title: G-protein-coupled receptor kinase 2 terminates G-protein-coupled receptor function in steroid hormone 20-hydroxyecdysone signaling.
abstract: G-protein-coupled receptors (GPCRs) transmit extracellular signals across the cell membrane. GPCR kinases (GRKs) desensitize GPCR signals in the cell membrane. However, the role and mechanism of GRKs in the desensitization of steroid hormone signaling are unclear. In this study, we propose that GRK2 is phosphorylated by protein kinase C (PKC) in response to induction by the steroid hormone 20-hydroxyecdysone (20E), which determines its translocation to the cell membrane of the lepidopteran Helicoverpa armigera. GRK2 protein expression is increased during the metamorphic stage because of induction by 20E. Knockdown of GRK2 in larvae causes accelerated pupation, an increase in 20E-response gene expression, and advanced apoptosis and metamorphosis. 20E induces translocation of GRK2 from the cytoplasm to the cell membrane via steroid hormone ecdysone-responsive GPCR (ErGPCR-2). GRK2 is phosphorylated by PKC on serine 680 after induction by 20E, which leads to the translocation of GRK2 to the cell membrane. GRK2 interacts with ErGPCR-2. These data indicate that GRK2 terminates the ErGPCR-2 function in 20E signaling in the cell membrane by a negative feedback mechanism.
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Wen-Li
authors.initials: WL
authors.lastname: Zhao
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Di
authors.initials: D
authors.lastname: Wang
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Liu
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000235:genetics; D004441:Ecdysterone / Q000235:genetics / Q000378:metabolism*; D054769:G-Protein-Coupled Receptor Kinase 2 / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D007814:Larva / Q000235:genetics / Q000254:growth & development; D007915:Lepidoptera / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics; D021381:Protein Transport / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics
chemical_list: D004441:Ecdysterone; D011493:Protein Kinase C; D054769:G-Protein-Coupled Receptor Kinase 2