The downstream core promoter element, DPE, is conserved from Drosophila to humans and is recognized by TAFII60 of Drosophila.
We analyzed the function of the downstream promoter element (DPE), a distinct 7-nucleotide core promoter element that is approximately 30 nucleotides downstream of the transcription start site of many TATA-box-deficient (TATA-less) promoters in Drosophila. There is a strict requirement for spacing between the Inr and DPE motifs, as an increase or decrease of 3 nucleotides in the distance between the Inr and DPE causes a seven- to eightfold reduction in transcription as well as a significant reduction in the binding of purified TFIID. These results suggest a specific and somewhat rigid interaction of TFIID with the Inr and DPE sequences. Photo-cross-linking analysis of purified TFIID with a TATA-less DPE-containing promoter revealed specific cross-linking of dTAFII60 and dTAFII40 to the DPE, with a higher efficiency of cross-linking to dTAFII60 than to dTAFII40. These data, combined with the previously well-characterized interactions between the two TAFs and their homology to histones H4 and H3, suggest that a dTAFII60-dTAFII40 heterotetramer binds to the DPE. Human and Drosophila transcription factors exhibit essentially the same requirements for DPE sequence and for Inr-DPE spacing. In addition, the TATA-less promoter of the human interferon regulatory factor-1 (IRF-1) gene contains a DPE that is important for transcriptional activity both in vitro and in cultured cells. Hence, these studies provide evidence for a direct role of TAFs in basal transcription of TATA-less DPE-containing genes and collectively indicate that the DPE is, in many respects, a downstream counterpart to the TATA box that is present in Drosophila to humans.
Burke
T W
TW
Department of Biology and Center for Molecular Genetics, University of California, San Diego, La Jolla, California 92093-0347 USA.
Kadonaga
J T
JT
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D011401:Promoter Regions, Genetic; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D035381:TATA-Binding Protein Associated Factors; C084976:Taf6 protein, Drosophila; D035362:Transcription Factor TFIID; D014157:Transcription Factors