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Updated: Jun 26, 2026
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High-throughput Screening for Protein-based Inheritance in S. cerevisiae
Published on: August 8, 2017
Yeast prions: evolution of the prion concept
Reed B Wickner1, Herman K Edskes, Frank Shewmaker
1Laboratory of Biochemistry and Genetics, The National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0830, USA. wickner@helix.nih.gov
Prion
|January 24, 2009
Summary
Prions, or infectious proteins, can act as genes in yeast. Their prion domains can be randomized, suggesting amino acid content, not sequence, determines prion formation.
Area of Science:
- Molecular Biology
- Protein Chemistry
- Genetics
Background:
- Prions are infectious proteins analogous to the scrapie agent.
- Prions have been identified in Saccharomyces cerevisiae and Podospora anserina.
- These prions function as genes, similar to nucleic acids acting as enzymes.
Purpose of the Study:
- To investigate the nature of prions in yeast.
- To understand the determinants of prion formation and propagation.
Main Methods:
- Identification and characterization of specific prions: [URE3], [PSI(+)], [PIN(+)], and [Het-s].
- Analysis of prion domains, including randomization of amino acid sequences.
- Structural analysis suggesting amyloid formation with parallel in-register beta-sheet structure.
Main Results:
- Identified four yeast prions: [URE3] (Ure2p), [PSI(+)] (Sup35p), [PIN(+)] (Rnq1p), and [Het-s] (HET-s protein).
- Demonstrated that prion domains of Ure2p and Sup35p can be randomized without losing prion-forming ability.
- Indicated that amino acid content, rather than specific sequence, determines prion formation.
- Structural studies suggest a parallel in-register beta-sheet amyloid structure.
Conclusions:
- Yeast prions ([URE3], [PSI(+)], [PIN(+)], [Het-s]) are self-propagating amyloids.
- Prion formation is primarily determined by amino acid composition, not sequence.
- The shuffleability of prion domains supports an amyloid structure with beta-sheet characteristics.
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