Figure 1.

The expression of two genes directly influenced by the prion [PSI⁺]. The appearance of [PSI⁺] increases stop codon readthrough efficiency of the PDE2 gene. The longer protein (Pde2L) is rapidly degraded by the proteasome reducing the total amount of Pde2 proteins in the cytoplasm. This leads to a global reduction of cAMP level within the cell resulting in the appearance of several phenotypes. [PSI⁺] also induces stop codon dependent frameshifting increasing the expression of the antizyme. The increased amount of functional antizyme reduces the overall polyamine concentration. At least half of the [PSI⁺]-dependent phenotypes are due to a modification of polyamine content.