
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Affiliation(s)
- Girish Sadananda
- Center for Preclinical and Translational Medicine Research, Central Research Facility, Sri Ramachandra Institute of Higher Education and Research, Chennai, 600116, India
| | - Jamuna R Subramaniam
- Center for Preclinical and Translational Medicine Research, Central Research Facility, Sri Ramachandra Institute of Higher Education and Research, Chennai, 600116, India.
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19
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Treinin M, Jin Y. Cholinergic transmission in C. elegans: Functions, diversity, and maturation of ACh-activated ion channels. J Neurochem 2020; 158:1274-1291. [PMID: 32869293 DOI: 10.1111/jnc.15164] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/13/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023]
Abstract
Acetylcholine is an abundant neurotransmitter in all animals. Effects of acetylcholine are excitatory, inhibitory, or modulatory depending on the receptor and cell type. Research using the nematode C. elegans has made ground-breaking contributions to the mechanistic understanding of cholinergic transmission. Powerful genetic screens for behavioral mutants or for responses to pharmacological reagents identified the core cellular machinery for synaptic transmission. Pharmacological reagents that perturb acetylcholine-mediated processes led to the discovery and also uncovered the composition and regulators of acetylcholine-activated channels and receptors. From a combination of electrophysiological and molecular cellular studies, we have gained a profound understanding of cholinergic signaling at the levels of synapses, neural circuits, and animal behaviors. This review will begin with a historical overview, then cover in-depth current knowledge on acetylcholine-activated ionotropic receptors, mechanisms regulating their functional expression and their functions in regulating locomotion.
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Affiliation(s)
- Millet Treinin
- Department of Medical Neurobiology, Hadassah Medical school - Hebrew University, Jerusalem, Israel
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
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20
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Endogenous neurotoxin-like protein Ly6H inhibits alpha7 nicotinic acetylcholine receptor currents at the plasma membrane. Sci Rep 2020; 10:11996. [PMID: 32686737 PMCID: PMC7371702 DOI: 10.1038/s41598-020-68947-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 07/03/2020] [Indexed: 11/08/2022] Open
Abstract
α7 nicotinic acetylcholine receptors (nAChRs) are widely expressed in the central nervous system and regarded as potential therapeutic targets for neurodegenerative conditions, such as Alzheimer's disease and schizophrenia. Yet, despite the assumed pathophysiological importance of the α7 nAChR, molecular physiological characterization remains poorly advanced because α7 nAChR cannot be properly folded and sorted to the plasma membranes in most mammalian cell lines, thus preventing the analyses in heterologous expression system. Recently, ER-resident membrane protein NACHO was discovered as a strong chaperone for the functional expression of α7 nAChR in non-permissive cells. Ly6H, a brain-enriched GPI-anchored neurotoxin-like protein, was reported as a novel modulator regulating intracellular trafficking of α7 nAChR. In this study, we established cell lines that stably and robustly express surface α7 nAChR by introducing α7 nAChR, Ric-3, and NACHO cDNA into HEK293 cells (Triple α7 nAChR/RIC-3/NACHO cells; TARO cells), and re-evaluated the function of Ly6H. We report here that Ly6H binds with α7 nAChRs on the cell membrane and modulates the channel activity without affecting intracellular trafficking of α7 nAChR.
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Téllez-Arreola JL, Silva M, Martínez-Torres A. MCTP-1 modulates neurotransmitter release in C. elegans. Mol Cell Neurosci 2020; 107:103528. [PMID: 32650044 DOI: 10.1016/j.mcn.2020.103528] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 06/17/2020] [Accepted: 06/23/2020] [Indexed: 11/30/2022] Open
Abstract
Multiple C2 and Transmembrane Domain Proteins (MCTPs) are putative calcium sensors. Proteins that contain C2 domains play essential roles in membrane trafficking and exocytosis; however, MCTPs functions in neurotransmitter release are not known. Here we report that in C. elegans mctp-1 is under the control of two promoters - one active in the nervous system and the second in the spermatheca. We generated and characterized a loss of function amt1 mutant and compared it to a previously published loss of function mutant (av112). Loss of mctp-1 function causes defects in egg-laying, crawling velocity, and thrashing rates. Both amt1 and av112 mutants are hyposensitive to the acetylcholinesterase blocker aldicarb, suggesting that MCTP-1 may play a role in synaptic vesicle release.
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Affiliation(s)
- José Luis Téllez-Arreola
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, C.P. 76215 Juriquilla, Querétaro, México; School of Biological Sciences, University of Utah, Salt Lake City, United States
| | - Malan Silva
- School of Biological Sciences, University of Utah, Salt Lake City, United States
| | - Ataúlfo Martínez-Torres
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, C.P. 76215 Juriquilla, Querétaro, México.
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Seven AB, Hilger D, Papasergi-Scott MM, Zhang L, Qu Q, Kobilka BK, Tall GG, Skiniotis G. Structures of Gα Proteins in Complex with Their Chaperone Reveal Quality Control Mechanisms. Cell Rep 2020; 30:3699-3709.e6. [PMID: 32126208 PMCID: PMC7192526 DOI: 10.1016/j.celrep.2020.02.086] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/31/2020] [Accepted: 02/24/2020] [Indexed: 01/14/2023] Open
Abstract
Many chaperones promote nascent polypeptide folding followed by substrate release through ATP-dependent conformational changes. Here we show cryoEM structures of Gα subunit folding intermediates in complex with full-length Ric-8A, a unique chaperone-client system in which substrate release is facilitated by guanine nucleotide binding to the client G protein. The structures of Ric-8A-Gαi and Ric-8A-Gαq complexes reveal that the chaperone employs its extended C-terminal region to cradle the Ras-like domain of Gα, positioning the Ras core in contact with the Ric-8A core while engaging its switch2 nucleotide binding region. The C-terminal α5 helix of Gα is held away from the Ras-like domain through Ric-8A core domain interactions, which critically depend on recognition of the Gα C terminus by the chaperone. The structures, complemented with biochemical and cellular chaperoning data, support a folding quality control mechanism that ensures proper formation of the C-terminal α5 helix before allowing GTP-gated release of Gα from Ric-8A.
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Affiliation(s)
- Alpay Burak Seven
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Daniel Hilger
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Makaía M Papasergi-Scott
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Li Zhang
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Qianhui Qu
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Georgios Skiniotis
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Sensory cilia as the Achilles heel of nematodes when attacked by carnivorous mushrooms. Proc Natl Acad Sci U S A 2020; 117:6014-6022. [PMID: 32123065 DOI: 10.1073/pnas.1918473117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Fungal predatory behavior on nematodes has evolved independently in all major fungal lineages. The basidiomycete oyster mushroom Pleurotus ostreatus is a carnivorous fungus that preys on nematodes to supplement its nitrogen intake under nutrient-limiting conditions. Its hyphae can paralyze nematodes within a few minutes of contact, but the mechanism had remained unclear. We demonstrate that the predator-prey relationship is highly conserved between multiple Pleurotus species and a diversity of nematodes. To further investigate the cellular and molecular mechanisms underlying rapid nematode paralysis, we conducted genetic screens in Caenorhabditis elegans and isolated mutants that became resistant to P. ostreatus We found that paralysis-resistant mutants all harbored loss-of-function mutations in genes required for ciliogenesis, demonstrating that the fungus induced paralysis via the cilia of nematode sensory neurons. Furthermore, we observed that P. ostreatus caused excess calcium influx and hypercontraction of the head and pharyngeal muscle cells, ultimately resulting in rapid necrosis of the entire nervous system and muscle cells throughout the entire organism. This cilia-dependent predatory mechanism is evolutionarily conserved in Pristionchus pacificus, a nematode species estimated to have diverged from C. elegans 280 to 430 million y ago. Thus, P. ostreatus exploits a nematode-killing mechanism that is distinct from widely used anthelmintic drugs such as ivermectin, levamisole, and aldicarb, representing a potential route for targeting parasitic nematodes in plants, animals, and humans.
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Small ST, Labbé F, Coulibaly YI, Nutman TB, King CL, Serre D, Zimmerman PA. Human Migration and the Spread of the Nematode Parasite Wuchereria bancrofti. Mol Biol Evol 2019; 36:1931-1941. [PMID: 31077328 PMCID: PMC6735882 DOI: 10.1093/molbev/msz116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The human disease lymphatic filariasis causes the debilitating effects of elephantiasis and hydrocele. Lymphatic filariasis currently affects the lives of 90 million people in 52 countries. There are three nematodes that cause lymphatic filariasis, Brugia malayi, Brugia timori, and Wuchereria bancrofti, but 90% of all cases of lymphatic filariasis are caused solely by W. bancrofti (Wb). Here we use population genomics to reconstruct the probable route and timing of migration of Wb strains that currently infect Africa, Haiti, and Papua New Guinea (PNG). We used selective whole genome amplification to sequence 42 whole genomes of single Wb worms from populations in Haiti, Mali, Kenya, and PNG. Our results are consistent with a hypothesis of an Island Southeast Asia or East Asian origin of Wb. Our demographic models support divergence times that correlate with the migration of human populations. We hypothesize that PNG was infected at two separate times, first by the Melanesians and later by the migrating Austronesians. The migrating Austronesians also likely introduced Wb to Madagascar where later migrations spread it to continental Africa. From Africa, Wb spread to the New World during the transatlantic slave trade. Genome scans identified 17 genes that were highly differentiated among Wb populations. Among these are genes associated with human immune suppression, insecticide sensitivity, and proposed drug targets. Identifying the distribution of genetic diversity in Wb populations and selection forces acting on the genome will build a foundation to test future hypotheses and help predict response to current eradication efforts.
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Affiliation(s)
- Scott T Small
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN
| | - Frédéric Labbé
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN
| | - Yaya I Coulibaly
- Head Filariasis Unit, NIAID-Mali ICER, University of Bamako, Bamako, Mali
| | | | - Christopher L King
- Global Health and Disease, Case Western Reserve University, Cleveland, OH
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD
| | - Peter A Zimmerman
- Global Health and Disease, Case Western Reserve University, Cleveland, OH
- Department of Biology, Case Western Reserve University, Cleveland, OH
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Govindarajan D, Chatterjee C, Shakambari G, Varalakshmi P, Jayakumar K, Balasubramaniem A. Oxidative stress response, epigenetic and behavioral alterations in Caenorhabditis elegans exposed to organophosphorus pesticide quinalphos. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.01.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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26
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Spensley M, Del Borrello S, Pajkic D, Fraser AG. Acute Effects of Drugs on Caenorhabditis elegans Movement Reveal Complex Responses and Plasticity. G3 (BETHESDA, MD.) 2018; 8:2941-2952. [PMID: 30061375 PMCID: PMC6118317 DOI: 10.1534/g3.118.200374] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/06/2018] [Indexed: 11/21/2022]
Abstract
Many drugs act very rapidly - they can turn on or off their targets within minutes in a whole animal. What are the acute effects of drug treatment and how does an animal respond to these? We developed a simple assay to measure the acute effects of drugs on C. elegans movement and examined the effects of a range of compounds including neuroactive drugs, toxins, environmental stresses and novel compounds on worm movement over a time period of 3 hr. We found a wide variety of acute responses. Many compounds cause rapid paralysis which may be permanent or followed by one or more recovery phases. The recoveries are not the result of some generic stress response but are specific to the drug e.g., recovery from paralysis due to a neuroactive drug requires neurotransmitter pathways whereas recovery from a metabolic inhibitor requires metabolic changes. Finally, we also find that acute responses can vary greatly across development and that there is extensive natural variation in acute responses. In summary, acute responses are sensitive probes of the ability of biological networks to respond to drug treatment and these responses can reveal the action of unexplored pathways.
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Affiliation(s)
- Mark Spensley
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Samantha Del Borrello
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Djina Pajkic
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
| | - Andrew G Fraser
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 3E1 Canada
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Blazie SM, Jin Y. Pharming for Genes in Neurotransmission: Combining Chemical and Genetic Approaches in Caenorhabditis elegans. ACS Chem Neurosci 2018; 9:1963-1974. [PMID: 29432681 DOI: 10.1021/acschemneuro.7b00509] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Synaptic transmission is central to nervous system function. Chemical and genetic screens are valuable approaches to probe synaptic mechanisms in living animals. The nematode Caenorhabditis elegans is a prime system to apply these methods to discover genes and dissect the cellular pathways underlying neurotransmission. Here, we review key approaches to understand neurotransmission and the action of psychiatric drugs in C. elegans. We start with early studies on cholinergic excitatory signaling at the neuromuscular junction, and move into mechanisms mediated by biogenic amines. Finally, we discuss emerging work toward understanding the mechanisms driving synaptic plasticity with a focus on regulation of protein translation.
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Affiliation(s)
- Stephen M. Blazie
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, United States
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28
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Papasergi-Scott MM, Stoveken HM, MacConnachie L, Chan PY, Gabay M, Wong D, Freeman RS, Beg AA, Tall GG. Dual phosphorylation of Ric-8A enhances its ability to mediate G protein α subunit folding and to stimulate guanine nucleotide exchange. Sci Signal 2018; 11:11/532/eaap8113. [PMID: 29844055 DOI: 10.1126/scisignal.aap8113] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Resistance to inhibitors of cholinesterase-8A (Ric-8A) and Ric-8B are essential biosynthetic chaperones for heterotrimeric G protein α subunits. We provide evidence for the direct regulation of Ric-8A cellular activity by dual phosphorylation. Using proteomics, Western blotting, and mutational analyses, we determined that Ric-8A was constitutively phosphorylated at five serines and threonines by the protein kinase CK2. Phosphorylation of Ser435 and Thr440 in rat Ric-8A (corresponding to Ser436 and Thr441 in human Ric-8A) was required for high-affinity binding to Gα subunits, efficient stimulation of Gα subunit guanine nucleotide exchange, and mediation of Gα subunit folding. The CK2 consensus sites that contain Ser435 and Thr440 are conserved in Ric-8 homologs from worms to mammals. We found that the homologous residues in mouse Ric-8B, Ser468 and Ser473, were also phosphorylated. Mutation of the genomic copy of ric-8 in Caenorhabditis elegans to encode alanine in the homologous sites resulted in characteristic ric-8 reduction-of-function phenotypes that are associated with defective Gq and Gs signaling, including reduced locomotion and defective egg laying. The C. elegans ric-8 phosphorylation site mutant phenotypes were partially rescued by chemical stimulation of Gq signaling. These results indicate that dual phosphorylation represents a critical form of conserved Ric-8 regulation and demonstrate that Ric-8 proteins are needed for effective Gα signaling. The position of the CK2-phosphorylated sites within a structural model of Ric-8A reveals that these sites contribute to a key acidic and negatively charged surface that may be important for its interactions with Gα subunits.
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Affiliation(s)
- Makaía M Papasergi-Scott
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Hannah M Stoveken
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Lauren MacConnachie
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Pui-Yee Chan
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Meital Gabay
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Dorothy Wong
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Robert S Freeman
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Asim A Beg
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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Caenorhabditis elegans susceptibility to Daldinia cf. concentrica bioactive volatiles is coupled with expression activation of the stress-response transcription factor daf-16, a part of distinct nematicidal action. PLoS One 2018; 13:e0196870. [PMID: 29723292 PMCID: PMC5933902 DOI: 10.1371/journal.pone.0196870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 04/20/2018] [Indexed: 12/15/2022] Open
Abstract
The bionematicidal effect of a synthetic volatile mixture (SVM) of four volatile organic compounds (VOCs) emitted by the endophytic fungus Daldinia cf. concentrica against the devastating plant-parasitic root-knot nematode Meloidogyne javanica has been recently demonstrated in both in vitro and greenhouse experiments. However, the mode of action governing the observed irreversible paralysis of J2 larvae upon exposure to SVM is unknown. To unravel the mechanism underlying the anthelmintic and nematicidal activities, we used the tractable model worm Caenorhabditis elegans. C. elegans was also susceptible to both the fungal VOCs and SVM. Among compounds comprising SVM, 3-methyl-1-butanol, (±)-2-methyl-1-butanol, and 4-heptanone showed significant nematicidal activity toward L1, L4 and young adult stages. Egg hatching was only negatively affected by 4-heptanone. To determine the mechanism underlying this activity, we examined the response of C. elegans mutants for glutamate-gated chloride channel and acetylcholine transporter, targets of the nematicidal drugs ivermectin and aldicarb, respectively, to 4-heptanone and SVM. These aldicarb- and ivermectin-resistant mutants retained susceptibility upon exposure to 4-heptanone and SVM. Next, we used C. elegans TJ356 strain zIs356 (daf-16::GFP+rol-6), LD1 ldIs7 [skn-1B/C::GFP + pRF4(rol-6(su1006))], LD1171 ldIs3 [gcs-1p::gfp; rol-6(su1006))], CL2166 dvIs19 (gst-4p::GFP) and CF1553 muIs84 (sod-3p::GFP+rol-6), which have mutations in genes regulating multiple stress responses. Following exposure of L4 larvae to 4-heptanone or SVM, there was clear nuclear translocation of DAF-16::GFP, and SKN-1::GFP indicating that their susceptibility involves DAF-16 and SKN1 regulation. Application of 4-heptanone, but not SVM, induced increased expression of, gcs-1::GFP and gst-4::GFP compared to controls. In contrast, application of 4-heptanone or SVM to the sod-3::GFP line elicited a significant decline in overall fluorescence intensity compared to controls, indicating SOD-3 downregulation and therefore overall reduction in cellular redox machinery. Our data indicate that the mode of action of SVM and 4-heptanone from D. cf. concentrica differs from that of currently available nematicides, potentially offering new solutions for nematode management.
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Matta JA, Gu S, Davini WB, Lord B, Siuda ER, Harrington AW, Bredt DS. NACHO Mediates Nicotinic Acetylcholine Receptor Function throughout the Brain. Cell Rep 2018; 19:688-696. [PMID: 28445721 DOI: 10.1016/j.celrep.2017.04.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/22/2017] [Accepted: 04/03/2017] [Indexed: 12/30/2022] Open
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) participate in diverse aspects of brain function and mediate behavioral and addictive properties of nicotine. Neuronal nAChRs derive from combinations of α and β subunits, whose assembly is tightly regulated. NACHO was recently identified as a chaperone for α7-type nAChRs. Here, we find NACHO mediates assembly of all major classes of presynaptic and postsynaptic nAChR tested. NACHO acts at early intracellular stages of nAChR subunit assembly and then synergizes with RIC-3 for receptor surface expression. NACHO knockout mice show profound deficits in binding sites for α-bungarotoxin, epibatidine, and conotoxin MII, illustrating essential roles for NACHO in proper assembly of α7-, α4β2-, and α6-containing nAChRs, respectively. By contrast, GABAA receptors are unaffected consistent with NACHO specifically modulating nAChRs. NACHO knockout mice show abnormalities in locomotor and cognitive behaviors compatible with nAChR deficiency and underscore the importance of this chaperone for physiology and disease associated with nAChRs.
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Affiliation(s)
- Jose A Matta
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Shenyan Gu
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Weston B Davini
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Brian Lord
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Edward R Siuda
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Anthony W Harrington
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - David S Bredt
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA.
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Tan JH, Fraser AG. The combinatorial control of alternative splicing in C. elegans. PLoS Genet 2017; 13:e1007033. [PMID: 29121637 PMCID: PMC5697891 DOI: 10.1371/journal.pgen.1007033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 11/21/2017] [Accepted: 09/19/2017] [Indexed: 12/31/2022] Open
Abstract
Normal development requires the right splice variants to be made in the right tissues at the right time. The core splicing machinery is engaged in all splicing events, but which precise splice variant is made requires the choice between alternative splice sites—for this to occur, a set of splicing factors (SFs) must recognize and bind to short RNA motifs in the pre-mRNA. In C. elegans, there is known to be extensive variation in splicing patterns across development, but little is known about the targets of each SF or how multiple SFs combine to regulate splicing. Here we combine RNA-seq with in vitro binding assays to study how 4 different C. elegans SFs, ASD-1, FOX-1, MEC-8, and EXC-7, regulate splicing. The 4 SFs chosen all have well-characterised biology and well-studied loss-of-function genetic alleles, and all contain RRM domains. Intriguingly, while the SFs we examined have varied roles in C. elegans development, they show an unexpectedly high overlap in their targets. We also find that binding sites for these SFs occur on the same pre-mRNAs more frequently than expected suggesting extensive combinatorial control of splicing. We confirm that regulation of splicing by multiple SFs is often combinatorial and show that this is functionally significant. We also find that SFs appear to combine to affect splicing in two modes—they either bind in close proximity within the same intron or they appear to bind to separate regions of the intron in a conserved order. Finally, we find that the genes whose splicing are regulated by multiple SFs are highly enriched for genes involved in the cytoskeleton and in ion channels that are key for neurotransmission. Together, this shows that specific classes of genes have complex combinatorial regulation of splicing and that this combinatorial regulation is critical for normal development to occur. Alternative splicing (AS) is a highly regulated process that is crucial for normal development. It requires the core splicing machinery, but the specific choice of splice site during AS is controlled by splicing factors (SFs) such as ELAV or RBFOX proteins that bind to specific sequences in pre-mRNAs to regulate usage of different splice sites. AS varies across the C. elegans life cycle and here we study how diverse SFs combine to regulate AS during C. elegans development. We selected 4 RRM-containing SFs that are all well studied and that have well-characterised loss-of-function genetic alleles. We find that these SFs regulate many of the same targets, and that combinatorial interactions between these SFs affect both individual splicing events and organism-level phenotypes including specific effects on the neuromuscular system. We further show that SFs combine to regulate splicing of an individual pre-mRNA in two distinct modes—either by binding in close proximity or by binding in a defined order on the pre-mRNA. Finally, we find that the genes whose splicing are most likely to be regulated by multiple SFs are genes that are required for the proper function of the neuromuscular system. These genes are also most likely to have changing AS patterns across development, suggesting that their splicing regulation is highly complex and developmentally regulated. Taken together, our data show that the precise splice variant expressed at any point in development is often the outcome of regulation by multiple SFs.
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Affiliation(s)
- June H. Tan
- The Donnelly Centre, University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada
| | - Andrew G. Fraser
- The Donnelly Centre, University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada
- * E-mail:
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32
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Bao H, Xu X, Liu W, Yu N, Liu Z. Dual effects of insect nAChR chaperone RIC-3 on hybrid receptor: Promoting assembly on endoplasmic reticulum but suppressing transport to plasma membrane on Xenopus oocytes. Neurochem Int 2017; 115:24-30. [PMID: 29032010 DOI: 10.1016/j.neuint.2017.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 09/21/2017] [Accepted: 10/10/2017] [Indexed: 12/27/2022]
Abstract
Resistance to inhibitors of cholinesterase (RIC) -3 promotes the maturation (folding and assembly) of neuronal nicotinic acetylcholine receptors (nAChRs) as a molecular chaperone. The modulation effects of RIC-3 on homomeric α7 nAChRs are always positive, but its effects on heteromeric subtypes are inconsistent among reports. In this study, five RIC-3 isoforms were identified from Locusta migratoria. Four isoforms showed obvious effects on hybrid receptor Locα1/rβ2 expressed in Xenopus oocytes. As a representative, the co-expression of RIC-3v4 exhibited the decreased agonist responses (Imax) on oocytes, lower specific [3H]epibatidine binding (Bmax) on plasma membrane protein (PMP), and reduced subunit levels in PMP, which showed that the mature Locα1/rβ2 on the plasma membrane was decreased by the co-expression of RIC-3. In contrast, the [3H]epibatidine binding and mature Locα1/rβ2 levels in the endoplasmic reticulum membrane protein (ERMP) were much increased when co-expressing with RIC-3v4. The [3H]epibatidine binding and mature Locα1/rβ2 levels in total membrane protein (TMP) gave the similar results as that in ERMP. Taking data together, the results showed that the co-expression of RIC-3 increased the mature Locα1/rβ2 receptor levels on ER of Xenopus oocytes, but these mature receptors were mostly kept on ER and suppressed to transport to plasma membrane.
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Affiliation(s)
- Haibo Bao
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Xixia Xu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Wei Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Na Yu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
| | - Zewen Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
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He D, Hu P, Deng X, Song Z, Yuan L, Yuan X, Deng H. Genetic analysis of the RIC3 gene in Han Chinese patients with Parkinson's disease. Neurosci Lett 2017; 653:351-354. [PMID: 28606768 DOI: 10.1016/j.neulet.2017.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 06/02/2017] [Accepted: 06/08/2017] [Indexed: 01/31/2023]
Abstract
Parkinson's disease (PD) is the second-most common etiologically complex neurodegenerative disease. Genetic abnormalities are thought to play an important role in the development of PD. Recently, mutations in the resistance to inhibitors of cholinesterase 3 gene (RIC3) have been reported to cause autosomal-dominant PD in Indian population. To determine whether RIC3 gene coding variant(s) are associated with PD in Han Chinese population, the RIC3 gene coding region in 218 mainland Han Chinese patients with PD and the identified variants in 242 normal controls were examined using direct sequencing analysis. Four known single nucleotide variants (c.354C>A, p.L118L, rs10839976; c.389G>A, p.C130Y, rs55990541; c.403C>T, p.P135S, rs73411617; and c.1054G>A, p.D352N, rs11826236) were identified in the RIC3 gene coding region. No significant differences were observed in either genotypic or allelic distributions between the PD patients and the normal controls (all P>0.05) for these four variants. Haplotype analysis showed that the presence of haplotype A-G-C-G (rs10839976-rs55990541-rs73411617-rs11826236) was associated with a 0.764-fold decreased risk (P=0.049, OR=0.764, 95% CI=0.585-0.999) for PD, whereas the presence of haplotype C-A-C-A was associated with a 2.143-fold increased risk (P=0.039, OR=2.143, 95% CI=1.023-4.488) for PD. The findings indicate that four variants: rs10839976, rs55990541, rs73411617 and rs11826236 in the RIC3 gene coding region may play little or no role in the development of PD. Two RIC3 gene haplotypes of four variants: A-G-C-G, and C-A-C-A might relate to either protection against or increased susceptibility to PD in the Han Chinese population, respectively.
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Affiliation(s)
- Dan He
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Pengzhi Hu
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China; Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lamei Yuan
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiuhong Yuan
- Department of Clinical Psychology, The Third Xiangya Hospital, Central South University, Changsha, China.
| | - Hao Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China; Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.
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The novel nematicide wact-86 interacts with aldicarb to kill nematodes. PLoS Negl Trop Dis 2017; 11:e0005502. [PMID: 28379972 PMCID: PMC5393889 DOI: 10.1371/journal.pntd.0005502] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 04/17/2017] [Accepted: 03/18/2017] [Indexed: 11/19/2022] Open
Abstract
Parasitic nematodes negatively impact human and animal health worldwide. The market withdrawal of nematicidal agents due to unfavourable toxicities has limited the available treatment options. In principle, co-administering nematicides at lower doses along with molecules that potentiate their activity could mitigate adverse toxicities without compromising efficacy. Here, we screened for new small molecules that interact with aldicarb, which is a highly effective treatment for plant-parasitic nematodes whose toxicity hampers its utility. From our collection of 638 worm-bioactive compounds, we identified 20 molecules that interact positively with aldicarb to either kill or arrest the growth of the model nematode Caenorhabditis elegans. We investigated the mechanism of interaction between aldicarb and one of these novel nematicides called wact-86. We found that the carboxylesterase enzyme GES-1 hydrolyzes wact-86, and that the interaction is manifested by aldicarb’s inhibition of wact-86’s metabolism by GES-1. This work demonstrates the utility of C. elegans as a platform to search for new molecules that can positively interact with industrial nematicides, and provides proof-of-concept for prospective discovery efforts. Many nematicides that have been used to kill plant and animal parasitic nematodes are being phased out over concerns of toxicity to humans. One potential solution to reduce toxicity is to use the nematicide at a lower concentration in combination with a second compound that together will produce a synergistic killing effect. That is, the use of either molecule alone at low concentrations is non-lethal, but when used together at these same concentrations, the cocktail is lethal. This strategy has two benefits. First, the killing effect is concentrated at the site of use and as the two molecules diffuse from the targeted site, toxicity is negated. Second, less of the toxic molecule is needed and therefore less is dispersed into the environment. Here, we describe our use of a model nematode called C. elegans to search for molecules that interact with aldicarb, which is one of the nematicides being phased out by environmental agencies. We identified 20 compounds that interact with aldicarb and describe how one of these, called wact-86, functions with aldicarb to kill worms. Our work provides proof-of-principle that C. elegans is a useful model for identifying compounds that positively interact with industrial nematicides and for understanding the nature of such interactions.
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Huang WK, Wu QS, Peng H, Kong LA, Liu SM, Yin HQ, Cui RQ, Zhan LP, Cui JK, Peng DL. Mutations in Acetylcholinesterase2 (ace2) increase the insensitivity of acetylcholinesterase to fosthiazate in the root-knot nematode Meloidogyne incognita. Sci Rep 2016; 6:38102. [PMID: 27897265 PMCID: PMC5126670 DOI: 10.1038/srep38102] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/04/2016] [Indexed: 12/05/2022] Open
Abstract
The root-knot nematode Meloidogyne incognita causes severe damage to continuously cropping vegetables. The control of this nematode relies heavily on organophosphate nematicides in China. Here, we described resistance to the organophosphate nematicide fosthiazate in a greenhouse-collected resistant population (RP) and a laboratory susceptible population (SP) of M. incognita. Fosthiazate was 2.74-fold less toxic to nematodes from RP than that from SP. Quantitative real-time PCR revealed that the acetylcholinesterase2 (ace2) transcription level in the RP was significantly higher than that in the SP. Eighteen nonsynonymous amino acid differences in ace2 were observed between the cDNA fragments of the RP and SP. The acetylcholinesterase (AChE) protein activity in the RP was significantly reduced compared with that in the SP. After knocking down the ace2 gene, the ace2 transcription level was significantly decreased, but no negative impact on the infection of juveniles was observed. The 50% lethal concentration of the RNAi RP population decreased 40%, but the inhibition rate of fosthiazate against AChE activity was significantly increased in RP population. Thus, the increased fosthiazate insensitivity in the M. incognita resistant population was strongly associated with mutations in ace2. These results provide valuable insights into the resistance mechanism of root-knot nematode to organophosphate nematicides.
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Affiliation(s)
- Wen-Kun Huang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Qin-Song Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Huan Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Ling-An Kong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Shi-Ming Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Hua-Qun Yin
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China.,Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Ru-Qiang Cui
- School of Agricultural Sciences, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Li-Ping Zhan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jiang-Kuan Cui
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - De-Liang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
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Sudhaman S, Muthane UB, Behari M, Govindappa ST, Juyal RC, Thelma BK. Evidence of mutations inRIC3acetylcholine receptor chaperone as a novel cause of autosomal-dominant Parkinson's disease with non-motor phenotypes. J Med Genet 2016; 53:559-66. [DOI: 10.1136/jmedgenet-2015-103616] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/10/2016] [Indexed: 12/18/2022]
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Gu S, Matta JA, Lord B, Harrington AW, Sutton SW, Davini WB, Bredt DS. Brain α7 Nicotinic Acetylcholine Receptor Assembly Requires NACHO. Neuron 2016; 89:948-55. [PMID: 26875622 DOI: 10.1016/j.neuron.2016.01.018] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 12/15/2015] [Accepted: 01/04/2016] [Indexed: 12/15/2022]
Abstract
Nicotine exerts its behavioral and additive actions through a family of brain nicotinic acetylcholine receptors (nAChRs). Enhancing α7-type nAChR signaling improves symptoms in Alzheimer's disease and schizophrenia. The pharmaceutical study of α7 receptors is hampered because these receptors do not form their functional pentameric structure in cell lines, and mechanisms that underlie α7 receptor assembly in neurons are not understood. Here, a genomic screening strategy solves this long-standing puzzle and identifies NACHO, a transmembrane protein of neuronal endoplasmic reticulum that mediates assembly of α7 receptors. NACHO promotes α7 protein folding, maturation through the Golgi complex, and expression at the cell surface. Knockdown of NACHO in cultured hippocampal neurons or knockout of NACHO in mice selectively and completely disrupts α7 receptor assembly and abolishes α7 channel function. This work identifies NACHO as an essential, client-specific chaperone for nAChRs and has implications for physiology and disease associated with these widely distributed neurotransmitter receptors.
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Affiliation(s)
- Shenyan Gu
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Jose A Matta
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Brian Lord
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Anthony W Harrington
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Steven W Sutton
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Weston B Davini
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - David S Bredt
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA.
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Jin Y. Unraveling the mechanisms of synapse formation and axon regeneration: the awesome power of C. elegans genetics. SCIENCE CHINA-LIFE SCIENCES 2015; 58:1084-8. [PMID: 26563175 PMCID: PMC4696538 DOI: 10.1007/s11427-015-4962-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 10/29/2015] [Indexed: 11/26/2022]
Abstract
Since Caenorhabditis elegans was chosen as a model organism by Sydney Brenner in 1960’s, genetic studies in this organism have been instrumental in discovering the function of genes and in deciphering molecular signaling network. The small size of the organism and the simple nervous system enable the complete reconstruction of the first connectome. The stereotypic developmental program and the anatomical reproducibility of synaptic connections provide a blueprint to dissect the mechanisms underlying synapse formation. Recent technological innovation using laser surgery of single axons and in vivo imaging has also made C. elegans a new model for axon regeneration. Importantly, genes regulating synaptogenesis and axon regeneration are highly conserved in function across animal phyla. This mini-review will summarize the main approaches and the key findings in understanding the mechanisms underlying the development and maintenance of the nervous system. The impact of such findings underscores the awesome power of C. elegans genetics.
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Affiliation(s)
- YiShi Jin
- Howard Hughes Medical Institute, Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, CA, 92093, USA.
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Opperman K, Moseley-Alldredge M, Yochem J, Bell L, Kanayinkal T, Chen L. A novel nondevelopmental role of the sax-7/L1CAM cell adhesion molecule in synaptic regulation in Caenorhabditis elegans. Genetics 2015; 199:497-509. [PMID: 25488979 PMCID: PMC4317657 DOI: 10.1534/genetics.114.169581] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 12/02/2014] [Indexed: 01/25/2023] Open
Abstract
The L1CAM family of cell adhesion molecules is a conserved set of single-pass transmembrane proteins that play diverse roles required for proper nervous system development and function. Mutations in L1CAMs can cause the neurological L1 syndrome and are associated with autism and neuropsychiatric disorders. L1CAM expression in the mature nervous system suggests additional functions besides the well-characterized developmental roles. In this study, we demonstrate that the gene encoding the Caenorhabditis elegans L1CAM, sax-7, genetically interacts with gtl-2, as well as with unc-13 and rab-3, genes that function in neurotransmission. These sax-7 genetic interactions result in synthetic phenotypes that are consistent with abnormal synaptic function. Using an inducible sax-7 expression system and pharmacological reagents that interfere with cholinergic transmission, we uncovered a previously uncharacterized nondevelopmental role for sax-7 that impinges on synaptic function.
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Affiliation(s)
- Karla Opperman
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Melinda Moseley-Alldredge
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455 Developmental Biology Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - John Yochem
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Leslie Bell
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Tony Kanayinkal
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Lihsia Chen
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455 Developmental Biology Center, University of Minnesota, Minneapolis, Minnesota 55455
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Cherra SJ, Jin Y. Advances in synapse formation: forging connections in the worm. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2014; 4:85-97. [PMID: 25472860 DOI: 10.1002/wdev.165] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 10/09/2014] [Accepted: 10/24/2014] [Indexed: 12/27/2022]
Abstract
UNLABELLED Synapse formation is the quintessential process by which neurons form specific connections with their targets to enable the development of functional circuits. Over the past few decades, intense research efforts have identified thousands of proteins that localize to the pre- and postsynaptic compartments. Genetic dissection has provided important insights into the nexus of the molecular and cellular network, and has greatly advanced our knowledge about how synapses form and function physiologically. Moreover, recent studies have highlighted the complex regulation of synapse formation with the identification of novel mechanisms involving cell interactions from non-neuronal sources. In this review, we cover the conserved pathways required for synaptogenesis and place specific focus on new themes of synapse modulation arising from studies in Caenorhabditis elegans. For further resources related to this article, please visit the WIREs website. CONFLICT OF INTEREST The authors have declared no conflicts of interest for this article.
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Affiliation(s)
- Salvatore J Cherra
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
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Ihara M, Okajima T, Yamashita A, Oda T, Asano T, Matsui M, Sattelle DB, Matsuda K. Studies on an Acetylcholine Binding Protein Identify a Basic Residue in Loop G on the β1 Strand as a New Structural Determinant of Neonicotinoid Actions. Mol Pharmacol 2014; 86:736-46. [DOI: 10.1124/mol.114.094698] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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A conserved dopamine-cholecystokinin signaling pathway shapes context-dependent Caenorhabditis elegans behavior. PLoS Genet 2014; 10:e1004584. [PMID: 25167143 PMCID: PMC4148232 DOI: 10.1371/journal.pgen.1004584] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 07/08/2014] [Indexed: 12/02/2022] Open
Abstract
An organism's ability to thrive in changing environmental conditions requires the capacity for making flexible behavioral responses. Here we show that, in the nematode Caenorhabditis elegans, foraging responses to changes in food availability require nlp-12, a homolog of the mammalian neuropeptide cholecystokinin (CCK). nlp-12 expression is limited to a single interneuron (DVA) that is postsynaptic to dopaminergic neurons involved in food-sensing, and presynaptic to locomotory control neurons. NLP-12 release from DVA is regulated through the D1-like dopamine receptor DOP-1, and both nlp-12 and dop-1 are required for normal local food searching responses. nlp-12/CCK overexpression recapitulates characteristics of local food searching, and DVA ablation or mutations disrupting muscle acetylcholine receptor function attenuate these effects. Conversely, nlp-12 deletion reverses behavioral and functional changes associated with genetically enhanced muscle acetylcholine receptor activity. Thus, our data suggest that dopamine-mediated sensory information about food availability shapes foraging in a context-dependent manner through peptide modulation of locomotory output. Animal behavior is profoundly affected by contextual information about the internal state of the organism as well as sensory information about the external environment. A class of signaling molecules known as neuropeptides have been implicated in driving transitions between behavioral states (e.g., from food seeking to satiety and back) but we have only a limited understanding of how neuropeptide signaling modulates neural circuit activity and elicits context-dependent behaviors. Here we identify a novel mechanism by which C. elegans modulate their behavior in response to sensory information about food. We show that dopaminergic regulation of NLP-12, a C. elegans homolog of the mammalian neuropeptide cholecystokinin (CCK), shapes behavioral transitions that are central to food searching. Given the conserved nature of these signaling pathways, our work raises the interesting possibility that dopamine modulation of CCK signaling represents a general mechanism by which nervous systems shape context-dependent behavioral changes.
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Caboni P, Tronci L, Liori B, Tocco G, Sasanelli N, Diana A. Tulipaline A: structure-activity aspects as a nematicide and V-ATPase inhibitor. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2014; 112:33-39. [PMID: 24974115 DOI: 10.1016/j.pestbp.2014.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/12/2014] [Accepted: 05/15/2014] [Indexed: 06/03/2023]
Abstract
Carbonyl groups are known to form covalent adducts with endogenous proteins, but so far, their nematicidal mechanism of action of has been overlooked. The nematicidal activity of ten lactones was tested in vitro against the root knot nematodes Meloidogyne incognita and Meloidogynearenaria. In particular, the saturated lactones α-methylene-γ-butyrolactone or tulipaline A (1) and γ-butyrolactone (3) were active against M. incognita with an EC50/48h of 19.3±10.0 and 40.0±16.2mg/L respectively. Moreover the α, β-unsaturated lactone 5,6-dihydro-2H-pyran-2-one (2) exhibited the strongest nematicidal activity against the two species with EC50/48h 14.5±5.3 and 21.2±9.7mg/L respectively. Here we propose that the toxic effects of lactones and aldehydes on M.incognita and M. arenaria might be a consequence of their vacuolar-type H(+)-ATPase (V-ATPase) inhibition activity; in fact α-methylene-γ-butyrolactone (1) and salicylaldehyde (12) produced an increased pH in lysosomal-like organelles on HeLa human cell line and this alteration was most likely related to a V-ATPase impairment.
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Affiliation(s)
- Pierluigi Caboni
- Department of Life and Environmental Sciences, University of Cagliari, via Ospedale 72, 09124 Cagliari, Italy.
| | - Laura Tronci
- Department of Life and Environmental Sciences, University of Cagliari, via Ospedale 72, 09124 Cagliari, Italy
| | - Barbara Liori
- Department of Life and Environmental Sciences, University of Cagliari, via Ospedale 72, 09124 Cagliari, Italy
| | - Graziella Tocco
- Department of Life and Environmental Sciences, University of Cagliari, via Ospedale 72, 09124 Cagliari, Italy
| | - Nicola Sasanelli
- Institute for Plant Protection, C.N.R., via G. Amendola 122/D, 70126 Bari, Italy
| | - Andrea Diana
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
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Dopamine signaling in C. elegans is mediated in part by HLH-17-dependent regulation of extracellular dopamine levels. G3-GENES GENOMES GENETICS 2014; 4:1081-9. [PMID: 24709946 PMCID: PMC4065251 DOI: 10.1534/g3.114.010819] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Caenorhabditis elegans, the dopamine transporter DAT-1 regulates synaptic dopamine (DA) signaling by controlling extracellular DA levels. In dat-1(ok157) animals, DA is not taken back up presynaptically but instead reaches extrasynpatic sites, where it activates the dopamine receptor DOP-3 on choligeneric motor neurons and causes animals to become paralyzed in water. This phenotype is called swimming-induced paralysis (SWIP) and is dependent on dat-1 and dop-3. Upstream regulators of dat-1 and dop-3 have yet to be described in C. elegans. In our previous studies, we defined a role for HLH-17 during dopamine response through its regulation of the dopamine receptors. Here we continue our characterization of the effects of HLH-17 on dopamine signaling. Our results suggest that HLH-17 acts downstream of dopamine synthesis to regulate the expression of dop-3 and dat-1. First, we show that hlh-17 animals display a SWIP phenotype that is consistent with its regulation of dop-3 and dat-1. Second, we show that this behavior is enhanced by treatment with the dopamine reuptake inhibitor, bupropion, in both hlh-17 and dat-1 animals, a result suggesting that SWIP behavior is regulated via a mechanism that is both dependent on and independent of DAT-1. Third, and finally, we show that although the SWIP phenotype of hlh-17 animals is unresponsive to the dopamine agonist, reserpine, and to the antidepressant, fluoxetine, hlh-17 animals are not defective in acetylcholine signaling. Taken together, our work suggests that HLH-17 is required to maintain normal levels of dopamine in the synaptic cleft through its regulation of dop-3 and dat-1.
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Kearn J, Ludlow E, Dillon J, O'Connor V, Holden-Dye L. Fluensulfone is a nematicide with a mode of action distinct from anticholinesterases and macrocyclic lactones. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2014; 109:44-57. [PMID: 24581383 DOI: 10.1016/j.pestbp.2014.01.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 01/21/2014] [Accepted: 01/22/2014] [Indexed: 06/03/2023]
Abstract
Plant parasitic nematodes infest crops and present a threat to food security worldwide. Currently available chemical controls e.g. methyl bromide, organophosphates and carbamates have an unacceptable level of toxicity to non-target organisms and are being withdrawn from use. Fluensulfone is a new nematicide of the fluoroalkenyl thioether group that has significantly reduced environmental impact with low toxicity to non-target insects and mammals. Here, we show that the model genetic organism Caenorhabditis elegans is susceptible to the irreversible nematicidal effects of fluensulfone. Whilst the dose required is higher than that which has nematicidal activity against Meloidogyne spp. the profile of effects on motility, egg-hatching and survival is similar to that reported for plant parasitic nematodes. C. elegans thus provides a tractable experimental paradigm to analyse the effects of fluensulfone on nematode behaviour. We find that fluensulfone has pleiotropic actions and inhibits development, egg-laying, egg-hatching, feeding and locomotion. In the case of feeding and locomotion, an early excitation precedes the gross inhibition. The profile of these effects is notably distinct from other classes of anthelmintic and nematicide: the inhibition of motility caused by fluensulfone is not accompanied by the hypercontraction which is characteristic of organophosphates and carbamates and C. elegans mutants that are resistant to the carbamate aldicarb and the macrocyclic lactone ivermectin retain susceptibility to fluensulfone. These data indicate fluensulfone's mode of action is distinct from currently available nematicides and it therefore presents a promising new chemical entity for crop protection.
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Affiliation(s)
- James Kearn
- Centre for Biological Sciences, University of Southampton, Building 85, University Road, Southampton SO17 1BJ, United Kingdom
| | - Elizabeth Ludlow
- Centre for Biological Sciences, University of Southampton, Building 85, University Road, Southampton SO17 1BJ, United Kingdom
| | - James Dillon
- Centre for Biological Sciences, University of Southampton, Building 85, University Road, Southampton SO17 1BJ, United Kingdom
| | - Vincent O'Connor
- Centre for Biological Sciences, University of Southampton, Building 85, University Road, Southampton SO17 1BJ, United Kingdom
| | - Lindy Holden-Dye
- Centre for Biological Sciences, University of Southampton, Building 85, University Road, Southampton SO17 1BJ, United Kingdom.
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Kowalski JR, Dube H, Touroutine D, Rush KM, Goodwin PR, Carozza M, Didier Z, Francis MM, Juo P. The Anaphase-Promoting Complex (APC) ubiquitin ligase regulates GABA transmission at the C. elegans neuromuscular junction. Mol Cell Neurosci 2014; 58:62-75. [PMID: 24321454 PMCID: PMC4036811 DOI: 10.1016/j.mcn.2013.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 11/23/2013] [Accepted: 12/02/2013] [Indexed: 01/05/2023] Open
Abstract
Regulation of both excitatory and inhibitory synaptic transmission is critical for proper nervous system function. Aberrant synaptic signaling, including altered excitatory to inhibitory balance, is observed in numerous neurological diseases. The ubiquitin enzyme system controls the abundance of many synaptic proteins and thus plays a key role in regulating synaptic transmission. The Anaphase-Promoting Complex (APC) is a multi-subunit ubiquitin ligase that was originally discovered as a key regulator of protein turnover during the cell cycle. More recently, the APC has been shown to function in postmitotic neurons, where it regulates diverse processes such as synapse development and synaptic transmission at glutamatergic synapses. Here we report that the APC regulates synaptic GABA signaling by acting in motor neurons to control the balance of excitatory (acetylcholine) to inhibitory (GABA) transmission at the Caenorhabditis elegans neuromuscular junction (NMJ). Loss-of-function mutants in multiple APC subunits have increased muscle excitation at the NMJ; this phenotype is rescued by expression of the missing subunit in GABA neurons. Quantitative imaging and electrophysiological analyses indicate that APC mutants have decreased GABA release but normal cholinergic transmission. Consistent with this, APC mutants exhibit convulsions in a seizure assay sensitive to reductions in GABA signaling. Previous studies in other systems showed that the APC can negatively regulate the levels of the active zone protein SYD-2 Liprin-α. Similarly, we found that SYD-2 accumulates in APC mutants at GABAergic presynaptic sites. Finally, we found that the APC subunit EMB-27 CDC16 can localize to presynapses in GABA neurons. Together, our data suggest a model in which the APC acts at GABAergic presynapses to promote GABA release and inhibit muscle excitation. These findings are the first evidence that the APC regulates transmission at inhibitory synapses and have implications for understanding nervous system pathologies, such as epilepsy, that are characterized by misregulated GABA signaling.
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Affiliation(s)
- Jennifer R Kowalski
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Hitesh Dube
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Denis Touroutine
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Kristen M Rush
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Patricia R Goodwin
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA.
| | - Marc Carozza
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Zachary Didier
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208 USA.
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Peter Juo
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA.
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Diomede L, Di Fede G, Romeo M, Bagnati R, Ghidoni R, Fiordaliso F, Salio M, Rossi A, Catania M, Paterlini A, Benussi L, Bastone A, Stravalaci M, Gobbi M, Tagliavini F, Salmona M. Expression of A2V-mutated Aβ in Caenorhabditis elegans results in oligomer formation and toxicity. Neurobiol Dis 2013; 62:521-32. [PMID: 24184799 PMCID: PMC4068289 DOI: 10.1016/j.nbd.2013.10.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 10/15/2013] [Accepted: 10/24/2013] [Indexed: 12/17/2022] Open
Abstract
Although Alzheimer's disease (AD) is usually sporadic, in a small proportion of cases it is familial and can be linked to mutations in β-amyloid precursor protein (APP). Unlike the other genetic defects, the mutation [alanine-673→valine-673] (A673V) causes the disease only in the homozygous condition with enhanced amyloid β (Aβ) production and aggregation; heterozygous carriers remain unaffected. It is not clear how misfolding and aggregation of Aβ is affected in vivo by this mutation and whether this correlates with its toxic effects. No animal models over-expressing the A673V–APP gene or alanine-2-valine (A2V) mutated human Aβ protein are currently available. Using the invertebrate Caenorhabditis elegans, we generated the first transgenic animal model to express the human Aβ1–40 wild-type (WT) in neurons or possess the A2V mutation (Aβ1–40A2V). Insertion of an Aβ-mutated gene into this nematode reproduced the homozygous state of the human pathology. Functional and biochemical characteristics found in the A2V strain were compared to those of transgenic C. elegans expressing Aβ1–40WT. The expression of both WT and A2V Aβ1–40 specifically reduced the nematode's lifespan, causing behavioral defects and neurotransmission impairment which were worse in A2V worms. Mutant animals were more resistant than WT to paralysis induced by the cholinergic agonist levamisole, indicating that the locomotor defect was specifically linked to postsynaptic dysfunctions. The toxicity caused by the mutated protein was associated with a high propensity to form oligomeric assemblies which accumulate in the neurons, suggesting this to be the central event involved in the postsynaptic damage and early onset of the disease in homozygous human A673V carriers. We generated the first transgenic animal model expressing in neurons the human Aβ1–40 wild-type or has the A2V mutation. Aβ1–40 expression reduced the worm's lifespan, caused behavioral and neuronal defects which were worse in the A2V strain. The behavioral defects of mutant worms were specifically linked to postsynaptic dysfunctions. The toxicity of Aβ1–40A2V was associated with its high propensity to form oligomers which accumulate in the neurons. These transgenic strains represent an attractive tools for an in vivo screening of compounds interfering with oligomers.
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Affiliation(s)
- Luisa Diomede
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy.
| | - Giuseppe Di Fede
- Division of Neurology and Neuropathology, "Carlo Besta" National Neurological Institute, 20133 Milan, Italy
| | - Margherita Romeo
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Renzo Bagnati
- Department of Environmental Health Sciences, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Roberta Ghidoni
- Proteomics Unit, IRCCS "Centro S. Giovanni di Dio-Fatebenefratelli", Via Pilastroni 4, 25125 Brescia, Italy
| | - Fabio Fiordaliso
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Monica Salio
- Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Alessandro Rossi
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Marcella Catania
- Division of Neurology and Neuropathology, "Carlo Besta" National Neurological Institute, 20133 Milan, Italy
| | - Anna Paterlini
- Proteomics Unit, IRCCS "Centro S. Giovanni di Dio-Fatebenefratelli", Via Pilastroni 4, 25125 Brescia, Italy
| | - Luisa Benussi
- Proteomics Unit, IRCCS "Centro S. Giovanni di Dio-Fatebenefratelli", Via Pilastroni 4, 25125 Brescia, Italy
| | - Antonio Bastone
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Matteo Stravalaci
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Marco Gobbi
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
| | - Fabrizio Tagliavini
- Division of Neurology and Neuropathology, "Carlo Besta" National Neurological Institute, 20133 Milan, Italy
| | - Mario Salmona
- Department of Molecular Biochemistry and Pharmacology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milan, Italy
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Alterations in gene expression in Caenorhabditis elegans associated with organophosphate pesticide intoxication and recovery. BMC Genomics 2013; 14:291. [PMID: 23631360 PMCID: PMC3760450 DOI: 10.1186/1471-2164-14-291] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 04/20/2013] [Indexed: 01/13/2023] Open
Abstract
Background The principal toxicity of acute organophosphate (OP) pesticide poisoning is the disruption of neurotransmission through inhibition of acetylcholinesterase (AChE). However, other mechanisms leading to persistent effects and neurodegeneration remain controversial and difficult to detect. Because Caenorhabditis elegans is relatively resistant to OP lethality—particularly through the inhibition of AChE—studies in this nematode provide an opportunity to observe alterations in global gene expression following OP exposure that cannot be readily observed in less resistant organisms. Results We exposed cultures of worms in axenic, defined medium to dichlorvos under three exposure protocols. In the first, worms were exposed continuously throughout the experiment. In the second and third, the worms were exposed for either 2 or 8 h, the dichlorvos was washed out of the culture, and the worms were allowed to recover. We then analyzed gene expression using whole genome microarrays from RNA obtained from worms sampled at multiple time points throughout the exposure. The worms showed a time-dependent increase in the expression of genes involved in stress responses. Early in the exposure, the predominant effect was on metabolic processes, while at later times, an immune-like response and cellular repair mechanisms dominated the expression pattern. Following removal of dichlorvos, the gene expression in the worms appeared to relatively rapidly return to steady-state levels. Conclusion The changes in gene expression observed in the worms following exposure to dichlorvos point towards two potential mechanisms of toxicity: inhibition of AChE and mitochondrial disruption.
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Dau A, Komal P, Truong M, Morris G, Evans G, Nashmi R. RIC-3 differentially modulates α4β2 and α7 nicotinic receptor assembly, expression, and nicotine-induced receptor upregulation. BMC Neurosci 2013; 14:47. [PMID: 23586521 PMCID: PMC3637639 DOI: 10.1186/1471-2202-14-47] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 04/03/2013] [Indexed: 12/04/2022] Open
Abstract
Background Recent work has shown that the chaperone resistant to inhibitors of acetylcholinesterase (RIC-3) is critical for the folding, maturation and functional expression of a variety of neuronal nicotinic acetylcholine receptors. α7 nicotinic receptors can only assemble and functionally express in select lines of cells, provided that RIC-3 is present. In contrast, α4β2 nicotinic receptors can functionally express in many cell lines even without the presence of RIC-3. Depending on the cell line, RIC-3 has differential effects on α4β2 receptor function – enhancement in mammalian cells but inhibition in Xenopus oocytes. Other differences between the two receptor types include nicotine-induced upregulation. When expressed in cell lines, α4β2 receptors readily and robustly upregulate with chronic nicotine exposure. However, α7 nicotinic receptors appear more resistant and require higher concentrations of nicotine to induce upregulation. Could the coexpression of RIC-3 modulate the extent of nicotine-induced upregulation not only for α7 receptors but also α4β2 receptors? We compared and contrasted the effects of RIC-3 on assembly, trafficking, protein expression and nicotine-induced upregulation on both α7 and α4β2 receptors using fluorescent protein tagged nicotinic receptors and Förster resonance energy transfer (FRET) microscopy imaging. Results RIC-3 increases assembly and cell surface trafficking of α7 receptors but does not alter α7 protein expression in transfected HEK293T cells. In contrast, RIC-3 does not affect assembly of α4β2 receptors but increases α4 and β2 subunit protein expression. Acute nicotine (30 min exposure) was sufficient to upregulate FRET between α4 and β2 subunits. Surprisingly, when RIC-3 was coexpressed with α4β2 receptors nicotine-induced upregulation was prevented. α7 receptors did not upregulate with acute nicotine in the presence or absence of RIC-3. Conclusions These results provide interesting novel data that RIC-3 differentially regulates assembly and expression of different nicotinic receptor subunits. These results also show that nicotine-mediated upregulation of α4β2 receptors can be dynamically regulated by the presence of the chaperone, RIC-3. This could explain a novel mechanism why high affinity α4β2 receptors are upregulated in specific neuronal subtypes in the brain and not others.
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Petrash HA, Philbrook A, Haburcak M, Barbagallo B, Francis MM. ACR-12 ionotropic acetylcholine receptor complexes regulate inhibitory motor neuron activity in Caenorhabditis elegans. J Neurosci 2013; 33:5524-32. [PMID: 23536067 PMCID: PMC3645261 DOI: 10.1523/jneurosci.4384-12.2013] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 01/23/2013] [Accepted: 02/04/2013] [Indexed: 12/11/2022] Open
Abstract
Heterogeneity in the composition of neurotransmitter receptors is thought to provide functional diversity that may be important in patterning neural activity and shaping behavior (Dani and Bertrand, 2007; Sassoè-Pognetto, 2011). However, this idea has remained difficult to evaluate directly because of the complexity of neuronal connectivity patterns and uncertainty about the molecular composition of specific receptor types in vivo. Here we dissect how molecular diversity across receptor types contributes to the coordinated activity of excitatory and inhibitory motor neurons in the nematode Caenorhabditis elegans. We show that excitatory and inhibitory motor neurons express distinct populations of ionotropic acetylcholine receptors (iAChRs) requiring the ACR-12 subunit. The activity level of excitatory motor neurons is influenced through activation of nonsynaptic iAChRs (Jospin et al., 2009; Barbagallo et al., 2010). In contrast, synaptic coupling of excitatory and inhibitory motor neurons is achieved through a second population of iAChRs specifically localized at postsynaptic sites on inhibitory motor neurons. Loss of ACR-12 iAChRs from inhibitory motor neurons leads to reduced synaptic drive, decreased inhibitory neuromuscular signaling, and variability in the sinusoidal motor pattern. Our results provide new insights into mechanisms that establish appropriately balanced excitation and inhibition in the generation of a rhythmic motor behavior and reveal functionally diverse roles for iAChR-mediated signaling in this process.
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Affiliation(s)
- Hilary A Petrash
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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