Gsα is involved in sugar perception in Drosophila melanogaster
Gsα is involved in sugar perception in Drosophila melanogaster
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DOI：
10.1523/jneurosci.0857-06.2006
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发表时间：
2006-06-07
影响因子：
5.3
通讯作者：
Kidokoro, Y
中科院分区：
文献类型：
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作者：
Ueno, K;Kohatsu, S;Kidokoro, Y
在果蝇中，味觉受体基因（Grs）编码味觉受体神经元（GRNs）和一些嗅觉受体神经元中的G蛋白偶联受体（GPCRs）。Gr基因之一Gr5a编码一种糖受体，该受体在GRNs的一个子集中表达，并且已经在分子和生理学上进行了最广泛的研究，但是与该糖受体偶联的G蛋白α亚基（G α）仍然未知。在这里，我们建议，Gs是G α，负责Gr5a介导的糖味转导，基于以下发现：首先，对Gs的免疫反应性检测在一个子集的GRNs，包括所有Gr5a表达神经元。第二，海藻糖摄入量减少果蝇杂合子无效突变inDGs α，哺乳动物Gs的同源物，和海藻糖诱导的电活动在糖敏感的GRNs在这些苍蝇被压抑。此外，野生型DGs α在杂合DGs α突变果蝇的糖敏感GRNs中的表达挽救了这些损伤。第三，糖敏感GRNs中DGs α的双链RNA表达抑制了对海藻糖的行为和电生理反应。总之，这些发现表明DG α参与海藻糖感知。我们认为，糖味信号处理通过Gs α介导的信号转导通路在糖敏感的GRNs在果蝇。
In Drosophila melanogaster, gustatory receptor genes (Grs) encode G-protein-coupled receptors (GPCRs) in gustatory receptor neurons (GRNs) and some olfactory receptor neurons. One of the Gr genes, Gr5a, encodes a sugar receptor that is expressed in a subset of GRNs and has been most extensively studied both molecularly and physiologically, but the G-protein alpha subunit (G alpha) that is coupled to this sugar receptor remains unknown. Here, we propose that Gs is the G alpha that is responsible for Gr5a-mediated sugar-taste transduction, based on the following findings: First, immunoreactivities against Gs were detected in a subset of GRNs including all Gr5a-expressing neurons. Second, trehalose-intake is reduced in flies heterozygous for null mutations inDGs alpha, a homolog of mammalian Gs, and trehalose-induced electrical activities in sugar-sensitive GRNs were depressed in those flies. Furthermore, expression of wild-type DGs alpha in sugar-sensitive GRNs in heterozygotic DGs alpha mutant flies rescued those impairments. Third, expression of double-stranded RNA for DGs alpha in sugar-sensitive GRNs depressed both behavioral and electrophysiological responses to trehalose. Together, these findings indicate that DGs alpha is involved in trehalose perception. We suggest that sugar-taste signals are processed through the Gs alpha-mediating signal transduction pathway in sugar-sensitive GRNs in Drosophila.