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

Past experiments have shown that the adenovirus E1A12S product activates the hsp70 promoter, dependent on the TATA element and dependent on N-terminal E1A sequences. Other experiments have identified a factor termed Dr1 that interacts with and inhibits the transcriptional activity of the TATA-binding protein (TBP). We now find that the E1A12S protein can disrupt the interaction of the Dr1 factor with the TATA-specific TBP factor, allowing the productive interaction of TBP with TFIIA. This E1A-mediated disruption is dependent on N-terminal sequences that are also essential for the TATA-dependent trans-activation of the hsp70 promoter. Moreover, we also find that Dr1 expression in transfected cells can inhibit transcription from the hsp70 promoter and that this can be overcome by coexpression of the wild-type E1A protein, dependent on N-terminal sequences. We conclude that the activation of hsp70 through the TATA element may be mechanistically similar to the activation of the E2 promoter via E2F, in each case involving a release of a transcription factor from an inactive complex.
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PMID:Interaction of the Dr1 inhibitory factor with the TATA binding protein is disrupted by adenovirus E1A. 802 73

We have utilized a number of well-defined, simple, synthetic promoters (upstream factor binding sites and TATA elements) to analyze the activation mechanisms of the human cytomegalovirus immediate-early (IE) proteins. We found that the 86-kDa IE protein (known as IEP86, IE2(559aa), or ppUL122a) can recognize and activate a variety of simple promoters, in agreement with the observation that it is a promiscuous activator. However, in the comparison of otherwise identical promoters IEP86 does have preferences for specific TATA elements (hsp70 > adenovirus E2 > simian virus 40 early) and specific upstream transcription factor binding sites (CAAT > SP1 approximately Tef-1 > ATF; no activation with AP1 or OCT). In contrast, the 72-kDa IE protein (known as IEP72, IE1(491aa), or ppUL123) alone did not significantly activate the simple promoters under our experimental conditions. However, each promoter activated by IEP86 was synergistically affected by the addition of IEP72. In addition, the 55-kDa IE protein (IEP55, a splice variant form of IE2, IE2(425aa), or ppUL122b) repeatedly had a negative effect, downregulating the activation of promoters caused by IEP86 and the synergy of IEP86 and IEP72. We show that the ability of IEP86 to activate many simple promoters correlates not only with its previously described ability to interact with the TATA-binding protein (TBP) (B. A. Furnari, E. Poma, T. F. Kowalik, S.-M. Huong, and E.-S. Huang, J. Virol. 67:4981-4991, 1993; C. Hagemeier, S. Walker, R. Caswell, T. Kouzarides, and J. Sinclair, J. Virol. 66:4452-4456, 1992; R. Jupp, S. Hoffman, R. M. Stenberg, J. A. Nelson, and P. Ghazal, J. Virol. 67:7539-7546, 1993) but also with its ability to interact with the transcription factors which bind to the upstream element of promoters it activated (e.g., SP1 and Tef-1 but not Oct-1). This ability to have multiple interactions with the promoter complex may be crucial for transcriptional activation, since the IE proteins cannot activate promoters having only a TATA element or only an upstream transcription factor binding site. In addition, we show that proteins which bind IEP86 also bind to IEP55. Thus, the negative effect on transcription noted with IEP55 may be the result of competition with IEP86 for interaction with the promoter complex. The synergy caused by IEP72 appears to be mediated by a more indirect mechanism. This is suggested by our observation that IEP72 could not bind to any of the proteins tested (TBP, Tef-1, or Oct-1) or to IEP86.
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PMID:Transcriptional activation by the human cytomegalovirus immediate-early proteins: requirements for simple promoter structures and interactions with multiple components of the transcription complex. 803 17

A TATA complex that forms on the hsp70 promoter has been found to depend on sequence-specific interactions that occur at the transcription start and regions further downstream. The complex was detected with a gel shift assay and further characterized with interference assays. Antibodies reveal that the TATA-binding protein is in the complex. Interference assays localize specific contacts in the TATA element, the start site, and in a region approximately 25 bp downstream of the start site that contribute to either the assembly or the maintenance of the complex. Contact at the TATA element is made in the minor groove, as has been reported for the recombinant TATA-binding protein. Mutation in the TATA element or the start site of hsp70 causes complex formation to be more strongly dependent on contacts in the +25 region than in the normal core promoter. Examination of the hsp26 and histone H4 genes indicates that similar contacts contribute to the TATA complexes that form on these promoters. The results suggest that specific contacts downstream of the TATA element could play a key role in establishing the transcriptional potential of a gene by contributing to the interaction of the TATA-binding protein.
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PMID:Contribution of sequences downstream of the TATA element to a protein-DNA complex containing the TATA-binding protein. 845 32

The immediate-early 1 and 2 (IE1 and IE2, respectively) proteins of human cytomegalovirus are known transcription factors, which regulate the expression of viral and cellular genes. Transcriptional activation by IE2 is dependent on the presence of a TATA motif in target promoters, and IE2 can interact directly with the TATA-binding protein (TBP) component of TFIID. TBP is known to be the target for transcriptional repression by the cellular Dr1 protein, and this factor has been shown to repress expression from the hsp70 promoter in vivo. Since this promoter is up-regulated by IE2, we asked whether the effects of Dr1 can be overcome by IE2. We report here that IE2 can overcome Dr1-mediated repression of the hsp70 promoter in vivo and that IE2 can interact with Dr1 in vivo and in vitro. We also demonstrate a previously unreported activity of Dr1, inhibition of DNA binding by TBP, and show that IE2 is able to overcome this inhibition in vitro, suggesting a mechanism for the TATA dependency of IE2-mediated trans activation.
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PMID:Human cytomegalovirus immediate-early 2 (IE2) protein can transactivate the human hsp70 promoter by alleviation of Dr1-mediated repression. 864 40

Drosophila heat shock factor (HSF) binds to specific sequence elements of heat shock genes and can activate their transcription 200-fold. Though HSF has an acidic activation domain, the mechanistic details of heat shock gene activation remain undefined. Here we report that HSF interacts directly with the general transcription factor TBP (TATA-box binding protein), and these two factors bind cooperatively to heat shock promoters. A third factor that binds heat shock promoters, GAGA factor, also interacts with HSF and further stabilizes HSF binding to heat shock elements (HSEs). The interaction of HSF and TBP is explored in some detail here and is shown to be mediated by residues in both the amino- and carboxyl-terminal portions of HSF. This HSF/TBP interaction can be specifically disrupted by competition with the potent acidic transcriptional activator VP16. We further show that the acidic domain of the largest subunit of Drosophila RNA polymerase II (Pol II) associates with TBP in vitro and is specifically displaced from TBP upon addition of HSF. The region of TBP that mediates both HSF and Pol II acidic domain binding maps to the conserved carboxyl-terminal repeats and depends on at least one of the TBP residues known to be contacted by VP16 and to be critical for transcription activation. We discuss these findings in the context of a model in which HSF triggers hsp70 transcription by freeing the hsp70 promoter-paused Pol II from the constraints on elongation caused by the affinity of Pol II for general transcription factors.
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PMID:Cooperative and competitive protein interactions at the hsp70 promoter. 940 12

Large T antigen (T antigen), the early gene product of simian virus 40 (SV40), is a potent transcriptional activator of both cellular and viral genes. Recently we have shown that T antigen is tightly associated with TFIID and, in this position, performs a TATA-binding protein (TBP)-associated factor (TAF)-like function. Based on this observation, we asked whether T antigen affected steps in preinitiation complex assembly. Using purified components in in vitro complex assembly assays, we found that T antigen specifically enhances the formation of the TBP-TFIIA complex on the TATA element. T antigen accomplishes this by increasing the rate of formation of the TBP-TFIIA complex on the TATA element and by stabilizing the complexes after they are formed on the promoter. In addition, DNA immunoprecipitation experiments indicate that T antigen is associated with the stabilized TBP-TFIIA complexes bound to the DNA. In this regard, it has previously been shown that T antigen interacts with TBP; in the present study, we show that T antigen also interacts with TFIIA in vitro. In testing the ability of T antigen to stabilize the TBP-TFIIA complex, we found that stabilization is highly sensitive to the specific sequence context of the TATA element. Previous studies showed that T antigen could activate simple promoters containing the TATA elements from the hsp70 and c-fos gene promoters but failed to significantly activate similar promoters containing the TATA elements from the promoters of the SV40 early and adenovirus E2a genes. We find that the ability to stabilize the TBP-TFIIA complex on the hsp70 and c-fos TATA elements, and not on the SV40 early and E2A TATA elements, correlates with the ability or inability to activate promoters containing these TATA elements.
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PMID:Simian virus 40 large T antigen stabilizes the TATA-binding protein-TFIIA complex on the TATA element. 963 77

Transcription of archaeal non-stress genes involves the basal factors TBP and TFB, homologs of the eucaryal TATA-binding protein and transcription factor IIB, respectively. No comparable information exists for the archaeal molecular-chaperone, stress genes hsp70(dnaK), hsp40(dnaJ), and grpE. These do not occur in some archaeal species, but are present in others possibly due to lateral transfer from bacteria, which provides a unique opportunity to study regulation of stress-inducible bacterial genes in organisms with eukaryotic-like transcription machinery. Among the Archaea with the genes, those from the mesophilic methanogen Methanosarcina mazeii are the only ones whose basal (constitutive) and stress-induced transcription patterns have been determined. To continue this work, tbp and tfb were cloned from M. mazeii, sequenced, and the encoded recombinant proteins characterized in solution, separately and in complex with each other and with DNA. M. mazeii TBP ranks among the shortest within Archaea and, contrary to other archaeal TBPs, it lacks tryptophan or an acidic tail at the C terminus and has a basic N-terminal third. M. mazeii TFB is similar in length to archaeal and eucaryal homologs and all have a zinc finger and HTH motifs. Phylogenetically, the archaeal and eucaryal proteins form separate clusters and the M. mazeii molecules are closer to the homologs from Archaeoglobus fulgidus than to any other. Antigenically, M. mazeii TBP and TFB are close to archaeal homologs within each factor family, but the two families are unrelated. The purified recombinant factors were functionally active in a cell-free in vitro transcription system, and were interchangeable with the homologs from Methanococcus thermolithotrophicus. The M. mazeii factors have a similar secondary structure by circular dichroism (CD). The CD spectra changed upon binding to the promoters of the stress genes grpE, dnaK, and dnaJ, with the changes being distinctive for each promoter; in contrast, no effect was produced by the promoter of a non-stress-gene. Factor(s)-DNA modeling predicted that modifications of H bonds are caused by TBP binding, and that these modifications are distinctive for each promoter. It also showed which amino acid residues would contact an extended TATA box with a B recognition element, and evolutionary conservation of the TBP-TFB-DNA complex orientation between two archaeal organisms with widely different optimal temperature for growth (37 and 100 degrees C).
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PMID:The basal transcription factors TBP and TFB from the mesophilic archaeon Methanosarcina mazeii: structure and conformational changes upon interaction with stress-gene promoters. 1139 82

Regulation of archaeal stress genes is not yet fully understood. This work is part of a research effort aimed at elucidating the molecular mechanisms of transcription initiation and regulation of the stress genes in the hsp70(dnaK) locus of the mesophilic, methanogenic archaeon Methanosarcina mazeii. The locus has the stress genes 5'-grpE-hsp70(dnaK)-hsp40(dnaJ)-3' encoding the chaperone machine components GrpE, Hsp70(DnaK), and Hsp40(DnaJ), respectively, flanked by non-heat shock inducible genes, orf16 and orf11-trkA. Thus, the M. mazeii hsp70(dnaK) locus offers the opportunity for studying heat shock and non-heat shock inducible genes side by side. The objectives of the work reported here were to develop procedures for studying basal transcription factors in the cytosol of M. mazeii and their interaction with these genes' promoters in stressed cells for comparison with unstressed counterparts. The preparation of non-radioactive DNA probes for electrophoretic mobility shift assay (EMSA), and the combination of EMSA with Western blotting for DNA-binding protein identification were standardized for this investigation. DNA probes bearing the genes' promoter regions were used for detecting and identifying DNA-binding proteins in the cytosol of unstressed and heat-shocked cells. Cytosolic TATA-binding protein (TBP) was found to bind the stress-gene promoters in both unstressed and heat-shocked cells but more strongly in the latter. Likewise, in stressed cells TBP-transcription factor B (TFB)(TFIIB) association was increased by comparison with unstressed controls. The level of cytosolic TBP assessed by its DNA-binding activity using EMSA remained unchanged during the various phases of culture growth in the absence of heat stress. The results indicate that heat stress of cells in culture modulates the level and/or the stress-gene promoter-binding activity of the M. mazeii TBP, and enhances TBP-TFB association in the cytosol and DNA binding.
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PMID:Effect of heat stress on promoter binding by transcription factors in the cytosol of the archaeon Methanosarcina mazeii. 1181 91

A procedure was developed for real-time measurement of the interaction between an archaeal TATA-binding protein (TBP) with stress-gene promoters from the archaeon Methanosarcina mazeii using surface plasmon resonance (SPR), the BIACORE 3000 equipment, and the SA (streptavidin) Sensor Chip. Measurements were based on the SPR optical phenomenon, which resulted in light extinction when TBP bound a promoter. This process, detected as a change in a particular angle, was recorded in a sensorgram. The BIA-evaluation program allowed the calculation of the equilibrium constant (K(A)) of the interaction of M. mazeii TBP with the promoters of the stress genes grpE, hsp70(dnaK), and hsp40(dnaJ) (0.47, 0.26, and 1.21x10(7)M(-1), respectively) and, for comparison, with the promoter of a non-heat-shock gene, orf16 (0.08x10(7)M(-1)). The association rate (k(a)) of the non-heat-shock gene orf16 was 0.4x10(4)M(-1)s(-1) and those for the stress genes, grpE, hsp70(dnaK), and hsp40(dnaJ) were higher: 2.8, 1.5, and 3.5x10(4)M(-1)s(-1), respectively. The new procedure will allow a comparative analysis of different TPBs and promoters (wild type and mutants) under physiologic and stress conditions, and a correlation of TBP binding parameters with constitutive and stress-induced gene expression.
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PMID:Surface plasmon resonance for measuring TBP-promoter interaction. 1241

The presence of general transcription factors and other coactivators at the Drosophila hsp70 gene promoter in vivo has been examined by polytene chromosome immunofluorescence and chromatin immunoprecipitation at endogenous heat-shock loci or at a hsp70 promoter-containing transgene. These studies indicate that the hsp70 promoter is already occupied by TATA-binding protein (TBP) and several TBP-associated factors (TAFs), TFIIB, TFIIF (RAP30), TFIIH (XPB), TBP-free/TAF-containg complex (GCN5 and TRRAP), and the Mediator complex subunit 13 before heat shock. After heat shock, there is a significant recruitment of the heat-shock transcription factor, RNA polymerase II, XPD, GCN5, TRRAP, or Mediator complex 13 to the hsp70 promoter. Surprisingly, upon heat shock, there is a marked diminution in the occupancy of TBP, six different TAFs, TFIIB, and TFIIF, whereas there is no change in the occupancy of these factors at ecdysone-induced loci under the same conditions. Hence, these findings reveal a distinct mechanism of transcriptional induction at the hsp70 promoters, and further indicate that the apparent promoter occupancy of the general transcriptional factors does not necessarily reflect the transcriptional state of a gene.
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PMID:Occupancy of the Drosophila hsp70 promoter by a subset of basal transcription factors diminishes upon transcriptional activation. 1633 Jul 56


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