We examined the SEPP1 promoter, from −1652 to +247, based on promoter ID #34663 in the Transcriptional Regulatory Element Database, to determine the region of the promoter responsible for this ecdysone-inducible transcription. Fragments of the promoter were tested using the luciferase reporter assay in the 293-EcR cells. Fragments included −1652 to +247, −1652 to −385, −391 to +247, −109 to +247, and −53 to +247 (Figure 2A). The greatest level of transcriptional activation following treatment with ponasterone A was observed on the −109 to +247 fragment, suggesting that a site within this region of the promoter may bind a component of the ecdysone-inducible system and induce transcription of SEPP1 (Figure 2B).
