Hsp104 catalyzes formation and elimination of self-replicating Sup35 prion conformers

J Shorter, S Lindquist - Science, 2004 - science.org
J Shorter, S Lindquist
Science, 2004science.org
The protein-remodeling factor Hsp104 governs inheritance of [PSI+], a yeast prion formed by
self-perpetuating amyloid conformers of the translation termination factor Sup35.
Perplexingly, either excess or insufficient Hsp104 eliminates [PSI+]. In vitro, at low
concentrations, Hsp104 catalyzed the formation of oligomeric intermediates that proved
critical for the nucleation of Sup 35 fibrillization de novo and displayed a conformation
common among amyloidogenic polypeptides. At higher Hsp104 concentrations …
The protein-remodeling factor Hsp104 governs inheritance of [PSI+], a yeast prion formed by self-perpetuating amyloid conformers of the translation termination factor Sup35. Perplexingly, either excess or insufficient Hsp104 eliminates [PSI+]. In vitro, at low concentrations, Hsp104 catalyzed the formation of oligomeric intermediates that proved critical for the nucleation of Sup 35 fibrillization de novo and displayed a conformation common among amyloidogenic polypeptides. At higher Hsp104 concentrations, amyloidogenic oligomerization and contingent fibrillization were abolished. Hsp104 also disassembled mature fibers in a manner that initially exposed new surfaces for conformational replication but eventually exterminated prion conformers. These Hsp104 activities differed in their reaction mechanism and can explain [PSI+] inheritance patterns.
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