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Calahorro F, Holden-Dye L, O'Connor V. Impact of drug solvents on C. elegans pharyngeal pumping. Toxicol Rep 2021; 8:1240-1247. [PMID: 34195015 PMCID: PMC8233170 DOI: 10.1016/j.toxrep.2021.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 05/20/2021] [Accepted: 06/14/2021] [Indexed: 02/05/2023] Open
Abstract
Caenorhabditis elegans provides a multi-cellular model organism for toxicology and drug discovery. These studies usually require solvents such as dimethyl sulfoxide (DMSO), ethanol or acetone as a vehicle. This raises the need to carefully consider whether the chemical vehicles used in these screens are anodyne towards C. elegans. Here, we use pharyngeal pumping as a bioassay to assess this. Pharyngeal pumping is a visually scoreable behaviour that is controlled by environmental cues activating sensory and integrative neural signalling to coordinate pharyngeal activity. As such it serves as a rich bioassay to screen for chemical modulation. We found that while pumping was insensitive to high concentrations of the widely used drug solvents ethanol and acetone, it was perturbed by concentrations of DMSO above 0.5 % v/v encompassing concentrations used as drug vehicle. This was manifested as an inhibition of pharyngeal pump rate followed by a slow recovery in the continued presence of the solvent. The inhibition was not observed in a neuroligin mutant, nlg-1, consistent with DMSO acting at the level of sensory processing that modulates pumping. We found that bus-17 mutants, which have enhanced cuticle penetration to drugs are more sensitive to DMSO. The effect of DMSO is accompanied by a progressive morphological disruption in which internal membrane-like structures of varying size accumulate. These internal structures are seen in all three genotypes investigated in this study and likely arise independent of the effects on pharyngeal pumping. Overall, these results highlight sensory signalling and strain dependent vehicle sensitivity. Although we define concentrations at which this can be mitigated, it highlights the need to consider time-dependent vehicle effects when evaluating control responses in C. elegans chemical biology.
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Wang X, Zhang C, Chen Q, Ma Z, Liu H, Huang J. Guanylate cyclases link serotoninergic signaling to modulate ethanol-induced food intake in C. elegans. Biochem Biophys Res Commun 2021; 567:29-34. [PMID: 34133999 DOI: 10.1016/j.bbrc.2021.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 06/02/2021] [Indexed: 11/30/2022]
Abstract
Ethanol affects the nervous system of animals to cause a boost of feeding, sexual, verbal, and locomotor behaviors. To understand the neural mechanisms of these ethanol-induced behaviors, we investigated a neural pathway of ethanol-induced feeding behavior by guanylate cyclases and serotonin signals in C. elegans. We recorded the intracellular calcium signaling of seven sensory neurons in response to ethanol, and only found a significant increase of calcium signaling in BAG among the seven sensor neurons. And both guanylate cyclases GCY-31 and GCY-33 were crucial signaling protein of calcium response in BAG neurons. In addition, serotonin, released from NSM motor neurons, promoted feeding behavior under ethanol stimulation. And the rescue experiment of double mutant indicated the guanylate cyclases and serotonin in the same signaling pathway. So BAG neurons respond to alcohol through the promotion of intracellular calcium signaling, and then the downstream motor neurons NSM release serotonin to regulate the feeding behavior in C. elegans. These findings revealed a neural circuit to understand how the nervous system responds to ethanol and generates corresponding behavior.
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Affiliation(s)
- Xin Wang
- Center for Molecular Medicine, School of Basic Medicine, Yangtze University, Jingzhou, Hubei, 434023, PR China
| | - Chunlong Zhang
- Laboratory for Neuroscience, The Central Hospital of Tujia&Miao Autonomous Prefecture, Enshi, Hubei, 435000, PR China
| | - Qirui Chen
- Center for Molecular Medicine, School of Basic Medicine, Yangtze University, Jingzhou, Hubei, 434023, PR China
| | - Zhaowu Ma
- Center for Molecular Medicine, School of Basic Medicine, Yangtze University, Jingzhou, Hubei, 434023, PR China
| | - Hui Liu
- Center for Molecular Medicine, School of Basic Medicine, Yangtze University, Jingzhou, Hubei, 434023, PR China.
| | - Jiangrong Huang
- Center for Molecular Medicine, School of Basic Medicine, Yangtze University, Jingzhou, Hubei, 434023, PR China.
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Shimizu C, Kasahara H, Furuta N, Shibata M, Nagashima K, Hashiguchi A, Takashima H, Ikeda Y. [Charcot-Marie-Tooth disease showing transient central nervous system lesions after a large amount of alcohol intake: A case report]. Rinsho Shinkeigaku 2018; 58:479-484. [PMID: 30068806 DOI: 10.5692/clinicalneurol.cn-001130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A 23-year-old man experienced numbness in the perioral region and right arm, and right leg weakness on the second day after drinking a large amount of alcohol during foreign travel. His symptoms disappeared but then reappeared repetitively. Cerebral MRI performed on the third day after onset showed multiple white matter lesions; however, these lesions disappeared 26 days after onset. Neurological examination and nerve conduction studies revealed demyelinating polyneuropathy. Genetic testing for Charcot-Marie-Tooth disease, X-linked dominant 1 (CMTX1) due to GJB1 mutation was conducted based on the symptoms of transient central nervous system lesions and polyneuropathy exhibited by the patient and his mother. As a result, a c.530T>C (p.V177A) substitution in exon 2 of GJB1 was identified. CMTX1 patients should be advised to avoid excessive drinking because this could induce central nervous system lesions.
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Affiliation(s)
- Chisato Shimizu
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Hiroo Kasahara
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Natsumi Furuta
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Makoto Shibata
- Department of Neurology, Gunma University Graduate School of Medicine
- Department of Neurology, National Hospital Organization Takasaki General Medical Center
| | - Kazuaki Nagashima
- Department of Neurology, Gunma University Graduate School of Medicine
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Yoshio Ikeda
- Department of Neurology, Gunma University Graduate School of Medicine
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Tellez-Gabriel M, Charrier C, Brounais-Le Royer B, Mullard M, Brown HK, Verrecchia F, Heymann D. Analysis of gap junctional intercellular communications using a dielectrophoresis-based microchip. Eur J Cell Biol 2017; 96:110-118. [DOI: 10.1016/j.ejcb.2017.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/29/2016] [Accepted: 01/09/2017] [Indexed: 01/20/2023] Open
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Cochet-Escartin O, Carter JA, Chakraverti-Wuerthwein M, Sinha J, Collins EMS. Slo1 regulates ethanol-induced scrunching in freshwater planarians. Phys Biol 2016; 13:055001. [DOI: 10.1088/1478-3975/13/5/055001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Dillon J, Holden-Dye L, O'Connor V, Hopper NA. Context-dependent regulation of feeding behaviour by the insulin receptor, DAF-2, in Caenorhabditis elegans. INVERTEBRATE NEUROSCIENCE : IN 2016; 16:4. [PMID: 27209024 PMCID: PMC4875951 DOI: 10.1007/s10158-016-0187-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/13/2016] [Indexed: 12/31/2022]
Abstract
Insulin signalling plays a significant role in both developmental programmes and pathways modulating the neuronal signalling that controls adult behaviour. Here, we have investigated insulin signalling in food-associated behaviour in adult C. elegans by scoring locomotion and feeding on and off bacteria, the worm's food. This analysis used mutants (daf-2, daf-18) of the insulin signalling pathway, and we provide evidence for an acute role for insulin signalling in the adult nervous system distinct from its impact on developmental programmes. Insulin receptor daf-2 mutants move slower than wild type both on and off food and showed impaired locomotory responses to food deprivation. This latter behaviour is manifest as a failure to instigate dispersal following prolonged food deprivation and suggests a role for insulin signalling in this adaptive response. Insulin receptor daf-2 mutants are also deficient in pharyngeal pumping on food and off food. Pharmacological analysis showed the pharynx of daf-2 is selectively compromised in its response to 5-HT compared to the excitatory neuropeptide FLP-17. By comparing the adaptive pharyngeal behaviour in intact worms and isolated pharyngeal preparations, we determined that an insulin-dependent signal extrinsic to the pharyngeal system is involved in feeding adaptation. Hence, we suggest that reactive insulin signalling modulates both locomotory foraging and pharyngeal pumping as the animal adapts to the absence of food. We discuss this in the context of insulin signalling directing a shift in the sensitivity of neurotransmitter systems to regulate the worm's response to changes in food availability in the environment.
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Affiliation(s)
- James Dillon
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK.
| | - Lindy Holden-Dye
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK
| | - Vincent O'Connor
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK
| | - Neil A Hopper
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK
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Report on the 13th symposium on invertebrate neurobiology held 26-30 August 2015 at the Balaton Limnological Institute, MTA Centre for ecological research of the Hungarian Academy of Sciences, Tihany, Hungary. INVERTEBRATE NEUROSCIENCE 2016; 16:3. [PMID: 27149972 DOI: 10.1007/s10158-016-0186-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This report summarizes the lectures and posters presented at the International Society for Invertebrate Neurobiology's 13th symposium held 26-30 August 2015, at the Balaton Limnological Institute, MTA Centre for Ecological Research, Tihany, Hungary. The symposium provided an opportunity for scientists working on a range of topics in invertebrate neurobiology to meet and present their research and discuss ways to advance the discipline.
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Kanteti R, Dhanasingh I, El-Hashani E, Riehm JJ, Stricker T, Nagy S, Zaborin A, Zaborina O, Biron D, Alverdy JC, Im HK, Siddiqui S, Padilla PA, Salgia R. C. elegans and mutants with chronic nicotine exposure as a novel model of cancer phenotype. Cancer Biol Ther 2015; 17:91-103. [PMID: 26574927 PMCID: PMC6093410 DOI: 10.1080/15384047.2015.1108495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We previously investigated MET and its oncogenic mutants relevant to lung cancer
in C. elegans. The inactive orthlogues of the receptor tyrosine
kinase Eph and MET, namely vab-1 and RB2088 respectively, the
temperature sensitive constitutively active form of KRAS, SD551
(let-60; GA89) and the inactive c-CBL equivalent mutants in
sli-1 (PS2728, PS1258, and MT13032) when subjected to
chronic exposure of nicotine resulted in a significant loss in egg-laying
capacity and fertility. While the vab-1 mutant revealed
increased circular motion in response to nicotine, the other mutant strains
failed to show any effect. Overall locomotion speed increased with increasing
nicotine concentration in all tested mutant strains except in the
vab-1 mutants. Moreover, chronic nicotine exposure, in
general, upregulated kinases and phosphatases. Taken together, these studies
provide evidence in support of C. elegans as initial in
vivo model to study nicotine and its effects on oncogenic mutations
identified in humans.
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Affiliation(s)
- Rajani Kanteti
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
| | - Immanuel Dhanasingh
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
| | | | - Jacob J Riehm
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
| | - Thomas Stricker
- c Department of Pathology , Microbiology and Immunology, Vanderbilt University School of Medicine , Nashville , TN , USA
| | - Stanislav Nagy
- d Department of Physics , James Franck Institute, and the College, University of Chicago , Chicago , IL , USA
| | - Alexander Zaborin
- e Department of Surgery , Pritzker School of Medicine, University of Chicago , Chicago , IL , USA
| | - Olga Zaborina
- e Department of Surgery , Pritzker School of Medicine, University of Chicago , Chicago , IL , USA
| | - David Biron
- d Department of Physics , James Franck Institute, and the College, University of Chicago , Chicago , IL , USA
| | - John C Alverdy
- e Department of Surgery , Pritzker School of Medicine, University of Chicago , Chicago , IL , USA
| | - Hae Kyung Im
- f Department of Medicine , Section of Genetic Medicine, University of Chicago , Chicago , IL , USA
| | - Shahid Siddiqui
- g Department of Medicine , University of Chicago, Chicago, IL and Department of Basic and Oral Biology, UQUDENT, U. Q. University , Makkah , KSA
| | - Pamela A Padilla
- h Department of Biological Sciences , University of North- Texas , Denton , TX , USA
| | - Ravi Salgia
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
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Grotewiel M, Bettinger JC. Drosophila and Caenorhabditis elegans as Discovery Platforms for Genes Involved in Human Alcohol Use Disorder. Alcohol Clin Exp Res 2015; 39:1292-311. [PMID: 26173477 PMCID: PMC4656040 DOI: 10.1111/acer.12785] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 05/18/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Despite the profound clinical significance and strong heritability of alcohol use disorder (AUD), we do not yet have a comprehensive understanding of the naturally occurring genetic variance within the human genome that drives its development. This lack of understanding is likely to be due in part to the large phenotypic and genetic heterogeneities that underlie human AUD. As a complement to genetic studies in humans, many laboratories are using the invertebrate model organisms (iMOs) Drosophila melanogaster (fruit fly) and Caenorhabditis elegans (nematode worm) to identify genetic mechanisms that influence the effects of alcohol (ethanol) on behavior. While these extremely powerful models have identified many genes that influence the behavioral responses to alcohol, in most cases it has remained unclear whether results from behavioral-genetic studies in iMOs are directly applicable to understanding the genetic basis of human AUD. METHODS In this review, we critically evaluate the utility of the fly and worm models for identifying genes that influence AUD in humans. RESULTS Based on results published through early 2015, studies in flies and worms have identified 91 and 50 genes, respectively, that influence 1 or more aspects of behavioral responses to alcohol. Collectively, these fly and worm genes correspond to 293 orthologous genes in humans. Intriguingly, 51 of these 293 human genes have been implicated in AUD by at least 1 study in human populations. CONCLUSIONS Our analyses strongly suggest that the Drosophila and C. elegans models have considerable utility for identifying orthologs of genes that influence human AUD.
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Affiliation(s)
- Mike Grotewiel
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
- Virginia Commonwealth University Alcohol Research Center, Richmond, Virginia
| | - Jill C Bettinger
- Department of Pharmacology and Toxicology , Virginia Commonwealth University, Richmond, Virginia
- Virginia Commonwealth University Alcohol Research Center, Richmond, Virginia
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Bettinger JC, Davies AG. The role of the BK channel in ethanol response behaviors: evidence from model organism and human studies. Front Physiol 2014; 5:346. [PMID: 25249984 PMCID: PMC4158801 DOI: 10.3389/fphys.2014.00346] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 08/22/2014] [Indexed: 11/30/2022] Open
Abstract
Alcohol abuse is a significant public health problem. Understanding the molecular effects of ethanol is important for the identification of at risk individuals, as well as the development of novel pharmacotherapies. The large conductance calcium sensitive potassium (BK) channel has emerged as an important player in the behavioral response to ethanol in genetic studies in several model organisms and in humans. The BK channel, slo-1, was identified in a forward genetics screen as a major ethanol target in C. elegans for the effects of ethanol on locomotion and egg-laying behaviors. Regulation of the expression of the BK channel, slo, in Drosophila underlies the development of rapid tolerance to ethanol and benzyl alcohol sedation. Rodent expression studies of the BK-encoding KCNMA1 gene have identified regulation of mRNA levels in response to ethanol exposure, and knock out studies in mice have demonstrated that the β subunits of the BK channel, β1 and β4, can modulate ethanol sensitivity of the channel in electrophysiological preparations, and can influence drinking behavior. In human genetics studies, both KCNMA1 and the genes encoding β subunits of the BK channel have been associated with alcohol dependence. This review describes the genetic data for a role for BK channels in mediating behavioral responses to ethanol across these species.
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Affiliation(s)
- Jill C Bettinger
- Department of Pharmacology and Toxicology, Virginia Commonwealth University Richmond, VA, USA
| | - Andrew G Davies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University Richmond, VA, USA
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An alcohol-sensing site in the calcium- and voltage-gated, large conductance potassium (BK) channel. Proc Natl Acad Sci U S A 2014; 111:9313-8. [PMID: 24927535 DOI: 10.1073/pnas.1317363111] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Ethanol alters BK (slo1) channel function leading to perturbation of physiology and behavior. Site(s) and mechanism(s) of ethanol-BK channel interaction are unknown. We demonstrate that ethanol docks onto a water-accessible site that is strategically positioned between the slo1 calcium-sensors and gate. Ethanol only accesses this site in presence of calcium, the BK channel's physiological agonist. Within the site, ethanol hydrogen-bonds with K361. Moreover, substitutions that hamper hydrogen bond formation or prevent ethanol from accessing K361 abolish alcohol action without altering basal channel function. Alcohol interacting site dimensions are approximately 10.7 × 8.6 × 7.1 Å, accommodating effective (ethanol-heptanol) but not ineffective (octanol, nonanol) channel activators. This study presents: (i) to our knowledge, the first identification and characterization of an n-alkanol recognition site in a member of the voltage-gated TM6 channel superfamily; (ii) structural insights on ethanol allosteric interactions with ligand-gated ion channels; and (iii) a first step for designing agents that antagonize BK channel-mediated alcohol actions without perturbing basal channel function.
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Morabito R, Marino A, Dossena S, La Spada G. Nematocyst discharge in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms can be affected by lidocaine, ethanol, ammonia and acetic acid. Toxicon 2014; 83:52-8. [PMID: 24637105 DOI: 10.1016/j.toxicon.2014.03.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 02/27/2014] [Accepted: 03/04/2014] [Indexed: 02/06/2023]
Abstract
Nematocyst discharge and concomitant delivery of toxins is triggered to perform both defence and predation strategies in Cnidarians, and may lead to serious local and systemic reactions in humans. Pelagia noctiluca (Cnidaria, Scyphozoa) is a jellyfish particularly abundant in the Strait of Messina (Italy). After accidental contact with this jellyfish, not discharged nematocysts or even fragments of tentacles or oral arms may tightly adhere to the human skin and, following discharge, severely increase pain and the other adverse consequences of the sting. The aim of the present study is to verify if the local anesthetic lidocaine and other compounds, like alcohols, acetic acid and ammonia, known to provide pain relief after jellyfish stings, may also affect in situ discharge of nematocysts. Discharge was induced by a combined physico-chemical stimulation of oral arms by chemosensitizers (such as N-acetylated sugars, aminoacids, proteins and nucleotides), in the presence or absence of 1% lidocaine, 70% ethanol, 5% acetic acid or 20% ammonia, followed by mechanical stimulation by a non-vibrating test probe. The above mentioned compounds failed to induce discharge per se, and dramatically impaired the chemosensitizer-induced discharge response. We therefore suggest that prompt local treatment of the stung epidermis with lidocaine, acetic acid, ethanol and ammonia may provide substantial pain relief and help in reducing possible harmful local and systemic adverse reaction following accidental contact with P. noctiluca specimens.
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Affiliation(s)
- Rossana Morabito
- Department of Human and Social Sciences, Via T. Cannizzaro 278, Messina, Italy.
| | - Angela Marino
- Department of Biological and Environmental Sciences, Viale F. Stagno D'Alcontres 31, Messina, Italy.
| | - Silvia Dossena
- Institute of Pharmacology and Toxicology Paracelsus Medizinische Privatuniversitat Strubergasse 21, A-5020 Salzburg, Austria.
| | - Giuseppa La Spada
- Department of Biological and Environmental Sciences, Viale F. Stagno D'Alcontres 31, Messina, Italy.
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Johnson JR, Kashyap S, Rankin K, Barclay JW. Rab-3 and unc-18 interactions in alcohol sensitivity are distinct from synaptic transmission. PLoS One 2013; 8:e81117. [PMID: 24244732 PMCID: PMC3828271 DOI: 10.1371/journal.pone.0081117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 10/18/2013] [Indexed: 01/31/2023] Open
Abstract
The molecular mechanisms underlying sensitivity to alcohol are incompletely understood. Recent research has highlighted the involvement of two presynaptic proteins, Munc18 and Rab3. We have previously characterised biochemically a number of specific Munc18 point mutations including an E466K mutation that augments a direct Rab3 interaction. Here the phenotypes of this and other Munc18 mutations were assessed in alcohol sensitivity and exocytosis using Caenorhabditis elegans. We found that expressing the orthologous E466K mutation (unc-18 E465K) enhanced alcohol sensitivity. This enhancement in sensitivity was surprisingly independent of rab-3. In contrast unc-18 R39C, which decreases syntaxin binding, enhanced sensitivity to alcohol in a manner requiring rab-3. Finally, overexpression of R39C could suppress partially the reduction in neurotransmitter release in rab-3 mutant worms, whereas wild-type or E465K mutants showed no rescue. These data indicate that the epistatic interactions between unc-18 and rab-3 in modulating sensitivity to alcohol are distinct from interactions affecting neurotransmitter release.
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Affiliation(s)
- James R. Johnson
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Sudhanva Kashyap
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Kim Rankin
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Jeff W. Barclay
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
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