Graduate School of Science, Nagoya University, Nagoya, Japan.
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
Elife. 2023 Aug 17;12:e83974. doi: 10.7554/eLife.83974.
G-protein-coupled receptors (GPCRs) transmit signals into cells depending on the G protein type. To analyze the functions of GPCR signaling, we assessed the effectiveness of animal G-protein-coupled bistable rhodopsins that can be controlled into active and inactive states by light application using zebrafish. We expressed Gq- and Gi/o-coupled bistable rhodopsins in hindbrain reticulospinal V2a neurons, which are involved in locomotion, or in cardiomyocytes. Light stimulation of the reticulospinal V2a neurons expressing Gq-coupled spider Rh1 resulted in an increase in the intracellular Ca level and evoked swimming behavior. Light stimulation of cardiomyocytes expressing the Gi/o-coupled mosquito Opn3, pufferfish TMT opsin, or lamprey parapinopsin induced cardiac arrest, and the effect was suppressed by treatment with pertussis toxin or barium, suggesting that Gi/o-dependent regulation of inward-rectifier K channels controls cardiac function. These data indicate that these rhodopsins are useful for optogenetic control of GPCR-mediated signaling in zebrafish neurons and cardiomyocytes.
G 蛋白偶联受体（GPCRs）根据 G 蛋白类型将信号传递到细胞内。为了分析 GPCR 信号转导的功能，我们评估了动物 G 蛋白偶联双稳态视蛋白的有效性，这些视蛋白可以通过光应用控制为活性和非活性状态，我们使用斑马鱼进行了表达。我们在参与运动的后脑网状脊髓 V2a 神经元或心肌细胞中表达了 Gq 和 Gi/o 偶联双稳态视蛋白。表达 Gq 偶联蜘蛛 Rh1 的网状脊髓 V2a 神经元的光刺激导致细胞内 Ca 水平升高，并引起游泳行为。表达 Gi/o 偶联蚊子 Opn3、河豚 TMT 视蛋白或七鳃鳗 parapinopsin 的心肌细胞的光刺激诱导心脏骤停，并且该效应被百日咳毒素或钡处理抑制，表明 Gi/o 依赖性内向整流钾通道的调节控制心脏功能。这些数据表明，这些视蛋白可用于光遗传学控制斑马鱼神经元和心肌细胞中 GPCR 介导的信号转导。
