title: Suicidal [PSI+] is a lethal yeast prion.
abstract: [PSI(+)] is a prion of the essential translation termination factor Sup35p. Although mammalian prion infections are uniformly fatal, commonly studied [PSI(+)] variants do not impair growth, leading to suggestions that [PSI(+)] may protect against stress conditions. We report here that over half of [PSI(+)] variants are sick or lethal. These "killer [PSI(+)]s" are compatible with cell growth only when also expressing minimal Sup35C, lacking the N-terminal prion domain. The severe detriment of killer [PSI(+)] results in rapid selection of nonkiller [PSI(+)] variants or loss of the prion. We also report variants of [URE3], a prion of the nitrogen regulation protein Ure2p, that grow much slower than ure2Δ cells. Our findings give a more realistic picture of the impact of the prion change than does focus on "mild" prion variants.
authors.affiliation: Laboratory of Biochemistry and Genetics, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0830, USA.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: McGlinchey
authors.forename: Dmitry
authors.initials: D
authors.lastname: Kryndushkin
authors.forename: Reed B
authors.initials: RB
authors.lastname: Wickner
mesh_terms: D000818:Animals; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D010454:Peptide Termination Factors / Q000235:genetics / Q000378:metabolism*; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010454:Peptide Termination Factors; D011328:Prions; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D005979:Glutathione Peroxidase; C067020:URE2 protein, S cerevisiae