Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

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

Unliganded human thyroid hormone receptor alpha (hTR alpha) can repress transcription by inhibiting the formation of a functional preinitiation complex (PIC) on promoters bearing thyroid hormone receptor (TR)-binding elements. Here we demonstrate that hTR alpha directly contacts the TATA-binding protein (TBP) and that preincubation of hTR alpha with TBP completely alleviates TR-mediated repression in vitro. Using stepwise preassembled PICs, we show that hTR alpha targets either the TBP/TFIIA or the TBP/TFIIA/TFIIB steps of PIC assembly for repression. We also show that the repression domain of hTR alpha maps to the C-terminal ligand-binding region and that direct TR-TBP interactions can be inhibited by thyroid hormone. Together, these results suggest a model in which unliganded hTR alpha contacts promoter-bound TBP and interferes with later steps in the initiation of transcription.
...
PMID:Unliganded thyroid hormone receptor alpha can target TATA-binding protein for transcriptional repression. 852 5

The transcriptional activation domain of the herpesvirus protein VP16 resides in the carboxyl-terminal 78 amino acids (residues 413-490). Fluorescence analyses of this domain indicated that critical amino acids are solvent-exposed in highly mobile segments. To examine interactions between VP16 and components of the basal transcriptional machinery, we incorporated (at position 442 or 473 of VP16) tryptophan analogs that can be selectively excited in complexes with other Trp-containing proteins. TATA-box binding protein (TBP) (but not transcription factor B (TFIIB)) caused concentration-dependent changes in the steady-state anisotropy of VP16, from which equilibrium binding constants were calculated. Quenching of the fluorescence from either position (442 or 473) was significantly affected by TBP, whereas TFIIB affected quenching only at position 473. 7-aza-Trp residues at either position showed a emission spectral shift in the presence of TBP (but not TFIIB), indicating a change to a more hydrophobic environment. In anisotropy decay experiments, TBP reduced the segmental motion at either position; in contrast, TFIIB induced a slight change only at position 473. Our results support models of TBP as a target protein for transcriptional activators and suggest that ordered structure in the VP16 activation domain is induced upon interaction with target proteins.
...
PMID:Transcriptional activation domain of the herpesvirus protein VP16 becomes conformationally constrained upon interaction with basal transcription factors. 861 52

ICP4 of herpes simplex virus is responsible for the activation of viral transcription during infection. It also efficiently activates and represses transcription in vitro depending on the promoter context. The contacts made between ICP4 and the cellular proteins that result in activated transcription have not been identified. The inability of ICP4 to activate transcription with TATA-binding protein in place of TFIID and the requirement for an initiator element for efficient ICP-4-activated transcription suggest that coactivators, such as TBP-associated factors, are involved (B. Gu and N. DeLuca, J. Virol. 68:7953-7965, 1994). In this study we showed that ICP4 activates transcription in vitro using an immunopurified TFIID, indicating that TBP-associated factors may be a sufficient subset of coactivators for ICP4-activated transcription. Similar to results seen in vivo, the presence of the ICP4 C-terminal region (amino acids 774 to 1298) was important for activation in vitro. With epitope-tagged ICP4 molecules in immunoaffinity experiments, it was shown that the C-terminal region was also required for ICP4 to interact with TFIID present in a crude transcription factor fraction. In the same assay, ICP4 was unable to interact with the basal transcription factors, TFIIB, TFIIE, TFIIF, and TFIIH and RNA polymerase II. ICP4 could also interact with TBP, independent of the C-terminal region. However, reflective of the interaction between ICP4 and TFIID, the ICP4 C-terminal region was required for an interaction with FAF250-TBP complexes and with TAF250 alone. Therefore, the interfaces or conformation of TBP mediating the interaction between ICP4 and TBP in solution is probably masked when TBP is bound to TAF250. With a series of mutant ICP4 molecules purified from herpes simplex virus-infected cells, it was shown that ICP4 molecules that can bind DNA and interact with TAF250 could activate transcription. Taken together, these results demonstrate that ICP4 interaction with TFIID involves the TAF250 molecule and the C-terminal region of ICP4 and that this interaction is part of the mechanism by which ICP4 activates transcription.
...
PMID:Interaction of the viral activator protein ICP4 with TFIID through TAF250. 864 20

Stage specific activator protein (SSAP) is a member of a newly discovered class of transcription factors that contain motifs more commonly found in RNA-binding proteins. Previously, we have shown that SSAP specifically binds to its recognition sequence in both the double strand and the single strand form and that this DNA-binding activity is localized to the N-terminal RNA recognition motif domain. Three copies of this recognition sequence constitute an enhancer element that is directly responsible for directing the transcriptional activation of the sea urchin late histone H1 gene at the midblastula stage of embryogenesis. Here we show that the remainder of the SSAP polypeptide constitutes an extremely potent bipartite transcription activation domain that can function in a variety of mammalian cell lines. This activity is as much as 3 to 5 times stronger than VP16 at activating transcription and requires a large stretch of amino acids that contain glutamine-glycine rich and serine-threonine-basic amino acid rich regions. We present evidence that SSAP's activation domain shares targets that are also necessary for activation by E1a and VP16. Finally, SSAP's activation domain is found to participate in specific interactions in vitro with the basal transcription factors TATA-binding protein, TFIIB, TFIIF74, and dTAF(II) 110.
...
PMID:The embryonic transcription factor stage specific activator protein contains a potent bipartite activation domain that interacts with several RNA polymerase II basal transcription factors. 865 Jan 73

The yeast RNA polymerase III (pol III) general transcription factor TFIIIB is composed of three subunits; the TATA-binding protein (TBP)1, the TFIIB-related factor (BRF1), and a third factor termed TFIIIB90 or B". Here we report the purification of yeast TFIIIB90, cloning of the gene encoding TFIIIB90, and reconstitution of TFIIIB from recombinant polypeptides. The TFIIIB90 open reading frame encodes a 68-kDa polypeptide and has no obvious similarity to any other known protein sequences. The gene encoding TFIIIB90 is essential for viability of yeast. Using recombinant TFIIIB subunits, we found that TFIIIB90 interacts weakly with TBP in the absence of BRF1, and that this interaction is enhanced at least 25-fold by BRF1. In addition, TFIIIB90 showed pol III specificity as it could not interact with the pol II-specific TFIIB-TBP-DNA complex. To localize the regions of the TBP-DNA complex that interact with BRF1 and TFIIIB90, we tested whether the pol II factors TFIIA and TFIIB interfered with the binding of BRF1 and TFIIIB90 to TBP-DNA. Our results suggest that the binding sites for BRF1 and TFIIIB90 on TBP-DNA both overlap the binding sites for TFIIA and TFIIB.
...
PMID:Cloning and functional characterization of the gene encoding the TFIIIB90 subunit of RNA polymerase III transcription factor TFIIIB. 866 56

The general transcription factor IIB (TFIIB) is required for RNA polymerase II transcription in eukaryotes. It provides a physical link between the TATA-binding protein (TBP) and the RNA polymerase and is a component previously suggested to respond to transcriptional activators in vitro. In this report, we compare the yeast (Saccharomyces cerevisiae) and human forms of the protein in yeast cells to study their functional differences. We demonstrate that human TFIIB fails to functionally replace yeast TFIIB in yeast cells. By analyzing various human-yeast hybrid TFIIB molecules, we show that a 14-amino-acid region at the amino terminus of the first repeat of yeast TFIIB plays an important role in determining species specificity in vivo. In addition, we identify four amino acids in this region that are critical for an amphipathic helix unique to yeast TFIIB. By site-directed mutagenesis analyses we demonstrate that these four amino acids are important for yeast TFIIB's activity in vivo. Finally, we show that mutations in the species-specific region of yeast TFIIB can differentially affect the expression of genes activated by different activators in vivo. These results provide strong evidence suggesting that yeast TFIIB is involved in the process of transcriptional activation in living cells.
...
PMID:Identifying a species-specific region of yeast TF11B in vivo. 866 81

Using a genetic screen, we isolated four TATA-binding protein (TBP) mutants that are specifically defective in vivo for the response to acidic activators. In contrast to previously described activation-defective TBP mutants, these TBP derivatives are not specifically defective for interactions with TATA elements or TFIIA. Three of these derivatives interact normally with a TATA element, TFIIA, TFIIB, or an acidic activation domain; presumably, they affect another protein-protein interaction important for transcriptional activation. The remaining derivative (with F-237 replaced by D) binds a TATA element with wild-type affinity, but the TBP-TATA complex has an altered electrophoretic mobility and interacts poorly with TFIIA and TFIIB; this suggests that the conformation of the TBP-TATA element complex plays a role in transcriptional activation. To determine the step at which the TBP derivatives were unable to activate transcription, we utilized an artificial recruitment assay in which TBP is targeted to the promoter via fusion to the LexA DNA-binding domain. Consistent with previous evidence that acidic activators can increase recruitment of TBP to the promoter in vivo, the activation defect of some of these TBP derivatives can be corrected by artificial recruitment. In contrast, the activation defect of the other TBP derivatives is not bypassed by artificial recruitment. Thus, these TBP mutants define two steps in the process of transcriptional stimulation by acidic activators: efficient recruitment to the TATA element and a postrecruitment interaction with a component(s) of the initiation complex.
...
PMID:A new class of activation-defective TATA-binding protein mutants: evidence for two steps of transcriptional activation in vivo. 875 46

Regions on the surface of human TATA-box binding protein (TBP) required for activated transcription in vivo were defined by construction of a library of 89 surface residue mutants with radical substitutions that were assayed for their ability to support activated transcription in vivo, basal transcription in vitro, and TFIIA and TFIIB binding in vitro. Four epitopes were identified in which substitutions in two to four neighboring surface residues greatly inhibited activated transcription in vivo. One epitope in which substitutions inhibited both basal and activated transcription (E284, L287) is the interface between TBP and TFIIB. Another (A184, N189, E191, R205) is the recently determined interface between TBP and TFIIA. Mutations in residues in this TFIIA interface greatly inhibit activated, but not basal transcription, demonstrating a requirement for the TFIIA-TBP interaction for activated transcription in vivo in mammalian cells. The remaining two activation epitopes (TBP helix 2 residues R231, R235, R239, plus F250; and G175, C176, P247) are probably interfaces with other proteins required for activated transcription. The library of mutants responded virtually identically to two different types of activators, GL4-E1A and GAL4-VP16, indicating that transcriptional activation by different classes of activators requires common interactions with TBP.
...
PMID:Radical mutations reveal TATA-box binding protein surfaces required for activated transcription in vivo. 884

The c-Myc oncoprotein has previously been shown to associate with transcription regulator YY1 and to inhibit its activity. We show herein that endogenous c-Myc and YY1 associate in vivo and that changes in c-Myc levels, which accompany mitogenic stimulation or differentiation of cultured cells, affect the ratio of free to c-Myc-associated YY1. We have also investigated the mechanism by which association with c-Myc inhibits YY1's ability to regulate transcription. c-Myc does not block binding of YY1 to DNA. However, protein association studies suggest that c-Myc interferes with the ability of YY1 to contact basal transcription proteins TATA-binding protein and TFIIB.
...
PMID:YY1 and c-Myc associate in vivo in a manner that depends on c-Myc levels. 885 31

We reported previously that cell-free transcription in the Archaea Methanococcus and Pyrococcus depends upon two archaeal transcription factors, archaeal transcription factor A (aTFA) and archaeal transcription factor B (aTFB). In the genome of Pyrococcus genes encoding putative homologues of eucaryal transcription factors TATA-binding protein (TBP) and TFIIB have been detected. Here, we report that Escherichia coli synthesized Pyrococcus homologues of TBP and TFIIB are able to replace endogenous aTFB and aTFA in cell-free transcription reactions. Antibodies raised against archaeal TBP and TFIIB bind to polypeptides of identical molecular mass in the aTFB and aTFA fraction. These data identify aTFB as archaeal TBP and aTFA as the archaeal homologue of TFIIB. At the Pyrococcus glutamate dehydrogenase (gdh) promoter these two bacterially produced transcription factors and endogenous RNA polymerase are sufficient to direct accurate and active initiation of transcription. DNase I protection experiments revealed Pyrococcus-TBP producing a characteristic footprint between position -20 and -34 centered around the TATA box of gdh promoter. Pyrococcus-TFIIB did not bind to the TATA box but bound cooperatively with Pyrococcus-TBP generating an extended DNase I footprinting pattern ranging from position -19 to -42. These data suggest that the Pyrococcus homologue of TFIIB associates with the TBP-promoter binary complex as its eucaryal counterpart, but in contrast to eucaryal TFIIB, it causes an extension of the protection to the region upstream of the TATA box.
...
PMID:Two transcription factors related with the eucaryal transcription factors TATA-binding protein and transcription factor IIB direct promoter recognition by an archaeal RNA polymerase. 893 64


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---