title: Prion properties of the Sup35 protein of yeast Pichia methanolica.
abstract: The Sup35 protein (Sup35p) of Saccharomyces cerevisiae is a translation termination factor of the eRF3 family. The proteins of this family possess a conservative C-terminal domain responsible for translation termination and N-terminal extensions of different structure. The N-terminal domain of Sup35p defines its ability to undergo a heritable prion-like conformational switch, which is manifested as the cytoplasmically inherited [PSI(+)] determinant. Here, we replaced the N-terminal domain of S.cerevisiae Sup35p with an analogous domain from Pichia methanolica. Overexpression of hybrid Sup35p induced the de novo appearance of cytoplasmically inherited suppressor determinants manifesting key genetic and biochemical traits of [PSI(+)]. In contrast to the conventional [PSI(+)], 'hybrid' [PSI(+)] showed lower mitotic stability and preserved their suppressor phenotype upon overexpression of the Hsp104 chaperone protein. The lack of Hsp104 eliminated both types of [PSI(+)]. No transfer of prion state between the two Sup35p variants was observed, which reveals a 'species barrier' for the [PSI(+)] prions. The data obtained show that prion properties are conserved within at least a part of this protein family.
authors.affiliation: Institute of Experimental Cardiology, Cardiology Research Center, 3(rd) Cherepkovskaya Street, 15A, Moscow 121552, Russia.
authors.forename: V V
authors.initials: VV
authors.lastname: Kushnirov
authors.forename: N V
authors.initials: NV
authors.lastname: Kochneva-Pervukhova
authors.forename: M B
authors.initials: MB
authors.lastname: Chechenova
authors.forename: N S
authors.initials: NS
authors.lastname: Frolova
authors.forename: M D
authors.initials: MD
authors.lastname: Ter-Avanesyan
mesh_terms: D000595:Amino Acid Sequence; D003433:Crosses, Genetic; D019286:Endopeptidase K; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D006360:Heat-Shock Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008938:Mitosis; D008969:Molecular Sequence Data; D010454:Peptide Termination Factors; D010843:Pichia / Q000235:genetics / Q000378:metabolism*; D011003:Ploidies; D011328:Prions / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D013489:Suppression, Genetic
chemical_list: D005656:Fungal Proteins; D006360:Heat-Shock Proteins; D010454:Peptide Termination Factors; D011328:Prions; D011993:Recombinant Fusion Proteins; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C070972:HsP104 protein, S cerevisiae; D019286:Endopeptidase K