title: Identification of ecdysone response elements (EcREs) in the Bombyx mori cathepsin D promoter.
abstract: Bombyx mori Cathepsin D (BmCatD) is specifically expressed in the fat body, and plays a critical role for the programmed cell death of the larval fat body and pupal gut during metamorphosis. To better understand the transcriptional control of BmCatD expression, we conducted this study to identify the ecdysone response elements (EcREs) in the BmCatD promoter and clarify their regulational functions. We inserted EcREs into a recombinant AcMNPV (Autographa californica multiple nucleopolyhedrovirus) vector and performed luciferase assay with a dual-luciferase quantitative assay system. Three putative EcREs were located at positions -109 to -99, -836 to -826 and -856 to -846 relative to the transcription start site. Overlapping deletion studies of this EcRE region showed that the three EcREs could suppress the ectopic expression of the BmCatD promoter. EcRE mutations resulted in the loss of the fat body-specific expression of the BmCatD gene. These results suggest that the EcREs are vital for activation of the promoter by 20-hydroxyecdysone (20E) in the larval fat body and further support the crucial role of ecdysone signaling to control cathepsin D gene transcription. It may suggest that the heterodimeric complex EcR/USP mediates the activation of ecdysone-dependent BmCatD transcription in the larval fat body of B. mori.
authors: Jiangsu University of Science and Technology, Zhenjiang 212018, China.
authors: Jie
authors: J
authors: Yu
authors: Feng-Yao
authors: FY
authors: Wu
authors: Feng-Ming
authors: FM
authors: Zou
authors: Jun-Qiang
authors: JQ
authors: Jia
authors: Sheng-Peng
authors: SP
authors: Wang
authors: Guo-Zheng
authors: GZ
authors: Zhang
authors: Xi-Jie
authors: XJ
authors: Guo
authors: Zhong-Zheng
authors: ZZ
authors: Gui
mesh_terms: D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics* / Q000254:growth & development; D002402:Cathepsin D / Q000235:genetics*; D004440:Ecdysone / Q000494:pharmacology / Q000502:physiology*; D004441:Ecdysterone / Q000494:pharmacology; D008156:Luciferases / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D020218:Response Elements / Q000187:drug effects / Q000235:genetics*; D024363:Transcription Initiation Site; D015533:Transcriptional Activation
chemical_list: D004440:Ecdysone; D004441:Ecdysterone; D008156:Luciferases; D002402:Cathepsin D