Figure 1

Regulatory sites of the human BRCA1 promoter. A specificity protein (Sp) consensus site located upstream of an activator protein (AP)-1 element in the intervening sequence between exon-1a and exon-1b contributes to basal and estrogen-regulated transcription. A cAMP response element (CRE) site located downstream of the AP-1 contributes to basal regulation. Numbers in parenthesis for the Sp, AP-1, and CRE elements are base pairs from the initiation of transcription (+1) on exon-1b. Nucleotides in boxes represent the sequence and spatial arrangement of the Sp, AP-1, and CRE domains. Arrows flanking the Sp/AP-1/CRE sites indicate the position of oligonucleotides used for real-time amplification after chromatin immunoprecipitation assays. The specific sequences of oligonucleotides are reported in the Materials and methods section. pGL3BRCA-1 represents a 1.692 kilobase BRCA1 promoter-luciferase (LUC) construct used in transfection studies. This promoter fragment extends from +140 base pairs to – 1.552 kilobases from the +1 of exon-1b. Details of the recruitment of a p300/ER-α/SRC-1 complex to the AP-1 site are described elsewhere [33].