Isolation of the gene encoding the S. cerevisiae heat shock transcription factor

Wiederrecht, Gregory; Seto, Donald; Parker, Carl S.

doi:10.1016/s0092-8674(88)91197-x

Cited by 389 publications

(296 citation statements)

References 56 publications

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“…We then examined the heat shock response in these strains. As shown in Figure 7D, the effect of overproduction of HSF was revealed in the elevation of steady-state ␤-galactosidase activity, as has been reported previously (Wiedderecht et al, 1988). In heat-shocked cells ( Figure 7E), no significant effect of Ssb1p overproduction could be detected.…”

supporting

confidence: 86%

Complex Regulation of the Yeast Heat Shock Transcription Factor

Bonner

Carlson

Fackenthal

et al. 2000

MBoC

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The yeast heat shock transcription factor (HSF) is regulated by posttranslational modification. Heat and superoxide can induce the conformational change associated with the heat shock response. Interaction between HSF and the chaperone hsp70 is also thought to play a role in HSF regulation. Here, we show that the Ssb1/2p member of the hsp70 family can form a stable, ATP-sensitive complex with HSF-a surprising finding because Ssb1/2p is not induced by heat shock. Phosphorylation and the assembly of HSF into larger, ATP-sensitive complexes both occur when HSF activity decreases, whether during adaptation to a raised temperature or during growth at low glucose concentrations. These larger HSF complexes also form during recovery from heat shock. However, if HSF is assembled into ATP-sensitive complexes (during growth at a low glucose concentration), heat shock does not stimulate the dissociation of the complexes. Nor does induction of the conformational change induce their dissociation. Modulation of the in vivo concentrations of the SSA and SSB proteins by deletion or overexpression affects HSF activity in a manner that is consistent with these findings and suggests the model that the SSA and SSB proteins perform distinct roles in the regulation of HSF activity. INTRODUCTIONIt has long been known that in cells of many species, including Escherichia coli and Saccharomyces cerevisiae, cell division rates are tightly coupled with the steady-state levels and rates of synthesis of ribosomal proteins and rRNA. For example, cells in rich media, with a short generation time, display higher abundance of rRNA and higher rates of synthesis of ribosomal proteins than do cells in poor media, with a long generation time. In E. coli, some of this regulation is achieved by transcriptional attenuation and translational regulation via binding of ribosomal proteins to the RNAs of target operons (Freedman et al., 1985;Cole and Nomura, 1986). In yeast, regulation is partly transcriptional, via RAP1 and its binding site, the upstream activating sequence (UAS) rpg (Herruer et al., 1987;Moehle and Hinnebusch, 1991;Kraakman et al., 1993), although much of the regulation of ribosomal protein abundance is achieved by a competition between the assembly into ribosomes and the rapid degradation of unassembled ribosomal proteins (Warner et al., 1985;Maicas et al., 1988).Growth rate control clearly modulates the level of the translational machinery, which in turn influences the overall rate of protein synthesis. Changes in the rates of protein synthesis must, in turn, have profound implications for the protein chaperone system. Newly synthesized polypeptides typically do not adopt their mature conformation immediately but instead follow a complex folding pathway. For many proteins, the cytoplasmic chaperone system plays an integral role in helping these polypeptides adopt their mature conformations (for review, see Hendrick and Hartl, 1995). The hsp70 proteins are generally believed to bind efficiently to nascent or newly synthesized polypeptides...

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supporting

confidence: 86%

Complex Regulation of the Yeast Heat Shock Transcription Factor

Bonner

Carlson

Fackenthal

et al. 2000

MBoC

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“…This COOH-terminal hydrophobic heptad repeat has been postulated to play a role in regulating the HSE-binding activity of HSF (8). S. cerevisiae and Kluyveromyces lactis HSF, both of which possess constitutive HSE-binding ability, lack this domain (23,50,58). Deletion of this domain from human HSF allows constitutive HSE-binding ability when HSF is transiently expressed in human cells (42).…”

Section: Resultsmentioning

confidence: 99%

The DNA-binding activity of the human heat shock transcription factor is regulated in vivo by hsp70.

Mosser¹,

Duchaine²,

Massie³

1993

Mol. Cell. Biol.

187

130

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The human heat shock transcription factor (HSF) is maintained in an inactive non-DNA-binding form under nonstress conditions and acquires the ability to bind specifically to the heat shock promoter element in response to elevated temperatures or other conditions that disrupt protein structure. Here we show that constitutive overexpression of the major inducible heat shock protein, hsp7O, in transfected human cells reduces the extent of HSF activation after a heat stress. HSF activation was inhibited more strongly in clones that express higher levels of hsp7O. These results demonstrate that HSF activity is negatively regulated in vivo by hsp7O and suggest that the cell might sense elevated temperature as a decreased availability of hsp7O. HSF activation in response to treatment with sodium arsenite or the proline analog azetidine was also depressed in hsp7O-expressing cells relative to that in the nontransfected control cells. As well, the level of activated HSF decreased more rapidly in the hsp7O-expressing clones when the cells were heat shocked and returned to 37°C. These results suggest that hsp7O could play an active role in the conversion of HSF back to a conformation that does not bind the heat shock promoter element during the attenuation of the heat shock response.

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“…Many hsps were identified in yeast cells, and some of the respective genes have been cloned. Some of these genes are highly homologous to each other and form subfam- (14,21,30,52,60,61,70,82). The HSF acts as a multimer (50,53,81) and in most organisms binds the HSE only upon heat shock (36,67,68).…”

mentioning

confidence: 99%

The yeast and mammalian Ras pathways control transcription of heat shock genes independently of heat shock transcription factor.

Engelberg¹,

Zandi²,

Parker³

et al. 1994

Mol. Cell. Biol.

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Yeast strains in which the Ras-cyclic AMP (cAMP) pathway is constitutively active are sensitive to heat shock, whereas mutants in which the activity of this pathway is low are hyperresistant to heat shock. To determine the molecular basis for these differences, we examined the transcriptional induction of heat shock genes in various yeast strains. Activation of heat shock genes was attenuated in the strains in which the Ras-cAMP pathway is constitutively active. In contrast, in a strain deficient in cAMP production, several heat shock genes were induced by removal of cAMP from the medium. These results indicate that the Ras-cAMP pathway affects the induction of heat shock genes. In all of the mutants, heat shock transcription factor expression and activity were identical to those in wild-type cells. The response to heat shock in Ha-rastransformed rat fibroblasts was also studied. While no induction of Hsp68 was observed in Ha-ras-transformed cells, proper regulation of heat shock transcription factor was found. Therefore, in mammals, as in Saccharomyces cerevisiae, the Ras pathway controls the transcription of heat shock genes via a mechanism not involving the heat shock transcription factor.The ras proto-oncogenes are highly conserved from yeasts to humans (reviewed in reference 12). These genes encode small membrane-associated GTP binding proteins that transduce signals generated at the cell surface to intracellular effectors (3,7,24,59). The mammalian Ha-Ras protein seems to interact with the serine or threonine kinase [77][78][79]85) and somehow leads to its activation. This results in activation of a protein kinase cascade (18,73,83) that induces gene expression through phosphorylation of transcription factors (reviewed in reference 25). One transcription factor affected by Ha-Ras is c-Jun (6), and another is NF-KB (17). In addition to positive modulation of the transcription factors' activity, HaRas may also negatively regulate certain transcription factors.In the yeast Saccharomyces cerevisiae, It was shown that expression of heat shock proteins (hsps) under nonshock conditions confers hyperresistance to heat shock (27,42,56). Therefore, it seems reasonable that resistance and sensitivity to heat shock are mediated at the level of hsp gene transcription. Indeed, it was shown that cyri cells express three proteins with a molecular mass of 72 kDa (65). These proteins, which were probably hsps, were not induced in the bcyl strain (65). Other studies showed that one of the heat shock genes, SSA3, was activated in the cyril strain in the absence of heat shock (9, 80). Also, the UBI4 gene, coding for polyubiquitin, was found to be regulated both by heat shock and cAMP (72). It is still not known, however, whether the Ras-cAMP pathway is a general regulator of hsp gene expression. It is also not known whether mammalian Ha-Ras activation also affects hsp gene expression. Furthermore, both in yeasts and in mammals, the relationship between the Ras pathway and the heat shock transcription factor (HSF [described bel...

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Isolation of the gene encoding the S. cerevisiae heat shock transcription factor

Cited by 389 publications

References 56 publications

Complex Regulation of the Yeast Heat Shock Transcription Factor

Complex Regulation of the Yeast Heat Shock Transcription Factor

The DNA-binding activity of the human heat shock transcription factor is regulated in vivo by hsp70.

The yeast and mammalian Ras pathways control transcription of heat shock genes independently of heat shock transcription factor.

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