Involvement of upstream stimulatory factor in regulation of the mouse Prnd gene coding for Doppel protein.

Promoter of the Prnd gene coding for the Prion-like protein Doppel contains two critical cis-regulatory elements, NF-Y consensus motif and canonical E-box. Here, we studied a role of the upstream stimulatory factor (USF) in the E-box-mediated activation of Prnd transcription. Co-expression of USF-1 with the luciferase reporter gene driven by the -185/+27 Prnd promoter fragment resulted in several fold increase of the luciferase activity. Conversely, mutations within the E-box led to a significantly reduced Prnd promoter activation. USF-1 binding was supported by the gel shift assay, supershift with USF-1 antibody and UV cross-linking. The activation capacity of the related USF-2, c-Myc and HIF-2alpha proteins was lower compared to USF-1 suggesting that USF-1 is the major E-box-binding transcription factor regulating the Prnd promoter.