As ligands of the sugar gustatory receptors,sugars have been known to activatethe insulin/insulin-like growth factor signaling pathway;however,the precise pathways thatare activated by the sugar-bound gustatory recept...As ligands of the sugar gustatory receptors,sugars have been known to activatethe insulin/insulin-like growth factor signaling pathway;however,the precise pathways thatare activated by the sugar-bound gustatory receptors in insects remain unclear.In this study,we aimed to investigate the signaling cascades activated by NlGr11,a sugar gustatory re-ceptor in the brown planthopper Nilaparvata lugens(Stal),and its ligand.Galactose-boundNGrl1(galactose-NIGr11)activated the-phosphatidylinositol 3-kinase(PI3K)-AKT signaling cascade via insulin receptor(InR)and Gβγin vitro.In addition,galactose-NlGr11inhibited the adenosine monophosphate-activated protein kinase(AMPK)phosphorylationby activating the AKT-phosphofructokinase(PFK)-ATP signaling cascade in vitro.Impor-tantly,the InR-PI3K-AKT-PFK-AKT signaling cascade was activated and the AMPKphosphorylation was inhibited after feeding the brown planthoppers with galactose solu-tion.Collectively,these findings confirm that NIGr1l can inhibit AMPK phosphorylationby activating the PI3K-AKT-PFK-ATP signaling cascades via both InR and GBy whenbound to galactose.Thus,our study provides novel insights into the signaling pathwaysregulated by the sugar gustatory receptors in insects.展开更多
基金the National Natural Science Foundation of China(U1401212)the China Postdoctoral Science Foundation(2017M612808).
文摘As ligands of the sugar gustatory receptors,sugars have been known to activatethe insulin/insulin-like growth factor signaling pathway;however,the precise pathways thatare activated by the sugar-bound gustatory receptors in insects remain unclear.In this study,we aimed to investigate the signaling cascades activated by NlGr11,a sugar gustatory re-ceptor in the brown planthopper Nilaparvata lugens(Stal),and its ligand.Galactose-boundNGrl1(galactose-NIGr11)activated the-phosphatidylinositol 3-kinase(PI3K)-AKT signaling cascade via insulin receptor(InR)and Gβγin vitro.In addition,galactose-NlGr11inhibited the adenosine monophosphate-activated protein kinase(AMPK)phosphorylationby activating the AKT-phosphofructokinase(PFK)-ATP signaling cascade in vitro.Impor-tantly,the InR-PI3K-AKT-PFK-AKT signaling cascade was activated and the AMPKphosphorylation was inhibited after feeding the brown planthoppers with galactose solu-tion.Collectively,these findings confirm that NIGr1l can inhibit AMPK phosphorylationby activating the PI3K-AKT-PFK-ATP signaling cascades via both InR and GBy whenbound to galactose.Thus,our study provides novel insights into the signaling pathwaysregulated by the sugar gustatory receptors in insects.
