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.

scholarly journals A heat shock-responsive domain of human HSF1 that regulates transcription activation domain function.

1995 ◽  
Vol 15 (6) ◽  
pp. 3354-3362 ◽  
Author(s):  
M Green ◽  
T J Schuetz ◽  
E K Sullivan ◽  
R E Kingston
Keyword(s):  
Heat Shock ◽  
Dna Binding ◽  
Transcriptional Activation ◽  
Binding Domain ◽  
Chimeric Proteins ◽  
Dna Binding Domain ◽  
Regulatory Domain ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domains

Human heat shock factor 1 (HSF1) stimulates transcription from heat shock protein genes following stress. We have used chimeric proteins containing the GAL4 DNA binding domain to identify the transcriptional activation domains of HSF1 and a separate domain that is capable of regulating activation domain function. This regulatory domain conferred heat shock inducibility to chimeric proteins containing the activation domains. The regulatory domain is located between the transcriptional activation domains and the DNA binding domain of HSF1 and is conserved between mammalian and chicken HSF1 but is not found in HSF2 or HSF3. The regulatory domain was found to be functionally homologous between chicken and human HSF1. This domain does not affect DNA binding by the chimeric proteins and does not contain any of the sequences previously postulated to regulate DNA binding of HSF1. Thus, we suggest that activation of HSF1 by stress in humans is controlled by two regulatory mechanisms that separately confer heat shock-induced DNA binding and transcriptional stimulation.

scholarly journals Identification, Mutational Analysis, and Coactivator Requirements of Two Distinct Transcriptional Activation Domains of the Saccharomyces cerevisiae Hap4 Protein

2004 ◽  
Vol 3 (2) ◽  
pp. 339-347 ◽  
Author(s):  
John L. Stebbins ◽  
Steven J. Triezenberg
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Mutational Analysis ◽  
Transcriptional Coactivator ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domain ◽  
Transcriptional Activation Domains

ABSTRACT The Hap4 protein of the budding yeast Saccharomyces cerevisiae activates the transcription of genes that are required for growth on nonfermentable carbon sources. Previous reports suggested the presence of a transcriptional activation domain within the carboxyl-terminal half of Hap4 that can function in the absence of Gcn5, a transcriptional coactivator protein and histone acetyltransferase. The boundaries of this activation domain were further defined to a region encompassing amino acids 359 to 476. Within this region, several clusters of hydrophobic amino acids are critical for transcriptional activity. This activity does not require GCN5 or two other components of the SAGA coactivator complex, SPT3 and SPT8, but it does require SPT7 and SPT20. Contrary to previous reports, a Hap4 fragment comprising amino acids 1 to 330 can support the growth of yeast on lactate medium, and when tethered to lexA, can activate a reporter gene with upstream lexA binding sites, demonstrating the presence of a second transcriptional activation domain. In contrast to the C-terminal activation domain, the transcriptional activity of this N-terminal region depends on GCN5. We conclude that the yeast Hap4 protein has at least two transcriptional activation domains with strikingly different levels of dependence on specific transcriptional coactivator proteins.

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 Transcriptional Activation Domains of Human Heat Shock Factor 1 Recruit Human SWI/SNF

2001 ◽  
Vol 21 (17) ◽  
pp. 5826-5837 ◽  
Author(s):  
E. Kelly Sullivan ◽  
Christine S. Weirich ◽  
Jeffrey R. Guyon ◽  
Saı̈d Sif ◽  
Robert E. Kingston
Keyword(s):  
Heat Shock ◽  
Chromatin Remodeling ◽  
Transcriptional Activation ◽  
Atp Hydrolysis ◽  
Heat Shock Factor ◽  
Transcriptional Elongation ◽  
Heat Shock Factor 1 ◽  
Transcriptional Initiation ◽  
Atpase Subunit ◽  
Activation Domains

ABSTRACT Chromatin remodeling complexes such as SWI/SNF use the energy of ATP hydrolysis to remodel nucleosomal DNA and increase transcription of nucleosomal templates. Human heat shock factor one (hHSF1) is a tightly regulated activator that stimulates transcriptional initiation and elongation using different portions of its activation domains. Here we demonstrate that hHSF1 associates with BRG1, the ATPase subunit of human SWI/SNF (hSWI/SNF) at endogenous protein concentrations. We also show that hHSF1 activation domains recruit hSWI/SNF to a chromatin template in a purified system. Mutation of hHSF1 residues responsible for activation of transcriptional elongation has the most severe effect on recruitment of SWI/SNF and association of hHSF1 with BRG1, suggesting that recruitment of chromatin remodeling activity might play a role in stimulation of elongation.

scholarly journals Functional domains of the transcription factor USF2: atypical nuclear localization signals and context-dependent transcriptional activation domains.

1996 ◽  
Vol 16 (4) ◽  
pp. 1367-1375 ◽  
Author(s):  
X Luo ◽  
M Sawadogo
Keyword(s):  
Dna Binding ◽  
Nuclear Localization ◽  
Transcriptional Activation ◽  
Core Promoter ◽  
Minimal Promoter ◽  
Functional Domains ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domains ◽  
Basic Region

USF is a family of basic helix-loop transcriptional factors that recognizes DNA-binding sites similar to those of the Myc oncoproteins. Here, various functional domains in the mouse USF2 protein were identified and characterized. Indirect immunofluorescence studies with transiently transfected cells revealed that both the basic region and the highly conserved USF-specific region (USR) are involved in the nuclear localization of USF2. Cotransfection assays with deletion mutants containing the DNA-binding domain of either USF2 or GAL4 identified two distinct transcriptional activation domains in USF2, the USR and the exon 5-encoded region. Activity of the exon 5 activation domain was detectable in both assay systems. Within USF2, however, its potency varied with the conformation induced by the surrounding regions, especially that encoded by alternatively spliced exon 4. In contrast, the USR activated transcription only in its natural context upstream of the USF2 basic region and only with reporter constructs containing the adenovirus major late minimal promoter but not the E1b minimal promoter. However, insertion of an initiator element downstream of the TATA box rescued the activity of the USR on the E1b-driven reporters. The USR therefore represents a new type of activation domain whose function depends very strongly on the core promoter context.

scholarly journals The carboxyl-terminal transactivation domain of heat shock factor 1 is negatively regulated and stress responsive.

1995 ◽  
Vol 15 (8) ◽  
pp. 4309-4318 ◽  
Author(s):  
Y Shi ◽  
P E Kroeger ◽  
R I Morimoto
Keyword(s):  
Heat Shock ◽  
Dna Binding ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Binding Domain ◽  
Heat Shock Factor 1 ◽  
Dna Binding Domain ◽  
Activation Domain ◽  
Transcriptional Activation Domain ◽  
Carboxyl Terminal

We have characterized a stress-responsive transcriptional activation domain of mouse heat shock factor 1 (HSF1) by using chimeric GAL4-HSF1 fusion proteins. Fusion of the GAL4 DNA-binding domain to residues 124 to 503 of HSF1 results in a chimeric factor that binds DNA yet lacks any transcriptional activity. Transactivation is acquired upon exposure to heat shock or by deletion of a negative regulatory domain including part of the DNA-binding-domain-proximal leucine zippers. Analysis of a collection of GAL4-HSF1 deletion mutants revealed the minimal region for the constitutive transcriptional activator to map within the extreme carboxyl-terminal 108 amino acids, corresponding to a region rich in acidic and hydrophobic residues. Loss of residues 395 to 425 or 451 to 503, which are located at either end of this activation domain, severely diminished activity, indicating that the entire domain is required for transactivation. The minimal activation domain of HSF1 also confers enhanced transcriptional response to heat shock or cadmium treatment. These results demonstrate that the transcriptional activation domain of HSF1 is negatively regulated and that the signal for stress induction is mediated by interactions between the amino-terminal negative regulator and the carboxyl-terminal transcriptional activation domain.

scholarly journals MLL and CREB Bind Cooperatively to the Nuclear Coactivator CREB-Binding Protein

2001 ◽  
Vol 21 (7) ◽  
pp. 2249-2258 ◽  
Author(s):  
Patricia Ernst ◽  
Jing Wang ◽  
Mary Huang ◽  
Richard H. Goodman ◽  
Stanley J. Korsmeyer
Keyword(s):  
Amino Acids ◽  
Transcriptional Activation ◽  
Binding Protein ◽  
Single Amino Acid ◽  
Creb Binding Protein ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domain ◽  
Adenovirus E1a

ABSTRACT A fragment of the mixed-lineage leukemia (MLL) gene (Mll, HRX, ALL-1) was identified in a yeast genetic screen designed to isolate proteins that interact with the CREB–CREB-binding protein (CBP) complex. When tested for binding to CREB or CBP individually, this MLL fragment interacted directly with CBP, but not with CREB. In vitro binding experiments refined the minimal region of interaction to amino acids 2829 to 2883 of MLL, a potent transcriptional activation domain, and amino acids 581 to 687 of CBP (the CREB-binding or KIX domain). The transactivation activity of MLL was dependent on CBP, as either adenovirus E1A expression, which inhibits CBP activity, or alteration of MLL residues important for CBP interaction proved effective at inhibiting MLL-mediated transactivation. Single amino acid substitutions within the MLL activation domain revealed that five hydrophobic residues, potentially forming a hydrophobic face of an amphipathic helix, were critical for the interaction of MLL with CBP. Using purified components, we found that the MLL activation domain facilitated the binding of CBP to phosphorylated CREB. In contrast with paradigms in which factors compete for limiting quantities of CBP, these results reveal that two distinct transcription factor activation domains can cooperatively target the same motif on CBP.

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