To gain a deep understanding of mRNA turnover dynamics in mammalian cells, we pulse labeled newly synthesized RNA in 3t3 cells for 2 h with 4sU. RNA samples were fractionated into the newly synthesized and pre-existing fractions. Both fractions and the total RNA sample were analyzed by mRNA sequencing. We estimated mRNA half-lives based on the ratios of newly synthesized RNA/total RNA ratio and the preexisting RNA/total RNA.
Global quantification of mammalian gene expression control.
No sample metadata fields
View SamplesAnalysis of genes regulated by Maf and donwstream of ErbB2 in P8 Schwann cells
Maf links Neuregulin1 signaling to cholesterol synthesis in myelinating Schwann cells.
Specimen part
View SamplesPI3K signaling and FOXO transcription factors play opposing roles at several B cell developmental stages. We show here abundant nuclear FOXO1 expression in the proliferative compartment of the germinal center (GC), its dark zone (DZ), and PI3K activity, downregulating FOXO1, in the GC light zone (LZ), where cells are selected for further differentiation. However, here FOXO1 is expressed in c-Myc+ cells destined for DZ reentry. Upon FOXO1 ablation by genetic means or induction of PI3K activity GCs become devoid of their DZ, due at least partly to the downregulation of the chemokine receptor CXCR4. While this is known to prevent proper cyclic selection of cells expressing high-affinity antibodies, the initiation of immunoglobulin switching is essentially dependent on FOXO1 activity.
PI3 Kinase and FOXO1 Transcription Factor Activity Differentially Control B Cells in the Germinal Center Light and Dark Zones.
Specimen part
View SamplesThe cellular response to genotoxic stress is mediated by a well-characterized network of DNA surveillance pathways. The contribution of posttranscriptional gene regulatory networks to the DNA damage response (DDR) has not been extensively studied. Here, we systematically identified RNA-binding proteins differentially interacting with polyadenylated transcripts upon exposure of human breast carcinoma cells to ionizing irradiation (IR). Interestingly, more than 260 proteins including many nucleolar proteins showed increased binding to poly(A) RNA in IR-exposed cells. The functional analysis of DDX54, a candidate genotoxic stress responsive RNA helicase, revealed that this protein is an immediate-to-early DDR regulator required for the splicing efficacy of its target IR-induced pre-mRNAs. Upon IR exposure, DDX54 acts by increased interaction with a well defined class of pre-mRNAs which harbor introns with weak acceptor splice sites, as well as by protein-protein contacts within components of U2 snRNP and spliceosomal B complex, resulting in lower intron retention and higher processing rates of its target transcripts. Since DDX54 promotes survival after exposure to IR its expression and/or mutation rate may impact DDR-related pathologies. Our work indicates the relevance of many uncharacterized RBPs potentially involved in the DDR. Overall design: Gene expression profiling of MCF-7 cells upon DDX54 knockdown exposed to ionizing radiation
DDX54 regulates transcriptome dynamics during DNA damage response.
Specimen part, Cell line, Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Orchestrated intron retention regulates normal granulocyte differentiation.
Specimen part
View SamplesUsing mRNA-seq, we determined intron retaining genes that were differentially regulated in FACS purified cells at three progressive stages of mouse granulopoiesis; CD34+Kit+Gr-1low promyelocytes, CD34-Kit-Gr-1mid myelocytes and CD34-Kit-Gr-1high granulocytes. We found that IR affects 86 genes, including those specific to granulocyte (Lyz2 and MMP8) and nuclear architecture (Lmnb1 and Lbr). IR was associated with the decrease in protein levels measured by mass spectrometry (P=0.0015, binomial test). Inhibition of NMD in granulocytes resulted in marked accumulation of 39/86 intron retaining mRNAs (P<0.05, RUV procedure with Holm-Bonferroni correction), indicating that IR triggers NMD to downregulate mRNA and protein expression.
Orchestrated intron retention regulates normal granulocyte differentiation.
Specimen part
View SamplesProtein-RNA interactions are fundamental to core biological processes, such as mRNA splicing, localization, degradation and translation. We developed a photoreactive nucleotide-enhanced UV crosslinking and oligo(dT) purification approach to identify the mRNA-bound proteome using quantitative proteomics and to display the protein occupancy on mRNA transcripts by next-generation sequencing. Application to a human embryonic kidney cell line identified close to 800 proteins. Close to one third of these proteins, were neither previously annotated nor could be functionally predicted to bind RNA. Protein occupancy profiling provides a transcriptome-wide catalog of potential cis-regulatory regions on mammalian mRNAs and showed that large stretches in 3'' UTRs can be contacted by the mRNA-bound proteome, with numerous putative binding sites in regions harboring disease-associated nucleotide polymorphisms. Our observations indicate the presence of a large number of unexpected mRNA-binders with novel molecular functions participating in combinatorial post-transcriptional gene-expression networks. Overall design: We generated protein occupancy cDNA libraries for two biological replicates. Briefly, we crosslinked 4SU-labeled cells and purified protein-mRNA complexes using oligo(dT)-beads. The precipitate was treated with RNAse I to reduce the protein-crosslinked RNA fragments to a length of about 30-60 nt. To remove non-crosslinked RNA, protein-RNA complexes were precipitated with ammonium sulfate and blotted onto nitrocellulose. The RNA was recovered by Proteinase K treatment, ligated to cloning adapters, and reverse transcribed. The resulting cDNA libraries were PCR-amplified and next-generation sequenced
The mRNA-bound proteome and its global occupancy profile on protein-coding transcripts.
Treatment, Subject
View SamplesProtein-RNA interactions are fundamental to core biological processes, such as mRNA splicing, localization, degradation and translation. We developed a photoreactive nucleotide-enhanced UV crosslinking and oligo(dT) purification approach to identify the mRNA-bound proteome using quantitative proteomics and to display the protein occupancy on mRNA transcripts by next-generation sequencing. Application to a human embryonic kidney cell line identified close to 800 proteins. Close to one third of these proteins, were neither previously annotated nor could be functionally predicted to bind RNA. Protein occupancy profiling provides a transcriptome-wide catalog of potential cis-regulatory regions on mammalian mRNAs and showed that large stretches in 3'' UTRs can be contacted by the mRNA-bound proteome, with numerous putative binding sites in regions harboring disease-associated nucleotide polymorphisms. Our observations indicate the presence of a large number of unexpected mRNA-binders with novel molecular functions participating in combinatorial post-transcriptional gene-expression networks. Overall design: To obtain a more detailed picture of the RNA present in the pooled precipitates of four consecutive oligo(dT)-purifications, we constructed a cDNA library by random priming of 4-thiouridine (4SU)- and 6-thioguanosine (6SG)-labeled RNA derived from UV-irradiated (365 nm)and non-irradiated cells. Digital gene expression analysis of the cDNA library of non-irradiated cells, labeled with 4SU and 6SG, was performed. To monitor the incorporation of photoreactive nucleotides into mRNA, we isolated 4SU- and 6SG-labeled RNA from the oligo(dT) precipitate of non-crosslinked cells by biotinylation and streptavidin purification (Dolken et al., 2008).
The mRNA-bound proteome and its global occupancy profile on protein-coding transcripts.
Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Sarcoma Cell Line Screen of Oncology Drugs and Investigational Agents Identifies Patterns Associated with Gene and microRNA Expression.
Specimen part, Cell line
View SamplesCharacterization of 68 cell lines derived from human sarcoma and 5 normal counterpart cells, including drug sensitivity testing, gene expression profiling and microRNA expression profiling have been completed. Data and tools for searching these data will be made publicly available through the NCI Developmental Therapeutics Program. The raw data (.cel files ) are provided through the GEO website. Sarcoma represents a variety of cancers at arise from cells of mesenchymal origin and have seen limited treatment advances in the last decade. Drug sensitivity data coupled with the transcription and microRNA profiles of a cohort of sarcoma cell lines may help define novel treatment paradigms.
Sarcoma Cell Line Screen of Oncology Drugs and Investigational Agents Identifies Patterns Associated with Gene and microRNA Expression.
No sample metadata fields
View Samples