The elimination of the yeast [PSI+] prion by guanidine hydrochloride is the result of Hsp104 inactivation

Ferreira, Paulo César Peregrino; Ness, Frédérique; Edwards, Suzanne R.; Cox, Brian S.; Tuite, Mick F.

doi:10.1046/j.1365-2958.2001.02478.x

Cited by 239 publications

(230 citation statements)

References 61 publications

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“…46,47 Given the sensitivity of RAC and Ssb mutants to cations including GuHCl, 48,49 we used a somewhat lower concentration (2.5 mM) than is typically used for prion curing (3-5 mM). Cells were plated on YEPDCGuHCl, incubated until single colonies formed, then individual colonies restreaked onto fresh YEPDCGuHCl plates to obtain single colonies.…”

Section: The Rac Antagonizes Induced and Spontaneous Formation Of Thementioning

confidence: 99%

The ribosome-associated complex antagonizes prion formation in yeast

Amor

Castanzo

Delany

et al. 2015

Prion

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ABSTRACT. The number of known fungal proteins capable of switching between alternative stable conformations is steadily increasing, suggesting that a prion-like mechanism may be broadly utilized as a means to propagate altered cellular states. To gain insight into the mechanisms by which cells regulate prion formation and toxicity we examined the role of the yeast ribosome-associated complex (RAC) in modulating both the formation of the [PSI C ] prion -an alternative conformer of Sup35 protein -and the toxicity of aggregation-prone polypeptides. The Hsp40 RAC chaperone Zuo1 anchors the RAC to ribosomes and stimulates the ATPase activity of the Hsp70 chaperone Ssb. We found that cells lacking Zuo1 are sensitive to over-expression of some aggregation-prone proteins, including the Sup35 prion domain, suggesting that co-translational protein misfolding increases in Dzuo1 strains. Consistent with this finding, Dzuo1 cells exhibit higher frequencies of spontaneous and induced prion formation. Cells expressing mutant forms of Zuo1 lacking either a C-terminal charged region required for ribosome association, or the J-domain responsible for Ssb ATPase stimulation, exhibit similarly high frequencies of prion formation. Our findings are consistent with a role for the RAC in chaperoning nascent Sup35 to regulate folding of the N-terminal prion domain as it emerges from the ribosome.

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Section: The Rac Antagonizes Induced and Spontaneous Formation Of Thementioning

confidence: 99%

The ribosome-associated complex antagonizes prion formation in yeast

Amor

Castanzo

Delany

et al. 2015

Prion

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“…Investigations into the mechanism of action of Hsp104 have been facilitated by experiments showing that Hsp104 in vivo can be inactivated by treating yeast with low levels of guanidinehydrochloride (Gdn) (20)(21)(22). Whereas it was demonstrated many years ago that such treatment cures [PSI ϩ ], recently it was shown that Gdn acts by inhibiting Hsp104 ATPase activity (23,24).…”

Section: Propagation Of the Yeast Prion [Psimentioning

confidence: 99%

“…On the other hand, others have suggested that Hsp104 is required only to break up aggregates to replicate them so that they are passed on to daughter cells when yeast divide (14-16). It was further proposed that Hsp104 breaks up only the small aggregates, whereas large aggregates form dead-end complexes unable to propagate the prion trait (15,(17)(18)(19).Investigations into the mechanism of action of Hsp104 have been facilitated by experiments showing that Hsp104 in vivo can be inactivated by treating yeast with low levels of guanidinehydrochloride (Gdn) (20)(21)(22). Whereas it was demonstrated many years ago that such treatment cures [PSI ϩ ], recently it was shown that Gdn acts by inhibiting Hsp104 ATPase activity (23,24).…”

mentioning

confidence: 99%

Curing of yeast [PSI ⁺ ] prion by guanidine inactivation of Hsp104 does not require cell division

Greene

Masison

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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Propagation of the yeast prion [PSIP rions (infectious proteins) are proteins that are normally soluble but autocatalytically propagate as amyloid, which is a fibrous polymer-like aggregate rich in ␤-sheet secondary structure (1). Normally folded mammalian prion protein has a high ␣-helical content, but its aggregated form contains much more ␤-sheet and is highly resistant to proteolysis. When this autocatalytic conversion occurs on a large scale in the central nervous system, the amyloid form accumulates and is associated with the neurodegeneration in fatal diseases such as scrapie in sheep, bovine spongiform encephalopathy in cows, and Creutzfeld-Jacob disease in humans (2). Other proteins form amyloid in an autocatalytic manner, but only prion protein is infectious.Prions also occur in yeast (3). The best-characterized yeast prion proteins are Sup35p, a translation termination factor, and Ure2p, which is involved in nitrogen metabolism (4). More recently, Rnq1p was identified as a prion protein, and New1p was shown to contain a domain that can substitute for the priondetermining region of Sup35p (5-7). Amyloidogenic yeast prion proteins have an Asn͞Gln-rich prion-forming domain that, like mammalian prion protein, can be converted to a ␤-sheet-rich, protease-resistant conformation in an autocatalytic manner. When yeast cells containing soluble Sup35p, for example, are mated to cells containing the prion form of Sup35p, the soluble form is converted to the aggregated form, which then continues to propagate as the yeast divide. is not yet understood. Lindquist and colleagues (11, 13) have suggested that the ability of Hsp104 both to nucleate Sup35p aggregation and to break up these aggregates plays a role in maintaining [PSI ϩ ]. On the other hand, others have suggested that Hsp104 is required only to break up aggregates to replicate them so that they are passed on to daughter cells when yeast divide (14-16). It was further proposed that Hsp104 breaks up only the small aggregates, whereas large aggregates form dead-end complexes unable to propagate the prion trait (15,(17)(18)(19).Investigations into the mechanism of action of Hsp104 have been facilitated by experiments showing that Hsp104 in vivo can be inactivated by treating yeast with low levels of guanidinehydrochloride (Gdn) (20)(21)(22). Whereas it was demonstrated many years ago that such treatment cures [PSI ϩ ], recently it was shown that Gdn acts by inhibiting Hsp104 ATPase activity (23,24). Because Gdn inactivates Hsp104 immediately, kinetics of [PSI ϩ ] curing after this inactivation can be monitored straightforwardly. When growing cells are exposed to Gdn there is a lag phase during which no curing occurs followed by a linear increase in the number of cured cells over time (25).These kinetic studies have supported the model that Hsp104 acts by breaking up prion polymers, thereby generating new prion ''seeds.'' During the lag phase that occurs after Hsp104 activity is inhibited, the prion polymers or seeds are thought to grow in size but, failing to...

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“…Although GdmCl seems to inhibit the replication of the prions (15,16), several lines of evidence suggest that it does not target the prion proteins themselves but Hsp104. First, GdmCl blocks the disaggregase activity of Hsp104 in vivo and reduces the thermotolerance of yeast (17,18). Second, both GdmCl-treated and Hsp104-deficient yeast cells have similar phenotypes in respect to prion propagation (17,18).…”

mentioning

confidence: 99%

“…First, GdmCl blocks the disaggregase activity of Hsp104 in vivo and reduces the thermotolerance of yeast (17,18). Second, both GdmCl-treated and Hsp104-deficient yeast cells have similar phenotypes in respect to prion propagation (17,18). A recent report showed that, in yeast strains with a point mutation in Hsp104 (D184S), prion phenotypes can no longer be cured by GdmCl (19).…”

mentioning

confidence: 99%

The Prion Curing Agent Guanidinium Chloride Specifically Inhibits ATP Hydrolysis by Hsp104

Grimminger

Richter

Imhof

et al. 2004

Journal of Biological Chemistry

127

132

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The molecular chaperone Hsp104 from Saccharomyces cerevisiae dissolves protein aggregates in the cell and is thus of crucial importance for the thermotolerance of yeast. In addition to this disaggregase activity, Hsp104 has a key function in yeast prion propagation, as Hsp104 was found to be essential for the maintenance of the associated phenotypes. In vivo data suggest that Hsp104 function is affected by guanidinium chloride. Adding small amounts of this compound to yeast medium causes curing of the prions: cells lose their prionrelated phenotype. Guanidinium chloride was also found to impair heat shock resistance. Here, we present a detailed in vitro analysis showing that guanidinium chloride is an uncompetitive inhibitor of Hsp104. Micromolar concentrations of this agent reduce the ATPase activity of Hsp104 to ϳ35% of its normal activity. This inhibition is not related to the denaturing properties of this compound, because Hsp104 was not affected by urea. Guanidinium ions selectively bind to the nucleotide-bound, hexameric state of the molecular chaperone. Thus, they increase the affinity of Hsp104 for adenine nucleotides and promote the nucleotide-dependent oligomerization of the chaperone. Our findings strongly suggest that guanidinium chloride causes curing of yeast prions by perturbing the ATPase of Hsp104, which is essential for both prion propagation and thermotolerance.

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The elimination of the yeast [PSI⁺] prion by guanidine hydrochloride is the result of Hsp104 inactivation

Abstract: SummaryIn the yeast Saccharomyces cerevisiae, Sup35p (eRF3), a subunit of the translation termination complex, can take up a prion-like, self-propagating conformation giving rise to the non-

Cited by 239 publications

References 61 publications

The ribosome-associated complex antagonizes prion formation in yeast

The ribosome-associated complex antagonizes prion formation in yeast

Curing of yeast [PSI ⁺ ] prion by guanidine inactivation of Hsp104 does not require cell division

The Prion Curing Agent Guanidinium Chloride Specifically Inhibits ATP Hydrolysis by Hsp104

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The elimination of the yeast [PSI+] prion by guanidine hydrochloride is the result of Hsp104 inactivation

Abstract: SummaryIn the yeast Saccharomyces cerevisiae, Sup35p (eRF3), a subunit of the translation termination complex, can take up a prion-like, self-propagating conformation giving rise to the non-

Cited by 239 publications

References 61 publications

The ribosome-associated complex antagonizes prion formation in yeast

The ribosome-associated complex antagonizes prion formation in yeast

Curing of yeast [PSI + ] prion by guanidine inactivation of Hsp104 does not require cell division

The Prion Curing Agent Guanidinium Chloride Specifically Inhibits ATP Hydrolysis by Hsp104

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The elimination of the yeast [PSI⁺] prion by guanidine hydrochloride is the result of Hsp104 inactivation

Curing of yeast [PSI ⁺ ] prion by guanidine inactivation of Hsp104 does not require cell division