Analysis of upstream sequences of the human estrogen receptor gene

An upstream region of the human estrogen receptor gene (ER) spanning from -2776 to -38 in relation to a previously described exon 1 was sequenced and analyzed for the possible presence of open reading frames (ORF) and regulatory motifs. We identified a long 459 bp ORF beginning at -2301. Most of the transcriptional regulatory motifs present within the ER upstream sequence are distributed either upstream or downstream of this long ORF which displays a TATA box, a CACC motif and a canonical cap site in the 5' flanking region.