title: Reconsidering movement of eukaryotic mRNAs between polysomes and P bodies.
abstract: Cell survival in changing environments requires appropriate regulation of gene expression, including posttranscriptional regulatory mechanisms. From reporter gene studies in glucose-starved yeast, it was proposed that translationally silenced eukaryotic mRNAs accumulate in P bodies and can return to active translation. We present evidence contradicting the notion that reversible storage of nontranslating mRNAs is a widespread and general phenomenon. First, genome-wide measurements of mRNA abundance, translation, and ribosome occupancy after glucose withdrawal show that most mRNAs are depleted from the cell coincident with their depletion from polysomes. Second, only a limited subpopulation of translationally repressed transcripts, comprising fewer than 400 genes, can be reactivated for translation upon glucose readdition in the absence of new transcription. This highly selective posttranscriptional regulation could be a mechanism for cells to minimize the energetic costs of reversing gene-regulatory decisions in rapidly changing environments by transiently preserving a pool of transcripts whose translation is rate-limiting for growth.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Arribere
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Doudna
authors.forename: Wendy V
authors.initials: WV
authors.lastname: Gilbert
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D011061:Poly A / Q000235:genetics / Q000378:metabolism; D039102:Poly(A)-Binding Proteins / Q000378:metabolism; D011132:Polyribosomes / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D039102:Poly(A)-Binding Proteins; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C450100:pab1 protein, S cerevisiae; D011061:Poly A; D005947:Glucose