title: Novel non-Mendelian determinant involved in the control of translation accuracy in Saccharomyces cerevisiae.
abstract: Two cytoplasmically inherited determinants related by their manifestation to the control of translation accuracy were previously described in yeast. Cells carrying one of them, [PSI(+)], display a nonsense suppressor phenotype and contain a prion form of the Sup35 protein. Another element, [PIN(+)], determines the probability of de novo generation of [PSI(+)] and results from a prion form of several proteins, which can be functionally unrelated to Sup35p. Here we describe a novel nonchromosomal determinant related to the SUP35 gene. This determinant, designated [ISP(+)], was identified as an antisuppressor of certain sup35 mutations. We observed its loss upon growth on guanidine hydrochloride and subsequent spontaneous reappearance with high frequency. The reversible curability of [ISP(+)] resembles the behavior of yeast prions. However, in contrast to known prions, [ISP(+)] does not depend on the chaperone protein Hsp104. Though manifestation of both [ISP(+)] and [PSI(+)] is related to the SUP35 gene, the maintenance of [ISP(+)] does not depend on the prionogenic N-terminal domain of Sup35p and Sup35p is not aggregated in [ISP(+)] cells, thus ruling out the possibility that [ISP(+)] is a specific form of [PSI(+)]. We hypothesize that [ISP(+)] is a novel prion involved in the control of translation accuracy in yeast.
authors.affiliation: Department of Genetics, St. Petersburg State University, St. Petersburg 199034, Russia.
authors.forename: Kirill V
authors.initials: KV
authors.lastname: Volkov
authors.forename: Anna Yu
authors.initials: AY
authors.lastname: Aksenova
authors.forename: Malle J
authors.initials: MJ
authors.lastname: Soom
authors.forename: Kirill V
authors.initials: KV
authors.lastname: Osipov
authors.forename: Anton V
authors.initials: AV
authors.lastname: Svitin
authors.forename: Cornelia
authors.initials: C
authors.lastname: Kurischko
authors.forename: Irina S
authors.initials: IS
authors.lastname: Shkundina
authors.forename: Michael D
authors.initials: MD
authors.lastname: Ter-Avanesyan
authors.forename: Sergey G
authors.initials: SG
authors.lastname: Inge-Vechtomov
authors.forename: Ludmila N
authors.initials: LN
authors.lastname: Mironova
mesh_terms: D000483:Alleles; D015825:Chromosomes, Fungal; D003470:Culture Media / Q000378:metabolism; D005111:Extrachromosomal Inheritance; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005799:Genes, Dominant; D019791:Guanidine / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000502:physiology; D009687:Nuclear Proteins; D010454:Peptide Termination Factors; D011328:Prions / Q000235:genetics; D014176:Protein Biosynthesis / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D013489:Suppression, Genetic
chemical_list: D003470:Culture Media; D005656:Fungal Proteins; D006360:Heat-Shock Proteins; D009687:Nuclear Proteins; D010454:Peptide Termination Factors; D011328:Prions; C093988:Psi protein, S pombe; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C070972:HsP104 protein, S cerevisiae; D019791:Guanidine