Buckingham S D, Matsuda K, Hosie A M, Baylis H A, Squire M D, Lansdell S J, Millar N S, Sattelle B
Babraham Institute Laboratory of Molecular Signalling, Department of Zoology, University of Cambridge, UK.
Neuropharmacology. 1996;35(9-10):1393-401. doi: 10.1016/s0028-3908(96)00087-1.
RDL is an ionotropic GABA receptor subunit, a product of the Rdl gene, originally identified in the Maryland strain of Drosophila melanogaster. Here, we report the generation of a Drosophila melanogaster cell line (S2-RDLA302S) stably expressing a mutated, dieldrin-resistant (A302S) form of RDL. The properties of this dieldrin-resistant, homo-oligomeric receptor have been compared with those of the stably expressed, wild-type form (S2-RDL). Using these stable lines, a striking reduction in sensitivity to both picrotoxinin and dieldrin was observed for responses to GABA of S2-RDLA302S compared to S2-RDL. To determine if these stable insect cell lines generate results similar to those obtained by transient expression in Xenopus laevis oocytes, we have examined the actions of two widely used convulsants, EBOB and TBPS, and a recently developed convulsant BIDN, on RDL-mediated GABA responses in the two expression systems. In both oocytes and S2 cells, the three convulsants suppressed the amplitude of responses to GABA. Thus, in accord with earlier work on agonist and allosteric sites, the S2-RDL cell line is found to yield similar pharmacological results to those obtained in transient expression studies. Stable cell lines are now available expressing susceptible and resistant forms of an ionotropic receptor by GABAergic insecticides.
RDL是一种离子型GABA受体亚基，是Rdl基因的产物，最初在黑腹果蝇的马里兰品系中被鉴定出来。在此，我们报告了一种稳定表达RDL突变的、对狄氏剂耐药（A302S）形式的黑腹果蝇细胞系（S2-RDLA302S）的产生。已将这种对狄氏剂耐药的同型寡聚体受体的特性与稳定表达的野生型形式（S2-RDL）的特性进行了比较。使用这些稳定细胞系，与S2-RDL相比，观察到S2-RDLA302S对GABA的反应对印防己毒素和狄氏剂的敏感性显著降低。为了确定这些稳定的昆虫细胞系产生的结果是否与在非洲爪蟾卵母细胞中瞬时表达所获得的结果相似，我们研究了两种广泛使用的惊厥剂EBOB和TBPS，以及一种最近开发的惊厥剂BIDN，对两种表达系统中RDL介导的GABA反应的作用。在卵母细胞和S2细胞中，这三种惊厥剂均抑制了对GABA的反应幅度。因此，与早期关于激动剂和变构位点的研究一致，发现S2-RDL细胞系产生的药理学结果与瞬时表达研究所获得的结果相似。现在已有稳定细胞系可表达对GABA能杀虫剂敏感和耐药形式的离子型受体。
