Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Ribosome profiling upon glucose starvation in S. cerevisiae

ABSTRACT: A universal feature of the response to stress and nutrient limitation is transcriptional upregulation of genes encoding proteins important for survival. Interestingly, under many of these conditions overall protein synthesis levels are reduced, thereby dampening the stress response at the level of protein expression. For example, during glucose starvation in yeast, translation is rapidly and reversibly repressed, yet transcription of many stress- and glucose-repressed genes is increased. Using ribosome profiling and microscopy, we found that this transcriptionally upregulated gene set consists of two classes: (1) one producing mRNAs that are preferentially translated during glucose limitation and are diffusely localized in the cytoplasm – this class includes many heat shock protein mRNAs; and (2) another producing mRNAs that are poorly translated during glucose limitation, have high rates of translation initiation, and are concentrated in foci that co-localize with P bodies and stress granules – this class is enriched for glucose metabolism mRNAs. Remarkably, the information specifying differential localization and translation of these two classes of mRNAs is encoded in the promoter sequence – promoter responsiveness to heat shock factor (Hsf1) specifies diffuse cytoplasmic localization and preferential translation upon glucose starvation, whereas different promoter elements upstream of genes encoding poorly translated glucose metabolism mRNAs direct these mRNAs to RNA granules under glucose starvation. Thus, promoter sequences and transcription factor binding can influence not only mRNA levels, but also subcellular localization of mRNAs and the efficiency with which they are translated, enabling cells to tailor protein production to environmental conditions. Examination of mRNA translation in S. cerevisiae upon glucose starvation.

ORGANISM(S): Saccharomyces cerevisiae

SUBMITTER: Brian Zid

PROVIDER: E-GEOD-56622 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:DEAD-box RNA helicases eIF4A and Ded1 are believed to promote translation initiation by resolving mRNA secondary structures that impede ribosome attachment at the mRNA 5’ end or subsequent scanning of the 5’UTR, but whether they perform distinct functions or act redundantly in vivo is poorly understood. We compared the effects of mutations in Ded1 or eIF4A on global translational efficiencies (TEs) in yeast by ribosome footprint profiling. Despite similar reductions in bulk translation, inactivation of a cold-sensitive Ded1 mutant substantially reduced the TEs of >600 mRNAs, whereas inactivation of a temperature-sensitive eIF4A mutant yielded <40 similarly impaired mRNAs. The broader requirement for Ded1 did not reflect more pervasive secondary structures at low temperature, as inactivation of temperature-sensitive and cold-sensitive ded1 mutants gave highly correlated results. Interestingly, Ded1-dependent mRNAs exhibit greater than average 5’UTR length and propensity for secondary structure, implicating Ded1 in scanning though structured 5' UTRs. Reporter assays confirmed that cap- distal stem-loop insertions increase dependence on Ded1 but not eIF4A for efficient translation. While only a small fraction of mRNAs is strongly dependent on eIF4A, this dependence is significantly correlated with requirements for Ded1 and 5’UTR features characteristic of Ded1- dependent mRNAs. Our findings suggest that Ded1 is critically required to promote scanning through secondary structures within 5’UTRs; and while eIF4A cooperates with Ded1 in this function, it also promotes a step of initiation common to virtually all yeast mRNAs. We compared the effects of mutations in Ded1 or eIF4A on global translational efficiencies (TEs) in yeast by ribosome footprint profiling.The study includes 32 samples, comprised of 16 mRNA-Seq samples and 16 ribosome footprint profiling samples, derived from biological replicates of 3 mutant strains, ded1-cs, ded1-ts and tif1-ts, and the corresponding wild-type strains. The tif1-ts mutant and its wild-type counterpart were analyzed at 30°C and 37°C.

Project description:Oxidative stress is an important mechanism of chemical toxicity, contributing to teratogenesis as well as to cardiovascular and neurodegenerative diseases. Developing animals may be especially sensitive to chemicals causing oxidative stress. To assess the response to chemicals at different stages of development, zebrafish (Danio rerio) embryos at 1, 2, 3, 4, 5, and 6 days post-fertilization (dpf) were exposed to 0.1% dimethyl sulfoxide (DMSO), 2 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), or 10 uM tert-butylhydroquinone (tBHQ) for 6 hr. Transcript abundance was assessed by real-time qRT-PCR and microarray (Agilent 22k). By microarray, 1477 probes were significantly different among the DMSO-, tBHQ-, and TCDD-treated embryos at 4 dpf. Of these, 220 were 2-fold or greater up-regulated and 108 were 2-fold or greater down-regulated by tBHQ. For TCDD, 17 probes were 2-fold or greater up-regulated and 6 were 2-fold or greater down-regulated. Genes induced by tBHQ, included genes involved in glutathione synthesis and utilization, signal transduction, and DNA damage / stress response. Keywords: Danio rerio, TCDD, tBHQ, oxidative stress, gene expression Separate groups of 30 embryos generated from TL adults were placed in 15 ml egg water in a 10-cm glass petri and at 1, 2, 3, 4, 5, and 6-dpf were exposed for 6 hr to 0.1% dimethyl sulfoxide (DMSO), 2 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), or 10 uM tert-butylhydroquinone (tBHQ) (4 replicates per compound per time point). Embyros were frozen immediately after the 6 hr exposure and RNA isolated for microarray analysis. A Universal RNA Reference Sample was created by mixing equal amounts of total RNA from 2 replicates each from all toxicants (TCDD, tBHQ, DMSO) and timepoints (1, 2, 3, 4, 5, 6-dpf). Based on qRT-PCR results, the 4 dpf timepoint was selected for microarray analysis, in which the RNA samples (4 replicates per compound) were Cy3 labeled and co-hybridized with Cy5 labeled Universal RNA Reference Sample to generate data for analysis of variance.

Dataset Information

Ribosome profiling upon glucose starvation in S. cerevisiae

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure