scholarly journals A severely defective TATA-binding protein-TFIIB interaction does not preclude transcriptional activation in vivo.

1997 ◽  
Vol 17 (3) ◽  
pp. 1336-1345 ◽  
Author(s):  
M Lee ◽  
K Struhl
Keyword(s):  
Dna Binding ◽  
Complex Formation ◽  
Transcriptional Activation ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Yeast Cells ◽  
Synthetic Lethal ◽  
Binding Surface

In yeast cells, mutations in the TATA-binding protein (TBP) that disrupt the interaction with the TATA element or with TFIIA can selectively impair the response to acidic activator proteins. We analyzed the transcriptional properties of TBP derivatives in which residues that directly interact with TFIIB were replaced by alanines. Surprisingly, a derivative with a 50-fold defect in TBP-TFIIB-TATA complex formation in vitro (E188A) supports viability and responds efficiently to activators in vivo. The E186A derivative, which displays a 100-fold defect in TBP-TFIIB-TATA complex formation, does not support viability, yet it does respond to activators. Conversely, the L189A mutation, which has the mildest effect on the interaction with TFIIB (10-fold), can abolish transcriptional activation and cell viability when combined with mutations on the DNA-binding surface. This "synthetic lethal" effect is not observed with E188A, suggesting that the previously described role of L189 in transcriptional activation may be related to its location on the DNA-binding surface and not to its interaction with TFIIB. Finally, when using TBP mutants defective on multiple interaction surfaces, we observed synthetic lethal effects between mutations on the TFIIA and TFIIB interfaces but found that mutations implicated in association with polymerase II and TFIIF did not have significant effects in vivo. Taken together, these results argue that, unlike the TBP-TATA and TBP-TFIIA interactions, the TBP-TFIIB interaction is not generally limiting for transcriptional activation in vivo.

scholarly journals A Human TATA Binding Protein-Related Protein with Altered DNA Binding Specificity Inhibits Transcription from Multiple Promoters and Activators

1999 ◽  
Vol 19 (11) ◽  
pp. 7610-7620 ◽  
Author(s):  
Paul A. Moore ◽  
Josef Ozer ◽  
Moreh Salunek ◽  
Gwenael Jan ◽  
Dennis Zerby ◽  
...  
Keyword(s):  
Dna Binding ◽  
Transcriptional Repression ◽  
Transcription Initiation ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Related Protein ◽  
Multiple Promoters ◽  
Binding Surface

ABSTRACT The TATA binding protein (TBP) plays a central role in eukaryotic and archael transcription initiation. We describe the isolation of a novel 23-kDa human protein that displays 41% identity to TBP and is expressed in most human tissue. Recombinant TBP-related protein (TRP) displayed barely detectable binding to consensus TATA box sequences but bound with slightly higher affinities to nonconsensus TATA sequences. TRP did not substitute for TBP in transcription reactions in vitro. However, addition of TRP potently inhibited basal and activated transcription from multiple promoters in vitro and in vivo. General transcription factors TFIIA and TFIIB bound glutathioneS-transferase–TRP in solution but failed to stimulate TRP binding to DNA. Preincubation of TRP with TFIIA inhibited TBP-TFIIA-DNA complex formation and addition of TFIIA overcame TRP-mediated transcription repression. TRP transcriptional repression activity was specifically reduced by mutations in TRP that disrupt the TFIIA binding surface but not by mutations that disrupt the TFIIB or DNA binding surface of TRP. These results suggest that TFIIA is a primary target of TRP transcription inhibition and that TRP may modulate transcription by a novel mechanism involving the partial mimicry of TBP functions.

Transcriptional activation requires protection of the TATA-binding protein Tbp1 by the ubiquitin-specific protease Ubp3

2010 ◽  
Vol 431 (3) ◽  
pp. 391-402 ◽  
Author(s):  
Boon Shang Chew ◽  
Wee Leng Siew ◽  
Benjamin Xiao ◽  
Norbert Lehming
Keyword(s):  
Mutant Strain ◽  
Transcriptional Activation ◽  
Glutathione Transferase ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Mutant Protein ◽  
Specific Protease ◽  
Ubiquitin Specific Protease

Tbp1, the TATA-binding protein, is essential for transcriptional activation, and Gal4 and Gcn4 are unable to fully activate transcription in a Saccharomyces cerevisiae TBP1E86D mutant strain. In the present study we have shown that the Tbp1E186D mutant protein is proteolytically instable, and we have isolated intragenic and extragenic suppressors of the transcription defects of the TBP1E186D mutant strain. The TBP1R6S mutation stabilizes the Tbp1E186D mutant protein and suppresses the defects of the TBP1E186D mutant strain. Furthermore, we found that the overexpression of the de-ubiquitinating enzyme Ubp3 (ubiquitin-specific protease 3) also stabilizes the Tbp1E186D mutant protein and suppresses of the defects of the TBP1E186D mutant strain. Importantly, the deletion of UBP3 and its cofactor BRE5 lead to increased degradation of wild-type Tbp1 protein and to defects in transcriptional activation by Gal4 and Gcn4. Purified GST (glutathione transferase)–Ubp3 reversed Tbp1 ubiquitination, and the deletion of UBP3 lead to the accumulation of poly-ubiquitinated species of Tbp1 in a proteaseome-deficient genetic background, demonstrating that Ubp3 reverses ubiquitination of Tbp1 in vitro and in vivo. Chromatin immunoprecipitation showed that Ubp3 was recruited to the GAL1 and HIS3 promoters upon the induction of the respective gene, indicating that protection of promoter-bound Tbp1 by Ubp3 is required for transcriptional activation.

scholarly journals Yeast Coactivator MBF1 Mediates GCN4-Dependent Transcriptional Activation

1998 ◽  
Vol 18 (9) ◽  
pp. 4971-4976 ◽  
Author(s):  
Ken-ichi Takemaru ◽  
Satoshi Harashima ◽  
Hitoshi Ueda ◽  
Susumu Hirose
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Dna Binding ◽  
Nuclear Receptor ◽  
Transcriptional Activation ◽  
Crucial Role ◽  
Tata Binding Protein ◽  
Binding Region

ABSTRACT Transcriptional coactivators play a crucial role in gene expression by communicating between regulatory factors and the basal transcription machinery. The coactivator multiprotein bridging factor 1 (MBF1) was originally identified as a bridging molecule that connects theDrosophila nuclear receptor FTZ-F1 and TATA-binding protein (TBP). The MBF1 sequence is highly conserved across species fromSaccharomyces cerevisiae to human. Here we provide evidence acquired in vitro and in vivo that yeast MBF1 mediates GCN4-dependent transcriptional activation by bridging the DNA-binding region of GCN4 and TBP. These findings indicate that the coactivator MBF1 functions by recruiting TBP to promoters where DNA-binding regulators are bound.

scholarly journals Functional interaction between p53, the TATA-binding protein (TBP), andTBP-associated factors in vivo.

1996 ◽  
Vol 16 (8) ◽  
pp. 4295-4304 ◽  
Author(s):  
G Farmer ◽  
J Colgan ◽  
Y Nakatani ◽  
J L Manley ◽  
C Prives
Keyword(s):  
Transcriptional Activation ◽  
Associated Factors ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Mutant P53 ◽  
Functional Interaction ◽  
General Transcription Factor ◽  
First Time

The transcriptional activator p53 is known to interact with components of the general transcription factor TFIID in vitro. To examine the relevance of these associations to transcriptional activation in vivo, plasmids expressing a p53-GAL4 chimera and Drosophila TATA-binding protein (dTBP) were transfected into Drosophila Schneider cells. p53-GAL4 and dTBP displayed a markedly synergistic effect on activated transcription from a GAL4 site-containing reporter that was at least 10-fold greater than observed with other activators tested. A mutant p53 previously shown to be defective in both transcriptional activation in vivo and in binding to TBP-associated factors (TAFs) in vitro, although still capable of binding dTBP, did not cooperate with dTBP, suggesting that TAFs may contribute to this synergy. Providing further support for this possibility, transfected dTBP assembled into rapidly sedimenting complexes and could be immunoprecipitated with anti-TAF antibodies. While overexpression of any of several TAFs did not affect basal transcription, in either the presence or the absence of cotransfected dTBP, overexpression of TAFII230 inhibited transcriptional activation mediated by p53-GAL4 as well as by GAL4-VP16 and Sp1. Overexpression of TAFII40 and TAFII60 also inhibited activation by p53-GAL4 but had negligible effects on activation by GAL4-VP16 and Sp1, while TAFII110 did not affect any of the activators. TAF-mediated inhibition of activated transcription could be rescued by high levels of exogenous dTBP, which also restored full synergy. These data demonstrate for the first time that functional interactions can occur in vivo between TBP, TAFs, and p53.

scholarly journals Binding of TATA Binding Protein to a Naturally Positioned Nucleosome Is Facilitated by Histone Acetylation

2001 ◽  
Vol 21 (4) ◽  
pp. 1404-1415 ◽  
Author(s):  
Gerald F. Sewack ◽  
Thomas W. Ellis ◽  
Ulla Hansen
Keyword(s):  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
General Mechanism ◽  
Native Promoter ◽  
Histone Hyperacetylation ◽  
Tata Sequence

ABSTRACT The TATA sequence of the human, estrogen-responsive pS2 promoter is complexed in vivo with a rotationally and translationally positioned nucleosome (NUC T). Using a chromatin immunoprecipitation assay, we demonstrate that TATA binding protein (TBP) does not detectably interact with this genomic binding site in MCF-7 cells in the absence of transcriptional stimuli. Estrogen stimulation of these cells results in hyperacetylation of both histones H3 and H4 within the pS2 chromatin encompassing NUC T and the TATA sequence. Concurrently, TBP becomes associated with the pS2 promoter region. The relationship between histone hyperacetylation and the binding of TBP was assayed in vitro using an in vivo-assembled nucleosomal array over the pS2 promoter. With chromatin in its basal state, the binding of TBP to the pS2 TATA sequence at the edge of NUC T was severely restricted, consistent with our in vivo data. Acetylation of the core histones facilitated the binding of TBP to this nucleosomal TATA sequence. Therefore, we demonstrate that one specific, functional consequence of induced histone acetylation at a native promoter is the alleviation of nucleosome-mediated repression of the binding of TBP. Our data support a fundamental role for histone acetylation at genomic promoters in transcriptional activation by nuclear receptors and provide a general mechanism for rapid and reversible transcriptional activation from a chromatin template.

scholarly journals Multiple Functions of the Nonconserved N-Terminal Domain of Yeast TATA-Binding Protein

Genetics ◽  
2001 ◽  
Vol 158 (1) ◽  
pp. 87-93
Author(s):  
Mark Lee ◽  
Kevin Struhl
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Protein S ◽  
Tata Binding Protein ◽  
Terminal Region ◽  
Core Domain ◽  
Terminal Domain ◽  
Two Factors

Abstract The TATA-binding protein (TBP) is composed of a highly conserved core domain sufficient for TATA-element binding and preinitiation complex formation as well as a highly divergent N-terminal region that is dispensable for yeast cell viability. In vitro, removal of the N-terminal region domain enhances TBP-TATA association and TBP dimerization. Here, we examine the effects of truncation of the N-terminal region in the context of yeast TBP mutants with specific defects in DNA binding and in interactions with various proteins. For a subset of mutations that disrupt DNA binding and the response to transcriptional activators, removal of the N-terminal domain rescues their transcriptional defects. By contrast, deletion of the N-terminal region is lethal in combination with mutations on a limited surface of TBP. Although this surface is important for interactions with TFIIA and Brf1, TBP interactions with these two factors do not appear to be responsible for this dependence on the N-terminal region. Our results suggest that the N-terminal region of TBP has at least two distinct functions in vivo. It inhibits the interaction of TBP with TATA elements, and it acts positively in combination with a specific region of the TBP core domain that presumably interacts with another protein(s).

scholarly journals Analysis of TFIIA Function In Vivo: Evidence for a Role in TATA-Binding Protein Recruitment and Gene-Specific Activation

1999 ◽  
Vol 19 (12) ◽  
pp. 8673-8685 ◽  
Author(s):  
Qing Liu ◽  
Scott E. Gabriel ◽  
Kelli L. Roinick ◽  
Robert D. Ward ◽  
Karen M. Arndt
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Gene Activation ◽  
Tata Binding Protein ◽  
New Class ◽  
Activation Of Transcription ◽  
Protein Recruitment ◽  
Dna Complex

ABSTRACT Activation of transcription can occur by the facilitated recruitment of TFIID to promoters by gene-specific activators. To investigate the role of TFIIA in TFIID recruitment in vivo, we exploited a class of yeast TATA-binding protein (TBP) mutants that is activation and DNA binding defective. We found that co-overexpression of TOA1 and TOA2, the genes that encode yeast TFIIA, overcomes the activation defects caused by the TBP mutants. Using a genetic screen, we isolated a new class of TFIIA mutants and identified three regions on TFIIA that are likely to be involved in TBP recruitment or stabilization of the TBP-TATA complex in vivo. Amino acid replacements in only one of these regions enhance TFIIA-TBP-DNA complex formation in vitro, suggesting that the other regions are involved in regulatory interactions. To determine the relative importance of TFIIA in the regulation of different genes, we constructed yeast strains to conditionally deplete TFIIA levels prior to gene activation. While the activation of certain genes, such asINO1, was dramatically impaired by TFIIA depletion, activation of other genes, such as CUP1, was unaffected. These data suggest that TFIIA facilitates DNA binding by TBP in vivo, that TFIIA may be regulated by factors that target distinct regions of the protein, and that promoters vary significantly in the degree to which they require TFIIA for activation.

scholarly journals GAL4 interacts with TATA-binding protein and coactivators.

1995 ◽  
Vol 15 (5) ◽  
pp. 2839-2848 ◽  
Author(s):  
K Melcher ◽  
S A Johnston
Keyword(s):  
Transcriptional Activation ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Negative Regulator ◽  
Binding Assays ◽  
Amino Acid Peptide ◽  
Eukaryotic Gene ◽  
Transcription In Vitro

A major goal in understanding eukaryotic gene regulation is to identify the target(s) of transcriptional activators. Efforts to date have pointed to various candidates. Here we show that a 34-amino-acid peptide from the carboxy terminus of GAL4 is a strong activation domain (AD) and retains at least four proteins from a crude extract: the negative regulator GAL80, the TATA-binding protein (TBP), and the putative coactivators SUG1 and ADA2. TFIIB was not retained. Concentrating on TBP, we demonstrate in in vitro binding assays that its interaction with the AD is specific, direct, and salt stable up to at least 1.6 M NaCl. The effects of mutations in the GAL4 AD on transcriptional activation in vivo correlate with their affinities to TBP. A point mutation (L114K) in yeast TBP, which has been shown to compromise the mutant protein in both binding to the VP16 AD domain and activated transcription in vitro, reduces the affinity to the GAL4 AD to the same degree as to the VP16 AD. This suggests that these two prototypic activators make similar contacts with TBP.

scholarly journals Mutations on the DNA-binding surface of TATA-binding protein can specifically impair the response to acidic activators in vivo.

1995 ◽  
Vol 15 (10) ◽  
pp. 5461-5469 ◽  
Author(s):  
M Lee ◽  
K Struhl
Keyword(s):  
Dna Binding ◽  
Protein Interactions ◽  
Convex Surface ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Protein Protein Interactions ◽  
Activator Proteins ◽  
Tata Element ◽  
Binding Surface

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.

scholarly journals Recruiting TATA-binding protein to a promoter: transcriptional activation without an upstream activator.

1995 ◽  
Vol 15 (10) ◽  
pp. 5757-5761 ◽  
Author(s):  
H Xiao ◽  
J D Friesen ◽  
J T Lis
Keyword(s):  
Dna Binding ◽  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Activator Proteins ◽  
Tata Element

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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