title: Puf3p induces translational repression of genes linked to oxidative stress.
abstract: In response to stress, the translation of many mRNAs in yeast can change in a fashion discordant with the general repression of translation. Here, we use machine learning to mine the properties of these mRNAs to determine specific translation control signals. We find a strong association between transcripts acutely translationally repressed under oxidative stress and those associated with the RNA-binding protein Puf3p, a known regulator of cellular mRNAs encoding proteins targeted to mitochondria. Under oxidative stress, a PUF3 deleted strain exhibits more robust growth than wild-type cells and the shift in translation from polysomes to monosomes is attenuated, suggesting puf3Δ cells perceive less stress. In agreement, the ratio of reduced:oxidized glutathione, a major antioxidant and indicator of cellular redox state, is increased in unstressed puf3Δ cells but remains lower under stress. In untreated conditions, Puf3p migrates with polysomes rather than ribosome-free fractions, but this is lost under stress. Finally, reverse transcriptase-polymerase chain reaction (RT-PCR) of Puf3p targets following affinity purification shows Puf3p-mRNA associations are maintained or increased under oxidative stress. Collectively, these results point to Puf3p acting as a translational repressor in a manner exceeding the global translational response, possibly by temporarily limiting synthesis of new mitochondrial proteins as cells adapt to the stress.
authors.affiliation: The Faculty of Life Sciences, The Michael Smith Building, The University of Manchester, Oxford Road, Manchester M13 9PT, UK and Manchester Institute of Biotechnology (MIB), Faculty of Life Sciences, The University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
authors.forename: William
authors.initials: W
authors.lastname: Rowe
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kershaw
authors.forename: Lydia M
authors.initials: LM
authors.lastname: Castelli
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Costello
authors.forename: Mark P
authors.initials: MP
authors.lastname: Ashe
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Grant
authors.forename: Paul F G
authors.initials: PF
authors.lastname: Sims
authors.forename: Graham D
authors.initials: GD
authors.lastname: Pavitt
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Hubbard
mesh_terms: D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D005978:Glutathione / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000235:genetics*; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C510155:PUF3 protein, S cerevisiae; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D005978:Glutathione