An upstream promoter element blocks the reverse transcription of the mouse insulin-degrading enzyme gene

► We investigate the transcriptional directionality of the mouse IDE promoter. ► The basic promoter region of mouse IDE has bidirectional transcriptional activities. ► An upstream promoter element blocks the reverse transcription of mouse IDE. ► This upstream promoter element contains two functional sub-regions. ► This work is suggestive for the transcriptional mechanism of bidirectional promoters.