Analysis of the human TATA binding protein promoter and identification of an Ets site critical for activity

The TATA binding protein (TBP) is a general transcription factor required for initiation by all three eukaryotic nuclear RNA polymerases. Little is known about how TBP gene expression is regulated. To identify sequence elements and proteins contributing to human TBP (hTBP) gene transcription, we have characterized the promoter in two human cell lines. Multiple 5'-ends of TBP mRNA mapped throughout a 111 bp region immediately upstream of a previously reported hTBP cDNA. Upon transient transfection into cells, the hTBP 5'-flanking region was shown to contain a fairly active promoter. The cis -acting elements responsible for this promoter activity in Namalwa and HeLa cells were localized in vivo by deletion analysis. The minimal promoter defined from these experiments was a 54 bp region that encompassed all but one minor start site and contained a functional Ets protein consensus binding site, which was shown to be required for promoter activity in both cell lines. The importance of other potential elements to promoter activity was found to differ between the two cell lines. Consistent with that finding, different complexes were formed on promoter-containing DNA fragments upon incubation with nuclear extracts prepared from the different cells.