The prion, an infectious protein implicated in transmissible spongiform encephalopathies (TSEs) seems to have a relative in yeast. The yeast version [PSI+] is not infectious, but serves as a novel agent for genetic inheritance. It can alter its conformation in a prion-like manner and this change causes an inherited new phenotype. The protein found in [PSI+] factors interacts with a "chaperone" protein, Hsp104 to affect its conformational change. Susan Lindquist (University of Chicago, Chicago, IL, USA) reports in an upcoming issue of The Proceedings of the National Academy of Sciences that this chaperone protein from yeast is also able to interact with PrP, the mammalian protein implicated in TSE, and affect its conversion to its disease-associated conformation. Such a link reinforces the idea that there is a broad class of these proteins capable of acting in a prion-like manner, and also opens up the possibility of learning more about prions by studying yeast cells, which are much easier to grow and manipulate than mammalian cells. (Contributed by Hannah Wunsch)

Relevant articles from the Lindquist lab

1. Interactions of the Chaperone Hsp104 with Yeast Sup35 and Mammalian PrP. Proceedings of the National Academy of Sciences, U.S.A. 94: 13,932

2. Mad Cows Meet Psi-chotic Yeast: The Expansion of the Prion Hypothesis Cell 89: 495-998.