Precise 5' splice site recognition is essential for both constitutive and regulated pre-mRNA splicing. The U1 snRNP specific protein U1C is involved in this first step of spliceosome assembly and important for stabilizing early splicing complexes. We used an embryonically lethal U1C knockout mutant zebrafish, hi1371, to investigate the potential genomewide role of U1C for splicing regulation. Surprisingly, genomewide RNA-Seq analysis of mutant versus wildtype embryos revealed a large set of specific target genes that changed their alternative splicing patterns in the absence of U1C. In sum, our findings provide evidence for a new role of a general snRNP protein, U1C, as a mediator of alternative splicing regulation.
RNA-Seq analysis in mutant zebrafish reveals role of U1C protein in alternative splicing regulation.
No sample metadata fields
View SamplesThe goal of the project was to isolate single miRNA-expressing cells labelled by GFP reporter genes under the control of endogenous miRNA promoters and analyze expression levels of miRNA target genes in these cells. GFP-positive miRNA-expressing cells and GFP-negative cells from the rest of the embryos were purified at the same developmental stage to the cellular resolution using fluorescent activated cell sorting (FACS). Focus was on regulation by miR-206 and miR-133 in the developing somites and miR-124 in the developing central nervous system. Comparison of wild-type embryos and those lacking miRNAs revealed predicted
Coherent but overlapping expression of microRNAs and their targets during vertebrate development.
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View SamplesSmall RNA deep sequencing analysis was conducted on primary human fibroblasts infected with human cytomegalovirus (HCMV). HCMV-encoded miRNAs accumulated to ~20% of the total smRNA population at late stages of infection, and our analysis led to improvements in viral miRNA annotations and identification of novel HCMV miRNAs. Through crosslinking and immunoprecipitation of Argonaute-bound RNAs from infected cells, followed by high-throughput sequencing (Ago CLIP-seq), we obtained direct evidence for incorporation of all HCMV miRNAs into the endogenous host silencing machinery. Additionally, significant upregulation was observed during infection for a host miRNA cluster containing miR-96, miR-182 and miR-183. We also identified novel non-miRNA forms of virus-derived smRNAs, revealing greater complexity within the smRNA population during HCMV infection. Overall design: High-throughput profiling of smRNAs, Ago1-, and Ago2-associated miRNAs from HCMV-infected fibroblast cells. Wild-type HCMV Towne (Genbank FJ616285.1) was used for these studies.
High-resolution profiling and analysis of viral and host small RNAs during human cytomegalovirus infection.
Specimen part, Treatment, Subject
View SamplesTranscriptional cofactors communicate regulatory cues from enhancers to promoters and are central effectors of transcription activation and gene expression, which is a hallmark of all multicellular organisms. However, the extent to which different cofactors display intrinsic specificity for distinct promoters is unclear. Testing intrinsic COF – core promoter (CP) compatibilities requires the systematic assessment of transcriptional activation for many CPs in the presence or absence of a given COF in an otherwise constant standardized reporter system. We therefore combined a plasmid-based high-throughput reporter assay, Self-Transcribing Active Core Promoter-sequencing (STAP-seq), with the specific recruitment of individual COFs to create a high-throughput activator bypass-like assay. Using this assay, we tested whether 5 different individually tethered human COFs (MED15, BRD4, EP300, MLL3 and EMSY) activate transcription from a selection of 12,000 candidate sequences encompassing different types of gene core promoters, enhancers and control sequences. In addition, we used the strong transcriptional activator P65 as a positive control and GFP as a negative control. We found that different COFs preferentially activate different CPs. For instance, MED15 prefers TATA-box containing CPs, while MLL3 preferentially activates CpG island promoters. The observed compatibilities between cofactors and promoters can explain how different enhancers specifically activate distinct sets of genes or alternative promoters within the same gene, and may underlie distinct transcriptional programs in human cells. Overall design: STAP-seq upon recruitment of individual transcriptional cofactor in HCT116 cells with 5 different cofactors and 2 controls, each in biological triplicate.
Transcriptional cofactors display specificity for distinct types of core promoters.
No sample metadata fields
View SamplesThe purpose of the experiment was to generate a time course of gene expression following irradiation. The goal was then to model this data to extract hidden variables - chiefly, the activity profiles of the p53 transcription factor. Using this information the aim was to predict which transcripts changed by IR were targets of p53. Cells in log phase (1 x 106 ml-1) were ?-irradiated with 5 Gy at room temperature (RT) at a dose rate of 2.45 Gy per minute with a 137Cs ?-irradiator. Cells were harvested at 0, 2, 4, 6, 8, 10 and 12 hours, and RNA and protein were extracted (Trizol, Invitrogen). Affymetrix U133A arrays were hybridized as standard (www.affymetrix.co.uk). Array quality was determined using R and GCOS .rpt file values. The time course was replicated three times from independent cell preparations.
Ranked prediction of p53 targets using hidden variable dynamic modeling.
Specimen part, Disease, Cell line, Time
View SamplesWe describe a chemical method to label and purify 4-thiouridine (s4U) -containing RNA. We demonstrate that methanethiolsulfonate (MTS) reagents form disulfide bonds with s4U more efficiently than the commonly used HPDP-biotin, leading to higher yields and less biased enrichment. This increase in efficiency allowed us to use s4U-labeling to study global microRNA (miRNA) turnover in proliferating cultured human cells without perturbing global miRNA levels or the miRNA processing machinery. This improved chemistry will enhance methods that depend on tracking different populations of RNA such as 4-thiouridine-tagging to study tissue-specific transcription and dynamic transcriptome analysis (DTA) to study RNA turnover. Overall design: s4U metabolic labeling of RNA in 293T cells, followed by biochemical enrichment of labeled RNA with two biotinylation reagents, RNAs >200nt and miRNAs in separate experiments
Tracking Distinct RNA Populations Using Efficient and Reversible Covalent Chemistry.
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View SamplesWe used an Illumina Gene Expression Array to understand in more detail how T387 phosphorylation affects ISG induction. mRNA preparations from U6A cells expressing wild-type or T387A STAT2, treated with IFN- for 0, 4, 8, or 24 h, were analyzed.
Negative regulation of type I IFN signaling by phosphorylation of STAT2 on T387.
Specimen part, Cell line
View SamplesHydroxyapatite-coated cellulose induces a quicker and stronger inflammatory response compared to uncoated cellulose. Furthermore, the coated cellulose increases the homing at circulating bone-marrow derived progenitor cells. For this reason, Illumina microarray was used to study the early gene expression of the forming granulation tissue in the hydroxyapatite-coated sponges.
Hemoglobin expression in rat experimental granulation tissue.
Age, Specimen part, Time
View Samples35 Melanoma cell lines hybridized to Affymetrix Hu133_Plus 2 microarrays were analysed for genes differentially expressed between cell lines carrying wild-type p14ARF and those with mutant 14ARF. All of these cell lines contained wild-type p53 (so that the effects of p14ARF mutations could be analysed without contamination from p53).
Gene expression profiling in melanoma identifies novel downstream effectors of p14ARF.
No sample metadata fields
View SamplesErlotinib is a tyrosine kinase inhibitor (TKI) that is approved as a second-line monotherapy in patients with advanced non-small cell lung cancer (NSCLC). In these patients, erlotinib prolongs survival but its benefit remains modest since many tumors express wild-type EGF receptor (wtEGFR) lacking a TKI-sensitizing mutation, develop a second-site EGFR mutation, e.g., EGFR-L858R/T790M, or activate an alternate receptor tyrosine kinase, e.g., through MET amplification. To test potential drug combinations that could improve the efficacy of erlotinib, we combined erlotinib with quinacrine, which inhibits the FACT (facilitates chromatin transcription) complex that is required for nuclear factor-B (NF-B) transcriptional activity. In A549 (wtEGFR), H1975 (EGFR-L858R/T790M) and H1993 (MET amplification) NSCLC cells, the combination of erlotinib and quinacrine was highly synergistic, as quantified by Chou-Talalay combination indices. The combination inhibited colony formation, induced cell cycle arrest and apoptosis, and slowed xenograft tumor growth. Quinacrine decreased the level of active FACT subunit SSRP1 and suppressed NF-B-dependent luciferase activity. Knockdown of SSRP1 decreased cell growth and sensitized cells to erlotinib.
Quinacrine overcomes resistance to erlotinib by inhibiting FACT, NF-κB, and cell-cycle progression in non-small cell lung cancer.
Cell line, Treatment
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