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

Transcription of the TRP3 gene of Saccharomyces cerevisiae is regulated by GCN4p from a position proximal to the transcriptional initiation sites. The promoter's apparent lack of a conventional TATA element sequence has led it to be used as a model for TATA-less promoters. Through mutational analysis of the TRP3 promoter, we have identified two additional regulatory elements required for expression. The first, located 57 base pairs (bp) upstream of the GCN4p binding site, binds ABF1p in vitro. The ABF1p binding site was required for maximal levels of GCN4p-activated transcription in vivo; however, the -fold activation by GCN4p was not altered by ABF1p. The second element, positioned 23 bp downstream of the GCN4p binding site, contained the TATA-like sequence, TATTAA. This element was required for both basal and activated expression and almost certainly functions as a TATA-binding protein interaction site. Mutations that improved its TATA character for native or an altered specificity mutant of TATA-binding protein correspondingly improved its function. Interestingly, basal expression induced by ABF1p was virtually unchanged in the presence of point mutations in the TATTAA element. Furthermore, unlike the case for HIS3 where only a limited subset of TATA-like sequences can activate transcription in conjunction with GCN4p, many divergent TATA-like sequences allowed GCN4p activation of TRP3. We suggest that the apparent promoter specific use of these TATA elements by GCN4p results from ABF1p amplifying the GCN4p-induced expression to a detectable level.
 ...
PMID:GCN4p activation of the yeast TRP3 gene is enhanced by ABF1p and uses a suboptimal TATA element. 819 16

The SUD1 gene was identified during a hunt for mutants that are able to express an sta1 gene (encoding an extracellular glucoamylase) lacking an upstream activation sequence (UAS) for transcription. A null allele of sud1 alleviated the transcriptional defect of the UAS-less sta1 and also suppressed mutations in trans-acting genes (GAM1/SNF2 and GAM3/ADR6) required for transcription of STA1. The mutation also increased expression from various core promoters (CYC1, CUP1, HIS3, PUT1, and PUT2), suggesting that the SUD1 protein is a global transcriptional regulator that plays a negative role at or near the TATA element. However, the SUD1 function was ineffective on promoters containing a UAS from either STA1 or GAL10 under derepressed conditions. The sud1 mutation suppressed the salt-sensitive cell growth phenotype caused by elevated levels of the TATA-binding protein (SPT15), further suggesting a transcriptional role for SUD1. sud1 cells showed additional pleiotropic phenotypes: temperature-sensitive (ts) growth, reduced efficiencies of sporulation, and sensitivity to heat shock and nitrogen starvation. The SUD1 gene is predicted to encode a 64 kDa, hydrophilic protein.
 ...
PMID:Isolation and characterization of the SUD1 gene, which encodes a global repressor of core promoter activity in Saccharomyces cerevisiae. 826 36

Previous studies demonstrated that mutations in the Saccharomyces cerevisiae NOT genes increase transcription from TATA-less promoters. In this report, I show that in contrast, mutations in the yeast MOT1 gene decrease transcription from TATA-less promoters. I also demonstrate specific genetic interactions between the Not complex, Mot1p, and another global regulator of transcription in S. cerevisiae, Spt3p. Five distinct genetic interactions have been established. First, a null allele of SPT3, or a mutation in SPT15 that disrupts the interaction between Spt3p and TATA-binding protein (TBP), allele specifically suppressed the not1-2 mutation. Second, in contrast to not mutations, mutations in MOT1 decreased HIS3 and HIS4 TATA-less transcription. Third, not mutations suppressed toxicity due to overexpression of TBP in mot1-1 mutants. Finally, overexpression of SPT3 caused a weak Not- mutant phenotype in mot1-1 mutants. Collectively, these results suggest a novel type of transcriptional regulation whereby the distribution of limiting TBP (TFIID) on weak and strong TBP-binding core promoters is regulated: Mot1p releases stably bound TBP to allow its redistribution to low-affinity sites, and the Not proteins negatively regulate the activity of factors such as Spt3p that favor distribution of TBP to these low-affinity sites.
 ...
PMID:The NOT, SPT3, and MOT1 genes functionally interact to regulate transcription at core promoters. 894 21

The hect-domain has been characterized as a conserved feature of a group of E3 ubiquitin ligases. Here we show that the yeast hect-domain protein TOM1p regulates transcriptional activation through effects on the ADA transcriptional coactivator proteins. Null mutations of tom1 result in similar defects in transcription from ADH2 and HIS3 promoters, and enhanced transcription from the GAL10 promoter as do null mutations in ngg1/ada3. Strains with disruptions of both ngg1 and tom1 have the same phenotype as strains with a disruption of only ngg1 implying that these genes are acting through the same pathway. In the absence of TOM1p, the normal associations of the ADA proteins with SPT3p and the TATA-binding protein are reduced. The action of TOM1p is most likely mediated through ubiquitination since mutation of Cys3235 to Ala, corresponding residues of which are required for thioester bond formation with ubiquitin in other hect-domain proteins, results in similar changes in transcription as the null mutation. A direct role for TOM1p in regulation of ADA-associated proteins is further supported by the finding that SPT7p is ubiquitinated in a TOM1p-dependent fashion and that TOM1p coimmunoprecipitates with the ADA proteins.
 ...
PMID:TOM1p, a yeast hect-domain protein which mediates transcriptional regulation through the ADA/SAGA coactivator complexes. 975 45

SAGA, a recently described protein complex in Saccharomyces cerevisiae, is important for transcription in vivo and possesses histone acetylation function. Here we report both biochemical and genetic analyses of members of three classes of transcription regulatory factors contained within the SAGA complex. We demonstrate a correlation between the phenotypic severity of SAGA mutants and SAGA structural integrity. Specifically, null mutations in the Gcn5/Ada2/Ada3 or Spt3/Spt8 classes cause moderate phenotypes and subtle structural alterations, while mutations in a third subgroup, Spt7/Spt20, as well as Ada1, disrupt the complex and cause severe phenotypes. Interestingly, double mutants (gcn5Delta spt3Delta and gcn5Delta spt8Delta) causing loss of a member of each of the moderate classes have severe phenotypes, similar to spt7Delta, spt20Delta, or ada1Delta mutants. In addition, we have investigated biochemical functions suggested by the moderate phenotypic classes and find that first, normal nucleosomal acetylation by SAGA requires a specific domain of Gcn5, termed the bromodomain. Deletion of this domain also causes specific transcriptional defects at the HIS3 promoter in vivo. Second, SAGA interacts with TBP, the TATA-binding protein, and this interaction requires Spt8 in vitro. Overall, our data demonstrate that SAGA harbors multiple, distinct transcription-related functions, including direct TBP interaction and nucleosomal histone acetylation. Loss of either of these causes slight impairment in vivo, but loss of both is highly detrimental to growth and transcription.
 ...
PMID:Functional organization of the yeast SAGA complex: distinct components involved in structural integrity, nucleosome acetylation, and TATA-binding protein interaction. 985 34

Spt-Ada-Gcn5 acetyltransferase (SAGA) is a previously described histone acetyltransferase/transcriptional coactivator complex in yeast. At promoters of certain genes (HIS3 and TRP3), SAGA has an inhibitory function involving a nonproductive TATA-binding protein interaction mediated by the Spt3 and Spt8 subunits. Related to this, Spt8-less SAGA is a major form of the complex under activating conditions for these genes. In the present study, we purify this activation-specific complex, called SALSA (SAGA altered, Spt8 absent). Besides lacking Spt8, SALSA contains Spt7 subunit that is truncated. Examining the role of this subunit, we find that C-terminally truncated SPT7 resulted in derepressed HIS3 transcription. Furthermore, when grown in rich media (repressing conditions), wild-type cells yielded predominantly SAGA, but Spt7 C-terminal truncations resulted primarily in a form of complex similar to SALSA. Thus, SALSA-like structure and activating function can be partially recapitulated in yeast by truncating the C terminus of Spt7. Overall, these results lead to a model that for a subset of promoters SAGA is inhibitory through Spt3, Spt8, and an Spt8-interacting subdomain of Spt7, whereas SALSA is a form of complex for positive transcriptional regulation. These data clarify a mechanism by which a transcriptional regulatory complex can switch between positive and negative modulation.
 ...
PMID:SALSA, a variant of yeast SAGA, contains truncated Spt7, which correlates with activated transcription. 1218 75

Mot1 stably associates with the TATA-binding protein (TBP), and it can dissociate TBP from DNA in an ATP-dependent manner. Mot1 acts as a negative regulator of TBP function in vitro, but genome-wide transcriptional profiling suggests that Mot1 positively affects about 10% of yeast genes and negatively affects about 5%. Unexpectedly, Mot1 associates with active RNA polymerase (Pol) II and III promoters, and it is rapidly recruited in response to activator proteins. At Pol II promoters, Mot1 association requires TBP and is strongly correlated with the level of TBP occupancy. However, the Mot1/TBP occupancy ratio at both Mot1-stimulated and Mot1-inhibited promoters is high relative to that at typical promoters, strongly suggesting that Mot1 directly affects transcriptional activity in a positive or negative manner, depending on the gene. The effect of Mot1 at the HIS3 promoter region depends on the functional quality and DNA sequence of the TATA element. Unlike TBP, Mot1 association is largely independent of the Srb4 component of Pol II holoenzyme, and it also can occur downstream of the promoter region. Mot1 removes TBP, but not TBP complexes or preinitiation complexes, from inappropriate genomic locations. Mot1 inhibits the association of NC2 with promoters, suggesting that the TBP-Mot1 and TBP-NC2 complexes compete for promoter occupancy in vivo. We speculate that Mot1 does not form transcriptionally active TBP complexes but rather regulates transcription in vivo by modulating the activity of free TBP and/or by affecting promoter DNA structure.
 ...
PMID:Mot1 associates with transcriptionally active promoters and inhibits association of NC2 in Saccharomyces cerevisiae. 1241 16

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.
 ...
PMID:Transcriptional activation requires protection of the TATA-binding protein Tbp1 by the ubiquitin-specific protease Ubp3. 2073 57