Dβ3, an atypical nicotinic acetylcholine receptor subunit from Drosophila: molecular cloning, heterologous expression and coassembly
Article first published online: 6 MAR 2002
Journal of Neurochemistry
Volume 80, Issue 6, pages 1009–1018, March 2002
How to Cite
Lansdell, S. J. and Millar, N. S. (2002), Dβ3, an atypical nicotinic acetylcholine receptor subunit from Drosophila: molecular cloning, heterologous expression and coassembly. Journal of Neurochemistry, 80: 1009–1018. doi: 10.1046/j.0022-3042.2002.00789.x
- Issue published online: 6 MAR 2002
- Article first published online: 6 MAR 2002
- Received September 6, 2001; revised manuscript received November 12, 2001; accepted December 12, 2001.
- cDNA cloning;
- nicotinic acetylcholine receptor
Insect nicotinic acetylcholine receptors (nAChRs) play a central role in mediating neuronal synaptic transmission and are the target sites for the increasingly important group of neonicotinoid insecticides. Six nicotinic acetylcholine receptor (nAChR) subunits (four α-type and two β-type) have been cloned previously from the model insect species Drosophila melanogaster. Despite extensive efforts, it has not been possible to generate functional recombinant nAChRs by heterologous expression of any combination of these six subunits. It has, however, been possible to express functional hybrid receptors when Drosophilaα subunits are co-expressed with vertebrate β subunits. This has led to the assumption that successful heterologous expression might require an, as yet, uncloned β-type insect subunit. Examination of the recently completed Drosophila genomic sequence data has identified a novel putative nAChR β-type subunit. Here we report the molecular cloning, heterologous expression and characterization of this putative Drosophila nAChR subunit (Dβ3). Phylogenetic comparisons with other ligand-gated ion channel subunit sequences support its classification as a nAChR subunit but show it to be a distantly related member of this neurotransmitter receptor subunit family. Evidence that the Dβ3 subunit is able to coassemble with other Drosophila nAChR subunits and contribute to recombinant nAChRs has been obtained by both radioligand binding and coimmunoprecipitation studies in transfected Drosophila S2 cells.