Drosophila nicotinic acetylcholine receptor subunits and their native interactions with insecticidal peptide toxins

Abstract

Drosophila nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that represent a target for insecticides. Peptide neurotoxins are known to block nAChRs by binding to their target subunits, however, a better understanding of receptor subunit composition is needed for effective design of insecticides. To facilitate the analysis of nAChRs we used a CRISPR/Cas9 strategy to generate null alleles for all ten nAChR subunit genes in a common genetic background. We studied interactions of nAChR subunits with peptide neurotoxins by larval injections and styrene maleic acid lipid particles (SMALPs) pull-down assays. For the null alleles we determined the effects of -Bungarotoxin (-Btx) and {omega}-Hexatoxin-Hv1a (Hv1a) administration, identifying potential receptor subunits implicated in the binding of these toxins. We employed pull-down assays to confirm -Btx interactions with the D5, D6, D7 subunits. Finally, we report the localization of fluorescent tagged endogenous D6 during nervous system development. Taken together this study elucidates native Drosophila nAChR subunit interactions with insecticidal peptide toxins and provides a resource for the in vivo analysis of insect nAChRs.