Helminth muscle nicotinic acetylcholine receptor (nAChR)

Helminth muscle nicotinic acetylcholine receptors are pentameric Cys-loop ligand-gated ion channels that serve as the primary targets for cholinergic anthelmintic drugs[2][5]. These receptors are present on the muscle cells of parasitic nematodes and helminths, where they control essential motor functions[7]. Three distinct pharmacological subtypes have been identified in nematode muscle: the L-subtype (most sensitive to levamisole and pyrantel), the N-subtype (most sensitive to nicotine, oxantel, and methyridine), and the B-subtype (most sensitive to bephenium)[5]. The receptors are composed of multiple subunits, with genes such as unc-38, unc-63, unc-29, lev-1, and lev-8 encoding critical subunits involved in levamisole sensitivity[2][5]. When activated by cholinergic agonists, these receptors cause muscle depolarization and paralysis, making them effective targets for antiparasitic therapy. However, the specific subunit composition varies between parasitic species, with many lacking orthologues to certain subunits found in model organisms, which has implications for drug development and resistance mechanisms[2]. The receptors require proper assembly and ancillary proteins for full functionality, and their pharmacological properties can be modulated by altering subunit ratios[5].

Other names

L-subtype nicotinic acetylcholine receptorlevamisole-sensitive acetylcholine receptor (L-AChR)N-subtype nicotinic acetylcholine receptorB-subtype nicotinic acetylcholine receptorcholinergic anthelmintic receptor

Ion channel activation leading to muscle depolarization and paralysis, Cholinergic agonism causing neuromuscular blockade