In vitro self-propagation of recombinant PrPSc-like conformation generated in the yeast cytoplasm

Self-propagation is characteristic property for a prion conformation. Previous studies revealed that prion protein expressed in the cytoplasm gained a PrPSc-like conformation. However, it remains unclear whether the PrPSc-like conformation has the self-propagating property. We found that PrP partially purified from yeast cytoplasm formed amyloid fiber like structures, and we found that the PrPSc-like conformation is able to convert normal PrPC in the brain homogenate to a proteinase K-resistant conformation. These results suggest that yeast cytoplasm expressed recombinant PrPSc-like conformation has the characteristic self-propagating property of a prion, which may have implications in the pathogenesis of sporadic and inherited prion diseases.