Yeast prions e.g. [PSI+], [PIN+] and [URE3] are similar to mammalian amyloids that cause neurodegenerative diseases. [PSI+] is the aggregated self-perpetuating (prion) isoform of Sup35, a translation termination factor. The molecular chaperone Hsp104 plays a crucial role in the maintenance and propagation of [PSI+]. Deletion of the GET2 gene has been shown to cause a [PSI+] curing defect by excess Hsp104 and [PSI+] instability on synthetic medium (S. Muller, J. Patterson and Y. Chernoff, unpublished data; and J. Patterson Honors Thesis). Get2 is a membrane protein working in a complex with Get1 and Get3 proteins. This complex, called GET (Golgi-to-ER Traffic), is known to retrieve resident ER proteins from Golgi. In this particular study we provide further evidence for the connection between the GET pathway and yeast prions. The get2 deletion also leads to a detectable loss of [PIN+] prion on synthetic medium. The role of the other two members of the Get complex in prion propagation is also explored. The levels and the activity of Hsp104 in the get2 mutants is analyzed. The size of [PSI+] aggregates in the get2Δ strain is compared to that found in wild type. Finally, other possible mechanisms for the effect of get2 on prion maintenance and propagation are addressed.

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