N-Terminal Domain of Yeast Hsp104 Chaperone Is Dispensable for Thermotolerance and Prion Propagation but Necessary for Curing Prions by Hsp104 Overexpression

Hung, G.H.; Masison, Daniel C.

doi:10.1534/genetics.106.056820

Cited by 143 publications

(186 citation statements)

References 59 publications

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“…Both in vivo and in vitro data suggest that Hsp104 disassembles amyloid-like aggregates of Sup35, Ure2, and Rnq1 (39 -41). Importantly, similar to our findings, these effects of Hsp104 are also modulated by its N-terminal domain (42).…”

Section: Discussionsupporting

confidence: 91%

AAA+ Chaperone ClpX Regulates Dynamics of Prokaryotic Cytoskeletal Protein FtsZ

Sugimoto

Yamanaka

Nishikori

et al. 2010

Journal of Biological Chemistry

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Section: Discussionsupporting

confidence: 91%

AAA+ Chaperone ClpX Regulates Dynamics of Prokaryotic Cytoskeletal Protein FtsZ

Sugimoto

Yamanaka

Nishikori

et al. 2010

Journal of Biological Chemistry

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“…S1). The NTD was shown to be dispensable for chaperone activity in Escherichia coli and Thermus thermophilus (Beinker et al, 2002;Mogk et al, 2003) and for thermotolerance in cyanobacteria and yeast (Clarke and Eriksson, 2000;Hung and Masison, 2006). However, work on E. coli ClpB showed that truncation of the NTD causes severe defects in molecular chaperone activity in vitro (Barnett et al, 2000;Li and Sha, 2003).…”

Section: Discussionmentioning

confidence: 99%

Interplay between Heat Shock Proteins HSP101 and HSA32 Prolongs Heat Acclimation Memory Posttranscriptionally in Arabidopsis

Juan

Hsu

et al. 2013

Plant Physiology

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Heat acclimation improves the tolerance of organisms to severe heat stress. Our previous work showed that in Arabidopsis (Arabidopsis thaliana), the "memory" of heat acclimation treatment decayed faster in the absence of the heat-stress-associated 32-kD protein HSA32, a heat-induced protein predominantly found in plants. The HSA32 null mutant attains normal short-term acquired thermotolerance but is defective in long-term acquired thermotolerance. To further explore this phenomenon, we isolated Arabidopsis defective in long-term acquired thermotolerance (dlt) mutants using a forward genetic screen. Two recessive missense alleles, dlt1-1 and dlt1-2, encode the molecular chaperone heat shock protein101 (HSP101). Results of immunoblot analyses suggest that HSP101 enhances the translation of HSA32 during recovery after heat treatment, and in turn, HSA32 retards the decay of HSP101. The dlt1-1 mutation has little effect on HSP101 chaperone activity and thermotolerance function but compromises the regulation of HSA32. In contrast, dlt1-2 impairs the chaperone activity and thermotolerance function of HSP101 but not the regulation of HSA32. These results suggest that HSP101 has a dual function, which could be decoupled by the mutations. Pulse-chase analysis showed that HSP101 degraded faster in the absence of HSA32. The autophagic proteolysis inhibitor E-64d, but not the proteasome inhibitor MG132, inhibited the degradation of HSP101. Ectopic expression of HSA32 confirmed its effect on the decay of HSP101 at the posttranscriptional level and showed that HSA32 was not sufficient to confer long-term acquired thermotolerance when the HSP101 level was low. Taken together, we propose that a positive feedback loop between HSP101 and HSA32 at the protein level is a novel mechanism for prolonging the memory of heat acclimation.

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“…51 Some (but not all) of the distantly related Hsp70 homologs from other organisms (plants and mammals) partly compensated the defect in [PSI + ] maintenance observed in the presence of mutant Ssa. 45 This shows that Ssa functions involved in [PSI + ] maintenance are at least to a certain extent conserved in evolution.…”

Section: Effects Of Other Chaperones On Prions and Polyglutamine Aggrmentioning

confidence: 92%

“…19 On the other hand, the dominant mutant derivative of Hsp104, bearing the A503V substitution in the middle region, increases size of the Sup35 aggregates in [PSI + ] cells, leading to accumulation of cytologically detectable clumps and cytotoxicity, but decreases aggregate size and cytotoxicity of the polyglutamine fragment of human huntingtin expressed in yeast, and does not affect thermotolerance. 43 A503V substitution impairs coordinated regulation of the NBD action without completely eliminating ATPase activity, 44 45 It is possible that excess Hsp104 solubilizes Sup35 prion polymers into monomers, that may require a mode of action distinct from one involved in oligomeric "seed" production. Alternatively, it was proposed that excess Hsp104 may impair prion segregation in cell divisions.…”

mentioning

confidence: 99%