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

Initiation of transcription by RNA polymerase II requires a TFIID factor, which can recognize the TATA element common to many promoters. Two distinct multisubunit TFIID factors can be resolved from extracts of mammalian cells, and both of them contain the well-characterized TATA-binding protein (TBP) and are capable of supporting RNA polymerase II transcription in an in vitro reaction system. The smaller complex, B-TFIID, was purified and its subunit composition was determined. B-TFIID consists of two subunits: the TBP and a TBP-associated factor (TAF) of 170 kDa. This TAF is specific for B-TFIID and appears not to be present in the D-TFIID complex. Furthermore, it was found that the highly purified B-TFIID fractions have (d)ATPase activity.
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PMID:Composition of transcription factor B-TFIID. 138 11

Recent evidence suggests that transcription initiation by all three eukaryotic RNA polymerases involves a complex of the TATA-binding protein (TBP) and multiple TBP-associated factors (TAFs). Here, we map the functional domains of the nucleolar HMG box protein hUBF, which binds to the human rRNA promoter and stimulates transcription by RNA polymerase I through cooperative interactions with a distinct TBP-TAF complex, hSL1. DNase I footprint analysis of mutant hUBF proteins and of a synthetic peptide of 84 amino acids reveals that HMG box 1 is necessary and sufficient for DNA sequence specificity, whereas other HMG boxes and the amino terminus modulate the binding efficiency. hUBF contains multiple activation domains that include the acidic carboxyl terminus and three HMG boxes. HMG boxes 3 and 4 and the acidic tail contribute significantly to an extended footprinting pattern in the presence of hSL1, suggestive of specific protein-protein interactions. Moreover, the inability of xUBF from Xenopus laevis to form an initiation complex with hSL1 can be overcome by hybrid proteins containing human HMG box 4 and the acidic carboxyl terminus. These results strongly suggest an important role of transcription activation domains of hUBF in mediating interactions with the TBP-TAF complex hSL1.
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PMID:Multiple domains of the RNA polymerase I activator hUBF interact with the TATA-binding protein complex hSL1 to mediate transcription. 139 72

RNA polymerases I, II, and III require the TATA-binding protein (TBP) to initiate promoter-specific transcription. We have separated HeLa TBP into four phosphocellulose fractions that elicit polymerase specificity in supplying TBP activity to TBP-depleted pol II and pol III transcription reactions. Polymerase specificity might arise in part through distinct TBP-associated factors (TAFs), which have recently been identified in pol I and II transcription. However, the requirement for pol III TAFs has not been established. Here we show that classical pol III transcription involves a minimum of two novel TAFs: TAF-172 and TAF-L. Not only does TAF-172 activate pol III transcription, but it also inhibits the binding of TBP to the TATA box, thereby repressing pol II transcription. The TBP-TAF-172-TAF-L complex can replace TFIIIB both in transcription reactions reconstituted with TFIIIC and in template commitment assays. Thus SL1, TFIID, and TFIIIB might be functionally similar TBP-TAF complexes that direct pol I, II, and III transcription, respectively.
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PMID:The TATA-binding protein and associated factors are components of pol III transcription factor TFIIIB. 145 33

We have previously shown that the TATA-binding protein (TBP) and multiple TBP-associated factors (TAFs) are required for regulated transcriptional initiation by RNA polymerase II. Here we report the biochemical properties of the RNA polymerase I promoter selectivity factor, SL1, and its relationship to TBP. Column chromatography and glycerol gradient sedimentation indicate that a subpopulation of TBP copurifies with SL1 activity. Antibodies directed against TBP efficiently deplete SL1 transcriptional activity, which can be restored with the SL1 fraction but not purified TBP. Thus, TBP is necessary but not sufficient to complement SL1 activity. Analysis of purified SL1 reveals a complex containing TBP and three distinct TAFs. Purified TAFs reconstituted with recombinant TBP complement SL1 activity, and this demonstrates that TBP plus novel associated factors are integral components of SL1. These findings suggest that TBP may be a universal transcription factor and that the TBP-TAF arrangement provides a unifying mechanism for promoter recognition in animal cells.
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PMID:The TATA-binding protein and associated factors are integral components of the RNA polymerase I transcription factor, SL1. 154 96

A key step in the regulation of transcription involves interactions between promoter-selective factors and various components of the transcriptional apparatus. Here we report the requirements for transcriptional activation directed by NTF-1, a developmentally regulated transcription factor in Drosophila. Reconstituted transcription with fractionated Drosophila basal factors reveals that activation by NTF-1 requires factors present in the endogenous TFIID fraction that are distinct from the purified TATA-binding protein (TBP). Glycerol gradient sedimentation and immunoprecipitation analyses indicate that TFIID is a multiprotein complex containing TBP and at least six tightly bound TBP-associated factors (TAFs). Preparations of TBP lacking TAFs after fractionation with denaturants no longer support activation by NTF-1 but retain basal level activity. Addition of immunopurified and renatured TAFs to free TBP restores the ability of NTF-1 to activate transcription without influencing basal transcription. These results suggest that one or more of the TAF polypeptides confer coactivator function.
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PMID:Isolation of coactivators associated with the TATA-binding protein that mediate transcriptional activation. 190 90

Although the mechanisms of transcriptional regulation by RNA polymerase II are apparently highly conserved from yeast to man, the identification of a yeast TATA-binding protein (TBP)-TBP-associated factor (TAFII) complex comparable to the metazoan TFIID component of the basal transcriptional machinery has remained elusive. Here, we report the isolation of a yeast TBP-TAFII complex which can mediate transcriptional activation by GAL4-VP16 in a highly purified yeast in vitro transcription system. We have cloned and sequenced the genes encoding four of the multiple yeast TAFII proteins comprising the TBP-TAFII multisubunit complex and find that they are similar at the amino acid level to both human and Drosophila TFIID subunits. Using epitope-tagging and immunoprecipitation experiments, we demonstrate that these genes encode bona fide TAF proteins and show that the yeast TBP-TAFII complex is minimally composed of TBP and seven distinct yTAFII proteins ranging in size from M(r) = 150,000 to M(r) = 25,000. In addition, by constructing null alleles of the cloned TAF-encoding genes, we show that normal function of the TAF-encoding genes is essential for yeast cell viability.
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PMID:Identification and characterization of a TFIID-like multiprotein complex from Saccharomyces cerevisiae. 766 72

Basal transcription by human RNA polymerase II requires the coordinate action of several ancillary factors (TFIIA-J) and can be regulated by various promoter-specific DNA binding proteins. An additional class of factors, called coactivators, are dispensable for basal transcription but are indispensable for regulation by transcriptional activators. Biochemical studies established that some coactivators are associated with the TATA-binding protein (TBP) to form the TFIID complex. We therefore set out to define the relationship between TBP and these TBP-associated factors (TAFs). Here we describe the cloning, expression and properties of the first human TAF, hTAFII250. The hTAFII250 gene is identical to a gene, CCG1, (ref 7,8), implicated in cell-cycle progression. Recombinant hTAFII250 binds directly to TBP both in vitro and in yeast, and participates in the formation of the TFIID complex. This largest TAF may therefore play a central role in TFIID assembly by interacting with both TBP and other TAFs, as well as serving to link the control of transcription to the cell cycle.
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PMID:Cloning and expression of human TAFII250: a TBP-associated factor implicated in cell-cycle regulation. 768 Jul 71

In mammalian and Drosophila cells, the central RNA polymerase II general transcription factor TFIID is a multisubunit complex containing the TATA-binding protein (TBP) and TBP-associated factors (TAFs) bound to the conserved TBP carboxy-terminal core domain. TBP also associates with alternative TAFs in these cells to form general transcription factors required for initiation by RNA polymerases I and III. Although extracts of human HeLa cells contain little TBP that is not associated with TAFs, free TBP is readily isolated from yeast cell extracts. However, recent studies indicate that yeast TBP can also interact with other yeast polypeptides to form multiprotein complexes. We established stable human HeLa cell lines expressing yeast TBP and several yeast-human TBP hybrids to study TBP-TAF interactions. We found that the yeast TBP core domain assembles with a complete set of human TAFs into a stable TFIID complex that can support activated transcription in vitro. The fact that the yeast TBP core, which differs from human TBP core in approximately 20% of its amino acid residues, has the structural features required to form a stable complex with human TAFs implies that Saccharomyces cerevisiae probably contains TAFs that are structurally and functionally analogous to human TAFs. Surprisingly, the non-conserved amino terminus of yeast TBP inhibited association between the yeast core domain and human TAFs.
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PMID:The yeast TATA-binding protein (TBP) core domain assembles with human TBP-associated factors into a functional TFIID complex. 779 63

RNA polymerase I and II transcription factors SL1 and TFIID, respectively, are composed of the TATA-binding protein (TBP) and a set of TBP-associated factors (TAFs) responsible for promoter recognition. How the universal transcription factor TBP becomes committed to a TFIID or SL1 complex has not been known. Complementary DNAs encoding each of the three TAFIs that are integral components of SL1 have not been isolated. Analysis of subunit interactions indicated that the three TAFIs can bind individually and specifically to TBP. In addition, these TAFIs interact with each other to form a stable TBP-TAF complex. When TBP was bound first by either TAFI110, 63, or 48, subunits of TFIID such as TAFII250 and 150 did not bind TBP. Conversely, if TBP first formed a complex with TAFII250 or 150, the subunits of SL1 did not bind TBP. These results suggest that a mutually exclusive binding specificity for TBP intrinsic to SL1 and TFIID subunits directs the formation of promoter- and RNA polymerase-selective TBP-TAF complexes.
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PMID:Reconstitution of transcription factor SL1: exclusive binding of TBP by SL1 or TFIID subunits. 780 Nov 23

TFIID is a multisubunit protein complex comprised of the TATA-binding protein (TBP) and multiple TBP-associated factors (TAFs). The TAFs in TFIID are essential for activator-dependent transcription. The cloning of a complementary DNA encoding a human TFIID TAF, TAFII55, that has no known homolog in Drosophila TFIID is now described. TAFII55 is shown to interact with the largest subunit (TAFII230) of human TFIID through its central region and with multiple activators--including Sp1, YY1, USF, CTF, adenoviral E1A, and human immunodeficiency virus-type 1 Tat proteins--through a distinct amino-terminal domain. The TAFII55-interacting region of Sp1 was localized to its DNA-binding domain, which is distinct from the glutamine-rich activation domains previously shown to interact with Drosophila TAFII110. Thus, this human TFIID TAF may be a co-activator that mediates a response to multiple activators through a distinct mechanism.
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PMID:Cloning of an intrinsic human TFIID subunit that interacts with multiple transcriptional activators. 782 54


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