Yeast Approach to Protein 'Prionization': SUP35-[PSI] System

Some human neurodegenerative diseases, such as Kuru, Creutzfeld-Jacob, Gerstmann-Streussler-Scheinker, as well as the animal ones (scrapie in sheeps, mad cow desease, etc.), are transmitted by prion, an infectious protein PrPSc. This protein is an oligomer form of the normal cellular neuropeptide PrPC. Both proteins are encoded by the same gene PrP, which is conserved at least among mammals. Mutations within the gene cause familial forms of the same prion diseases in men. In the latter case duplications of characteristic aminoacid repeats had been discovered in the N-terminal part of PrP protein. Deletion of PrP gene in mice confers resistance to prion infection in the animal. Overexpression of the same gene induces PrPSc and prion disease in mice (see a review by Wickner et al1).