College of Fisheries, Huazhong Agricultural University, No.1, Shizishan Street, Hongshan District, Wuhan 430070, China.
Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China.
Int J Mol Sci. 2024 Sep 18;25(18):10035. doi: 10.3390/ijms251810035.
Metabotropic glutamate receptor 4 (mGluR4) is widely regarded as an umami receptor activated by L-glutamate to exert essential functions. Numerous studies have shown that umami receptors participate in food intake regulation. However, little is known about mGluR4's role in mediating food ingestion and its possible molecular mechanism. Mandarin fish, a typical carnivorous fish, is sensitive to umami substances and is a promising vertebrate model organism for studying the umami receptor. In this study, we identified the mGluR4 gene and conducted evolutionary analyses from diverse fish species with different feeding habits. mGluR4 of mandarin fish was cloned and functionally expressed to investigate the effects of L-glutamate on mGluR4. We further explored whether the signal pathway mGluR4-Ca-ERK1/2 participates in the process in mandarin fish brain cells. The results suggest that L-glutamate could regulate Neuropeptide Y (Npy) via the mGluR4-Ca-ERK1/2 signaling pathway in mandarin fish. Our findings unveil the role of mGluR4 in feeding decisions and its possible molecular mechanisms in carnivorous fishes.
代谢型谷氨酸受体 4（mGluR4）被广泛认为是一种鲜味受体，可被 L-谷氨酸激活以发挥重要功能。许多研究表明，鲜味受体参与了食物摄入的调节。然而，对于 mGluR4 在介导摄食中的作用及其可能的分子机制知之甚少。鳜鱼是一种典型的肉食性鱼类，对鲜味物质敏感，是研究鲜味受体的很有前途的脊椎动物模式生物。在这项研究中，我们从具有不同摄食习性的多种鱼类中鉴定了 mGluR4 基因，并进行了进化分析。克隆了鳜鱼的 mGluR4 并进行了功能表达，以研究 L-谷氨酸对 mGluR4 的影响。我们进一步探讨了 mGluR4-Ca-ERK1/2 信号通路是否参与了鳜鱼脑细胞中的这一过程。结果表明，L-谷氨酸可以通过 mGluR4-Ca-ERK1/2 信号通路调节鳜鱼的神经肽 Y（Npy）。我们的研究结果揭示了 mGluR4 在摄食决策中的作用及其在肉食性鱼类中的可能分子机制。
