Function and pharmacology of glutamate-gated chloride channel exon 9 splice variants from the diamondback moth Plutella xylostella
Function and pharmacology of glutamate-gated chloride channel exon 9 splice variants from the diamondback moth Plutella xylostella
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小菜蛾谷氨酸门控氯通道外显子 9 剪接变体的功能和药理学
DOI：
10.1016/j.ibmb.2018.12.005
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发表时间：
2019
影响因子：
3.8
通讯作者：
Yidong Wu
中科院分区：
文献类型：
--
作者：
Xingliang Wang;Andrias O. O'Reilly;Martin S. Williamson;Alin M. Puinean;Yihua Yang;Shuwen Wu;Yidong Wu
谷氨酸门控氯离子通道（GluCls）仅在无脊椎动物中发现，并介导快速抑制性神经传递。GluCls的结构和功能多样性是通过多个亚基的组装和转录后改变产生的。选择性剪接是在昆虫GluCl中实现这一点的最常见方式，并且剪接主要发生在外显子3和9处。由于对无脊椎动物GluCl基因外显子9选择性剪接的表达模式和药理学特性知之甚少，本研究构建了小菜蛾PxGluCl基因的3个选择性剪接变体（9a、9b和9c）的cDNA，并利用电生理学方法研究了它们的药理学特性。当在爪蟾卵母细胞中单独或共表达亚基时，外显子9的选择性剪接对PxGluCl对激动剂谷氨酸的敏感性几乎没有影响。相比之下，变构调节剂阿维菌素和氯离子通道阻断剂氟虫腈对PxGluCl剪接变体具有不同的影响。PxGluCl9c通道对阿维菌素更耐药，PxGluCl9b通道对氟虫腈更敏感。此外，含有不同剪接变体的异聚体通道对阿维菌素的敏感性相似（9c除外），对氟虫腈的敏感性低于同聚体通道。这些发现表明，功能上不可区分，但不同的GluCls可以形成在P。并且特定变体的组成性表达上调可能有助于小菜蛾杀虫剂抗性的进化。xylostella和其他节肢动物。
Glutamate-gated chloride channels (GluCls) are found only in invertebrates and mediate fast inhibitory neurotransmission. The structural and functional diversity of GluCls are produced through assembly of multiple subunits and via posttranscriptional alternations. Alternative splicing is the most common way to achieve this in insect GluCls and splicing occurs primarily at exons 3 and 9. As expression pattern and pharmacological properties of exon 9 alternative splices in invertebrate GluCls remain poorly understood, the cDNAs encoding three alternative splice variants (9a, 9b and 9c) of the PxGluCl gene from the diamondback mothPlutella xylostellawere constructed and their pharmacological characterizations were examined using electrophysiological studies. Alternative splicing of exon 9 had little to no impact on PxGluCl sensitivity towards the agonist glutamate when subunits were singly or co-expressed in Xenopus oocytes. In contrast, the allosteric modulator abamectin and the chloride channel blocker fipronil had differing effects on PxGluCl splice variants. PxGluCl9c channels were more resistant to abamectin and PxGluCl9b channels were more sensitive to fipronil than other homomeric channels. In addition, heteromeric channels containing different splice variants showed similar sensitivity to abamectin (except for 9c) and reduced sensitivity to fipronil than homomeric channels. These findings suggest that functionally indistinguishable but pharmacologically distinct GluCls could be formed inP. xylostellaand that the upregulated constitutive expression of the specific variants may contribute to the evolution of insecticide resistance inP. xylostellaand other arthropods.