Initiator sequences direct downstream promoter binding by human transcription factor IID.
Whereas the human transcription factor IID generally interacts with only the TATA box element on most class II gene promoters, on certain promoters (e.g., the adenovirus 2 major late promoter) TFIID protects DNA sequences up to +35 base pairs downstream of the start site of transcription from DNase I cleavage. In this study, we show that Ad2 MLP sequences from -3 to +5 were sufficient to direct downstream promoter binding by TFIID when introduced into the human hsp70 gene promoter. These sequences correspond to the initiator transcription control element. Initiator mutations resulting in a loss of downstream binding demonstrated a diminished transcription efficiency in vitro. Likewise, initiator-dependent transcription stimulation required TFIID fractions capable of downstream promoter binding. Given the recent findings that immunopurified, human TFIID exhibited downstream promoter binding on the Ad2 MLP (Zhou, Q., Lieberman, P.M., Boyer, T.G. and Berk, A.J. (1992) Genes Dev. 6, 1964-1974), our data suggest that human TFIID can recognize the initiator element and that this interaction is required for maximally efficient transcription initiation.
Wang
J C
JC
Department of Tumor Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Van Dyke
M W
MW
D001483:Base Sequence; D003850:Deoxyribonuclease I / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D016385:TATA Box; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D006360:Heat-Shock Proteins; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D003850:Deoxyribonuclease I