Copyright information:Taken from "Use of adenoviral E1A protein to analyze K18 promoter deregulation in colon carcinoma cells discloses a role for CtBP1 and BRCA1"BMC Molecular Biology 2005;6():8-8.Published online 14 Apr 2005PMCID:PMC1087485.ce of plasmid pE1A-13S or pE1A-d30-76, as indicated. Luciferase activities are expressed relative to that obtained with the reporter plasmid alone for each cell clone. Error bars represent the standard deviation of the mean of two experiments. Structure of the promoter of the human K18 gene. The binding site of the Sp1 transcription factor, the initiation site (arrow at position -11; we have shown that the initiation is located 11 bp upstream of previously published +1 position [22]) and the TATA box are indicated. Numbers indicate positions in nucleotides. K18(80) and K18(41), the two forms of the promoter inserted into luciferase expression vectors are shown.