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Query: UNIPROT:P20226 (TATA-binding protein)
 1,297 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In mammalian and Drosophila cells, the central RNA polymerase II general transcription factor TFIID is a multisubunit complex containing the TATA-binding protein (TBP) and TBP-associated factors (TAFs) bound to the conserved TBP carboxy-terminal core domain. TBP also associates with alternative TAFs in these cells to form general transcription factors required for initiation by RNA polymerases I and III. Although extracts of human HeLa cells contain little TBP that is not associated with TAFs, free TBP is readily isolated from yeast cell extracts. However, recent studies indicate that yeast TBP can also interact with other yeast polypeptides to form multiprotein complexes. We established stable human HeLa cell lines expressing yeast TBP and several yeast-human TBP hybrids to study TBP-TAF interactions. We found that the yeast TBP core domain assembles with a complete set of human TAFs into a stable TFIID complex that can support activated transcription in vitro. The fact that the yeast TBP core, which differs from human TBP core in approximately 20% of its amino acid residues, has the structural features required to form a stable complex with human TAFs implies that Saccharomyces cerevisiae probably contains TAFs that are structurally and functionally analogous to human TAFs. Surprisingly, the non-conserved amino terminus of yeast TBP inhibited association between the yeast core domain and human TAFs.
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PMID:The yeast TATA-binding protein (TBP) core domain assembles with human TBP-associated factors into a functional TFIID complex. 779 63

Eukaryotic transcriptional activators have been classified on the basis of the characteristics of their activation domains. Acidic activation domains, such as those in the yeast GAL4 or GNC4 proteins and the herpes simplex virus activator VP16, stimulate RNA polymerase II transcription when introduced into a variety of eukaryotic cells. This species interchangeability demonstrates that the mechanism by which acidic activation domains function is highly conserved in the eukaryotic kingdom. To determine whether such a conservation of function exists for a different class of activation domain, we have tested whether the glutamine-rich activation domains of the human transcriptional activator Sp1 function in the yeast Saccharomyces cerevisiae. We report here that the glutamine-rich domains of Sp1 do not stimulate transcription in S. cerevisiae, even when accompanied by human TATA-box binding protein (TBP) or human-yeast TATA-box binding protein hybrids. Thus, in contrast to the case for acidic activation domains, the mechanism by which glutamine-rich domains stimulate transcription is not conserved between S. cerevisiae and humans.
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PMID:The glutamine-rich activation domains of human Sp1 do not stimulate transcription in Saccharomyces cerevisiae. 782 62

The proximal sequence element (PSE), found in both RNA polymerase II (Pol II)- and RNA Pol III-transcribed small nuclear RNA (snRNA) genes, is specifically bound by the PSE-binding transcription factor (PTF). We have purified PTF to near homogeneity from HeLa cell extracts by using a combination of conventional and affinity chromatographic methods. Purified PTF is composed of four polypeptides with apparent molecular masses of 180, 55, 45, and 44 kDa. A combination of preparative electrophoretic mobility shift and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses has conclusively identified these four polypeptides as subunits of human PTF, while UV cross-linking experiments demonstrate that the largest subunit of PTF is in close contact with the PSE. The purified PTF activates transcription from promoters of both Pol II- and Pol III-transcribed snRNA genes in a PSE-dependent manner. In addition, we have investigated factor requirements in transcription of Pol III-dependent snRNA genes. We show that in extracts that have been depleted of TATA-binding protein (TBP) and associated factors, recombinant TBP restores transcription from U6 and 7SK promoters but not from the VAI promoter, whereas the highly purified TBP-TBP-associated factor complex TFIIIB restores transcription from the VAI but not the U6 or 7SK promoter. Furthermore, by complementation of heat-treated extracts lacking TFIIIC activity, we show that TFIIIC1 is required for transcription of both the 7SK and VAI genes, whereas TFIIIC2 is required only for transcription of the VAI gene. From these observations, we conclude (i) that PTF and TFIIIC2 function as gene-specific as gene-specific factors for PSE-and B-box-containing Pol III genes, respectively, (ii) that the form of TBP used by class III genes with upstream promoter elements differs from the from used by class III genes with internal promoters, and (iii) that TFIIIC1 is required for both internal and external Pol III promoters.
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PMID:Proximal sequence element-binding transcription factor (PTF) is a multisubunit complex required for transcription of both RNA polymerase II- and RNA polymerase III-dependent small nuclear RNA genes. 789 97

A core promoter element called an initiator (Inr) overlaps the transcription start site of numerous mammalian protein-coding genes. In promoters that lack a TATA box, the Inr is functionally analogous to TATA, in that it is capable of directing basal transcription by RNA polymerase II and of determining the precise site of transcription initiation. In promoters that contain a TATA box, the Inr can greatly enhance promoter strength. Mammalian Inr consensus sequences have been defined through functional studies and sequence comparisons of the start site regions of protein-coding genes. Here, we show that, in a DNase I footprinting assay with synthetic promoters, the purified TATA-binding protein complex TFIID specifically contacted the Inr. The TFIID-Inr interaction relies on the precise nucleotides needed for Inr function. Detection of the interaction was dependent either on a TATA box or on Sp1 bound to upstream sites. Furthermore, recombinant TFIIB appeared to influence the TFIID-Inr interaction, whereas TFIIA stabilized the TFIID-TATA interaction. These results demonstrate that distinct components of TFIID interact with the TATA boxes and Inr elements of core promoters for RNA polymerase II.
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PMID:Direct recognition of initiator elements by a component of the transcription factor IID complex. 792 70

TATA-binding protein (TBP)-associated factors (TAFs) in TFIID are required for activator proteins to stimulate transcription, but the mechanism by which TAFs function is poorly understood. To study how TAFs participate in transcriptional activation by the Epstein-Barr virus activator Zta, we used agarose gel electrophoresis and DNase I footprinting to compare transcription complex assembly in reactions with either TFIID or TBP in the presence and absence of wild-type Zta or a deletion of Zta lacking its activation domain. A stable complex of promoter DNA with Zta, TFIIA, and TFIID rapidly formed on a template with Zta-binding sites. Zta stimulation of stable complex formation required TAFs as well as the Zta activation domain and TFIIA. The Zta activation domain also induced a TAF-dependent DNA-protein interaction near and downstream of the transcription star site. Stable complexes formed within 1 min supported activated transcription when RNA polymerase II and the remaining general transcription factors were subsequently added. This rapid assembly of a stable Zta-TFIIA-TFIID-promoter complex is probably a significant component of the mechanism by which TAFs and the Zta activation domain cooperate to stimulate transcription.
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PMID:A mechanism for TAFs in transcriptional activation: activation domain enhancement of TFIID-TFIIA--promoter DNA complex formation. 792 93

We report here that the largest subunit of yeast RNA polymerase II contains an acidic domain that is similar to acidic activators of transcription. This domain includes the highly conserved homology box H. A hybrid protein containing this acidic domain fused to the DNA-binding domain of GAL4 is a potent activator of transcription in the yeast Saccharomyces cerevisiae. Interestingly, mutations that reduce the upstream activating activity of this acidic domain also abolish the normal function of RNA polymerase II. Such functional defects can be rescued by the acidic activation domains of VP16 and GAL4 when inserted into the mutant derivatives of RNA polymerase II. We further show that this acidic domain of RNA polymerase II interacts directly with two general transcription factors, the TATA-binding protein and TFIIB, and that the acidic activation domain of VP16 can compete specifically with the acidic domain of the RNA polymerase for these interactions. We discuss the implications of this finding for the mechanisms of transcriptional activation in eucaryotes.
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PMID:A highly conserved domain of RNA polymerase II shares a functional element with acidic activation domains of upstream transcription factors. 793 66

The rate at which the TATA-binding protein (TBP) interacts with the TATA element and promotes transcription by RNA polymerase II was determined in yeast cells. A TBP derivative with altered TATA-element specificity was rapidly induced, and transcription from promoters with appropriately mutated TATA elements was measured. Without a functional activator protein, basal transcription was observed only after a lag of several hours. In contrast, GCN4-activated transcription occurred rapidly upon induction of the TBP derivative. These results suggest that accessibility of TBP to the chromatin template in vivo is rate limiting and that activation domains increase recruitment of TBP to the promoter.
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PMID:Increased recruitment of TATA-binding protein to the promoter by transcriptional activation domains in vivo. 793 64

The human general transcription factor IIF (TFIIF) is required for an accurate transcription initiation by RNA polymerase II and shares some analogous features with the sigma subunit of bacterial RNA polymerase. As an attempt to analyze the function of TFIIF, we examined its effect on bacterial transcription in vitro. TFIIF significantly enhanced the initiation of transcription by the bacterial RNA polymerase while other general transcription factors, TATA-binding protein, TFIIB, and TFIIE, did not. The enhancement of the bacterial transcription was ascribed to the 74 kDa subunit of TFIIF (RAP74). RAP74 had an activity of enhancing the binding of the bacterial RNA polymerase to the promoter. The enhancing activity of RAP74 depended on a low molar ratio of the RNA polymerase to the template DNA. The action of RAP74 in the bacterial transcription may be related to a possible regulatory role of RAP74 in the eukaryotic transcription initiation.
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PMID:Enhancement of bacterial transcription initiation in vitro by the 74 kDa subunit of human general transcription factor IIF (RAP74). 794 16

Regulation of transcription by RNA polymerase II in eukaryotic cells requires both basal and accessory factors, which interact through specific protein-DNA or protein-protein interactions. The high mobility group 1 protein (HMG1) was previously demonstrated to be a nonhistone chromatin-associated protein, which selectively recognizes cruciform DNA rather than a specific primary sequence element. During our investigations of proteins that interact with TFIID, we found that purified mammalian HMG1, as well as recombinant human HMG1, can interact with TATA-binding protein (TBP) in the presence of a TATA box-containing oligonucleotide to form a specific HMG1.TBP.promoter complex. This complex prevents TFIIB binding to TBP and consequently blocks formation of the preinitiation complex. In contrast, TFIIA can compete with HMG1 for binding to TBP. In an in vitro transcription assay reconstituted with highly purified or recombinant general factors, HMG1 is able to inhibit transcription by RNA polymerase II over 30-fold. As expected, addition of TFIIA can partially reverse this repression in a concentration-dependent manner. These results demonstrate that HMG1, a chromatin-associated protein, has the potential to act as a TBP-dependent negative transcription factor and may provide an important link between chromatin structure and the modulation of class II gene transcription.
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PMID:The high mobility group protein HMG1 can reversibly inhibit class II gene transcription by interaction with the TATA-binding protein. 800 19

The minimal requirements for transcription initiation from supercoiled templates were determined for the two major forms of TATA-binding factors found in cell extracts, the 300-kDa B-TFIID and the 1000-kDa D-TFIID complexes. As had been observed for the TATA-binding protein (TBP) subunit (Parvin and Sharp, 1993), transcription from the IgH promoter minimally requires TFIID activity plus TFIIB and RNA polymerase II. This minimal reaction is only active on negatively supercoiled template DNA. In contrast, the supercoiled templates encoding the adenovirus major late promoter (MLP), or several other promoters, require the addition of TFIIF to the minimal reaction. Further addition of TFIIE and TFIIH boosts the level of transcription from these latter promoters but is not required. In contrast to the complete reaction on linear template, transcription from supercoiled IgH or MLP templates does not require the hydrolysis of the beta-gamma bond of ATP. Fourteen different core promoters were compared in complete and minimal basal transcription reactions reconstituted with one of the three TATA activities: TBP, B-TFIID, and D-TFIID. Of these 14 promoters, only the IgH was active in the absence of TFIIF, and the other promoters demonstrated different levels of transcription depending on which basal factors were present in reaction. It is proposed that a significant level of basal transcription only requires a minimal set of factors, and stimulation by upstream activators may in part be mediated by the inclusion of additional basal factors into the initiation reaction.
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PMID:Multiple sets of basal factors initiate transcription by RNA polymerase II. 803 89


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