Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

90 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Ribosome profiling study of dom34 and hbs1 knockout strains using short (16-nt) and long (28-nt) monosome-protected footprints and disome-protected footprints

ABSTRACT: Ribosomes that stall before completing peptide synthesis must be recycled and returned to the cytoplasmic pool. The protein Dom34 and cofactors Hbs1 and Rli1 can dissociate stalled ribosomes in vitro, but the identity of targets in the cell is unknown. Here we use ribosome profiling methodology to reveal a high- resolution molecular characterization of Dom34 function in vivo. We show that Dom34 removes stalled ribosomes from mRNAs that are truncated but, in contrast, does not generally dissociate ribosomes on coding sequences known to trigger stalling, such as polyproline. We also show that Dom34 targets arrested ribosomes near the ends of 3 ? UTRs. These ribosomes appear to gain access to the 3 ? UTR via a mechanism that does not require decoding of the mRNA. These results suggest that Dom34 carries out the important task of rescuing ribosomes found in noncoding regions. 25 samples are included in the study (2 mRNA-Seq samples and 23 ribosome footprint profiling samples). These include wild-type and dom34 or hbs1 knockout strains that were created in a variety of genetic backgrounds, treated with various agents in cell culture (e.g. diamide, 3-AT, or glucose starvation), treated differently during cell lysis (use of cycloheximide vs. other ribosome-stabilizing agents), or prepared in different ways after cell lysis (e.g. retention of short vs. long monosome-protected footprints or disome footprints).

ORGANISM(S): Saccharomyces cerevisiae

SUBMITTER: Nicholas Guydosh

PROVIDER: E-GEOD-52968 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Redefining the translational status of 80S monosomes

Project description:Fully assembled ribosomes exist in two populations: polysomes and monosomes. While the former has been studied extensively, to what extent translation occurs on monosomes and its importance for overall translational output remains controversial. Here, we used ribosome profiling to examine the translational status of 80S monosomes in Saccharomyces cerevisiae. We found that the vast majority of 80S monosomes are elongating, not initiating. Further, most mRNAs exhibit some degree of monosome occupancy, with monosomes predominating on nonsense-mediated decay (NMD) targets, upstream open reading frames (uORFs), canonical ORFs shorter than ~590 nucleotides and ORFs for which the total time required to complete elongation is substantially shorter than that required for initiation. Importantly, mRNAs encoding low-abundance regulatory proteins tend to be enriched in the monosome fraction. Our data highlight the importance of monosomes for the translation of highly regulated mRNAs.Â We examined the translational status of single 80S ribosomes using ribosome profiling, and compared these monosome footprints to both polysome ribosome footprints and general ribosome profiling. RNASeq libraries were also prepared from the overall sample input.

2016-02-11 | E-GEOD-76117 | biostudies-arrayexpress

Optimization of codon translation rates via tRNA modifications maintains proteome integrity

Project description:Proteins begin to fold as they emerge from translating ribosomes. The kinetics of ribosome transit along a given mRNA can influence nascent chain folding, but the extent to which individual codon translation rates impact proteome integrity remains unknown. Here, we show that slower decoding of discrete codons elicits widespread protein aggregation in vivo. Using ribosome profiling, we find that loss of anticodon wobble uridine (U34) modifications in a subset of tRNAs leads to ribosome pausing at their cognate codons in S. cerevisiae and C. elegans. Yeast cells lacking U34 modifications exhibit gene expression hallmarks of proteotoxic stress and accumulate aggregates of endogenous proteins with key cellular functions. Moreover, these cells are severely compromised in clearing stress-induced protein aggregates. Overexpression of hypomodified tRNAs alleviates ribosome pausing, concomitantly restoring protein homeostasis. Our findings demonstrate that modified U34 is an evolutionarily conserved accelerator of decoding and reveal an unanticipated role for tRNA anticodon modifications in maintaining proteome integrity. Ribosome profiling of wild-type and tRNA modification-deficient yeast and nematodes. Yeast samples were generated in various growth conditions (rich medium versus stress induced by treatment with diamide or rapamycin) and paired mRNA-Seq was performed on a subset of samples. Dataset contains three biological replicates for yeast samples and two biological replicates for nematode samples.

2015-06-04 | E-GEOD-67387 | biostudies-arrayexpress

Dual randomization of oligonucleotides to reduce the bias in ribosome-profiling libraries

Project description:Protein translation is at the heart of cellular metabolism and its in-depth characterization is key for many lines of research. Recently, ribosome profiling became the state-of-the-art method to quantitatively characterize translation dynamics at a transcriptome-wide level. However, the strategy of library generation affects its outcomes. Here, we present a modified ribosomeprofiling protocol starting from yeast, human cells and vertebrate brain tissue. We use a DNA linker carrying four randomized positions at its 5â and a reverse-transcription (RT) primer with three randomized positions to reduce artifacts during library preparation. The use of seven randomized nucleotides allows to efficiently detect library-generation artifacts. We find that the effect of polymerase chain reaction (PCR) artifacts is relatively small for global analyses when sufficient input material is used. However, when input material is limiting, our strategy improves the sensitivity of gene-specific analyses. Furthermore, randomized nucleotides alleviate the skewed frequency of specific sequences at the 3â end of ribosome-protected fragments (RPFs) likely resulting from ligase specificity. Finally, strategies that rely on dual ligation show a high degree of gene-coverage variation. Taken together, our approach helps to remedy two of the main problems associated with ribosome-profiling data. This will facilitate the analysis of translational dynamics and increase our understanding of the influence of RNA modifications on translation. Ribosome profiling and mRNA-seq libraries from wt yeast comparing different library preparation approaches using different combinations of randomized and non-randomized linkers and RT primers.

2016-08-01 | E-GEOD-84746 | biostudies-arrayexpress

Selective ribosome profiling reveals the co-translational chaperone action of trigger factor in vivo

Project description:As nascent polypeptides exit ribosomes, they are engaged by a series of processing, targeting and folding factors. Here we present a selective ribosome profiling strategy that enables global monitoring of when these factors engage polypeptides in the complex cellular environment. Studies of the Escherichia coli chaperone Trigger Factor (TF) reveal that, while TF can interact with many polypeptides, Î²-barrel outer membrane proteins are the most prominent substrates. Loss of TF leads to broad outer membrane defects and premature, cotranslational protein translocation. While in vitro studies suggested that TF is prebound to ribosomes waiting for polypeptides to emerge from the exit channel, we find that in vivo TF engages ribosomes only after ~100 amino acids are translated. Moreover, excess TF interferes with cotranslational removal of the N-terminal formyl methionine. Our studies support a triaging model in which proper protein biogenesis relies on the fine-tuned, sequential engagement of processing, targeting ad folding factors. Examination of translation in the Gram-negative bacterium Escherichia coli, as well as an analysis of the interactions between nascent chains and the molecular chaperone Trigger Factor.

2011-12-09 | E-GEOD-33671 | biostudies-arrayexpress

Extensive and coordinated control of allele-specific expression by both transcription and translation in Candida albicans

Project description:Though sequence differences between alleles are often limited to a few polymorphisms, these differences can cause large and widespread allelic variation at the expression level. Such allele-specific expression (ASE) has been extensively explored at the level of transcription but not translation. Here we measured ASE in the diploid yeast Candida albicans at both the transcriptional and translational levels using RNA-seq and ribosome profiling, respectively. Since C. albicans is an obligate diploid, our analysis isolates ASE arising from cis elements in a natural, non-hybrid organism, where allelic effects reflect evolutionary forces. Importantly, we find that ASE arising from translation is of a similar magnitude as transcriptional ASE, both in terms of the number of genes affected and the magnitude of the bias. We further observe coordination between ASE at the levels of transcription and translation for single genes. Specifically, reinforcing relationshipsM-bM-^@M-^Twhere transcription and translation favor the same alleleM-bM-^@M-^Tare more frequent than expected by chance, consistent with selective pressure tuning ASE at multiple regulatory steps. Finally, we parameterize alleles based on a range of properties and find that SNP location and predicted mRNA-structure stability are associated with translational ASE in cis. Since this analysis probes more than 4,000 allelic pairs spanning a broad range of variations, our data provide a genome-wide view into the relative impacts of cis elements that regulate translation. Two biological replicates of WT Candida albicans ribosome profiling and RNA-seq

2014-03-14 | E-GEOD-52236 | biostudies-arrayexpress

Clarifying the translational pausing landscape in bacteria by ribosome profiling

Project description:The rate of protein synthesis varies according to the mRNA sequence in ways that affect gene expression. Global analysis of translational pausing is now possible with ribosome profiling. Here, we revisit an earlier report that Shine-Dalgarno sequences are the major determinant of translational pausing in bacteria. Using refinements in the profiling method as well as biochemical assays, we find that SD motifs have little (if any) effect on elongation rates. We argue that earlier evidence of pausing arose from two factors. First, in previous analyses, pauses at Gly codons were difficult to distinguish from pauses at SD motifs. Second, and more importantly, the initial study preferentially isolated long ribosome-protected mRNA fragments that are enriched in SD motifs. These findings clarify the landscape of translational pausing in bacteria as observed by ribosome profiling. Ribosome profiling (three replicates) and RNAseq (two replicates) of E. coli MG1655

2016-01-13 | E-GEOD-72899 | biostudies-arrayexpress

A dynamic unfolded protein response contributes to the control of cortical neurogenesis

Project description:The cerebral cortex contains layers of neurons sequentially generated by distinct lineage-related progenitors. At the onset of corticogenesis, the first-born progenitors are apical progenitors (APs) whose asymmetric division give birth directly to neurons. Later, they switch to indirect neurogenesis by generating intermediate progenitors (IPs), which give rise to projection neurons of all cortical layers. While a direct lineage relationship between APs and IPs has been established, the molecular mechanism that controls their transition remains elusive. Our data suggest that interfering with codon translation speed triggers endoplasmic reticulum stress and the unfolded protein response (UPR), further impairing the generation of IPs and leading to microcephaly. Moreover, we demonstrate that a progressive downregulation of UPR in cortical progenitors acts as physiological signal to amplify IPs and promotes indirect neurogenesis. Thus, our findings reveal a hitherto unrecognized contribution of UPR to cell fate acquisition during mammalian brain development. Ribosome profiling and RNA-Seq of forebrains from E14.5 mouse embryos from wild type animals and mutants carrying a conditional knockout of ELP3 in cortical progenitors

2015-12-11 | E-GEOD-74683 | biostudies-arrayexpress

Global response to chemotherapy-induced apoptosis

Project description:Here we use an integrated systems-level examination of transcription, translation, and proteolysis to explore how cancer cells struggle with a chemotherapeutic drug prior to succumbing to apoptosis. As a model system we study myeloma cells exposed to the proteasome inhibitor bortezomib, a first-line clinical treatment. Despite robust transcriptional changes, unbiased quantitative proteomics detects production of only a few critical anti-apoptotic proteins against a background of general translation inhibition. Ribosome profiling further reveals potential translational regulation of stress response genes following bortezomib treatment. Once the apoptotic machinery is engaged, degradation by caspases is largely independent of changes at the transcriptional level. Moreover, previously uncharacterized non-caspase proteolytic events also participate in cellular deconstruction. As suggested by these data, we find that inhibition of the anti-apoptotic response regulator HSF1 promotes cell death by bortezomib. Thus, monitoring global cellular dynamics after chemotherapy offers in-depth insight into apoptosis and can also guide potential therapeutic combinations. We examined MM1.S myeloma cells exposed to 20 nM bortezomib across a time course with independent samples of poly(A) mRNA and ribosome footprints isolated at each of six time points (0h (untreated), 1.5h, 3h, 6h, 9h, 12h). Sequencing was performed on a Illumina HiSeq 2000 with single-end.

2013-10-17 | E-GEOD-48785 | biostudies-arrayexpress

The ribosome profiling strategy for monitoring translation in vivo by deep sequencing of ribosome-protected mRNA fragments

Project description:Recent studies highlight the importance of translational control in determining protein abundance, underscoring the value of measuring gene expression at the level of translation. We present a protocol for genome-wide, quantitative analysis of in vivo translation by deep sequencing. This ribosome profiling approach maps the exact positions of ribosomes on transcripts by nuclease footprinting. The nuclease-protected mRNA fragments are converted into a DNA library suitable for deep sequencing using a strategy that minimizes bias. The abundance of different footprint fragments in deep sequencing data reports on the amount of translation of a gene. Additionally, footprints reveal the exact regions of the transcriptome that are translated. To better define translated reading frames, we describe an adaptation that reveals the sites of translation initiation by pre-treating cells with harringtonine to immobilize initiating ribosomes. The protocol we describe requires 5 - 7 days to generate a completed ribosome profiling sequencing library. Ribosome profiling in cultured mammalian cells under three different footprinting conditions

2012-07-26 | E-GEOD-37744 | biostudies-arrayexpress

Time resolved ribosome profiling study of oxygen and glucose deprivation of rat pheochromocytoma cells

Project description:Oxygen and glucose metabolism plays a pivotal role in many (patho)physiological conditions. In particular, oxygen and glucose deprivation (OGD) occurs during ischemia and stroke, resulting in extensive tissue injury and cell death. We applied time-resolved ribosome profiling technique to assess early events at the level of gene expression in rat pheochromocytoma PC12 cells during short-term OGD. Most substantial alterations in transcripts levels and their translation were seen to occur in the first 20 minutes of OGD. The rapid adaptation of translation apparatus to OGD is global and involves altered elongation and initiation rates. We also observed salient and reproducible alterations in ribosome densities of individual mRNAs such as increased translation of particular upstream Open Reading Frames (uORFs); induced site-specific arrests of the ribosomes and synthesis of extended protein isoforms. Ribosome profiling (with mRNA-seq sequencing) was carried out at 0,20,40 and 60 minutes of OGD. Two biological replicates were used.

2015-04-10 | E-GEOD-60752 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data