Factors involved in specific transcription by mammalian RNA polymerase II: purification, genetic specificity, and TATA box-promoter interactions of TFIID.
AUTOR(ES)
Nakajima, N
RESUMO
Selective and accurate transcription of purified genes by RNA polymerase II requires multiple factors. The factor designated TFIID was purified extensively from HeLa cell nuclear extracts by using a simple and novel complementation assay. Thus, TFIID was preferentially inactivated by mild heat treatment of a nuclear extract, and supplementation of the heat-treated extract with TFIID-containing fractions restored adenovirus major late (ML) promoter-dependent transcription. By using this assay, TFIID was purified approximately 300-fold by conventional chromatographic methods. The most purified TFIID fraction was demonstrated to be required for transcription of a number of other cellular and viral class II genes. This factor showed specific interactions with both the adenovirus ML promoter and a human heat shock 70 (hsp-70) promoter. On the ML promoter, the DNase I-protected region extended from around position -40 to position +35, although some discontinuities (and associated hypersensitive sites) were apparent near the initiation site and near position +27; the upstream and downstream boundaries of the TFIID-binding site were also confirmed by exonuclease III digestion experiments. In contrast to these results, the DNase I-protected regions on the human hsp-70 promoter were confined to a smaller area that extended from positions -35 to -19. DNase I hypersensitive sites were observed in both the adenovirus ML and hsp-70 promoters, most notably in the region at position -47. These results indicate either that there are different forms of TFIID or that a single TFIID can interact differently with distinct promoters.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=365471Documentos Relacionados
- Factors involved in specific transcription by mammalian RNA polymerase II: purification and characterization of general transcription factor TFIIE.
- Factors involved in specific transcription by mammalian RNA polymerase II: identification of general transcription factor TFIIG.
- Factors involved in specific transcription by mammalian RNA polymerase II: purification and analysis of transcription factor IIA and identification of transcription factor IIJ.
- RNA polymerase II/III transcription specificity determined by TATA box orientation.
- Factors involved in specific transcription by mammalian RNA polymerase II: role of transcription factors IIA, IID, and IIB during formation of a transcription-competent complex.