Novel alternative splicing of GABA receptor RDL exon 9 from Laodelphax striatellus modulates agonist potency

AbstractThe resistance to dieldrin gene (RDL) encodes the primary subunit of the insect ionotropicγ‐aminobutyric acid (GABA) receptor (GABAR), which is the target of phenylpyrazole and isoxazoline insecticides. The splice variants in exons 3 and 6 ofRDL, which have been widely explored in many insects, modulate the agonist potency of the homomeric RDL GABAR and potentially play an important role in the development of insects. In the present study, four splice variants of exon 9 were identified inRDL of the small brown planthopper,Laodelphax striatellus (LsRDL), resulting in LsRDL‐9a, LsRDL‐9a’, LsRDL‐9b, and LsRDL‐9c. LsRDL‐9a has one more amino acid (E, glutamic acid) compared with LsRDL‐9a’, and LsRDL‐9b lacked two amino acids and had seven different amino acids compared with LsRDL‐9c. Two‐electrode voltage‐clamp recording on LsRDLs expressed inXenopus oocytes showed that alternative splicing of exon 9 has significant impact on LsRDL sensitivity to the agonists GABA andβ‐alanine, whereas no significant difference was observed in the potencies of the non‐competitive antagonists (NCAs) ethiprole and fluralaner on the splice variants. Our results suggest that alternative splicing ofRDL exon 9 broadens functional capabilities of the GABAR inL. striatellus by influencing the action of GABA.

Source: Insect Science - August 23, 2020 Category: Biology Authors: Jie Jiang, Li ‐Xin Huang, Feng Chen, Cheng‐Wang Sheng, Qiu‐Tang Huang, Zhao‐Jun Han, Chun‐Qing Zhao Tags: ORIGINAL ARTICLE Source Type: research