scholarly journals Binding of basal transcription factor TFIIH to the acidic activation domains of VP16 and p53.

1994 ◽  
Vol 14 (10) ◽  
pp. 7013-7024 ◽  
Author(s):  
H Xiao ◽  
A Pearson ◽  
B Coulombe ◽  
R Truant ◽  
S Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Mammalian Cells ◽  
Point Mutations ◽  
Factor B ◽  
Activation Domains ◽  
Binding Domains ◽  
General Transcription Factors ◽  
Transcriptional Activation Domains ◽  
Simplex Virus

Acidic transcriptional activation domains function well in both yeast and mammalian cells, and some have been shown to bind the general transcription factors TFIID and TFIIB. We now show that two acidic transactivators, herpes simplex virus VP16 and human p53, directly interact with the multisubunit human general transcription factor TFIIH and its Saccharomyces cerevisiae counterpart, factor b. The VP16- and p53-binding domains in these factors lie in the p62 subunit of TFIIH and in the homologous subunit, TFB1, of factor b. Point mutations in VP16 that reduce its transactivation activity in both yeast and mammalian cells weaken its binding to both yeast and human TFIIH. This suggests that binding of activation domains to TFIIH is an important aspect of transcriptional activation.

Binding of basal transcription factor TFIIH to the acidic activation domains of VP16 and p53

1994 ◽  
Vol 14 (10) ◽  
pp. 7013-7024 ◽  
Author(s):  
H Xiao ◽  
A Pearson ◽  
B Coulombe ◽  
R Truant ◽  
S Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Mammalian Cells ◽  
Point Mutations ◽  
Factor B ◽  
Activation Domains ◽  
Binding Domains ◽  
General Transcription Factors ◽  
Transcriptional Activation Domains ◽  
Simplex Virus

Acidic transcriptional activation domains function well in both yeast and mammalian cells, and some have been shown to bind the general transcription factors TFIID and TFIIB. We now show that two acidic transactivators, herpes simplex virus VP16 and human p53, directly interact with the multisubunit human general transcription factor TFIIH and its Saccharomyces cerevisiae counterpart, factor b. The VP16- and p53-binding domains in these factors lie in the p62 subunit of TFIIH and in the homologous subunit, TFB1, of factor b. Point mutations in VP16 that reduce its transactivation activity in both yeast and mammalian cells weaken its binding to both yeast and human TFIIH. This suggests that binding of activation domains to TFIIH is an important aspect of transcriptional activation.

scholarly journals Identification and Characterization of ART-27, a Novel Coactivator for the Androgen Receptor N Terminus

2002 ◽  
Vol 13 (2) ◽  
pp. 670-682 ◽  
Author(s):  
Steven M. Markus ◽  
Samir S. Taneja ◽  
Susan K. Logan ◽  
Wenhui Li ◽  
Susan Ha ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Transcriptional Activation ◽  
Mammalian Cells ◽  
Hybrid Approach ◽  
Independent Manner ◽  
Activation Domains ◽  
Cell Library ◽  
Nuclear Extracts ◽  
N Terminus ◽  
Transcriptional Activation Domains

The androgen receptor (AR) is a ligand-regulated transcription factor that stimulates cell growth and differentiation in androgen-responsive tissues. The AR N terminus contains two activation functions (AF-1a and AF-1b) that are necessary for maximal transcriptional enhancement by the receptor; however, the mechanisms and components regulating AR transcriptional activation are not fully understood. We sought to identify novel factors that interact with the AR N terminus from an androgen-stimulated human prostate cancer cell library using a yeast two-hybrid approach designed to identify proteins that interact with transcriptional activation domains. A 157-amino acid protein termed ART-27 was cloned and shown to interact predominantly with the AR153–336, containing AF-1a and a part of AF-1b, localize to the nucleus and increase the transcriptional activity of AR when overexpressed in cultured mammalian cells. ART-27 also enhanced the transcriptional activation by AR153–336 fused to the LexA DNA-binding domain but not other AR N-terminal subdomains, suggesting that ART-27 exerts its effect via an interaction with a defined region of the AR N terminus. ART-27 interacts with AR in nuclear extracts from LNCaP cells in a ligand-independent manner. Interestingly, velocity gradient sedimentation of HeLa nuclear extracts suggests that native ART-27 is part of a multiprotein complex. ART-27 is expressed in a variety of human tissues, including sites of androgen action such as prostate and skeletal muscle, and is conserved throughout evolution. Thus, ART-27 is a novel cofactor that interacts with the AR N terminus and plays a role in facilitating receptor-induced transcriptional activation.

scholarly journals Structural and functional properties of the N transcriptional activation domain of thyroid transcription factor-1: similarities with the acidic activation domains

1998 ◽  
Vol 329 (2) ◽  
pp. 395-403 ◽  
Author(s):  
Gianluca TELL ◽  
Lorena PERRONE ◽  
Dora FABBRO ◽  
Lucia PELLIZZARI ◽  
Carlo PUCILLO ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domain ◽  
Acidic Domain ◽  
Thyroid Transcription Factor 1 ◽  
Thyroid Transcription Factor ◽  
Transcriptional Activation Domains ◽  
Transcription Factor 1

The thyroid transcription factor 1 (TTF-1) is a tissue-specific transcription factor involved in the development of thyroid and lung. TTF-1 contains two transcriptional activation domains (N and C domain). The primary amino acid sequence of the N domain does not show any typical characteristic of known transcriptional activation domains. In aqueous solution the N domain exists in a random-coil conformation. The increase of the milieu hydrophobicity, by the addition of trifluoroethanol, induces a considerable gain of α-helical structure. Acidic transcriptional activation domains are largely unstructured in solution, but, under hydrophobic conditions, folding into α-helices or β-strands can be induced. Therefore our data indicate that the inducibility of α-helix by hydrophobic conditions is a property not restricted to acidic domains. Co-transfections experiments indicate that the acidic domain of herpes simplex virus protein VP16 (VP16) and the TTF-1 N domain are interchangeable and that a chimaeric protein, which combines VP16 linked to the DNA-binding domain of TTF-1, undergoes the same regulatory constraints that operate for the wild-type TTF-1. In addition, we demonstrate that the TTF-1 N domain possesses two typical properties of acidic activation domains: TBP (TATA-binding protein) binding and ability to activate transcription in yeast. Accordingly, the TTF-1 N domain is able to squelch the activity of the p65 acidic domain. Altogether, these structural and functional data suggest that a non-acidic transcriptional activation domain (TTF-1 N domain) activates transcription by using molecular mechanisms similar to those used by acidic domains. TTF-1 N domain and acidic domains define a family of proteins whose common property is to activate transcription through the use of mechanisms largely conserved during evolutionary development.

scholarly journals Fungal Mediator Tail Subunits Contain Classical Transcriptional Activation Domains

2015 ◽  
Vol 35 (8) ◽  
pp. 1363-1375 ◽  
Author(s):  
Zhongle Liu ◽  
Lawrence C. Myers
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Weak Interactions ◽  
Primary Role ◽  
Eukaryotic Transcription ◽  
Content Type ◽  
Activation Domains ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Transcriptional Activation Domains

Classical activation domains within DNA-bound eukaryotic transcription factors make weak interactions with coactivator complexes, such as Mediator, to stimulate transcription. How these interactions stimulate transcription, however, is unknown. The activation of reporter genes by artificial fusion of Mediator subunits to DNA binding domains that bind to their promoters has been cited as evidence that the primary role of activators is simply to recruit Mediator. We have identified potent classical transcriptional activation domains in the C termini of several tail module subunits ofSaccharomyces cerevisiae,Candida albicans, andCandida dubliniensisMediator, while their N-terminal domains are necessary and sufficient for their incorporation into Mediator but do not possess the ability to activate transcription when fused to a DNA binding domain. This suggests that Mediator fusion proteins actually are functioning in a manner similar to that of a classical DNA-bound activator rather than just recruiting Mediator. Our finding that deletion of the activation domains ofS. cerevisiaeMed2 and Med3, as well asC. dubliniensisTlo1 (a Med2 ortholog), impairs the induction of certain genes shows these domains function at native promoters. Activation domains within coactivators are likely an important feature of these complexes and one that may have been uniquely leveraged by a common fungal pathogen.

scholarly journals Transcriptional Activation in Yeast Cells Lacking Transcription Factor IIA

Genetics ◽  
1999 ◽  
Vol 153 (4) ◽  
pp. 1573-1581 ◽  
Author(s):  
Susanna Chou ◽  
Sukalyan Chatterjee ◽  
Mark Lee ◽  
Kevin Struhl
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Large Subunit ◽  
Yeast Cells ◽  
Specific Cell ◽  
Wild Type ◽  
Activation Domains ◽  
Cycle Arrest ◽  
General Transcription Factor

Abstract The general transcription factor IIA (TFIIA) forms a complex with TFIID at the TATA promoter element, and it inhibits the function of several negative regulators of the TATA-binding protein (TBP) subunit of TFIID. Biochemical experiments suggest that TFIIA is important in the response to transcriptional activators because activation domains can interact with TFIIA, increase recruitment of TFIID and TFIIA to the promoter, and promote isomerization of the TFIID-TFIIA-TATA complex. Here, we describe a double-shut-off approach to deplete yeast cells of Toa1, the large subunit of TFIIA, to <1% of the wild-type level. Interestingly, such TFIIA-depleted cells are essentially unaffected for activation by heat shock factor, Ace1, and Gal4-VP16. However, depletion of TFIIA causes a general two- to threefold decrease of transcription from most yeast promoters and a specific cell-cycle arrest at the G2-M boundary. These results indicate that transcriptional activation in vivo can occur in the absence of TFIIA.

scholarly journals The regulatory domain of human heat shock factor 1 is sufficient to sense heat stress.

1996 ◽  
Vol 16 (3) ◽  
pp. 839-846 ◽  
Author(s):  
E M Newton ◽  
U Knauf ◽  
M Green ◽  
R E Kingston
Keyword(s):  
Amino Acids ◽  
Heat Shock ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Acid Activation ◽  
Regulatory Domain ◽  
Activation Domain ◽  
Control Temperature ◽  
Activation Domains ◽  
Transcriptional Activation Domains

Heat shock factor (HSF) activates transcription in response to cellular stress. Human HSF1 has a central regulatory domain which can repress the activity of its activation domains at the control temperature and render them heat shock inducible. To determine whether the regulatory domain works in tandem with specific features of the HSF1 transcriptional activation domains, we first used deletion and point mutagenesis to define these activation domains. One of the activation domains can be reduced to just 20 amino acids. A GAL4 fusion protein containing the HSF 1 regulatory domain and this 20-amino-acid activation domain is repressed at the control temperature but potently activates transcription in response to heat shock. No specific amino acids in this activation domain are required for response to the regulatory domain; in particular, none of the potentially phosphorylated serine and threonine residues are required for heat induction, implying that heat-induced phosphorylation of the transcriptional activation domains is not required for induction. The regulatory domain is able to confer heat responsiveness to an otherwise completely heterologous chimeric activator that contains a portion of the VP16 activation domain, suggesting that the regulatory domain can sense heat in the absence of other portions of HSF1.

RNA polymerase II cofactor PC2 facilitates activation of transcription by GAL4-AH in vitro

1994 ◽  
Vol 14 (6) ◽  
pp. 3927-3937
Author(s):  
M Kretzschmar ◽  
G Stelzer ◽  
R G Roeder ◽  
M Meisterernst
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Activation Domains ◽  
Positive Effects ◽  
Activation Of Transcription ◽  
Transcriptional Activation Domains ◽  
Necessary And Sufficient ◽  
Specific Pathway

We have isolated from a crude Hela cell cofactor fraction (USA) a novel positive cofactor that cooperates with the general transcription machinery to effect efficient stimulation of transcription by GAL4-AH, a derivative of the Saccharomyces cerevisiae regulatory factor GAL4. PC2 was shown to be a 500-kDa protein complex and to be functionally and biochemically distinct from native TFIID and previously identified cofactors. In the presence of native TFIID and other general factors, PC2 was necessary and sufficient for activation by GAL4-AH. Cofactor function was specific for transcriptional activation domains of GAL4-AH. The repressor histone H1 further potentiated but was not required for activation of transcription by GAL4-AH. On the basis of the observation that PC2 exerts entirely positive effects on transcription, we propose a model in which PC2 increases the activity of the preinitiation complex in the presence of an activator, thereby establishing a specific pathway during activation of RNA polymerase II.

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