Yeast Prion Diseases

Tuesday, October 09, 2012 — Poster Session I
1:00 p.m. – 3:00 p.m	Natcher Conference Center, Building 45	NIDDK	BIOCHEM-14

* FARE Award Winner

Authors

• R Wickner
• A Kelly
• F Shewmaker
• D Kryndushkin
• R McGlinchey

Abstract

Yeast prions are self-propagating amyloids (beta-sheet – rich filamentous protein multimers) resulting, in most cases, in partial inactivation of the normal function of the prion protein. When the essential translation termination factor Sup35p forms the [PSI+] prion, increased readthru of stop codons occurs. When the nitrogen catabolism gene repressor Ure2p forms the [URE3] prion, many regulated genes are derepressed. Although mammalian prions are uniformly lethal, some believe that yeast prions are actually beneficial to their host, perhaps because only the least detrimental prion variants are the ones usually studied. We have examined this claim by looking at the effects of random prion isolates. We found that many [PSI+] isolates kill cells unless they are rescued by providing with a prion-immune form of Sup35p (Sup35C)1. We observed that many [URE3] isolates slow growth dramatically in strains whose growth is not affected by a ure2 mutation. These results show that yeast prions are far more harmful than had been thought.

back to top