Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20226 (TATA-binding protein)
 1,297 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human T-lymphotropic virus type I (HTLV-I) promoter contains the structural features of a typical RNA polymerase II (pol II) template. The promoter contains a TATA box 30 bp upstream of the transcription initiation site and binding sites for several pol II transcription factors, and long poly(A)+ RNA is synthesized from the integrated HTLV-I proviral DNA in vivo. Consistent with these characteristics, HTLV-I transcription activity was reconstituted in vitro by using TATA-binding protein, TFIIA, recombinant TFIIB, TFIIE, and TFIIF, TFIIH, and pol II. Transcription of the HTLV-I promoter in the reconstituted system requires RNA pol II. In HeLa whole cell extracts, however, the HTLV-I long terminal repeat also contains an overlapping transcription unit (OTU). HTLV-I OTU transcription is initiated at the same nucleotide site as the RNA isolated from the HTLV-I-infected cell line MT-2 but was not inhibited by the presence of alpha-amanitin at concentrations which inhibited the adenovirus major late pol II promoter (6 micrograms/ml). HTLV-I transcription was inhibited when higher concentrations of alpha-amanitin (60 micrograms/ml) were used, in the range of a typical pol III promoter (VA-I). Neutralization and depletion experiments with three distinct pol II antibodies demonstrate that RNA pol II is not required for HTLV-I OTU transcription. Antibodies to basal transcription factors TATA-binding protein and TFIIB, but not TFIIIC, inhibited HTLV-I OTU transcription. These observations suggest that the HTLV-I long terminal repeat contains overlapping promoters, a typical pol II promoter and a unique pol III promoter which requires a distinct set of transcription factors.
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PMID:Transcription of the human T-cell lymphotropic virus type I promoter by an alpha-amanitin-resistant polymerase. 752 15

Transcription factor IIB (TFIIB) plays a central role in the assembly of the RNA polymerase II initiation complex. Monoclonal antibodies (mAbs) that react with human TFIIB were prepared and used as probes to identify portions of TFIIB that are accessible when the factor is in solution and when it is contained in a complex with DNA. Seven mAbs were examined and were mapped to three regions of the TFIIB molecule. Only the mAbs that mapped to residues 52-105 inhibited transcription, immunoprecipitated recombinant TFIIB and TFIIB from HeLa cell nuclear extract (NE), and supershifted a complex containing TFIIB, the TATA-binding protein, and DNA. The mAbs that mapped to residues 1-51 and the mAb that mapped to residues 106-316 did not show activity in the functional assays, with the exception of the far N-terminal mAbs (residues 1-51), which immunoprecipitated recombinant TFIIB, but not TFIIB from HeLa cell NE. These data indicate that the region containing residues 52-105 is exposed in solution and when TFIIB is part of the preinitiation complex and that some far N-terminal epitopes are accessible on the purified protein, but become blocked when TFIIB is in HeLa cell NE or in the preinitiation complex.
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PMID:Accessibility of epitopes on human transcription factor IIB in the native protein and in a complex with DNA. 753 65

The conformation of an eight base pair DNA oligonucleotide duplex bound to the human testis determining factor SRY and the orientation of the protein domain within the complex have been analyzed by a variety of NMR methods which permit the selective observation of protons attached to 12C nuclei in the presence of uniformly enriched 13C/15N protein. Qualitative analysis of nuclear and rotating frame Overhauser enhancement spectra at multiple mixing times indicates that the conformation of the SRY-bound DNA is distinct from that of A- and B-DNA, in agreement with the recent three-dimensional structure determination of the complex [Werner, M. W., Huth, J. R., Gronenborn, A. M., & Clore, G. M. (1995) Cell 81, 705-714]. Selective observation of intermolecular NOEs between protein and DNA indicates that partial intercalation of a protein side chain occurs between two adenine bases in the DNA octamer. The analysis of structural features by NMR for this unusual DNA conformer and the orientation of the protein domain on the DNA is discussed. The structural features of the DNA complexed to SRY are remarkably similar, but not identical, to those of DNA complexed to the TATA-binding protein (TBP).
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PMID:NMR spectroscopic analysis of the DNA conformation induced by the human testis determining factor SRY. 754 37

Tumor suppressor protein p53 is a potent transcriptional activator and regulates cell growth negatively. To characterize the transcriptional activation domain (TAD) of p53, various point mutants were constructed in the context of Gal4 DNA binding domain and tested for their transactivation ability. Our results demonstrated that the positionally conserved hydrophobic residues shared with herpes simplex virus VP16 and other transactivators are essential for transactivation. Also, the negatively charged residues and proline residues are necessary for full activity, but not essential for the activity of p53 TAD. Deletion analyses showed that p53 TAD can be divided into two subdomains, amino acids 1-40 and 43-73. An in vitro glutathione S-transferase pull-down assay establishes a linear correlation between p53 TAD-mediated transactivation in vivo and the binding activity of p53 TAD to TATA-binding protein (TBP) in vitro. Mutations that diminish the transactivation ability of Gal4-p53 TAD also impair the binding activity to TBP severely. Our results suggest that at least TBP is a direct target for p53 TAD and that the binding strength of TAD to TBP (TFIID) is an important parameter controlling activity of p53 TAD. In addition, circular dichroism spectroscopy has shown that p53 TAD peptide lacks any regular secondary structure in solution and that there is no significant difference between the spectra of the wild type TAD and that of the transactivation deficient mutant type.
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PMID:Transactivation ability of p53 transcriptional activation domain is directly related to the binding affinity to TATA-binding protein. 755 31

The TATA-binding protein (TBP) contains a concave surface that interacts specifically with TATA promoter elements and a convex surface that mediates protein-protein interactions with general and gene-specific transcription factors. Biochemical experiments suggest that interactions between activator proteins and TBP are important in stimulating transcription by the RNA polymerase II machinery. To gain insight into the role of TBP in mediating transcriptional activation in vivo, we implemented a genetic strategy in Saccharomyces cerevisiae that involved the use of a TBP derivative with altered specificity for TATA elements. By genetically screening a set of TBP mutant libraries that were biased to the convex surface that mediates protein-protein interactions, we identified TBP derivatives that are impaired in the response to three acidic activators (Gcn4, Gal4, and Ace1) but appear normal for constitutive polymerase II transcription. A genetic complementation assay indicates that the activation-defective phenotypes reflect specific functional properties of the TBP derivatives rather than an indirect effect on transcription. Surprisingly, three of the four activation-defective mutants affect residues that directly contact DNA. Moreover, all four mutants are defective for TATA element binding, but they interact normally with an acidic activation domain and TFIIB. In addition, we show that a subset of TBP derivatives with mutations on the DNA-binding surface of TBP are also compromised in their responses to acidic activators in vivo. These observations suggest that interactions at the TBP-TATA element interface can specifically affect the response to acidic activator proteins in vivo.
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PMID:Mutations on the DNA-binding surface of TATA-binding protein can specifically impair the response to acidic activators in vivo. 756 97

The binding of TATA-binding protein (TBP) to the TATA element is the first step in the initiation of RNA polymerase II transcription from many promoters in vitro. It has been proposed that upstream activator proteins stimulate transcription by recruiting TBP to the promoter, thus facilitating the assembly of a transcription complex. However, the role of activator proteins acting at this step to stimulate transcription in vivo remains largely speculative. To test whether recruitment of TBP to the promoter is sufficient for transcriptional activation in vivo, we constructed a hybrid protein containing TBP of the yeast Saccharomyces cerevisiae fused to the DNA-binding domain of GAL4. Our results show that TBP recruited by the GAL4 DNA-binding domain to promoters bearing a GAL4-binding site can interact with the TATA element and direct high levels of transcription. This finding indicates that binding of TBP to promoters in S. cerevisiae is a major rate-limiting step accelerated by upstream activator proteins.
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PMID:Recruiting TATA-binding protein to a promoter: transcriptional activation without an upstream activator. 756 28

Transcription regulation by DNA-bound activators is thought to be mediated by a direct interaction between these proteins and TATA-binding protein (TBP), TFIIB, or TBP-associated factors, although occasionally cofactors or adapters are required. For ligand-induced activation by the retinoic acid receptor-retinoid X receptor (RAR-RXR) heterodimer, the RAR beta 2 promoter is dependent on the presence of E1A or E1A-like activity, since this promoter is activated by retinoic acid only in cells expressing such proteins. The mechanism underlying this E1A requirement is largely unknown. We now show that direct interaction between RAR and E1A is a requirement for retinoic acid-induced RAR beta 2 activation. The activity of the hormone-dependent activation function 2 (AF-2) of RAR beta is upregulated by E1A, and an interaction between this region and E1A was observed, but not with AF-1 or AF-2 of RXR alpha. This interaction is dependent on conserved region III (CRIII), the 13S mRNA-specific region of E1A. Deletion analysis within this region indicated that the complete CRIII is needed for activation. The putative zinc finger region is crucial, probably as a consequence of interaction with TBP. Furthermore, the region surrounding amino acid 178, partially overlapping with the TBP binding region, is involved in both binding to and activation by AF-2. We propose that E1A functions as a cofactor by interacting with both TBP and RAR, thereby stabilizing the preinitiation complex.
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PMID:Adenovirus E1A functions as a cofactor for retinoic acid receptor beta (RAR beta) through direct interaction with RAR beta. 756 39

Mouse F9 embryonic carcinoma (EC) cells differentiate in culture to parietal endoderm (PE) cells upon induction with retinoic acid and cyclic AMP. In the course of this process, the expression of polymerase III transcripts, e.g., 5S rRNA and U6 small nuclear RNA, is dramatically reduced. This reduction of endogenous RNA content is accompanied by a loss of transcriptional capacity in cell extracts from PE cells. Partial purification of such extracts reveals that the DNA-binding activity of transcription factor PBP, binding specifically to the proximal sequence element (PSE) sequence of vertebrate U6 genes, is significantly reduced. This finding is corroborated by a loss in the transcriptional activity of this factor in reconstitution assays with partially purified polymerase III transcription components. In contrast, the activity of TFIIIA and TFIIIB and the amount of free TATA-binding protein remain unchanged during the differentiation process analyzed here. These data show for the first time that the PSE-binding protein PBP is essentially involved in the differential regulation of polymerase III genes governed by external promoters.
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PMID:The activity of transcription factor PBP, which binds to the proximal sequence element of mammalian U6 genes, is regulated during differentiation of F9 cells. 756 41

The promoter of vertebrate U6 small nuclear RNA genes consists of a TATA box and a snRNA proximal sequence element (PSE), and the combination of these two elements directs RNA polymerase III transcription. We detected RNA polymerase II transcription as well as pol III transcription from the human U6 promoter in a HeLa nuclear extract. The pol II-specific transcription was independent of the PSE and dependent on the presence of the TATA box. Both pol III- and pol II-specific transcription were stimulated by addition of recombinant TATA-binding protein (TBP). We conclude that both pol III and pol II preinitiation complexes can assemble on the U6 promoter in vitro and could compete during the bona fide process in the cell.
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PMID:Both RNA polymerase III and RNA polymerase II accurately initiate transcription from a human U6 promoter in vitro. 757 66

Phosphorylated and dephosphorylated isoforms of Tetrahymena macronuclear H1 were separated from each other by cation-exchange high performance liquid chromatography and used to generate a pairwise set of antisera that discriminate the phosphorylation state of this linker histone. Affinity-purified antibodies from each sera recognize appropriate H1 isoforms and stain macronuclei under appropriate physiological conditions. Immunogold localizations demonstrate that phosphorylated and dephosphorylated H1 localize nonrandomly in distinct subdomains of macronuclear chromatin. Dephosphorylated H1 is strongly enriched in the electron-dense chromatin bodies that punctuate macronuclear chromatin. In contrast, phosphorylated H1 isoforms, as well as an evolutionarily conserved H2A.F/Z-like variant (hv1) believed to function in the establishment of transcriptionally competent chromatin, are modestly enriched at the periphery of chromatin bodies and in the surrounding euchromatin. Using antibodies against TATA-binding protein, we show that transcriptionally active chromatin lies outside of the chromatin bodies in an area relatively devoid of H1. Antibodies against general core histones are more or less evenly distributed across these domains. Together, these data are consistent with a model in which phosphorylation of H1, perhaps in association with hv1, loosens the binding of H1 in chromatin leading to chromatin decondensation as part of a first-step mechanism in gene activation. In contrast, our data support the view that dephosphorylation of this linker histone facilitates or stabilizes condensed, transcriptionally silent chromatin.
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PMID:Phosphorylated and dephosphorylated linker histone H1 reside in distinct chromatin domains in Tetrahymena macronuclei. 757 9


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