[Psi(+)] prion generation in yeast: characterization of the 'strain' difference

Yeast. 2001 Apr;18(6):489-97. doi: 10.1002/yea.700.


The yeast cytoplasmically-inherited nonsense suppressor [PSI(+)] determinant is presumed to be a manifestation of the aggregated prion-like state of the Sup35 protein. Overexpression of the Sup35 protein induces generation of [PSI(+)] determinants with various suppressor efficiency and mitotic stabilities. Here, we demonstrate that the relative frequency of appearance of [PSI(+)] with different properties depends on the SUP35 allele used to induce their generation. The difference in properties of [PSI(+)] determinants was preserved after their transmission from one yeast strain to another. This difference correlated with variation in properties of the Sup35 protein. A novel type of prion instability was observed: some [PSI(+)] with weak suppressor efficiency could convert spontaneously into strong suppressor determinants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Blotting, Western
  • Cell Aggregation / genetics
  • Cell Cycle
  • Fungal Proteins / biosynthesis
  • Fungal Proteins / genetics*
  • Gene Expression Regulation, Fungal / genetics
  • Peptide Termination Factors
  • Phenotype
  • Plasmids
  • Prions / genetics
  • Prions / metabolism
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Species Specificity
  • Suppression, Genetic / genetics*


  • Fungal Proteins
  • Peptide Termination Factors
  • Prions
  • SUP35 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins