title: Hsc70 binds to ultraspiracle resulting in the upregulation of 20-hydroxyecdsone-responsive genes in Helicoverpa armigera.
abstract: To probe the specific functions of the chaperone protein Hsc70 in 20-hydroxyecdysone signaling, we report on the roles of the Hsc70 from Helicoverpa armigera. RT-PCR analysis revealed that the genes for HaEcRB1 and HaUSP1 were upregulated in 5th molting and metamorphic molting larvae, whereas HaHsc70 maintained a constitutive expression level throughout larval development. Silencing HaEcRB1, HaUSP1 or HaHsc70 by RNAi inhibited the expression of a set of 20E-responsive genes. Immunocytochemical assay demonstrated that HaHsc70 is located predominantly in the cytoplasm of unstimulated cells and partially translocated to the nucleus after stimulation by 20E. Knockdown of HaHsc70 by RNAi decreased the amount of both HaEcRB1 and HaUSP1 in the nucleus. HaHsc70 was capable of binding to HaUSP1 in pull-down assays. These data suggest that Hsc70 participates in the 20E signal transduction pathway via binding to USP1 and mediating the expression of EcRB1, USP1 and then a set of 20E-responsive genes.
authors.affiliation: School of Life Sciences, the Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong University, Shanda Road 27, Jinan 250100, Shandong, China.
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Zheng
authors.forename: Dan-Tong
authors.initials: DT
authors.lastname: Yang
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
authors.forename: Qi-Sheng
authors.initials: QS
authors.lastname: Song
authors.forename: Lawrence I
authors.initials: LI
authors.lastname: Gilbert
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D004441:Ecdysterone / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D008726:Methoprene / Q000378:metabolism; D008969:Molecular Sequence Data; D018978:Molting / Q000502:physiology; D009036:Moths / Q000235:genetics / Q000502:physiology; D011485:Protein Binding; D034622:RNA Interference; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D050883:HSC70 Heat-Shock Proteins; D014157:Transcription Factors; C066030:USP protein, Drosophila; D004441:Ecdysterone; D008726:Methoprene