title: Destabilizing interactions among [PSI(+)] and [PIN(+)] yeast prion variants.
abstract: The yeast Sup35 and Rnq1 proteins can exist in either the noninfectious soluble forms, [psi-] or [pin-], respectively, or the multiple infectious amyloid-like forms called [PSI+] or [PIN+] prion variants (or prion strains). It was previously shown that [PSI+] and [PIN+] prions enhance one another's de novo appearance. Here we show that specific prion variants of [PSI+] and [PIN+] disrupt each other's stable inheritance. Acquiring [PSI+] often impedes the inheritance of particular [PIN+] variants. Conversely, the presence of some [PIN+] variants impairs the inheritance of weak [PSI+] but not strong [PSI+] variants. These same [PIN+] variants generate a single-dot fluorescence pattern when a fusion of Rnq1 and green fluorescent protein is expressed. Another [PIN+] variant, which forms a distinctly different multiple-dot fluorescence pattern, does not impair [PSI+] inheritance. Thus, destabilization of prions by heterologous prions depends upon the variants involved. These findings may have implications for understanding interactions among other amyloid-forming proteins, including those associated with certain human diseases.
authors.affiliation: Department of Biological Sciences, Laboratory for Molecular Biology, University of Illinois, Chicago, Illinois 60607, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Bradley
authors.forename: Susan W
authors.initials: SW
authors.lastname: Liebman
mesh_terms: D015966:Gene Expression Regulation, Fungal; D014644:Genetic Variation; D049452:Green Fluorescent Proteins; D006360:Heat-Shock Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D010454:Peptide Termination Factors; D010641:Phenotype; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D006360:Heat-Shock Proteins; D008164:Luminescent Proteins; D010454:Peptide Termination Factors; D011328:Prions; C404807:RNQ1 protein, S cerevisiae; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C070972:HsP104 protein, S cerevisiae; D049452:Green Fluorescent Proteins