Resistance to dieldrin (RDL) GABA-gated chloride channel (GABACl)

The Resistance to dieldrin (RDL) GABA-gated chloride channel is a critical inhibitory neurotransmitter receptor found in the central nervous system of insects and acarines, such as ticks and mites [PubMed: 23103374]. As a member of the Cys-loop ligand-gated ion channel superfamily, it mediates fast inhibitory synaptic transmission by allowing chloride ions to flow into neurons upon the binding of gamma-aminobutyric acid (GABA) [UniProt: P25123]. This influx causes membrane hyperpolarization, effectively dampening neuronal excitability [PubMed: 28445611]. These channels are primary targets for several major classes of insecticides and acaricides because they exhibit significant structural and pharmacological differences from mammalian GABA receptors, ensuring high selective toxicity [PubMed: 24814634]. Drugs like fipronil and the isoxazoline class (e.g., fluralaner) act as non-competitive antagonists that bind within the channel pore to block chloride conductance [PubMed: 25239189]. This blockage results in uncontrolled nervous system activity, convulsions, and the eventual death of the target organism [PubMed: 24814634]. Resistance to these chemicals is frequently linked to specific point mutations in the RDL gene, such as the substitution of alanine at position 302, which reduces drug binding affinity [PubMed: 11113255].

Other names

RDL receptorGamma-aminobutyric acid receptor subunit RDLInvertebrate GABA-gated chloride channelIonotropic GABA receptorGABA-A-like receptor

Non-competitive antagonism of the chloride channel pore, which prevents the influx of chloride ions into neurons, leading to hyperexcitation, paralysis, and death of the parasite.