Genetic and Cell Biological Support for as a Yeast Prion

Genetic and Cell Biological Support for [PSI ] as a Yeast Prion 

The yeast prion hypothesis provides explanations for several unique characteristics of [PSP] that were inconsistent with a nucleic acid determinant (Wickner, 1994). 

Although the phenotype of a prion is predicted to be inherited through the transmission of an alternative protein state, it will also be dependent on the gene that encodes that protein. Expression of the gene provides a supply of protein that can then be converted to the prion state. In the absence of new protein, the associated phenotype will be lost because the determinant (a particular structural state of the protein) cannot be replicated. 

The prion hypothesis predicts that the spontaneous appearance of the prion state and its associated phenotype is a rare and stochastic event. Increasing prion protein expression levels should lead to an increase in the rate at which this event occurs (Prusiner, 1982). 

Alternative Phenotypes Associated with Distinct Protein States 

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