Glutamate-gated chloride channel alpha subunit (GluCl alpha)

The Glutamate-gated chloride channel alpha subunit (GluCl alpha) is a critical component of inhibitory neurotransmission in invertebrates, including nematodes and arthropods (UniProt P34909). As members of the Cys-loop ligand-gated ion channel superfamily, these receptors mediate the influx of chloride ions into neurons and muscle cells in response to glutamate, leading to hyperpolarization and reduced excitability (Hibbs and Gouaux, 2011). GluCl alpha subunits are the primary molecular targets for macrocyclic lactone antiparasitics, such as ivermectin, which bind to the transmembrane domain to stabilize the open state of the channel (Wolstenholme, 2012). This interaction results in persistent chloride conductance, causing flaccid paralysis and eventual death of the parasite. Because these channels are not found in vertebrates, they provide a high therapeutic index for treating infections like river blindness and various veterinary parasitic infestations. However, safety risks can arise in vertebrate hosts with blood-brain barrier defects, where drugs may interact with homologous GABA-A or glycine receptors.

Other names

GluClGlutamate-gated chloride channelAvermectin-sensitive glutamate-gated chloride channelGLC-1AVR-14GluCl-alpha

Positive allosteric modulation and direct activation of the channel, leading to an influx of chloride ions, membrane hyperpolarization, and flaccid paralysis of the parasite's pharyngeal and somatic muscles.