Proteolysis suppresses spontaneous prion generation in yeast.

ABSTRACT: Prions are infectious proteins that cause fatal neurodegenerative disorders including Creutzfeldt-Jakob and bovine spongiform encephalopathy (mad cow) diseases. The yeast [PSI⁺] prion is formed by the translation-termination factor Sup35, is the best-studied prion, and provides a useful model system for studying such diseases. However, despite recent progress in the understanding of prion diseases, the cellular defense mechanism against prions has not been elucidated. Here, we report that proteolytic cleavage of Sup35 suppresses spontaneous de novo generation of the [PSI⁺] prion. We found that during yeast growth in glucose media, a maximum of 40% of Sup35 is cleaved at its N-terminal prion domain. This cleavage requires the vacuolar proteases PrA

SUBMITTER: Okamoto A 

PROVIDER: S-EPMC5724000 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature