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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 of protein-encoding genes by RNA polymerase II was thought to require transcription factor TFIID, a complex comprising the TATA-binding protein (TBP) and TBP-associated factors (TAFs). In the presence of TBP-free TAF complex (TFTC), initiation of polymerase II transcription can occur in the absence of TFIID. TFTC contains several subunits that have been shown to play the role of transcriptional coactivators, including the GCN5 histone acetyltransferase (HAT), which acetylates histone H3 in a nucleosomal context. Here we analyze the coactivator function of TFTC. We show direct physical interactions between TFTC and the two distinct activation regions (H1 and H2) of the VP16 activation domain, whereas the HAT-containing coactivators, p300/CBP (CREB-binding protein), interact only with the H2 subdomain of VP16. Accordingly, cell transfection experiments demonstrate the requirement of both p300 and TFTC for maximal transcriptional activation by GAL-VP16. In agreement with this finding, we show that in vitro on a chromatinized template human TFTC mediates the transcriptional activity of the VP16 activation domain in concert with p300 and in an acetyl-CoA-dependent manner. Thus, our results suggest that these two HAT-containing co-activators, p300 and TFTC, have complementary rather than redundant roles during the transcriptional activation process.
J Biol Chem 2002 Sep 06
PMID:TATA-binding protein-free TAF-containing complex (TFTC) and p300 are both required for efficient transcriptional activation. 1210 88

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.
Proc Natl Acad Sci U S A 2002 Sep 03
PMID:SALSA, a variant of yeast SAGA, contains truncated Spt7, which correlates with activated transcription. 1218 75

The relationship between chromatin remodeling and histone acetylation at the yeast CUP1 gene was addressed. CUP1 encodes a metallothionein required for cell growth at high copper concentrations. Induction of CUP1 with copper resulted in targeted acetylation of both H3 and H4 at the CUP1 promoter. Nucleosomes containing upstream activating sequences and sequences farther upstream were the targets for H3 acetylation. Targeted acetylation of H3 and H4 required the transcriptional activator (Ace1p) and the TATA boxes, suggesting that targeted acetylation occurs when TATA-binding protein binds to the TATA box or at a later stage in initiation. We have shown previously that induction results in nucleosome repositioning over the entire CUP1 gene, which requires Ace1p but not the TATA boxes. Therefore, the movement of nucleosomes occurring on CUP1 induction is independent of targeted acetylation. Targeted acetylation of both H3 and H4 also required the product of the SPT10 gene, which encodes a putative histone acetylase implicated in regulation at core promoters. Disruption of SPT10 was lethal at high copper concentrations and correlated with slower induction and reduced maximum levels of CUP1 mRNA. These observations constitute evidence for a novel mechanism of chromatin activation at CUP1, with a major role for the TATA box.
Mol Cell Biol 2002 Sep
PMID:Targeted histone acetylation at the yeast CUP1 promoter requires the transcriptional activator, the TATA boxes, and the putative histone acetylase encoded by SPT10. 1219 40

TAF(II)250, the largest subunit of the general transcription factor TFIID, is expressed from the human X chromosome, at least in somatic cells. In male meiosis, however, the sex chromosomes are transcriptionally silenced, while the autosomes remain active. How then are protein-encoding genes transcribed during human male meiosis? Here we present a novel autosomal human gene, TAF1L, which is homologous to TAF(II)250 and is expressed specifically in the testis, apparently in germ cells. We hypothesize that during male meiosis, transcription of protein-encoding genes relies upon TAF1L as a functional substitute for TAF(II)250. Like TAF(II)250, the human TAF1L protein can bind directly to TATA-binding protein, an essential component of TFIID. Most importantly, transfection with human TAF1L rescued the temperature-sensitive lethality of a hamster cell line mutant in TAF(II)250. TAF1L lacks introns and evidently arose by retroposition of a processed TAF(II)250 mRNA during primate evolution. The observation that TAF1L can functionally replace TAF(II)250 provides experimental support for the hypothesis that during male meiosis, autosomes provide cellular functions usually supplied by the X chromosome in somatic cells.
Hum Mol Genet 2002 Sep 15
PMID:Functional substitution for TAF(II)250 by a retroposed homolog that is expressed in human spermatogenesis. 1221 62

The majority of the TATA-binding protein (TBP)-associated factors (TAFs) that constitute transcription factor II D (TFIID) contain histone fold motifs (HFMs). Our previous results utilizing DT40 cells containing a conditional TAF9 allele indicated that the histone 3-like TAF9 is essential for cell viability but largely dispensable for general transcription. In this study, we investigated further the role of TAF9 structural domains in TFIID integrity and cell growth and the functions of a TAF9-related factor, TAF9L. We first show that TAF9 depletion severely disrupts TFIID, indicating that the observed ongoing transcription is initiated with at least partially TAF-free TATA-binding protein. We also provide evidence for specific roles of TAF HFMs, highlighting the functional significance of HFM specificity observed in vitro and, importantly, of the TAF9-histone 3 similarity. Although we provide evidence that TAF9 and TAF9L are partly redundant, RNA interference experiments suggest that TAF9L is essential for HeLa cell growth. Strikingly, we provide evidence that TAF9L plays a role in transcriptional repression and/or silencing.
J Biol Chem 2003 Sep 12
PMID:In vivo functional analysis of the histone 3-like TAF9 and a TAF9-related factor, TAF9L. 1283 53

Histones are thought to have specific roles in mammalian spermatogenesis, because several subtypes of histones emerge that are post-translationally modified during spermatogenesis. Though regular assembly of nucleosome is guaranteed by histone chaperones, their involvement in spermatogenesis is yet to be characterized. Here we identified a histone chaperone-related factor, which we designated as CCG1-interacting factor A-II (CIA-II), through interaction with bromodomains of TAFII250/CCG1, which is the largest subunit of human transcription initiation factor IID (TFIID). We found that human CIA-II (hCIA-II) localizes in HeLa nuclei and is highly expressed in testis and other proliferating cell-containing tissues. Expression of mouse CIA-II (mCIA-II) does not occur in the germ cell-lacking testes of adult WBB6F1-W/Wv mutant mice, indicating its expression in testis to be specific to germ cells. Fractionation of testicular germ cells revealed that mCIA-II transcripts accumulate in pachytene spermatocytes but not in spermatids. In addition, the mCIA-II transcripts in testis were present as early as 4 days after birth and decreased at 56 days after birth. These findings indicate that mCIA-II expression in testis is restricted to premeiotic to meiotic stages during spermatogenesis. Also, we found that hCIA-II interacts with histone H3 in vivo and with histones H3/H4 in vitro and that it facilitates supercoiling of circular DNA when it is incubated with core histones and topoisomerase I in vitro. These data suggest that CIA-II is a histone chaperone and is implicated in the regulation of mammalian spermatogenesis.
J Biol Chem 2003 Sep 12
PMID:Transcription initiation factor IID-interactive histone chaperone CIA-II implicated in mammalian spermatogenesis. 1284 4

RF2a is a bZIP transcription factor that regulates expression of the promoter of rice tungro bacilliform badnavirus. RF2a is predicted to include three domains that contribute to its function. The results of transient assays with mutants of RF2a from which one or more domains were removed demonstrated that the acidic domain was essential for the activation of gene expression, although the proline-rich and glutamine-rich domains each played a role in this function. Studies using fusion proteins of different functional domains of RF2a with the 2C7 synthetic zinc finger DNA-binding domain showed that the acidic region is a relatively strong activation domain, the function of which is dependent on the context in which the domain is placed. Data from transgenic plants further supported the conclusion that the acidic domain was important for maintaining the biological function of RF2a. RF2a and TBP (TATA-binding protein) synergistically activate transcription in vitro (Zhu, Q., Ordiz, M. I., Dabi, T., Beachy, R. N., and Lamb, C. (2002) Plant Cell 14, 795-803). In vitro and in vivo assays showed that RF2a interacts with TBP through the glutamine-rich domain but not the acidic domain. Functional analysis of such interactions indicates that the acidic domain activates transcription through mechanisms other than via the direct recruitment of TBP.
J Biol Chem 2003 Sep 19
PMID:Functional analysis of RF2a, a rice transcription factor. 1285 76

Mediator is a general cofactor implicated in the functions of many transcriptional activators. Although Mediator with different protein compositions has been isolated, it remains unclear how Mediator facilitates activator-dependent transcription, independent of its general stimulation of basal transcription. To define the mechanisms of Mediator function, we isolated two forms of human Mediator complexes (Mediator-P.5 and Mediator-P.85) and demonstrated that Mediator-P.5 clearly functions by enhancing activator-mediated recruitment of RNA polymerase II (pol II), whereas Mediator-P.85 works mainly by stimulating overall basal transcription. The coactivator function of Mediator-P.5 was not impaired when TATA-binding protein (TBP) was used in place of TFIID, but it was abolished when another general cofactor, PC4, was omitted from the reaction or when Mediator-P.5 was added after pol II entry into the preinitiation complex. Moreover, Mediator- P.5 is able to enhance TBP binding to the TATA box in an activator-dependent manner. Our data provides biochemical evidence that Mediator functions by facilitating activator-mediated recruitment of pol II and also promoter recognition by TBP, both of which can occur in the absence of TBP-associated factors in TFIID.
Mol Cell Biol 2003 Sep
PMID:Human mediator enhances activator-facilitated recruitment of RNA polymerase II and promoter recognition by TATA-binding protein (TBP) independently of TBP-associated factors. 1291 44

Mammalian cells infected with poliovirus, the prototype member of the picornaviridae family, undergo rapid macromolecular and metabolic changes resulting in efficient replication and release of virus from infected cells. Although this virus is predominantly cytoplasmic, it does shut-off transcription of all three cellular transcription systems. Both biochemical and genetic studies have shown that a virally encoded protease, 3C(pro), is responsible for host cell transcription shut-off. The 3C protease cleaves a number of RNA polymerase II transcription factors including the TATA-binding protein (TBP), the cyclic AMP-responsive element binding protein (CREB), the Octamer binding protein (Oct-1), p53, and RNA polymerase III transcription factor IIICalpha, and Polymerase I factor SL-1. Most of these cleavages occur at glutamine-glycine bonds. Additionally, a second viral protease, 2A(pro), also cleaves TBP at a tyrosine-glycine bond. The latter cleavage could be responsible for shut-off of small nuclear RNA transcription. Recent studies indicate that the viral protease-polymerase precursor 3CD can enter nucleus in poliovirus-infected cells. The nuclear localization signal (NLS) present within the 3D sequence appears to play a role in the nuclear entry of 3CD. Thus, 3C may be delivered to the infected cell nucleus in the form the precursor 3CD or other 3C-containing precursors. Auto-proteolytic cleavage of these precursors could then generate 3C. Thus, for a small RNA virus that strictly replicates in the cytoplasm, a portion of its life cycle does include interaction with the host cell nucleus.
Virus Res 2003 Sep
PMID:The interaction of cytoplasmic RNA viruses with the nucleus. 1292 97

X-linked dystonia parkinsonism (XDP) is an X-linked recessive adult onset movement disorder characterized by both dystonia and parkinsonism. We report delineation of the disease gene within a 300-kb interval of Xq13.1 by allelic association. Sequencing of this region in a patient revealed five disease-specific single-nucleotide changes (here referred to as DSC) and a 48-bp deletion unique to XDP. One of the DSCs is located within an exon of a not previously described multiple transcript system that is composed of at least 16 exons. There is a minimum of three different transcription start sites that encode four different transcripts. Two of these transcripts include distal portions of the TAF1 gene (TATA-box binding protein-associated factor 1) and are alternatively spliced. Three exons overlap with ING2 (a putative tumor suppressor) and with a homologue of CIS4 (cytokine-inducible SH2 protein 4), both of which are encoded by the opposite strand. Although all DSCs are located within this multiple transcript system, only DSC3 lies within an exon. This exon is used by all alternative transcripts making a pathogenic role of DSC3 in XDP likely. The multiple transcript system is therefore referred to as DYT3 (disease locus in XDP).
Proc Natl Acad Sci U S A 2003 Sep 02
PMID:Specific sequence changes in multiple transcript system DYT3 are associated with X-linked dystonia parkinsonism. 1292 96


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