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)

We have cloned and characterized the human TATA-binding protein (TBP)-associated factor hTAFII55. hTAFII55, which has no known Drosophila counterpart, is present in both of the previously described TFIIDalpha and TFIIDbeta subpopulations. We describe the interactions of hTAFII55 with other subunits of the transcription factor TFIID. By cotransfection in COS cells, we show that hTAFII55 interacts with hTAFII250, hTAFII100, hTAFII28, hTAFII20, and hTAFII18, but not with hTAFII30 or TBP. Analysis of the binding of hTAFII55 and TBP to hTAFII28 deletion mutants indicates that distinct regions of hTAFII28 are required for these interactions. Although hTAFII55 does not interact by itself with TBP, stable ternary complexes containing hTAFII55 and TBP can be formed in the presence of hTAFII250, hTAFII100, or hTAFII28. These results not only show that hTAFII100 and hTAFII28 interact with TBP, but also that they can nucleate the formation of partial TFIID complexes.
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PMID:Multiple interactions between hTAFII55 and other TFIID subunits. Requirements for the formation of stable ternary complexes between hTAFII55 and the TATA-binding protein. 870 84

Human transcription initiation factor TFIID contains the TATA-binding protein (TBP) and several TBP-associated factors (TAFs). To investigate the structural organization and function of TFIID, we have cloned and expressed a DNA encoding the third largest human TFIID subunit, hTAFII100. Immunoprecipitation studies demonstrate that hTAFII100 is an integral subunit that is associated with all transcriptionally-competent forms of TFIID. They further suggest that at least part of the N-terminal region lies on the surface of TFIID, while a C-terminal region containing conserved WD-40 repeats appears inaccessible. Both in vivo and in vitro assays indicate that hTAFII100 interacts strongly with the histone H4-related hTAFII80 and the histone H3-related hTAFII31, as well as a stable complex comprised of both hTAFII80 and hTAFII31. Apparently weaker interactions of hTAFII100 with TBP, hTAFII250, hTAFII28, and hTAFII20, but not hTAFII55, also have been observed. These results suggest a role for hTAFII100 in stabilizing interactions of TAFs, especially the histone-like TAFs, in TFIID. In addition, functional studies show that anti-hTAFII100 antibodies selectively inhibit basal transcription from a TATA-less initiator-containing promoter, relative to a TATA-containing promoter, suggesting a possible core promoter-specific function for hTAFII100.
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PMID:Specific interactions and potential functions of human TAFII100. 904 4

Transport of mRNA from the nucleus to the cytoplasm is one of the important steps in gene expression in eukaryotic cells. To elucidate a mechanism of mRNA export, we identified a novel ptr [poly(A)+ RNA transport] mutation, ptr6, which causes accumulation of mRNA in the nucleus and inhibition of growth at the nonpermissive temperature. The ptr6(+) gene was found to encode an essential protein of 393 amino acids, which shares significant homology in amino acid sequence with yTAFII67 of budding yeast Saccharomyces cerevisiae and human hTAFII55, a subunit of the general transcription factor complex TFIID. A Ptr6p-GFP fusion protein is localized in the nucleus, suggesting that Ptr6p functions there. Northern blot analysis using probes for 10 distinct mRNAs showed that the amount of tbp+ mRNA encoding the TATA-binding protein is increased five- to sixfold, whereas amounts of others are rapidly decreased at the nonpermissive temperature in ptr6-1. ptr6 has no defects in nuclear import of an NLS-GFP fusion protein. These results suggest that Ptr6p required for mRNA transport is a Schizosaccharomyces pombe homologue of yTAFII67 and hTAFII55. This is the first report suggesting that a TAF is involved in the nucleocytoplasmic transport of mRNA in addition to the transcription of the protein-coding genes.
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PMID:Characterization of the ptr6(+) gene in fission yeast: a possible involvement of a transcriptional coactivator TAF in nucleocytoplasmic transport of mRNA. 1038 8

We have identified novel interactions between the human (h)TATA-binding protein-associated factor TAF(II)55 and the ligand-binding domains (LBDs) of the nuclear receptors for vitamin D(3) (VDR) and thyroid hormone (TRalpha). Following expression in Cos cells, hTAF(II)55 interacts with the VDR and TRalpha LBDs in a ligand-independent manner whereas no interactions with the retinoid X receptors (RXRs) or with other receptors were observed. Deletion mapping indicates that hTAF(II)55 interacts with a 40-amino-acid region spanning alpha-helices H3 to H5 of the VDR and TRalpha LBDs but not with the equivalent highly related region of RXRgamma. TAF(II)55 also interacts with chimeric receptors in which the H3-to-H5 region of RXRgamma has been replaced with that of the VDR or TRalpha. Furthermore, replacement of two single amino acids of the RXRgamma LBD with their VDR counterparts allows the RXRgamma LBD to interact with hTAF(II)55 while the corresponding double substitution allows a much stronger interaction. In transfection experiments, the single mutated RXRgamma LBDs activate transcription to fivefold higher levels than wild-type RXRgamma while the double mutation activates transcription to a level comparable to that observed with the VDR. There is therefore a correlation between the ability of the modified RXRs to interact with hTAF(II)55 and transactivation. These results strongly suggest that the TAF(II)55 interactions with the modified RXR LBDs modulate transcriptional activation.
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PMID:Human TAF(II)55 interacts with the vitamin D(3) and thyroid hormone receptors and with derivatives of the retinoid X receptor that have altered transactivation properties. 1040 38

The basal transcription factor TFIID consists of the TATA-binding protein (TBP) and TBP-associated factors (TAFs). Yeast Taf67 is homologous to mammalian TAF(II)55. Using a yeast two-hybrid screen to identify proteins that interact with Taf67, we isolated Bromodomain factor 1 (Bdf1) and its homolog (Bdf2). The Bdf proteins are genetically redundant, as cells are inviable without at least one of the two BDF genes. Both proteins contain two bromodomains, a motif found in several proteins involved in transcription and chromatin modification. The BDF genes interact genetically with TAF67. Furthermore, Bdf1 associates with TFIID and is recruited to a TATA-containing promoter. Deletion of Bdf1 or the Taf67 Bdf-interacting domain leads to defects in gene expression. Interestingly, the higher eukaryotic TAF(II)250 has an acetyltransferase activity, two bromodomains, and an associated kinase activity. Its yeast homolog, Taf145, has acetyltransferase activity but lacks the bromodomains and kinase. Bdf1, like TAF(II)250, has a kinase activity that maps carboxy-terminal to the bromodomains. The structural and functional similarities suggest that Bdf1 corresponds to the carboxy-terminal region of higher eukaryotic TAF(II)250 and that the interaction between TFIID and Bdf1 is important for proper gene expression.
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PMID:Bromodomain factor 1 corresponds to a missing piece of yeast TFIID. 1078 67

Protein-protein interactions between human heat shock transcription factor 1 (hHSF1) and general transcription factors TFIIA-gamma, TFIIB, TBP, TAF(II)32, and TAF(II)55 and positive coactivator PC4 were characterized in order to identify potential targets of contact in the transcriptional preinitiation complex. These contacts represent one of the final steps in the signal transfer of heat stress to the transcriptional apparatus. TATA-binding protein (TBP) and transcription factor IIB (TFIIB) were identified as major targets for HSF1 transcriptional activation domains AD1 and AD2 based on in vitro interaction assays. TBP showed affinity for AD2 and a fragment containing AD1, while the core domain of TFIIB interacted primarily with the AD1 fragment. Interactions were also detected between full-length HSF1 and the small subunit (gamma) of TFIIA. PC4 interacted weakly with HSF2 and showed even less affinity for HSF1. Coimmunoprecipitation of transiently expressed TBP in HeLa cells demonstrated that HSF1 AD2 and AD1+AD2 are able to bind TBP in vivo. Assays based on transcriptional interference confirmed predictions that both TBP and TFIIB can interact with HSF1 activation domains in HeLa cells. The negative regulatory region (NR) of HSF1 did not interact with any general factors tested in vitro but did bind TFIID in nuclear extracts through contacts that probably involve TATA associated proteins (TAFs). These results suggest a model for transcriptional regulation by HSF1 that involves a shift between formation of dysfunctional TFIID complexes with the NR and transcriptionally competent complexes with the C-terminal activation domains.
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PMID:Potential targets for HSF1 within the preinitiation complex. 1100 81

The general transcription factor, TFIID, consists of the TATA-binding protein (TBP) associated with a series of TBP-associated factors (TAFs) that together participate in the assembly of the transcription preinitiation complex. One of the TAFs, TAF(II)250, has acetyltransferase (AT) activity that is necessary for transcription of MHC class I genes: inhibition of the AT activity represses transcription. To identify potential cellular factors that might regulate the AT activity of TAF(II)250, a yeast two-hybrid library was screened with a TAF(II)250 segment (amino acids 848-1279) that spanned part of its AT domain and it's the domain that binds to the protein, RAP74. The TFIID component, TAF(II)55, was isolated and found to interact predominantly with the RAP74-binding domain. TAF(II)55 binding to TAF(II)250 inhibits its AT activity. Importantly, the addition of recombinant TAF(II)55 to in vitro transcription assays inhibits TAF(II)250-dependent MHC class I transcription. Thus, TAF(II)55 is capable of regulating TAF(II)250 function by modulating its AT activity.
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PMID:TAFII55 binding to TAFII250 inhibits its acetyltransferase activity. 1159 77

Host RNA polymerase II (RNAP II) is responsible for viral transcription of the herpes simplex virus type 1 (HSV-1) genome and is relocalized to viral DNA replication compartments. Thus, we investigated whether TATA-binding protein (TBP) and TBP-associated factors (TAFs) are recruited to sites of viral transcription and replication and whether TBP/TAF expressions are influenced upon infection. The protein levels of TBP, hsTAF1/TAF(II)250, hsTAF4/TAF(II)135, and hsTAF5/TAF(II)100 were constant during the early phase of infection and started to decrease late during infection. Only for hsTAF7/TAF(II)55 we sometimes observed a decrease already at 4-8h postinfection (p.i.). Concomitantly with the relocalization of RNAP II, TBP and hsTAFs were redistributed to sites of viral DNA replication and transcription. In the absence of viral DNA replication TBP/hsTAFs were present in distinct nuclear dots, however, enlargement of the nuclear structures did not take place. Our results show that HSV-1 infection has no influence on the protein levels of TFIID components and leads to a redistribution of TBP and hsTAFs to prereplicative sites that enlarge to viral DNA replication compartments.
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PMID:TATA-binding protein and TBP-associated factors during herpes simplex virus type 1 infection: localization at viral DNA replication sites. 1627 Dec 77