scholarly journals Glycogen Synthase Phosphatase Interacts with Heat Shock Factor To Activate CUP1 Gene Transcription inSaccharomyces cerevisiae

1999 ◽  
Vol 19 (5) ◽  
pp. 3237-3245 ◽  
Author(s):  
Janine T. Lin ◽  
John T. Lis
Keyword(s):  
Heat Shock ◽  
Gene Transcription ◽  
Transcriptional Activation ◽  
Genomic Library ◽  
Glycogen Synthase ◽  
Heat Shock Factor ◽  
Regulatory Subunit ◽  
Cup1 Gene ◽  
Inducible Genes

ABSTRACT Upon heat shock, transcription of many stress-inducible genes is rapidly and dramatically stimulated by heat shock factor (HSF). A central region of the yeast HSF (designated HSFrr for “repression region”) was previously identified and proposed to be involved in repressing the activation domain under non-heat-shock conditions. Here, we used the phage display system to isolate proteins that interact with HSFrr. This should identify factors that modulate HSF activity or directly participate in HSF-mediated transcriptional activation. We constructed a randomly sheared yeast genomic library to express yeast proteins on the surface of λ phage. HSFrr binding phages were selected by cycles of affinity chromatography. DNA sequencing identified an HSFrr-interacting phage that contains theGAC1 gene. The GAC1 gene encodes the regulatory subunit for a type 1 serine/threonine phosphoprotein phosphatase, Glc7. Both gac1 and glc7 mutations had little effect on HSF activation of gene transcription of two heat shock genes,SSA4 and HSP82. In contrast, heat shock induction of CUP1 gene expression was completely abolished in a glc7 mutant and reduced in a gac1 mutant. The results demonstrate that the Glc7 phosphatase and its Gac1 regulatory subunit play positive roles in HSF activation ofCUP1 transcription.

scholarly journals Heat shock transcription factor activates yeast metallothionein gene expression in response to heat and glucose starvation via distinct signalling pathways

1994 ◽  
Vol 14 (12) ◽  
pp. 8155-8165 ◽  
Author(s):  
K T Tamai ◽  
X Liu ◽  
P Silar ◽  
T Sosinowski ◽  
D J Thiele
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Heat Shock ◽  
Gene Transcription ◽  
Transcriptional Activation ◽  
Signalling Pathways ◽  
Glucose Starvation ◽  
Gene Encoding ◽  
Metallothionein Gene ◽  
Cup1 Gene

Metallothioneins constitute a class of low-molecular-weight, cysteine-rich metal-binding stress proteins which are biosynthetically regulated at the level of gene transcription in response to metals, hormones, cytokines, and other physiological and environmental stresses. In this report, we demonstrate that the Saccharomyces cerevisiae metallothionein gene, designated CUP1, is transcriptionally activated in response to heat shock and glucose starvation through the action of heat shock transcription factor (HSF) and a heat shock element located within the CUP1 promoter upstream regulatory region. CUP1 gene activation in response to both stresses occurs rapidly; however, heat shock activates CUP1 gene expression transiently, whereas glucose starvation activates CUP1 gene expression in a sustained manner for at least 2.5 h. Although a carboxyl-terminal HSF transcriptional activation domain is critical for the activation of CUP1 transcription in response to both heat shock stress and glucose starvation, this region is dispensable for transient heat shock activation of at least two genes encoding members of the S. cerevisiae hsp70 family. Furthermore, inactivation of the chromosomal SNF1 gene, encoding a serine-threonine protein kinase, or the SNF4 gene, encoding a SNF1 cofactor, abolishes CUP1 transcriptional activation in response to glucose starvation without altering heat shock-induced transcription. These studies demonstrate that the S. cerevisiae HSF responds to multiple, distinct stimuli to activate yeast metallothionein gene transcription and that these stimuli elicit responses through nonidentical, genetically separable signalling pathways.

scholarly journals Heat shock transcription factor activates yeast metallothionein gene expression in response to heat and glucose starvation via distinct signalling pathways.

1994 ◽  
Vol 14 (12) ◽  
pp. 8155-8165 ◽  
Author(s):  
K T Tamai ◽  
X Liu ◽  
P Silar ◽  
T Sosinowski ◽  
D J Thiele
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Heat Shock ◽  
Gene Transcription ◽  
Transcriptional Activation ◽  
Signalling Pathways ◽  
Glucose Starvation ◽  
Gene Encoding ◽  
Metallothionein Gene ◽  
Cup1 Gene

Metallothioneins constitute a class of low-molecular-weight, cysteine-rich metal-binding stress proteins which are biosynthetically regulated at the level of gene transcription in response to metals, hormones, cytokines, and other physiological and environmental stresses. In this report, we demonstrate that the Saccharomyces cerevisiae metallothionein gene, designated CUP1, is transcriptionally activated in response to heat shock and glucose starvation through the action of heat shock transcription factor (HSF) and a heat shock element located within the CUP1 promoter upstream regulatory region. CUP1 gene activation in response to both stresses occurs rapidly; however, heat shock activates CUP1 gene expression transiently, whereas glucose starvation activates CUP1 gene expression in a sustained manner for at least 2.5 h. Although a carboxyl-terminal HSF transcriptional activation domain is critical for the activation of CUP1 transcription in response to both heat shock stress and glucose starvation, this region is dispensable for transient heat shock activation of at least two genes encoding members of the S. cerevisiae hsp70 family. Furthermore, inactivation of the chromosomal SNF1 gene, encoding a serine-threonine protein kinase, or the SNF4 gene, encoding a SNF1 cofactor, abolishes CUP1 transcriptional activation in response to glucose starvation without altering heat shock-induced transcription. These studies demonstrate that the S. cerevisiae HSF responds to multiple, distinct stimuli to activate yeast metallothionein gene transcription and that these stimuli elicit responses through nonidentical, genetically separable signalling pathways.

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.

Role of heat shock transcription factor in yeast metallothionein gene expression

1991 ◽  
Vol 11 (7) ◽  
pp. 3676-3681
Author(s):  
W M Yang ◽  
W Gahl ◽  
D Hamer
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Heat Shock ◽  
Gene Transcription ◽  
Heat Shock Factor ◽  
Heat Shock Transcription Factor ◽  
Wild Type ◽  
Promoter Sequences ◽  
Metallothionein Gene ◽  
Upstream Promoter

The induction of Saccharomyces cerevisiae metallothionein gene transcription by Cu and Ag is mediated by the ACE1 transcription factor. In an effort to detect additional stimuli and factors that regulate metallothionein gene transcription, we isolated a Cu-resistant suppressor mutant of an ACE1 deletion strain. Even in the absence of metals, the suppressor mutant exhibited high basal levels of metallothionein gene transcription that required upstream promoter sequences. The suppressor gene was cloned, and its predicted product was shown to correspond to yeast heat shock transcription factor with a single-amino-acid substitution in the DNA-binding domain. The mutant heat shock factor bound strongly to metallothionein gene upstream promoter sequences, whereas wild-type heat shock factor interacted weakly with the same region. Heat treatment led to a slight but reproducible induction of metallothionein gene expression in both wild-type and suppressor strains, and Cd induced transcription in the mutant strain. These studies provide evidence for multiple pathways of metallothionein gene transcriptional regulation in S. cerevisiae.

Constitutive binding of yeast heat shock factor to DNA in vivo

1988 ◽  
Vol 8 (11) ◽  
pp. 5040-5042
Author(s):  
B K Jakobsen ◽  
H R Pelham
Keyword(s):  
Heat Shock ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Heat Shock Factor ◽  
Promoter Element ◽  
Synthetic Promoter

We measured the binding of yeast heat shock factor (HSF) to DNA in vivo by using an interference assay in which HSF excludes GAL4 from a synthetic promoter element containing overlapping binding sites for each protein. The results show that HSF binds to DNA in unstressed cells and that binding is not sufficient for transcriptional activation.

Inhibition of Heat Shock Factor 1 Enhances Repressive Molecular Mechanisms on the POMC Promoter

2019 ◽  
Vol 109 (4) ◽  
pp. 362-373
Author(s):  
Denis Ciato ◽  
Ran Li ◽  
Jose Luis Monteserin Garcia ◽  
Lilia Papst ◽  
Sarah D’Annunzio ◽  
...  
Keyword(s):  
Heat Shock ◽  
Clinical Features ◽  
Transcriptional Activation ◽  
Molecular Mechanisms ◽  
Primary Cultures ◽  
Heat Shock Protein 90 ◽  
Heat Shock Factor ◽  
Heat Shock Factor 1 ◽  
Promising Treatment ◽  
Acth Secreting

Background: Cushing’s disease (CD) is caused by adrenocorticotropic hormone (ACTH)-secreting pituitary tumours. They express high levels of heat shock protein 90 and heat shock factor 1 (HSF1) in comparison to the normal tissue counterpart, indicating activated cellular stress. Aims: Our objectives were: (1) to correlate HSF1 expression with clinical features and hormonal/radiological findings of CD, and (2) to investigate the effects of HSF1 inhibition as a target for CD treatment. Patients/Methods: We examined the expression of total and pSer326HSF1 (marker for its transcriptional activation) by Western blot on eight human CD tumours and compared to the HSF1 status of normal pituitary. We screened a cohort of 45 patients with CD for HSF1 by immunohistochemistry and correlated the HSF1 immunoreactivity score with the available clinical data. We evaluated the effects of HSF1 silencing with RNA interference and the HSF1 inhibitor KRIBB11 in AtT-20 cells and four primary cultures of human corticotroph tumours. Results: We show that HSF1 protein is highly expressed and transcriptionally active in CD tumours in comparison to normal pituitary. The immunoreactivity score for HSF1 did not correlate with the typical clinical features of the disease. HSF1 inhibition reduced proopiomelanocortin (Pomc) transcription in AtT-20 cells. The HSF1 inhibitor KRIBB11 suppressed ACTH synthesis from 75% of human CD tumours in primary cell culture. This inhibitory action on Pomc transcription was mediated by increased glucocorticoid receptor and suppressed Nurr77/Nurr1 and AP-1 transcriptional activities. Conclusions: These data show that HSF1 regulates POMC transcription. Pharmacological targeting of HSF1 may be a promising treatment option for the control of excess ACTH secretion in CD.

scholarly journals Inhibition of the activation of heat shock factor in vivo and in vitro by flavonoids.

1992 ◽  
Vol 12 (8) ◽  
pp. 3490-3498 ◽  
Author(s):  
N Hosokawa ◽  
K Hirayoshi ◽  
H Kudo ◽  
H Takechi ◽  
A Aoike ◽  
...  
Keyword(s):  
Heat Shock ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Mobility Shift ◽  
Human Colon Cancer ◽  
Heat Shock Element ◽  
Mrna Accumulation ◽  
Cell Extracts

Transcriptional activation of human heat shock protein (HSP) genes by heat shock or other stresses is regulated by the activation of a heat shock factor (HSF). Activated HSF posttranslationally acquires DNA-binding ability. We previously reported that quercetin and some other flavonoids inhibited the induction of HSPs in HeLa and COLO 320DM cells, derived from a human colon cancer, at the level of mRNA accumulation. In this study, we examined the effects of quercetin on the induction of HSP70 promoter-regulated chloramphenicol acetyltransferase (CAT) activity and on the binding of HSF to the heat shock element (HSE) by a gel mobility shift assay with extracts of COLO 320DM cells. Quercetin inhibited heat-induced CAT activity in COS-7 and COLO 320DM cells which were transfected with plasmids bearing the CAT gene under the control of the promoter region of the human HSP70 gene. Treatment with quercetin inhibited the binding of HSF to the HSE in whole-cell extracts activated in vivo by heat shock and in cytoplasmic extracts activated in vitro by elevated temperature or by urea. The binding of HSF activated in vitro by Nonidet P-40 was not suppressed by the addition of quercetin. The formation of the HSF-HSE complex was not inhibited when quercetin was added only during the binding reaction of HSF to the HSE after in vitro heat activation. Quercetin thus interacts with HSF and inhibits the induction of HSPs after heat shock through inhibition of HSF activation.

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