Research Progress on G-Protein-Coupled Receptor for 20-hydroxyecdysone
XinLe Kang, JunYing Zhang, Di Wang, JinXing Wang, XiaoFan Zhao*
Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China. *
It is generally accepted that insect molting hormone 20-hydroxyecdysone (20E), a lipid soluble molecule, freely enters cells to regulate gene expression via binding to its nuclear receptor (EcR) and formation of transcription complex with the heteropatner Ultraspirecle (USP) for insect molting and metamorphosis. Interestingly, we found 20E also upregulates PKCδ expression via EcRB1 and USP1. The catalytic domain of overexpressed-PKCδ was autophosphorylated and localized in the nucleus, which can phosphorylate EcRB1 at T468 directly. The phosphorylated-EcRB1 interacted with phosphorylated and acetylated USP (P-USP1-Ac) to form the EcRB1/USP1 transcriptional complex to promote expression of apoptotic genes and apoptosis. In addition to the nuclear pathway, we also identified two G-protein-coupled-receptors (GPCR) that conduct 20E signal at the plasma membrane. Swift deciphering 20E signal by GPCRs led a rapid influx of calcium ion, promoted cell apoptosis and metamorphosis. The G-protein αq (Gαq), gamma phospholipase C1 (PLCG1), protein kinases (PKA, PKC, CDK10, CaMKII) and calcium ion channel ORAI1 are key components in plasma membrane signaling of 20E. 20E membrane and nuclear signaling pathways relate to each other. The membrane signaling pathway is upstream of the nuclear signaling pathway. GPCR-mediated 20E signaling at cell surface regulates nuclear pathway of 20E, including phosphorylation and acetylation of USP1, formation of EcRB1/USP1 complex, and the binding of transcription complex to DNA response elements. These regulations of gene transcription led to cell apoptosis and completion of insect metamorphosis. Binding of 20E to GPCRs is dynamically, associated and dissociated rapidly. Detection sensitivity of GPCR binding to 20E can be improved when analytic methods were improved.
Acknowledgements: the National Natural Science Foundation of China (31730083 and 31572328) to Zhao XiaoFan.
Key Words: Insect, steroid hormone, 20-hydroxyecdyone, nuclear receptor, G-protein-coupled receptor, signal pathway
XinLe Kang, JunYing Zhang, Di Wang, JinXing Wang, XiaoFan Zhao*
Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China. *
It is generally accepted that insect molting hormone 20-hydroxyecdysone (20E), a lipid soluble molecule, freely enters cells to regulate gene expression via binding to its nuclear receptor (EcR) and formation of transcription complex with the heteropatner Ultraspirecle (USP) for insect molting and metamorphosis. Interestingly, we found 20E also upregulates PKCδ expression via EcRB1 and USP1. The catalytic domain of overexpressed-PKCδ was autophosphorylated and localized in the nucleus, which can phosphorylate EcRB1 at T468 directly. The phosphorylated-EcRB1 interacted with phosphorylated and acetylated USP (P-USP1-Ac) to form the EcRB1/USP1 transcriptional complex to promote expression of apoptotic genes and apoptosis. In addition to the nuclear pathway, we also identified two G-protein-coupled-receptors (GPCR) that conduct 20E signal at the plasma membrane. Swift deciphering 20E signal by GPCRs led a rapid influx of calcium ion, promoted cell apoptosis and metamorphosis. The G-protein αq (Gαq), gamma phospholipase C1 (PLCG1), protein kinases (PKA, PKC, CDK10, CaMKII) and calcium ion channel ORAI1 are key components in plasma membrane signaling of 20E. 20E membrane and nuclear signaling pathways relate to each other. The membrane signaling pathway is upstream of the nuclear signaling pathway. GPCR-mediated 20E signaling at cell surface regulates nuclear pathway of 20E, including phosphorylation and acetylation of USP1, formation of EcRB1/USP1 complex, and the binding of transcription complex to DNA response elements. These regulations of gene transcription led to cell apoptosis and completion of insect metamorphosis. Binding of 20E to GPCRs is dynamically, associated and dissociated rapidly. Detection sensitivity of GPCR binding to 20E can be improved when analytic methods were improved.
Acknowledgements: the National Natural Science Foundation of China (31730083 and 31572328) to Zhao XiaoFan.
Key Words: Insect, steroid hormone, 20-hydroxyecdyone, nuclear receptor, G-protein-coupled receptor, signal pathway