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Translation-complex profiling of fission yeast cells reveals dynamic rearrangements of scanning ribosomal subunits upon nutritional stress.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Duncan, Caia Deborah Suzanne 

Abstract

Control of mRNA translation is key for stress responses. Translation initiation is usually rate-limiting and, in eukaryotes, involves mRNA scanning by the small ribosomal subunit. Despite its importance, many aspects of translation in vivo have not been explored fully, especially at the transcriptome-wide level. A recent method termed translation-complex profiling (TCP-seq) allows transcriptome-wide views of scanning ribosomal subunits. We applied TCP-seq to nutritional stress in the fission yeast Schizosaccharomyces pombe. At initiation sites, we observed multiple complexes resembling those of mammals, and consistent with queuing of scanning subunits. In 5' UTRs, small subunit accumulations were common and may reflect impediments to scanning. A key mediator of stress responses in S. pombe is the Fil1 transcription factor, which is regulated translationally by a poorly-understood mechanism involving upstream Open Reading Frames (uORFs). TCP-seq data of fil1 shows that stress allows scanning subunits to by-pass specific uORFs and reach the fil1 coding sequence. The integration of these observations with reporter assays revealed that fil1 translational control is mediated by a combination of scanning reinitiation-repressive and permissive uORFs, and establishes fil1 as a model for uORF-mediated translational control. Altogether, our transcriptome-wide study reveals general and gene-specific features of translation in a model eukaryote.

Description

Keywords

Animals, Schizosaccharomyces, Transcription Factors, Ribosomes, 5' Untranslated Regions, Ribosome Subunits, Open Reading Frames, Protein Biosynthesis, Mammals

Journal Title

Nucleic Acids Res

Conference Name

Journal ISSN

0305-1048
1362-4962

Volume Title

Publisher

Oxford University Press (OUP)
Sponsorship
Biotechnology and Biological Sciences Research Council (BB/S015833/1)