Recruitment of human TBP selectively activates RNA polymerase II TATA-dependent promoters.

摘要: An increasing body of evidence suggests that eukaryotic activators stimulate polymerase II transcription by facilitating the assembly functional basal machinery at promoter. Here we describe experiments provide added support for idea recruitment TATA-binding protein (TBP) is a rate-limiting step activation in mammalian cells. We found that, human cell lines, TBP to promoter, as GAL4-TBP fusion protein, can substantial transcription. Activation mediated hTBP, tethered promoter DNA, strictly dependent upon presence TATA element, and it directs faithful initiation. Interestingly, GAL4-hTBP was not observed from initiator (Inr) -dependent TATA-less promoters. These results suggest binding DNA initial stages TFIID initiator-dependent Finally, synergy between defined domains restricted activators, such VP16 Tat, which are likely function steps subsequent recruitment. findings strengthen represents an important mechanism TATA-dependent promoters, on other hand, they TBP-DNA interactions largely dispensable specific