An alternative pathway for transcription initiation involving TFII-I.
The minimal promoter elements required for initiation by RNA polymerase II include the TATA box and/or an initiator element (Inr) at or near the transcription start site. Studies of the adenovirus major late core promoter (containing both elements) have demonstrated an initiation pathway that involves binding of the transcription factor TFIID (or the derived subunit, the TATA-binding protein TBP (TFIID tau)) to the TATA element, which is facilitated by transcription factor TFIIA, followed by sequential interactions of other general factors. Here we describe a novel pathway that requires an intact Inr and the Inr-binding factor TFII-I (ref. 3). Sequential addition of the general factors generated TFII-I-dependent preinitiation complexes different from those formed with TFIIA. Furthermore, TBP bound cooperatively (with only TFII-I) to an Inr-containing TATA-less promoter, suggesting a means for activation of TATA-less promoters, which nonetheless require TFIID (refs 9-11). These observations provide support for functionally distinct pathways which could be subject to differential regulation by specific activators or repressors.
Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021-6399.
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Roy
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Malik
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Meisterernst
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Roeder
D000256:Adenoviridae / Q000235:genetics; D001483:Base Sequence; D004279:DNA, Viral / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D035362:Transcription Factor TFIID; D014157:Transcription Factors