Functional Characteristics of the Lepidopteran Ionotropic GABA Receptor 8916 Subunit Interacting with the LCCH3 or the RDL Subunit

The ionotropic ?-aminobutyric acid (iGABA) receptor is commonly considered as a fast inhibitory channel and an important insecticide target. Since 1990, RDL, LCCH3, GRD have been successively isolated found to be potential subunits of the insect iGABA receptor. More recently, one orphan gene named 8916 was another subunit according its amino sequence. However, little information about has reported. Here, from Chilo suppressalis studied determine whether it can form part functional by co-expressing this with CsRDL1 or CsLCCH3 in Xenopus oocyte system. Cs8916 did not ion channels when expressed alone. able heteromeric either CsRDL1. recombinant Cs8916/LCCH3 cation-selective channel, which sensitive GABA ?-alanine. current inhibited dieldrin, endosulfan, fipronil, ethiprole. In contrast, fluralaner, broflanilide, avermectin showed effect on (IC50s > 10 000 nM). Cs8916/RDL1 GABA, but significantly different EC50 Imax for those homomeric Fluralaner, dieldrin antagonistic actions Cs8916/RDL1. conclusion, subunit, interact generate that several insecticides. Also, higher than CsRDL1, may affect physiological functions therefore play role fine-tuning GABAergic signaling.