Opposing chemosensory functions of closely related gustatory receptors.
Opposing chemosensory functions of closely related gustatory receptors.
复制标题
DOI：
10.7554/elife.89795
复制
发表时间：
2023-12-07
期刊：
影响因子：
7.7
通讯作者：
Amrein H
中科院分区：
文献类型：
--
作者：
Ahn JE;Amrein H
在果蝇黑腹果蝇中，味觉感觉神经元表达味觉感受器，这些感受器与不同的化学物质组相适应，从而激活神经集合，引发摄食或回避行为。味觉受体(GRs)是配体门控受体通道家族中的一员，在这些行为中发挥着核心作用。一般来说，密切相关的、进化上保守的Gr蛋白在同一类型的味觉神经元中共表达，与化学相关的化合物相协调，从而触发相同的行为反应。在这里，我们报告了Gr28亚家族的成员在果蝇幼虫的味觉神经元中表达，检测不同价态的化学物质，并触发相反的取食行为。我们通过表达哺乳动物香草样受体1(VR1)来确定Gr28神经元的内在特性，该受体由辣椒素激活，辣椒素是一种野生型果蝇幼虫不反应的化学物质。当VR1在Gr28a神经元中表达时，幼虫会被辣椒素吸引，这与报告显示Gr28a本身编码一种营养RNA受体是一致的。相反，VR1在两对Gr28b.c神经元中的表达触发了对辣椒素的回避。此外，神经元失活实验表明，Gr28b.c神经元是避免几种苦味化合物所必需的。最后，对Gr28缺乏幼虫的行为学实验和对Gr28b.c神经元的活体钙成像研究表明，苯甲酸变性是一种结构上与天然苦味化合物相似的合成苦味化合物，是含有Gr28b.c或Gr28b.a亚基的受体复合体的配体。因此，Gr28蛋白在昆虫中被进化保守了2.6亿年，它代表了第一个味觉受体亚家族，其中特定的成员以相反的价态调节行为。
In the fruit fly Drosophila melanogaster, gustatory sensory neurons express taste receptors that are tuned to distinct groups of chemicals, thereby activating neural ensembles that elicit either feeding or avoidance behavior. Members of a family of ligand -gated receptor channels, the Gustatory receptors (Grs), play a central role in these behaviors. In general, closely related, evolutionarily conserved Gr proteins are co-expressed in the same type of taste neurons, tuned to chemically related compounds, and therefore triggering the same behavioral response. Here, we report that members of the Gr28 subfamily are expressed in largely non-overlapping sets of taste neurons in Drosophila larvae, detect chemicals of different valence, and trigger opposing feeding behaviors. We determined the intrinsic properties of Gr28 neurons by expressing the mammalian Vanilloid Receptor 1 (VR1), which is activated by capsaicin, a chemical to which wild-type Drosophila larvae do not respond. When VR1 is expressed in Gr28a neurons, larvae become attracted to capsaicin, consistent with reports showing that Gr28a itself encodes a receptor for nutritious RNA. In contrast, expression of VR1 in two pairs of Gr28b.c neurons triggers avoidance to capsaicin. Moreover, neuronal inactivation experiments show that the Gr28b.c neurons are necessary for avoidance of several bitter compounds. Lastly, behavioral experiments of Gr28 deficient larvae and live Ca2+ imaging studies of Gr28b.c neurons revealed that denatonium benzoate, a synthetic bitter compound that shares structural similarities with natural bitter chemicals, is a ligand for a receptor complex containing a Gr28b.c or Gr28b.a subunit. Thus, the Gr28 proteins, which have been evolutionarily conserved over 260 million years in insects, represent the first taste receptor subfamily in which specific members mediate behavior with opposite valence.
DOI：
10.1016/j.tjnut.2023.03.010
发表时间：
2023-05
期刊：
The Journal of nutrition
影响因子：
--
作者：
Fujii S;Ahn JE;Jagge C;Shetty V;Janes C;Mohanty A;Slotman M;Adelman ZN;Amrein H
通讯作者：
Amrein H
影响因子：
9.8
作者：
Mishra D;Thorne N;Miyamoto C;Jagge C;Amrein H
通讯作者：
Amrein H