1. The
- Author
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Tina V A, Hansen, Heinz, Sager, Céline E, Toutain, Elise, Courtot, Cédric, Neveu, and Claude L, Charvet
- Subjects
GABA Plasma Membrane Transport Proteins ,genetic structures ,Communication ,DEG-3/DES-2 ,Receptors, Nicotinic ,nAChR ,monepantel ,Membrane Potentials ,Xenopus laevis ,Aminoacetonitrile ,Animals ,betaine ,sense organs ,Sulfones ,Caenorhabditis elegans ,Caenorhabditis elegans Proteins ,Ion Channel Gating - Abstract
Natural plant compounds, such as betaine, are described to have nematocidal properties. Betaine also acts as a neurotransmitter in the free-living model nematode Caenorhabditis elegans, where it is required for normal motility. Worm motility is mediated by nicotinic acetylcholine receptors (nAChRs), including subunits from the nematode-specific DEG-3 group. Not all types of nAChRs in this group are associated with motility, and one of these is the DEG-3/DES-2 channel from C. elegans, which is involved in nociception and possibly chemotaxis. Interestingly, the activity of DEG-3/DES-2 channel from the parasitic nematode of ruminants, Haemonchus contortus, is modulated by monepantel and its sulfone metabolite, which belong to the amino-acetonitrile derivative anthelmintic drug class. Here, our aim was to advance the pharmacological knowledge of the DEG-3/DES-2 channel from C. elegans by functionally expressing the DEG-3/DES-2 channel in Xenopus laevis oocytes and using two-electrode voltage-clamp electrophysiology. We found that the DEG-3/DES-2 channel was more sensitive to betaine than ACh and choline, but insensitive to monepantel and monepantel sulfone when used as direct agonists and as allosteric modulators in co-application with betaine. These findings provide important insight into the pharmacology of DEG-3/DES-2 from C. elegans and highlight the pharmacological differences between non-parasitic and parasitic nematode species.
- Published
- 2021