Figure 2.

Identification of a repressor element in the porcine and human IL-1α gene. A, Schematic representation of the porcine IL-1α gene promoter and first 2 exons. The nucleotide sequence of a repressor element (boxed) is shown. Because the repressor element is located “downstream” or 3′ to the IL-1α gene promoter, between exon 1 and exon 2, we named it repressor downstream, or RepD (see below). B, The IL-1α gene promoter or the promoter plus 700 bp of contiguous 3′ sequence (downstream) encoding the first 2 exons of IL-1α was cloned into a luciferase reporter plasmid, and the reporter plasmids were transfected into porcine aortic endothelial cells. Production of the luciferase reporter measured 36 hours later revealed that the 700-bp sequence abolished luciferase reporter gene production. The bar graph reflects the mean±SEM of triplicate samples and is representative of 3 experiments. Deletions within the 700-bp repressor region sequence showed that the 163-bp region located ≈100 bp 3′ of the IL-1α gene promoter contained the repressor.