Neuronal nicotinic acetylcholine receptors of Drosophila melanogaster: the α‐subunit Dα3 and the β‐type subunit ARD co‐assemble within the same receptor complex

Dalpha3 is a functional alpha-subunit of Drosophila melanogaster nicotinic acetylcholine receptors (nAChRs). Here, we produced Dalpha3-specific antibodies to study which other nAChR subunits can co-assemble with Dalpha3 in receptor complexes of the Drosophila nervous system. Immunohistochemical studies revealed that Dalpha3 is co-distributed with the beta-subunit ARD in synaptic neuropil regions of the optic lobe. Both subunits can be co-purified by alpha-bungarotoxin affinity chromatography. Dalpha3 antibodies co-immunoprecipitate Dalpha3 and ARD proteins and, vice versa, anti-ARD antibodies co-precipitate ARD and Dalpha3. These data demonstrate that one type of fly nAChRs includes these two subunits as integral components.