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GSE22809
Saccharomyces cerevisiae
12 Downloadable Samples
Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
To investigate the role of DNA topoisomerases in transcription, we have studied global gene expression in Saccharomyces cerevisiae cells deficient for topoisomerases I and II and performed single-gene analyses to support our findings. The genome-wide studies show a general transcriptional down-regulation upon lack of the enzymes, which correlates with gene activity but not gene length. Furthermore, our data reveal a distinct subclass of genes with a strong requirement for topoisomerases. These genes are characterized by high transcriptional plasticity, chromatin regulation, TATA box presence, and enrichment of a nucleosome at a critical position in the promoter region, in line with a repressible/inducible mode of regulation. Single-gene studies with a range of genes belonging to this group demonstrate that topoisomerases play an important role during activation of these genes. Subsequent in-depth analysis of the inducible PHO5 gene reveals that topoisomerases are essential for binding of the Pho4p transcription factor to the PHO5 promoter, which is required for promoter nucleosome removal during activation. In contrast, topoisomerases are dispensable for constitutive transcription initiation and elongation of PHO5, as well as the nuclear entrance of Pho4p. Finally, we provide evidence that topoisomerases are required to maintain the PHO5 promoter in a superhelical state, which is competent for proper activation. In conclusion, our results reveal a hitherto unknown function of topoisomerases during transcriptional activation of genes with a repressible/inducible mode of regulation
Publication Title
DNA Topoisomerases maintain promoters in a state competent for transcriptional activation in Saccharomyces cerevisiae.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Hsp90 is critical for regulation of the phenotype and functional activity of human T lymphocytes and natural killer (NK) cells.
Publication Title
Heat shock protein 90 is critical for regulation of phenotype and functional activity of human T lymphocytes and NK cells.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Saccharomyces cerevisiae
- 47 Downloadable Samples
Illumina HiSeq 2000
Description
During meiosis in yeast, global splicing efficiency increases. The mechanism for this is relief of competition for the splicing machinery by repression of intron-containing ribosomal protein genes (RPGs). Repression of RPGs with rapamycin also increases splicing efficiency in vegetative cells. Reducing levels of an RPG-dedicated transcription factor globally improves splicing and suppresses the temperature-sensitive growth defect of a spliceosome mutation. These results indicate that the spliceosome is limiting and pre-mRNAs compete with each other. Under these conditions, splicing efficiency of a given pre-mRNA therefore depends on both its concentration and affinity for the limiting splicing factor(s) as well as those of the competing pre-mRNAs. We propose that trans-competition control of splicing helps repress meiotic gene expression in vegetative cells, and promotes efficient meiosis. Competition between RNAs for a limiting factor may be a general condition important for function of a variety of post-transcriptional control mechanisms. Overall design: Splicing and gene expression profiles of 1) wild type yeast cells treated with rapamycin (2 biological replicates) relative to untreated cells and 2) prp4-1 pGAL-IFH1 (down-regulated expression of IFH1 transcription factor(specific for ribosomal protein genes)) relative to prp4-1 yeast.
Publication Title
Competition between pre-mRNAs for the splicing machinery drives global regulation of splicing.
Sample Metadata Fields
Treatment, Subject
View Samples- Homo sapiens
- 25 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Room temperature whole blood mRNA stabilization procedures, such as the PAX gene system, are critical for the application of transcriptional analysis to population-based clinical studies. Global transcriptome analysis of whole blood RNA using microarrays has proven to be challenging due to the high abundance of globin transcripts that constitute 70% of whole blood mRNA in the blood. This is a particular problem in patients with sickle-cell disease, secondary to the high abundance of globin-expressing nucleated red blood cells and reticulocytes in the circulation . In order to more accurately measure the steady state whole blood transcriptome in sickle-cell patients, we evaluated the efficacy of reducing globin transcripts in PAXgene stabilized RNA samples for genome-wide transcriptome analyses using oligonucleotide arrays. We demonstrate here by both microarrays and Q-PCR that the globin mRNA depletion method resulted in 55-65 fold reduction in globin transcripts in whole blood collected from healthy volunteers and sickle-cell disease patients. This led to an improvement in microarray data quality with increased detection rate of expressed genes and improved overlap with the expression signatures of isolated peripheral blood mononuclear (PBMC) preparations. The differentially modulated genes from the globin depleted samples had a higher correlation coefficient to the 112 genes identified to be significantly altered in our previous study on sickle-cell disease using PBMC preparations. Additionally, the analysis of differences between the whole blood transcriptome and PBMC transcriptome reveals important erythrocyte genes that participate in sickle-cell pathogenesis and compensation. The combination of globin mRNA reduction after whole-blood RNA stabilization represents a robust clinical research methodology for the discovery of biomarkers for hematologic diseases and in multicenter clinical trials investigating a wide range of nonhematologic disorders where fractionation of cell types is impracticable.
Publication Title
Characterization of whole blood gene expression profiles as a sequel to globin mRNA reduction in patients with sickle cell disease.
Sample Metadata Fields
Specimen part, Subject
View Samples- Rattus norvegicus
- 60 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Pyrethroids are neurotoxicants that disrupt nervous system function by interacting with a variety of membrane bound ion channels on neuronal plasma membranes. This study is designed to investigate the transcriptional events downstream of pyrethroid-induced disruption of nervous system excitability. Adult, male Long-Evans rats were orally dosed in vivo with a single dose of either permethrin (1, 10, or 100 mg/kg) or deltamethrin (0.3, 1, 3 mg/kg) at levels that produce only modest behaviroal effects in the whole animal (Wolansky et al. 2006). Transcriptional profiles were obtained from frontal cerebrocortical tissue 6 hours after acute exposure. The primary goals were 1) to identify dose-responsive biomarkers of effect for pyrethroids and 2) identify sensitive intracellular signaling or metabolic pathways sensitive to pyrethroid compounds.
Publication Title
Transcriptional response of rat frontal cortex following acute in vivo exposure to the pyrethroid insecticides permethrin and deltamethrin.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 49 Downloadable Samples
- NextSeq 500
Description
Reprogram-Seq leverages organ-specific cell atlas data with single-cell perturbation and computational analysis to predict, evaluate, and optimize TF combinations that reprogram a cell type of interest. Overall design: Focusing on the cardiac system, we performed Reprogram-Seq on P0 mouse heart cells to generate a reference transcriptomic map. Based on the reference map, we selected TF candidates and tests 1000s of TF cocktails for direct lineage conversion by scRNA-Seq.
Publication Title
Rational Reprogramming of Cellular States by Combinatorial Perturbation.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 36 Downloadable Samples
- NextSeq 500
Description
Reprogram-Seq leverages organ-specific cell atlas data with single-cell perturbation and computational analysis to predict, evaluate, and optimize TF combinations that reprogram a cell type of interest. Overall design: Focusing on the cardiac system, we performed Reprogram-Seq on P0 mouse heart cells to generate a reference transcriptomic map. Based on the reference map, we selected TF candidates and tests 1000s of TF cocktails for direct lineage conversion by scRNA-Seq.
Publication Title
Rational Reprogramming of Cellular States by Combinatorial Perturbation.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 7 Downloadable Samples
- NextSeq 500
Description
Reprogram-Seq leverages organ-specific cell atlas data with single-cell perturbation and computational analysis to predict, evaluate, and optimize TF combinations that reprogram a cell type of interest. Overall design: Focusing on the cardiac system, we performed Reprogram-Seq on P0 mouse heart cells to generate a reference transcriptomic map. Based on the reference map, we selected TF candidates and tests 1000s of TF cocktails for direct lineage conversion by scRNA-Seq. This series includes uninfected, non-transformed MEFs.
Publication Title
Rational Reprogramming of Cellular States by Combinatorial Perturbation.
Sample Metadata Fields
Specimen part, Subject
View Samples- Homo sapiens
- 3 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
To study effects of IFNalpha treatment on monocyte-derived macrophages which may influence susceptibility or resistance to HIV.
Publication Title
Interleukin-27 inhibition of HIV-1 involves an intermediate induction of type I interferon.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 1 Downloadable Sample
- NextSeq 500
Description
Reprogram-Seq leverages organ-specific cell atlas data with single-cell perturbation and computational analysis to predict, evaluate, and optimize TF combinations that reprogram a cell type of interest. Overall design: Focusing on the cardiac system, we performed Reprogram-Seq on P0 mouse heart cells to generate a reference transcriptomic map. Based on the reference map, we selected TF candidates and tests 1000s of TF cocktails for direct lineage conversion by scRNA-Seq.
Publication Title
Rational Reprogramming of Cellular States by Combinatorial Perturbation.
Sample Metadata Fields
Specimen part, Subject
View Samples