Levamisole-sensitive nicotinic acetylcholine receptor (L-nAChR) (L-nAChR)

The Levamisole-sensitive nicotinic acetylcholine receptor (L-nAChR), also known as the L-type nicotinic receptor, is a pentameric ligand-gated ion channel primarily found in the neuromuscular junctions of nematodes, such as Caenorhabditis elegans and various parasitic helminths. It is composed of specific subunits, including UNC-38, UNC-29, and UNC-63, which distinguish it from the nicotine-sensitive (N-type) receptors and vertebrate muscle-type receptors. This receptor is the primary molecular target for the anthelmintic drug levamisole and related compounds like pyrantel and morantel. These drugs act as potent agonists, causing persistent opening of the ion channel, which leads to massive depolarization of the muscle cells and subsequent spastic paralysis of the parasite. Because the L-type subunit composition is unique to nematodes and absent in vertebrate hosts, these drugs exhibit high selective toxicity, making them effective for treating parasitic infections. However, the widespread use of these drugs has led to the emergence of resistance, often arising from genetic mutations that alter receptor composition or function. While the term "L-type" is more commonly associated with voltage-gated calcium channels in vertebrates, in the context of nicotinic receptors, it specifically refers to this levamisole-sensitive subtype in nematodes.

Other names

Nicotinic acetylcholine receptor, L-typeLevamisole receptorL-type nAChRUNC-38/UNC-29/UNC-63/LEV-1/LEV-8 complex

Agonist-induced persistent depolarization of the nematode muscle cell membrane, leading to spastic paralysis and expulsion of the parasite.