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Translation termination efficiency can be regulated in Saccharomyces cerevisiae by environmental stress through a prion‐mediated mechanism
Author(s) -
Eaglestone Simon S.,
Cox Brian S.,
Tuite Mick F.
Publication year - 1999
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/18.7.1974
Subject(s) - biology , saccharomyces cerevisiae , mechanism (biology) , translation (biology) , environmental stress , genetics , computational biology , microbiology and biotechnology , yeast , gene , evolutionary biology , messenger rna , philosophy , epistemology
[PSI + ] is a protein‐based heritable phenotype of the yeast Saccharomyces cerevisiae which reflects the prion‐like behaviour of the endogenous Sup35p protein release factor. [PSI + ] strains exhibit a marked decrease in translation termination efficiency, which permits decoding of translation termination signals and, presumably, the production of abnormally extended polypeptides. We have examined whether the [PSI + ]‐ induced expression of such an altered proteome might confer some selective growth advantage over [psi − ] strains. Although otherwise isogenic [PSI + ] and [psi − ] strains show no difference in growth rates under normal laboratory conditions, we demonstrate that [PSI + ] strains do exhibit enhanced tolerance to heat and chemical stress, compared with [psi − ] strains. Moreover, we also show that the prion‐like determinant [PSI + ] is able to regulate translation termination efficiency in response to environmental stress, since growth in the presence of ethanol results in a transient increase in the efficiency of translation termination and a loss of the [PSI + ] phenotype. We present a model to describe the prion‐mediated regulation of translation termination efficiency and discuss its implications in relation to the potential physiological role of prions in S.cerevisiae and other fungi.