Initiation Pausing of 80S Ribosome on mRNA Is Governed by 5'UTR and Responsive to mTORC1 Signaling (RNA-Seq)
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Shu-Bing Qian
PROVIDER: E-GEOD-25626 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:This SuperSeries is composed of the following subset Series: GSE25331: Initiation pausing of mRNA translation controlled by mTORC1 signaling (microarray) GSE25626: Initiation pausing of mRNA translation controlled by mTORC1 signaling (RNA-Seq) Refer to individual Series
2011-11-12 | E-GEOD-25627 | biostudies-arrayexpress
Project description:Recent studies have revealed that the mRNA translation is punctuated by ribosomal pauses through the body of transcripts. However, little is known about its physiological significance and regulatory aspects. Here we present a multi-dimensional ribosome profiling approach to quantify the dynamics of initiation and elongation of 80S ribosomes across the entire transcriptome in mammalian cells. We show that a subset of transcripts have a significant pausing of 80S ribosome around the start codon, creating a major barrier to the commitment of translation elongation. Intriguingly, genes encoding ribosome proteins themselves exhibit an exceptionally high initiation pausing on their transcripts. Our studies also reveal that the initiation pausing is dependent on the 5’ untranslated region (5’ UTR) of mRNAs and subject to the regulation of mammalian target of rapamycin complex 1 (mTORC1). Thus, the initiation pausing of 80S ribosome represents a novel regulatory step in translational control mediated by nutrient signaling pathway. Untreated TSC2 WT MEFs, TSC2 KO MEFs and TSC2 WT MEFs, TSC2 KO MEFs treated with 20nM rapamycin for 30 minutes or 3hours were harvested for ribosme profiling. The fraction samples were pooled into three groups based on velocity sedimentation: single ribosome fraction (Small group), fractions with 2 ~ 4 ribosomes (Medium group), and the one with ≥5 ribosomes (Large group). RNA were extracted from the whole cell lysis and each fraction group.
2011-11-12 | E-GEOD-25331 | biostudies-arrayexpress
Project description:Pig induced pluripotent stem cells (piPSCs) have significant biomedical and agricultural applications. We analyzed the transcriptional profiles of pig iPSC lines derived from different labs using Affymetrix GeneChip Pig Genome Array and published microarray datasets of mouse and human iPSCs. Our results demonstrated that cell surface proteins of EpCAM (epithelial cells adhesion molecule) were significantly upregulated in complete fully reprogrammed pig iPSCs, but not in partially reprogrammed cells. EpCAM could be markers for evaluating pig cell reprogramming and selecting successful reprogramming. We analyzed gene expression levels of the six key developmental signaling pathways, including JAK-STAT, NOTCH, TGF-M-NM-2b, WNT, MAPK and VEGF in pig, human and mouse iPSCs, respectively. The result demonstrates that the core transcriptional network to maintain pluripotency and self-renewal in pig are different from mouse and human. Pig iPSCs lacked expression of specific naM-CM-/ve state markers (e.g. Klf family genes Klf2/4/5, Tbx3), but expressed unregulated primed state markers (e.g. Otx2 and Fabp7). Dlk1-Dio3 domain was silenced in piPSCs as previously seen in mouse and human iPSCs, which explantsexplains rare success of generation of pig chimeric and cloned offspring. Our analyses decipher pig somatic cells undergoes reprogramming into a primed state and maintains its regulatory network with define feature with human iPSCs and mouse EpiSCs. We compare gene expression profiles of pig iPS cell lines generated by our lab with cell lines derived from other labs with different levels of marker expression and plasticity.
2013-11-21 | E-GEOD-48434 | biostudies-arrayexpress
Project description:Using an RNA interference-based genetic screen in mouse F9 cells we identify the transcriptional corepressor CTBP2 as a coactivator critically required for retinoic acid (RA)-induced transcription. Here we perfom a whole genome transcriptome analysis in F9 cells expressing shRNA for Ctbp2 and Rxr in the absence or presence of retinoic acid (RA). A total of 2,754 genes were found to be upregulated (>2 fold) and 1518 genes were downregulated (>2 fold) in response to RA treatment in the control cells. We find that around 52% and 55% of upregulated genes are dependent on Ctbp2 and Rxr for activation respectively suggesting that Ctbp2 is a coactivator of RA signaling. Whole genome RNA-sequencing in F9 cells expressing shGFP or shCtbp2 or shRxr
2013-06-21 | E-GEOD-47708 | biostudies-arrayexpress
Project description:Here, we focused on the intermediate stages of SCR by comparing the somatic cell line induced by OCT4, SOX2, and KLF4 (OSK) for 7 days with mouse embryonic fibroblasts (MEFs), iPSCs, and embryonic stem cells (ESCs). Transcriptional profiles of these four cell lines were analyzed by microarray, and we found that the transition process from day 7 to the formation of iPSCs is crucial for SCR and that the reverse expression patterns can provide more candidate markers to distinguish ESCs and somatic cells iPSC. Data confirmed that the viral infection results in defense innate immunity, DNA damage, and apoptosis in MEFs, which slows down cell proliferation and immortalization to inhibit SCR. Although SCR is initiated by OSK, the p53 signaling pathway can affect the transcriptional regulatory networks through cell cycle and genomic instability as a powerful core node. MEFs were derived from embryonic day 13.5 C57BL6 mice embryos. Cell line day7 is MEF induced by OCT4, SOX2, and KLF4 (OSK) for 7 days with mouse embryonic fibroblasts (MEFs), iPSCs, and embryonic stem cells (ESCs).
2012-10-01 | E-GEOD-37397 | biostudies-arrayexpress
Project description:Ribosome profiling suggests that ribosomes occupy many regions of the transcriptome thought to be non-coding, including 5' UTRs and lncRNAs. Apparent ribosome footprints outside of protein-coding regions raise the possibility of artifacts unrelated to translation, particularly when they occupy multiple, overlapping open reading frames (ORFs). Here we show hallmarks of translation in these footprints: co-purification with the large ribosomal subunit, response to drugs targeting elongation, trinucleotide periodicity, and initiation at early AUGs. We develop a metric for distinguishing between 80S footprints and nonribosomal sources using footprint size distributions, which validates the vast majority of footprints outside of coding regions. We present evidence for polypeptide production beyond annotated genes, including induction of immune responses following human cytomegalovirus (HCMV) infection. Translation is pervasive on cytosolic transcripts outside of conserved reading frames, and direct detection of this expanded universe of translated products enables efforts to understand how cells manage and exploit its consequences. Ribosome profiling to verify that true ribosome footprints shift in response to different elongation inhibitors (CHX vs Emetine) and co-purify with an affinity-tagged large ribosomal subunit (bound vs input)
2014-08-21 | E-GEOD-60095 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2013-06-05 | E-GEOD-40962 | biostudies-arrayexpress
Project description:The interaction of Cryptococcus neoformans with phagocytic cells of the innate immune system is a key step in disseminated disease leading to meningoencephalitis in immunocompromised individuals. Transcriptional profiling of cryptococcal cells harvested from cell culture medium or from macrophages found differential expression of metabolic and other functions during fungal adaptation to the intracellular environment by SAGE analysis. We focused on the ACL1 gene for ATP-citrate lyase, which converts citrate to acetyl-CoA, because this gene showed elevated transcript levels in macrophages and because of the importance of acetyl-CoA as a central metabolite. Mutants lacking ACL1 showed delayed growth on medium containing glucose, reduced cellular levels of acetyl-CoA, defective production of virulence factors, increased susceptibility to the antifungal drug fluconazole and decreased survival within macrophages. Importantly, acl1 mutants were unabl e to cause disease in a murine inhalation model, a phenotype that was more extreme than other mutants with defects in acetyl-CoA production (e.g., an acetyl-CoA synthetase mutant). Loss of virulence is likely due to perturbation of critical physiological interconnections between virulence factor expression and metabolism in C. neoformans. Phylogenetic analysis and structural modeling of cryptococcal Acl1 identified three indels unique to fungal protein sequences; these differences may provide opportunities for the development of pathogen-specific inhibitors. SAGE analysis of C. neoformans cells isolated from macrophages The murine macrophage-like cell line J774A.1 was maintained at 37M-BM-0C in 10% CO2 in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% heat-inactivated fetal calf serum (FBS), 1% nonessential amino acids, 100 M-BM-5g mL-1 penicillin-streptomycin, and 4 mM L-glutamine (Invitrogen). Cryptococcus cells were opsonized with monoclonal antibody 18B7 against capsule (1 M-BM-5g mL-1), and macrophages were treated with recombinant mouse gamma interferon (IFN-gamma) (50 U mL-1) and lipopolysaccharide (LPS) (0.3 M-BM-5g mL-1) prior to co-incubation at a multiplicity of infection (MOI) of 1:1. Macrophages were inoculated with H99 cells and washed after 1 h of inoculation to remove unattached, extracellular fungal cells. After 6 h of incubation, sterile, ice-cold distilled H2O was applied to each well to lyse the macrophages, and the fungal cells (4 x 107) were harvested by centrifugation. H99 control cells were prepared by growth under the same condition but without macrophages, and 108 cell s were harvested. SAGE library construction, sequencing and analysis SAGE library construction, sequencing and analysis were as previously described (Hu et al., 2007; Hu et al., 2008; Steen et al., 2002; Steen et al., 2003). Briefly, RNA was isolated from lyophilized cells by vortexing with glass beads (3.0 mm, acid-washed and RNase-free) for 15 min in 15 mL of TRIZOL extraction buffer (Invitrogen, Carlsbad, CA, USA). The mixture was incubated for 15 min at room temperature and total RNA was isolated according to the manufacturer's instructions. Total RNA was used directly for SAGE library construction as described by Velculescu et al. (1995) using the I-Long SAGE kit (Invitrogen). The tagging enzyme for cDNA digestion was NlaIII and 29 PCR cycles were performed to amplify the ditags during library construction. Colonies were screened by PCR (M13F and M13R primers) to assess the average clone insert size and the percentage of recombinants. Clones from the libraries were sequenced by BigDye primer cycle sequencing on an ABI PRISM 3700 DNA analy zer. Sequence chromatograms were processed using PHRED (Ewing et al., 1998), and vector sequence was detected using Cross_match (Gordon et al., 1998). Fourteen-base-pair tags were extracted from the vector-clipped sequence, and an overall quality score for each tag was derived based on the cumulative PHRED score. Duplicate ditags and linker sequences were removed as described previously (Steen et al., 2002). Only tags with a predicted accuracy of 99% were used, and statistical differences between tag abundance in different libraries were determined as described (Audic and Claverie, 1997). The libraries yielded 23,904 tags from cells grown in media without macrophages for 6hr and 38,5444 tags from cells grown in media with macrophages for 6hr. An overview of the abundance classes for both SAGE libraries is presented in Table S1 in the supplementary material, with both the number of different tag sequences and the total number of tags present in each class for the cells from th e 6h infection and the control. All libraries were normalized to 23,904 to allow direct comparisons, and the tags that appeared less than once in any given library were removed. The EST database available for strain H99 at the University of Oklahoma's Advanced Center for Genome Technology http://www.genome.ou.edu/cneo.html) was used for the preliminary assignment of tags to genes. When an EST sequence could not be identified for a particular tag, the genomic sequence for H99 at the Duke University Center for Genome Technology (http://cgt.genetics.duke.edu/data/index.html) and the Broad Institute (http://cneo.genetics.duke.edu/) was used to identify contigs with unambiguous tag assignments. Note that a limitation of the SAGE approach is that some transcripts are not detected because of low abundance and/or the absence of an NlaIII site for transcript processing. The control (fungal cells alone) and cryptococcal-macrophage interaction SAGE datasets were deposited to the NCBI under accession number GSM986206 and GSM986207 respectively.
2013-08-15 | E-GEOD-41066 | biostudies-arrayexpress
Project description:Human mesenchymal stem cells (hMSC) are being successfully evaluated for the treatment of a wide range of pathological conditions, including graft versus host disease (GVHD), bone and cartilage degeneration, complex fistula and myocardial infarction. Many of these clinical trials use hMSC, which have been previously expanded in vitro for 8-12 weeks under pro-oxidative M-bM-^@M-^\standardM-bM-^@M-^] cell culture conditions. These conditions could have negative effects over genetic stability and promote mutations and chromosomal abnormalities. Our FISH (Fluorescence in situ hybridization) analysis shows that aneuploidy is not unusual phenomenon in conventional cultures of hMSC and that it progressively increases with the passages. We further demonstrate that senescence is linked to transcriptional deregulation of a set of genes that have been previously implicated in cancer and ploidy control. Overexpression of hTERT reversed the deregulation of these ploidy control genes and maintained the basal levels of ploidy even during long-term culture, through its canonical function of telomere elongation and by reducing the levels of oxidative stress. We propose that the high levels of aneuploidy and deregulation of these genes would be relevant biomarkers of senescence in standard cultures of hMSC. We compared the RNA expression profiles of adipose tissue-derived human mesenchymal stem cells cultured in standard cell culture condition at passages 2 with the same primary cell lines cultured by 21 passages. A total of four independent samples were used.
2012-10-30 | E-GEOD-39250 | biostudies-arrayexpress
Project description:Mitochondrial oxidative function is tightly controlled to maintain energy homeostasis in response to nutrient and hormonal signals. An important cellular component in the energy sensing response is the target of rapamycin (TOR) kinase pathway; however whether and how mTOR controls mitochondrial oxidative activity is unknown. Here, we show that mTOR kinase activity stimulates mitochondrial gene expression and oxidative function. In skeletal muscle cells and TSC2-/- MEFs, the mTOR inhibitor rapamycin largely decreased gene expression of mitochondrial transcriptional regulators such as PGC-1alpha and the transcription factors ERRalpha and NRFs. As a consequence, mitochondrial gene expression and oxygen consumption were reduced upon mTOR inhibition. Using computational genomics, we identified the transcription factor YY1 as a common target of mTOR and PGC-1alpha that controls mitochondrial gene expression. Inhibition of mTOR resulted in a failure of YY1 to interact and be coactivated by PGC-1alpha. Notably, knock-down of YY1 in skeletal muscle cells caused a significant decrease in mRNAs of mitochondrial regulators and mitochondrial genes that resulted in a decrease in respiration. Moreover, YY1 was required for rapamycin-dependent repression of mitochondrial genes. Thus, we have identified a novel mechanism in which a nutrient sensor (mTOR) balances energy metabolism via transcriptional control of mitochondrial oxidative function. These results have important implications for our understanding of how these pathways might be altered in metabolic diseases and cancer. Experiment Overall Design: Using Affymetrix MOE430 v2 gene chips, biological triplicates of each condition were analyzed: vehicle-treated, rapamycin-treated, gfp-infected, and pgc-1alpha-infected resulting in a total of 12 samples. Experiment Overall Design: Data were analyzed by RMA (with default settings) in BioConductor 1.2 -- one batch for the Rapamycin vs. Vehicle, and another batch for the PGC vs GFP.
2008-06-13 | E-GEOD-5332 | biostudies-arrayexpress