Characterization of the Drosophila Methoprene -tolerant gene product. Juvenile hormone binding and ligand-dependent gene regulation.

摘要: Juvenile hormones (JHs) of insects are sesquiterpenoids that regulate a great diversity processes in development and reproduction. As yet the molecular modes action JH poorly understood. The Methoprene-tolerant (Met) gene Drosophila melanogaster has been found to be responsible for resistance analogue (JHA) insecticide, methoprene. Previous studies on Met have implicated its involvement signaling, although direct evidence is lacking. We now examined product (MET) terms binding ligand-dependent regulation. In vitro synthesized MET directly bound III with high affinity (Kd = 5.3 +/- 1.5 nm, mean SD), consistent physiological concentration. transient transfection assays using S2 cells yeast GAL4-DNA domain fused exerted JH- or JHA-dependent activation reporter gene. Activation was highly JHA-specific order effectiveness: >> II > I methoprene; compounds which only structurally related JHA did not induce any activation. Localization nuclear irrespective presence absence JH. These results suggest may function as JH-dependent transcription factor.