Juvenile hormone (JH) is a major hormone that regulates various developmental events during an insect’s life cycle. JH response elements (JHRE) identified in the promoter region of JH- and 20-hydroxyecdysone (20E)-responsive JH esterase (jhe) gene and ecdysone receptor (EcR) deficient Drosophila melanogaster
cell line (L57) were used to study gene regulation by JH and 20E. In L57 cells, a reporter gene placed under the control of JHRE is induced by JH in a dose-and time-dependent manner. JH-induced reporter gene expression was suppressed by 20E in L57 cells transfected with EcR expressed under the control of baculovirus IE1 promoter. The nuclear proteins isolated from L57 cells specifically bound to JHRE. JH-induced dephosphorylation of nuclear proteins is a prerequisite for their binding to JHRE. Exposure of nuclear proteins to JH either in vivo
or in vitro led to their dephosphorylation followed by binding to JHRE. 20E in the presence of EcR can block JH-regulated dephosphorylation of nuclear proteins and prevent their binding to JHRE. These data suggest that 20E can modulate JH-induced gene expression by regulating phosphorylation of nuclear proteins.
Species 1: Diptera Drosophilidae Drosophila Melanogaster (Fruit fly)
Keywords: Juvenile hormone, ecdysone
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