title: Steroid hormone 20-hydroxyecdysone regulation of the very-high-density lipoprotein (VHDL) receptor phosphorylation for VHDL uptake.
abstract: During the metamorphic stage of holometabolous insects, the biosynthetic precursors needed for the synthesis of a large number of adult proteins are acquired from the selective absorption of storage proteins. The very-high-density lipoprotein (VHDL), a non-hexameric storage protein, is consumed by the fat body from the hemolymph through VHDL receptor (VHDL-R)-mediated endocytosis. However, the mechanism of the uptake of VHDL by a VHDL-R remains unclear. In this study, a VHDL-R from Helicoverpa armigera was found to be involved in 20E-regulated VHDL uptake through the regulation of steroid hormone 20-hydroxyecdysone (20E). The transcripts of VHDL-R were detected mainly in the fat body and integument during the wandering stage. The transcription of VHDL-R was upregulated by 20E through the ecdysteroid receptor (EcRB1) and Ultraspiracle (USP1). In addition, 20E stimulates the phosphorylation of VHDL-R through protein kinase C for ligand binding. VHDL-R knockdown in larvae results the inhibition of development to adulthood. These data imply that 20E regulates VHDL-R on both transcriptional and posttranslational levels for VHDL absorption.
authors: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100 Shandong, China.
authors: Du-Juan
authors: DJ
authors: Dong
authors: Wen
authors: W
authors: Liu
authors: Mei-Juan
authors: MJ
authors: Cai
authors: Jin-Xing
authors: JX
authors: Wang
authors: Xiao-Fan
authors: XF
authors: Zhao
mesh_terms: D000818:Animals; D001692:Biological Transport; D004441:Ecdysterone / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D007301:Insect Hormones / Q000378:metabolism*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008075:Lipoproteins, HDL / Q000235:genetics / Q000378:metabolism*; D009036:Moths / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010766:Phosphorylation; D015854:Up-Regulation
chemical_list: D007301:Insect Hormones; D019476:Insect Proteins; D008075:Lipoproteins, HDL; C026277:very high density lipoproteins; D004441:Ecdysterone