[Phenotypic manifestation of epigenetic determinant [ISP+] in Saccharomyces serevisiae depends on combination of mutations in SUP35 and SUP45 genes].
It is known that translation fidelity in Saccharomyces yeast is determined by factors of genetic and epigenetic (prion) nature. The work represents results of further analysis of strains containing non-chromosomal determinant [ISP+], described earlier. This determinant is involved in the control of translation fidelity and some of its properties indicate that it is a prion. [ISP+] manifests phenotypically as antisuppressor of two sup35 mutations and can be cured by guanidine hydrochloride (GuHCl). Here we have shown that sup35 mutants containing [ISP+] contain also additional sup45 mutations. These mutations cause amino acid replacements in different regions of eRF1 translation termination factor, encoded by SUP45 gene. Strains bearing sup35-25 mutation contain sup45 mutation, which causes amino acid replacement at position 400 of eRF1; strains bearing sup35-10 contain mutation causing replacement, which alters eRF1 at position 75. Thus, antisuppressor phenotype of [ISP+] strains depends on interaction of sup35 and sup45 mutations, as well as on the GuHCl-curable epigenetic determinant.
Aksenova
A Iu
AIu
Volkov
K V
KV
Rovinskiĭ
N S
NS
Svitin
A V
AV
Mironova
L N
LN
D015825:Chromosomes, Fungal; D044127:Epigenesis, Genetic; D019791:Guanidine / Q000494:pharmacology; D009154:Mutation; D010454:Peptide Termination Factors / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D011328:Prions / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
D010454:Peptide Termination Factors; D011328:Prions; C068068:SUP35 protein, S cerevisiae; C080775:SUP45 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D019791:Guanidine