Ebbinghaus-Kintscher Ulrich, Luemmen Peter, Lobitz Nicole, Schulte Thomas, Funke Christian, Fischer Rüdiger, Masaki Takao, Yasokawa Noriaki, Tohnishi Masanori
Bayer CropScience AG, Alfred-Nobel-Strasse 50, D-40789 Monheim, Germany.
Cell Calcium. 2006 Jan;39(1):21-33. doi: 10.1016/j.ceca.2005.09.002. Epub 2005 Oct 10.
Flubendiamide represents a novel chemical family of substituted phthalic acid diamides with potent insecticidal activity. So far, the molecular target and the mechanism of action were not known. Here we present for the first time evidence that phthalic acid diamides activate ryanodine-sensitive intracellular calcium release channels (ryanodine receptors, RyR) in insects. With Ca(2+) measurements, we showed that flubendiamide and related compounds induced ryanodine-sensitive cytosolic calcium transients that were independent of the extracellular calcium concentration in isolated neurons from the pest insect Heliothis virescens as well as in transfected CHO cells expressing the ryanodine receptor from Drosophila melanogaster. Binding studies on microsomal membranes from Heliothis flight muscles revealed that flubendiamide and related compounds interacted with a site distinct from the ryanodine binding site and disrupted the calcium regulation of ryanodine binding by an allosteric mechanism. This novel insecticide mode of action seems to be restricted to specific RyR subtypes because the phthalic acid diamides reported here had almost no effect on mammalian type 1 ryanodine receptors.
氟苯虫酰胺代表了一类具有强大杀虫活性的新型取代邻苯二甲酸二酰胺化学家族。到目前为止，其分子靶点和作用机制尚不清楚。在此，我们首次提出证据表明邻苯二甲酸二酰胺可激活昆虫体内对瑞香毒素敏感的细胞内钙释放通道（瑞香毒素受体，RyR）。通过钙测量，我们发现氟苯虫酰胺及相关化合物可诱导对瑞香毒素敏感的胞质钙瞬变，这在害虫烟草天蛾的分离神经元以及表达来自黑腹果蝇的瑞香毒素受体的转染CHO细胞中均与细胞外钙浓度无关。对烟草天蛾飞行肌微粒体膜的结合研究表明，氟苯虫酰胺及相关化合物与一个不同于瑞香毒素结合位点的位点相互作用，并通过变构机制破坏了瑞香毒素结合的钙调节。这种新型杀虫剂作用模式似乎仅限于特定的RyR亚型，因为此处报道的邻苯二甲酸二酰胺对哺乳动物1型瑞香毒素受体几乎没有影响。
