Cloning and Functional Characterisation of Two Novel Nicotinic Acetylcholine Receptor α Subunits from the Insect Pest Myzus persicae

: Nicotinic acetylcholine receptors play a major role in excitatory neurotransmission in insect CNSs and constitute an important target for insecticides. Here, we report the isolation and functional characterisation of two cDNAs encoding nicotinic acetylcholine receptor α subunits from a major insect pest, the peach‐potato aphid Myzus persicae. These two subunits, termed Mpα1 and Mpα2, are respective structural homologues of the Drosophila Dα2/Schistocerca gregariaαL1 α‐subunit pair and the Drosophila ALS α subunit. Xenopus oocyte expression confirmed that each Myzus subunit can form functional acetylcholine‐ or nicotine‐gated channels. However, some electrophysiological and pharmacological properties of the Myzus subunits were distinct from those encoded by the corresponding Drosophila subunits. Coexpression of the Myzus subunits with the chick β2 subunit revealed other differences from the Drosophila system, as only very limited potentiation of agonist‐induced currents was observed with Mpα2 and none with Mpα1. Available data therefore indicate that structurally homologous insect nicotinic acetylcholine receptor α subunits from different species can exhibit distinctive physiological and pharmacological characteristics.