Stress‐driven structural and functional switching of Ypt1p from a GTPase to a molecular chaperone mediates thermo tolerance in Saccharomyces cerevisiae

2015 ◽  
Vol 29 (11) ◽  
pp. 4424-4434 ◽  
Author(s):  
Chang Ho Kang ◽  
Sun Yong Lee ◽  
Joung Hun Park ◽  
Yuno Lee ◽  
Hyun Suk Jung ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Chaperone ◽  
Functional Switching

Survey of molecular chaperone requirement for the biosynthesis of hamster polyomavirus VP1 protein in Saccharomyces cerevisiae

2016 ◽  
Vol 161 (7) ◽  
pp. 1807-1819 ◽  
Author(s):  
Monika Valaviciute ◽  
Milda Norkiene ◽  
Karolis Goda ◽  
Rimantas Slibinskas ◽  
Alma Gedvilaite
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Chaperone ◽  
Vp1 Protein ◽  
Hamster Polyomavirus

scholarly journals The effect of calnexin deletion on the expression level of PDI in Saccharomyces cerevisiae under heat stress conditions

2008 ◽  
Vol 13 (1) ◽  
Author(s):  
Huili Zhang ◽  
Jianwei He ◽  
Yanyan Ji ◽  
Akio Kato ◽  
Youtao Song
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Heat Stress ◽  
Protein Expression ◽  
Molecular Chaperone ◽  
Mrna Level ◽  
Stress Conditions ◽  
Mrna Levels ◽  
Wild Type ◽  
Wild Type Yeast

AbstractWe cultured calnexin-disrupted and wild-type Saccharomyces cerevisiae strains under conditions of heat stress. The growth rate of the calnexin-disrupted yeast was almost the same as that of the wild-type yeast under those conditions. However, the induced mRNA level of the molecular chaperone PDI in the ER was clearly higher in calnexin-disrupted S. cerevisiae relative to the wild type at 37°C, despite being almost the same in the two strains under normal conditions. The western blotting analysis for PDI protein expression in the ER yielded results that show a parallel in their mRNA levels in the two strains. We suggest that PDI may interact with calnexin under heat stress conditions, and that the induction of PDI in the ER can recover part of the function of calnexin in calnexin-disrupted yeast, and result in the same growth rate as in wild-type yeast.

scholarly journals Cns1 Is an Essential Protein Associated with the Hsp90 Chaperone Complex in Saccharomyces cerevisiae That Can Restore Cyclophilin 40-Dependent Functions in cpr7ΔCells

1998 ◽  
Vol 18 (12) ◽  
pp. 7353-7359 ◽  
Author(s):  
James A. Marsh ◽  
Helen M. Kalton ◽  
Richard F. Gaber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Chaperone ◽  
Single Gene ◽  
Normal Growth ◽  
Maximal Activity ◽  
Negative Regulation ◽  
Growth Defect ◽  
Chaperone Complex ◽  
Cyclophilin 40

ABSTRACT Saccharomyces cerevisiae harbors two cyclophilin 40-type enzymes, Cpr6 and Cpr7, which are components of the Hsp90 molecular chaperone machinery. Cpr7 is required for normal growth and is required for maximal activity of heterologous Hsp90-dependent substrates, including glucocorticoid receptor (GR) and the oncogenic tyrosine kinase pp60v-src . In addition, it has recently been shown that Cpr7 plays a major role in negative regulation of the S. cerevisiae heat shock transcription factor (HSF). To better understand functions associated with Cpr7, a search was undertaken for multicopy suppressors of the cpr7Δ slow-growth phenotype. The screen identified a single gene, designatedCNS1 (for cyclophilin seven suppressor), capable of suppressing the cpr7Δ growth defect. Overexpression ofCNS1 in cpr7Δ cells also largely restored GR activity and negative regulation of HSF. In vitro protein retention experiments in which Hsp90 heterocomplexes were precipitated resulted in coprecipitation of Cns1. Interaction between Cns1 and the carboxy terminus of Hsp90 was also shown by two-hybrid analysis. The functional consequences of CNS1 overexpression and its physical association with the Hsp90 machinery indicate that Cns1 is a previously unidentified component of molecular chaperone complexes. Thus far, Cns1 is the only tetratricopeptide repeat-containing component of Hsp90 heterocomplexes found to be essential for cell viability under all conditions tested.

scholarly journals Guanidine Hydrochloride Inhibits the Generation of Prion “Seeds” but Not Prion Protein Aggregation in Yeast

2002 ◽  
Vol 22 (15) ◽  
pp. 5593-5605 ◽  
Author(s):  
Frédérique Ness ◽  
Paulo Ferreira ◽  
Brian S. Cox ◽  
Mick F. Tuite
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Chaperone ◽  
Guanidine Hydrochloride ◽  
Free Medium ◽  
Seed Number ◽  
Cycle Model ◽  
Yeast Prions ◽  
Independent Process ◽  
Kinetics Of ◽  
Number Of Seeds

ABSTRACT [PSI +] strains of the yeast Saccharomyces cerevisiae replicate and transmit the prion form of the Sup35p protein but can be permanently cured of this property when grown in millimolar concentrations of guanidine hydrochloride (GdnHCl). GdnHCl treatment leads to the inhibition of the replication of the [PSI +] seeds necessary for continued [PSI +] propagation. Here we demonstrate that the rate of incorporation of newly synthesized Sup35p into the high-molecular-weight aggregates, diagnostic of [PSI +] strains, is proportional to the number of seeds in the cell, with seed number declining (and the levels of soluble Sup35p increasing) in the presence of GdnHCl. GdnHCl does not cause breakdown of preexisting Sup35p aggregates in [PSI +] cells. Transfer of GdnHCl-treated cells to GdnHCl-free medium reverses GdnHCl inhibition of [PSI +] seed replication and allows new prion seeds to be generated exponentially in the absence of ongoing protein synthesis. Following such release the [PSI +] seed numbers double every 20 to 22 min. Recent evidence (P. C. Ferreira, F. Ness, S. R. Edwards, B. S. Cox, and M. F. Tuite, Mol. Microbiol. 40:1357-1369, 2001; G. Jung and D. C. Masison, Curr. Microbiol. 43:7-10, 2001), together with data presented here, suggests that curing yeast prions by GdnHCl is a consequence of GdnHCl inhibition of the activity of molecular chaperone Hsp104, which in turn is essential for [PSI +] propagation. The kinetics of elimination of [PSI +] by coexpression of a dominant, ATPase-negative allele of HSP104 were similar to those observed for GdnHCl-induced elimination. Based on these and other data, we propose a two-cycle model for “prionization” of Sup35p in [PSI +] cells: cycle A is the GdnHCl-sensitive (Hsp104-dependent) replication of the prion seeds, while cycle B is a GdnHCl-insensitive (Hsp104-independent) process that converts these seeds to pelletable aggregates.

scholarly journals Alteration of the Protein Kinase Binding Domain Enhances Function of the Saccharomyces cerevisiae Molecular Chaperone Cdc37

2007 ◽  
Vol 6 (8) ◽  
pp. 1363-1372 ◽  
Author(s):  
Min Ren ◽  
Arti Santhanam ◽  
Paul Lee ◽  
Avrom Caplan ◽  
Stephen Garrett
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Molecular Chaperone ◽  
Binding Domain ◽  
Growth Defect ◽  
Temperature Sensitive ◽  
Physical Interaction ◽  
General Function ◽  
Amino Terminal

ABSTRACT Cdc37 is a molecular chaperone that has a general function in the biogenesis of protein kinases. We identified mutations within the putative “protein kinase binding domain” of Cdc37 that alleviate the conditional growth defect of a strain containing a temperature-sensitive allele, tpk2(Ts), of the cyclic AMP-dependent protein kinase (PKA). These dominant mutations alleviate the temperature-sensitive growth defect by elevating PKA activity, as judged by their effects on PKA-regulated processes, localization and phosphorylation of the PKA effector Msn2, as well as in vitro PKA activity. Although the tpk2(Ts) growth defect is also alleviated by Cdc37 overproduction, the CDC37 dominant mutants contain wild-type Cdc37 protein levels. In addition, Saccharomyces cerevisiae Ste11 protein kinase has an elevated physical interaction with the altered Cdc37 protein. These results implicate specific amino-terminal residues in the interaction between Cdc37 and client protein kinases and provide further genetic and biochemical support for a model in which Cdc37 functions as a molecular chaperone for protein kinases.

scholarly journals The molecular chaperone Hsp90 is required for high osmotic stress response in Saccharomyces cerevisiae

2006 ◽  
Vol 6 (2) ◽  
pp. 195-204 ◽  
Author(s):  
Xiao-Xian Yang ◽  
Kick C. T. Maurer ◽  
Michiel Molanus ◽  
Willem H. Mager ◽  
Marco Siderius ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stress Response ◽  
Osmotic Stress ◽  
Molecular Chaperone ◽  
Osmotic Stress Response

scholarly journals Crystal structures of Hsp104 N-terminal domains fromSaccharomyces cerevisiaeandCandida albicanssuggest the mechanism for the function of Hsp104 in dissolving prions

2017 ◽  
Vol 73 (4) ◽  
pp. 365-372 ◽  
Author(s):  
Peng Wang ◽  
Jingzhi Li ◽  
Clarissa Weaver ◽  
Aaron Lucius ◽  
Bingdong Sha
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
High Resolution ◽  
Crystal Structures ◽  
Molecular Chaperone ◽  
Peptide Binding ◽  
Dimer Formation ◽  
Peptide Substrates ◽  
Peptide Binding Groove ◽  
Binding Groove

Hsp104 is a yeast member of the Hsp100 family which functions as a molecular chaperone to disaggregate misfolded polypeptides. To understand the mechanism by which the Hsp104 N-terminal domain (NTD) interacts with its peptide substrates, crystal structures of the Hsp104 NTDs fromSaccharomyces cerevisiae(ScHsp104NTD) andCandida albicans(CaHsp104NTD) have been determined at high resolution. The structures of ScHsp104NTD and CaHsp104NTD reveal that the yeast Hsp104 NTD may utilize a conserved putative peptide-binding groove to interact with misfolded polypeptides. In the crystal structures ScHsp104NTD forms a homodimer, while CaHsp104NTD exists as a monomer. The consecutive residues Gln105, Gln106 and Lys107, and Lys141 around the putative peptide-binding groove mediate the monomer–monomer interactions within the ScHsp104NTD homodimer. Dimer formation by ScHsp104NTD suggests that the Hsp104 NTD may specifically interact with polyQ regions of prion-prone proteins. The data may reveal the mechanism by which Hsp104 NTD functions to suppress and/or dissolve prions.

scholarly journals Functional switching of ascorbate peroxidase 2 of rice (OsAPX2) between peroxidase and molecular chaperone

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Sung Hyun Hong ◽  
Bhumi Nath Tripathi ◽  
Moon-Soo Chung ◽  
Chuloh Cho ◽  
Sungbeom Lee ◽  
...  
Keyword(s):  
Ascorbate Peroxidase ◽  
Molecular Chaperone ◽  
Functional Switching

Fes1p acts as a nucleotide exchange factor for the ribosome-associated molecular chaperone Ssb1p

2006 ◽  
Vol 387 (12) ◽  
pp. 1593-1600 ◽  
Author(s):  
Zdravko Dragovic ◽  
Yasuhito Shomura ◽  
Nikolay Tzvetkov ◽  
F. Ulrich Hartl ◽  
Andreas Bracher
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Chaperone ◽  
Point Mutations ◽  
Nucleotide Exchange ◽  
Exchange Factor ◽  
Nucleotide Analog ◽  
Nucleotide Exchange Factor ◽  
Similar Affinity ◽  
Stimulation Of

Abstract The HspBP1 homolog Fes1p was recently identified as a nucleotide exchange factor (NEF) of Ssa1p, a canonical Hsp70 molecular chaperone in the cytosol of Saccharomyces cerevisiae. Besides the Ssa-type Hsp70s, the yeast cytosol contains three additional classes of Hsp70, termed Ssb, Sse and Ssz. Here, we show that Fes1p also functions as NEF for the ribosome-bound Ssb Hsp70s. Sequence analysis indicated that residues important for interaction with Fes1p are highly conserved in Ssa1p and Ssb1p, but not in Sse1p and Ssz1p. Indeed, Fes1p interacts with Ssa1p and Ssb1p with similar affinity, but does not form a complex with Sse1p. Functional analysis showed that Fes1p accelerates the release of the nucleotide analog MABA-ADP from Ssb1p by a factor of 35. In contrast to the interaction between mammalian HspBP1 and Hsp70, however, addition of ATP only moderately decreases the affinity of Fes1p for Ssb1p. Point mutations in Fes1p abolishing complex formation with Ssa1p also prevent the interaction with Ssb1p. The ATPase activity of Ssb1p is stimulated by the ribosome-associated complex of Zuotin and Ssz1p (RAC). Interestingly, Fes1p inhibits the stimulation of Ssb1p ATPase by RAC, suggesting a complex regulatory role of Fes1p in modulating the function of Ssb Hsp70s in co-translational protein folding.

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