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 proximal sequence element (PSE), found in both RNA polymerase II (Pol II)- and RNA Pol III-transcribed small nuclear RNA (snRNA) genes, is specifically bound by the PSE-binding transcription factor (PTF). We have purified PTF to near homogeneity from HeLa cell extracts by using a combination of conventional and affinity chromatographic methods. Purified PTF is composed of four polypeptides with apparent molecular masses of 180, 55, 45, and 44 kDa. A combination of preparative electrophoretic mobility shift and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses has conclusively identified these four polypeptides as subunits of human PTF, while UV cross-linking experiments demonstrate that the largest subunit of PTF is in close contact with the PSE. The purified PTF activates transcription from promoters of both Pol II- and Pol III-transcribed snRNA genes in a PSE-dependent manner. In addition, we have investigated factor requirements in transcription of Pol III-dependent snRNA genes. We show that in extracts that have been depleted of TATA-binding protein (TBP) and associated factors, recombinant TBP restores transcription from U6 and 7SK promoters but not from the VAI promoter, whereas the highly purified TBP-TBP-associated factor complex TFIIIB restores transcription from the VAI but not the U6 or 7SK promoter. Furthermore, by complementation of heat-treated extracts lacking TFIIIC activity, we show that TFIIIC1 is required for transcription of both the 7SK and VAI genes, whereas TFIIIC2 is required only for transcription of the VAI gene. From these observations, we conclude (i) that PTF and TFIIIC2 function as gene-specific as gene-specific factors for PSE-and B-box-containing Pol III genes, respectively, (ii) that the form of TBP used by class III genes with upstream promoter elements differs from the from used by class III genes with internal promoters, and (iii) that TFIIIC1 is required for both internal and external Pol III promoters.
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PMID:Proximal sequence element-binding transcription factor (PTF) is a multisubunit complex required for transcription of both RNA polymerase II- and RNA polymerase III-dependent small nuclear RNA genes. 789 97

We showed previously that coactivators mediating stimulation by different activators were associated with the TATA-binding protein (TBP) in distinct TFIID complexes. We have characterized a human TBP-associated factor (TAF), hTAFII30, associated with a subset of TFIID complexes. hTAFII30 interacts with the AF-2-containing region E of the human estrogen receptor (ER), but not with ER AF-1 or VP16. An antibody against hTAFII30 inhibited transcriptional stimulation by the ER AF-2 without affecting basal or VP16-activated transcription and allowed the separation of TFIID complex(es) containing hTAFII30 from complexes mediating the activity of VP16. These results directly demonstrate the existence of functionally distinct TFIID populations that share common TAFIIs but differ in specific TAFIIs.
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PMID:Human TAFII30 is present in a distinct TFIID complex and is required for transcriptional activation by the estrogen receptor. 792 69

Unlike genes transcribed by RNA polymerases II and III, transcription by RNA polymerase I is highly species-specific. Ribosomal promoter selectivity is brought about by a multisubunit transcription factor (SL1/TIF-IB) which consists of the TATA-binding protein (TBP) and three TBP-associated factors (TAFs). To determine the basis for the inability of SL1/TIF-IB to recognize heterologous rDNA, the transcriptional properties and the subunit composition of the murine and the human factor, as well as a chimeric complex containing epitope-tagged human TBP and murine TAFs, have been compared. We show that TBP can be exchanged between the human and mouse factor indicating that the variable N-terminal domain of TBP does not play a significant role in rDNA promoter selectivity. Instead, DNA binding is brought about by the TAFs. UV crosslinking experiments demonstrate that binding to the ribosomal gene promoter is mediated by two TAFs (TAFI48 and TAFI68) which have the same electrophoretic mobility in the human and mouse factor. The largest TAF is different in both species and is suggested to play a role in the species-specific assembly of productive preinitiation complexes. Thus, evolutionary changes of rDNA promoter sequences have been accompanied by changes in specific TAFs.
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PMID:TBP-associated factors interact with DNA and govern species specificity of RNA polymerase I transcription. 801 60

Transcription by RNA polymerase I (pol I), pol II, and pol III requires the TATA-binding protein (TBP). This protein functions in association with distinct TBP-associated factors (TAFs) which may specify the nature of the polymerase selected for initiation at a promoter site. In the pol III transcription system, the TBP-TAF complex is a component of the TFIIIB factor. This factor has been resolved into a TBP-TAF complex and another component, both of which are required for reconstitution of transcription by pol III. Neither the TBP-TAF complexes B-TFIID and D-TFIID, which were previously characterized as active for pol II transcription, nor TBP alone can complement pol III transcription reactions that are dependent upon the TBP-TAF subcomponent of TFIIIB. Surprisingly, the TBP-TAF subcomponent of TFIIIB is active in reconstitution of pol II transcription.
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PMID:TATA-binding protein and associated factors in polymerase II and polymerase III transcription. 824 10

The proximal sequence element (PSE)-binding transcription factor (PTF) specifically recognizes the PSEs of both RNA polymerase II- and RNA polymerase III-transcribed small nuclear RNA (snRNA) genes. We previously have shown that PTF purified from human HeLa cells is a multisubunit complex of four polypeptides designated PTF alpha, -beta, -gamma, and -delta. We now report the isolation and expression of cDNAs encoding PTF gamma and PTF delta, as well as functional studies with cognate antibodies that recognize the native PTF complex in HeLa extracts. Immunoprecipitation studies confirm that the four PTF subunits originally found to copurify during conventional chromatography indeed form a tightly associated complex; they further show that the PTF so defined, including the gamma and delta subunits specifically, is essential for transcription of both class II and class III snRNA genes. Immunoprecipitation assays also show a weak substoichiometric association of the TATA-binding protein (TBP) with PTF, consistent with the previous report of a PTF-related complex (SNAPc) containing substoichiometric levels of TBP and a component (SNAPc43) identical in sequence to the PTF gamma reported here. Glutathione S-transferase pulldown assays further indicate relatively strong direct interactions of both recombinant PTF gamma and PTF delta with TBP, consistent either with the natural association of TBP with PTF in a semistable TBP-TBP-associated factor complex or with possible functional interactions between PSE-bound PTF and TATA-bound TBP during promoter activation. In addition, we show that in extracts depleted of TBP and TBP-associated factors, transcription from the U1 promoter is restored by recombinant TBP but not by TFIID or TFIIIB, indicating that transcription of class II snRNA genes requires a TBP complex different from the one used for mRNA-encoding genes.
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PMID:Cloning of two proximal sequence element-binding transcription factor subunits (gamma and delta) that are required for transcription of small nuclear RNA genes by RNA polymerases II and III and interact with the TATA-binding protein. 852 84

The CT element is a positively acting homopyrimidine tract upstream of the c-myc gene to which the well-characterized transcription factor Spl and heterogeneous nuclear ribonucleoprotein (hnRNP) K, a less well-characterized protein associated with hnRNP complexes, have previously been shown to bind. The present work demonstrates that both of these molecules contribute to CT element-activated transcription in vitro. The pyrimidine-rich strand of the CT element both bound to hnRNP K and competitively inhibited transcription in vitro, suggesting a role for hnRNP K in activating transcription through this single-stranded sequence. Direct addition of recombinant hnRNP K to reaction mixtures programmed with templates bearing single-stranded CT elements increased specific RNA synthesis. If hnRNP K is a transcription factor, then interactions with the RNA polymerase II transcription apparatus are predicted. Affinity columns charged with recombinant hnRNP K specifically bind a component(s) necessary for transcription activation. The depleted factors were biochemically complemented by a crude TFIID phosphocellulose fraction, indicating that hnRNP K might interact with the TATA-binding protein (TBP)-TBP-associated factor complex. Coimmunoprecipitation of a complex formed in vivo between hnRNP K and epitope-tagged TBP as well as binding in vitro between recombinant proteins demonstrated a protein-protein interaction between TBP and hnRNP K. Furthermore, when the two proteins were overexpressed in vivo, transcription from a CT element-dependent reporter was synergistically activated. These data indicate that hnRNP K binds to a specific cis element, interacts with the RNA polymerase II transcription machinery, and stimulates transcription and thus has all of the properties of a transcription factor.
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PMID:Heterogeneous nuclear ribonucleoprotein K is a transcription factor. 862 2

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.
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PMID:Functional interaction between p53, the TATA-binding protein (TBP), andTBP-associated factors in vivo. 875 30

The transcription factor TFIID, a central component of the eukaryotic RNA polymerase II (Pol II) transcription apparatus, comprises the TATA-binding protein (TBP) and approximately ten TBP-associated factors (TAFs). Although the essential role of TBP in all eukaryotic transcription has been extensively analysed in vivo and in vitro, the function of the TAFs is less clear. In vitro, TAFs are dispensable for basal transcription but are required for the response to activators. In addition, specific TAFs may act as molecular bridges between particular activators and the general transcription machinery. In vivo, TAFS are required for yeast and mammalian cell growth, but little is known about their specific transcriptional functions. Using conditional alleles created by a new double-shutoff method, we show here that TAF depletion in yeast cells can reduce transcription from some promoters lacking conventional TATA elements. However, TAF depletion has surprisingly little effect on transcriptional enhancement by several activators, indicating that TAFs are not generally required for transcriptional activation in yeast.
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PMID:TBP-associated factors are not generally required for transcriptional activation in yeast. 877 74

Initiation of RNA polymerase I transcription in Xenopus laevis requires Rib 1 and upstream binding factor (UBF). UBF and Rib 1 combine to form a stable transcription complex on the Xenopus ribosomal gene promoter. Here we show that Rib 1 comprises TATA-binding protein (TBP) and TBP-associated factor components. Thus, Rib 1 is the Xenopus equivalent of mammalian SL 1. In contrast to SL 1, Rib 1 is an unstable complex that readily dissociates into TBP and associated components. We identify a novel function for UBF in stabilizing Rib 1 by multiple protein interactions. This stabilization occurs in solution in a DNA-independent manner. These results may partially explain the difference in UBF requirement between Xenopus and mammalian systems.
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PMID:Upstream binding factor stabilizes Rib 1, the TATA-binding-protein-containing Xenopus laevis RNA polymerase I transcription factor, by multiple protein interactions in a DNA-independent manner. 881 69

TFIID is the main sequence-specific DNA-binding component of the RNA polymerase II (Pol II) transcriptional machinery. It is a multiprotein complex composed of the TATA-binding protein (TBP) and TBP-associated factors (TAF(II)s). Here we report the cloning and characterization of a novel human TBP-associated factor, hTAF(II)68. It contains a consensus RNA-binding domain (RNP-CS) and binds not only RNA, but also single stranded (ss) DNA. hTAF(II)68 shares extensive sequence similarity with TLS/FUS and EWS, two human nuclear RNA-binding pro-oncoproteins which are products of genes commonly translocated in human sarcomas. Like hTAF(II)68, TLS/FUS is also associated with a sub-population of TFIID complexes chromatographically separable from those containing hTAF(II)68. Therefore, these RNA and/or ssDNA-binding proteins may play specific roles during transcription initiation at distinct promoters. Moreover, we demonstrate that hTAF(II)68 co-purifies also with the human RNA polymerase II and can enter the preinitiation complex together with Pol II.
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PMID:hTAF(II)68, a novel RNA/ssDNA-binding protein with homology to the pro-oncoproteins TLS/FUS and EWS is associated with both TFIID and RNA polymerase II. 889 Jan 75


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