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GSE18128
Saccharomyces cerevisiae
22 Downloadable Samples
Affymetrix Yeast Genome S98 Array (ygs98)
Description
Despite the scientific and applied interest in anaerobic metabolism of Saccharomyces cerevisiae, not all genes whose transcription is up-regulated under anaerobic conditions have yet been linked to known transcription factors. Experiments with a reporter construct in which the promoter of the anaerobically up-regulated TIR1 gene was fused to LacZ revealed a complete loss of anaerobic up-regulation in a snf7 mutant. Anaerobic up-regulation was restored by expression of a truncated allele of RIM101 that encodes for a constitutively active Rim101p transcription factor. Analysis of LacZ expression in several deletion mutants confirmed that the effect of Snf7p on anaerobic up-regulation of TIR1 involved Rim101p and did not require a functional multi-vesicular body sorting pathway (in which Snf7p also participates). Transcriptome analysis in anaerobic chemostat cultures revealed that 26 additional genes exhibited a Snf7p/Rim101p dependent anaerobic up-regulation. Since, in its activated form, Rim101p is generally known as a transcriptional repressor, its role in anaerobic up regulation of TIR1 and other anaerobic yeast genes must involve additional factors. Further studies with deletion mutants in NRG1, NRG2 and SMP1, which were previously shown to be regulated by Rim101p, showed that these genes were not involved in the regulation of TIR1. However, the aerobic repression mechanism of TIR1 involved the general repressor Ssn6p-Tup1p complex. The physiological relevance of Snf7p/Rim101p-mediated transcriptional up-regulation of several genes in anaerobic yeast cultures was evident from reduced growth of a snf7 under anaerobic conditions.
Publication Title
Involvement of Snf7p and Rim101p in the transcriptional regulation of TIR1 and other anaerobically upregulated genes in Saccharomyces cerevisiae.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Use existing public data, cell lines and patient tumors with a personalized medicine approach to predict effective therapies for treatment of Neurofibroma tumors.
Publication Title
Molecular-guided therapy predictions reveal drug resistance phenotypes and treatment alternatives in malignant peripheral nerve sheath tumors.
Sample Metadata Fields
Specimen part
View Samples- Drosophila melanogaster
- 24 Downloadable Samples
Illumina HiSeq 2500
Description
Eukaryotic mRNAs undergo a cycle of transcription, nuclear export, and degradation. A major challenge is to obtain a global, quantitative view of these processes. Here we measured the genome-wide nucleocytoplasmic dynamics of mRNA in Drosophila cells by metabolic labeling in combination with cellular fractionation. By mathematical modeling of these data we determined rates of transcription, export and cytoplasmic decay for >5,000 genes. We characterized these kinetic rates and investigated links with mRNA features, RNA-binding proteins (RBPs) and chromatin states. We found prominent correlations between mRNA decay rate and transcript size, while nuclear export rates are linked to the size of the 3''UTR. Transcription, export and decay rates are each associated with distinct spectra of RBPs. Specific classes of genes, such as those encoding cytoplasmic ribosomal proteins, exhibit characteristic combinations of rate constants, suggesting modular control. Overall, transcription and decay rates have a major impact on transcript abundance, while nuclear export is of minor importance. Finally, correlations between rate constants suggest global coordination between the three processes. Our approach should be generally applicable to other cell systems and provides insights into the genome-wide nucleocytoplasmic kinetics of mRNA. Overall design: 24 RNA-seq experiments comprising 2 biological replicates: pre-exsiting nuclear mRNA time 0h (samples 1&13), pre-exsiting nuclear mRNA time 0.5h (samples 2&14), pre-exsiting nuclear mRNA time 1.5h (samples 3&15) , pre-exsiting nuclear mRNA time 3h (samples 4&16), pre-exsiting nuclear mRNA time 5h (samples 5&17), pre-exsiting nuclear mRNA time 7.5h (samples 6&18), pre-exsiting cytoplasmic mRNA time 0h (samples 7&19), pre-exsiting cytoplasmic mRNA time 0.5h (samples 8&20), pre-exsiting cytoplasmic mRNA time 1.5h (samples 9&21) , pre-exsiting cytoplasmic mRNA time 3h (samples 10&22), pre-exsiting cytoplasmic mRNA time 5h (samples 11&23), pre-exsiting cytoplasmic mRNA time 7.5h (samples 12&24)
Publication Title
Comprehensive analysis of nucleocytoplasmic dynamics of mRNA in Drosophila cells.
Sample Metadata Fields
Cell line, Treatment, Subject
View Samples- Mus musculus
- 4 Downloadable Samples
- Illumina HiSeq 2000
Description
In mammals, the nuclear lamina interacts with hundreds of large genomic regions, termed lamina-associated domains (LADs) that are generally in a transcriptionally repressed state. Lamins form the major structural component of the lamina and have been reported to bind DNA and chromatin. Here we systematically evaluated whether lamins are necessary for the peripheral localization of LADs in murine embryonic stem cells. Surprisingly, removal of essentially all lamins did not have any detectable effect on the genome-wide interaction pattern of chromatin with the inner nuclear membrane. This suggests that other components of the inner nuclear membrane mediate these interactions. Overall design: 2 samples, each with a biological replicate: wt mESC, B type lamin null (dKO) dKO mESC
Publication Title
Nuclear lamins are not required for lamina-associated domain organization in mouse embryonic stem cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Drosophila melanogaster
- 6 Downloadable Samples
- Illumina HiSeq 2000
Description
Dam identification (DamID) is a powerful technique to generate genome-wide maps of chromatin protein binding. Due to its high sensitivity it is particularly suited to study the genome interactions of chromatin proteins in small tissue samples in model organisms such as Drosophila. Here we report an intein-based approach to tune the expression level of Dam and Dam-fusion proteins in Drosophila by addition of a ligand to fly food. This helps to suppress toxic effects of Dam. In addition we describe a strategy for genetically controlled expression of Dam in a specific cell type in complex tissues. We demonstrate the utility of the latter by generating a glia-specific map of Polycomb in small samples of brain tissue. Overall design: RNA sequencing of 3 samples, each using 2 biological replicates.
Publication Title
Inducible DamID systems for genomic mapping of chromatin proteins in Drosophila.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The spatial organization of DNA in the cell nucleus is an emerging key contributor to genomic function. We have developed 4C technology, or 3C-on-chip, which allows for an unbiased genome-wide search for DNA loci that contact a given locus in the nuclear space. We demonstrate here that active and inactive genes are engaged in many long-range intrachromosomal interactions and can also form interchromosomal contacts. The active b-globin locus in fetal liver contacts mostly transcribed, but not necessarily tissue-specific, loci elsewhere on chromosome 7, while the inactive locus in fetal brain contacts different, transcriptionally silent, loci. A housekeeping gene in a gene dense region on chromosome 8 forms long-range contacts predominantly with other active gene clusters, both in cis and in trans, and many of these intra- and interchromosomal interactions are conserved between the tissues analyzed. Our data demonstrate that chromosomes fold into areas of active chromatin and areas of inactive chromatin and establish 4C technology as a powerful tool to study nuclear architecture.
Publication Title
Nuclear organization of active and inactive chromatin domains uncovered by chromosome conformation capture-on-chip (4C).
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 24 Downloadable Samples
- Illumina HiSeq 2000
Description
Background. Cellular senescence is a mechanism that virtually irreversibly suppresses the proliferative capacity of cells in response to various stress signals. This includes the expression of activated oncogenes, which cause Oncogene-Induced Senescence (OIS). A body of evidence points to the involvement of chromatin reorganization, including the formation of senescence-associated heterochromatic foci (SAHF). The nuclear lamina (NL) is an important contributor to genome organization and has been involved in cellular senescence and organismal aging. It interacts with multiple regions of the genome called lamina-associated domains (LADs). Some LADs are cell type-specific, while others are conserved between cell types and are referred to as constitutive LADs. Here, we used DamID to investigate the changes in genome-NL interactions in a model of OIS triggered by the expression of the BRAFV600E oncogene.Results. We found that OIS cells lose most of their constitutive LADs (cLADS), suggesting the loss of a specific mechanism that targets cLADs to the NL. In addition, multiple genes relocated to the NL. Unexpectedly, they were not repressed, implying the abrogation of the repressive activity of the NL during OIS. Finally, OIS cells displayed an increased association of telomeres with the NL.Conclusions. Our study reveals that senescent cells acquire a new type of LAD organization and suggest the existence of as yet unknown mechanisms that tether cLADs to the NL and repress gene expression at the NL.
Publication Title
Massive reshaping of genome-nuclear lamina interactions during oncogene-induced senescence.
Sample Metadata Fields
Specimen part, Cell line, Subject, Time
View Samples- Mus musculus
- 11 Downloadable Samples
- Illumina HiSeq 2000
Description
Reporter genes integrated into the genome are a powerful tool to reveal effects of regulatory elements and local chromatin context on gene expression. However, so far such reporter assays have been of low throughput. Here we describe a multiplexing approach for the parallel monitoring of transcriptional activity of thousands of randomly integrated reporters. More than 27,000 distinct reporter integrations in mouse embryonic stem cells, obtained with two different promoters, show ~1,000-fold variation in expression levels. Data analysis indicates that lamina-associated domains act as attenuators of transcription, likely by reducing access of transcription factors to binding sites. Furthermore, chromatin compaction is predictive of reporter activity. We also found evidence for cross-talk between neighboring genes, and estimate that enhancers can influence gene expression on average over ~20 kb. The multiplexed reporter assay is highly flexible in design and can be modified to query a wide range of aspects of gene regulation. Overall design: mRNA profiles of 11 mouse embryonic cell lines each harboring multiple barcoded reporter constructs with mouse PGK promoter integrated at random positions in the genome, single replicate.
Publication Title
Chromatin position effects assayed by thousands of reporters integrated in parallel.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Drosophila melanogaster
- 2 Downloadable Samples
- Illumina Genome Analyzer II
Description
The local protein composition of chromatin is important for the regulation of transcription and other functions. By integrative analysis of genome-wide binding maps of 53 broadly selected chromatin components in Drosophila cells, we show that the genome is segmented into five principal chromatin types that are defined by unique, yet overlapping combinations of proteins, and form domains that can extend over >100 kb. We identify a novel repressive chromatin type that covers about half of the genome and lacks classic heterochromatin markers. Furthermore, transcriptionally active euchromatin consists of two distinct types that differ in molecular organization and H3K36 methylation, and regulate distinct classes of genes. Finally, we provide evidence that the different chromatin types act as guides that help to target DNA-binding factors to specific subsets of their recognition motifs. These results uncover basic principles of chromatin organization in a higher eukaryote. For this study, we generated whole-genome DamID binding profiles of 45 chromatin proteins in Drosophila Kc167 cells. Additionally, we perused published binding data of 8 chromatin proteins and generated a binding profile of one exogenous (yeast) DNA binding factor in Kc167 cells. On the same array platform, we obtained ChIP-on-chip profiles of histone H3, H1, H3K9me2, H3K27me3, H3K4me2, and H3K79me3. See supplementary files below. Gene expression was measured by RNA tag profiling. See GeneCounts supplementary file below. Overall design: [1] RNA tag sequences were optained on an Illumina GAII with the digital gene expression (DGE) module from duplicate RNA samples. [2] All DamID and ChIP experiments were done in Drosophila Kc167 cells in duplicate. Samples were hybridized to 380k NimbleGen arrays with 300 bp probe spacing. Every experiment was done in duplicate in the reverse dye orientation, where Dam-fusion material was hybridized over Dam-only material. For ChIP, immunoprecipitated material was hybridized over ChIP input material. 18 previously-submitted Samples were included in this study. 10 of 18 Samples have been renormalized for the GSE22069 study: GSM509087, GSM509088, GSM509089, GSM509090, GSM509091, GSM509092, GSM509093, GSM509094, GSM509095, GSM509096 New GSM accession numbers have been issued for these 10 samples. 8 of 18 Samples are identical in the original studies and in GSE22069: GSM423290, GSM423291, GSM423298, GSM423299, GSM493592, GSM493593, GSM509085, GSM509086 [3] The genomic locations in files GSE22069_norm_aggregated_discretized_tiling_arrays.txt and GSE22069_norm_aggregated_tiling_arrays.txt are relative to FlyBase release 5 (BDGP R5/dm3).
Publication Title
Systematic protein location mapping reveals five principal chromatin types in Drosophila cells.
Sample Metadata Fields
Cell line, Treatment, Subject
View Samples- Homo sapiens
- 12 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
Analysis of the role of PARP1 in gene transcription in MCF7 cells under non-stress conditions. The hypothesis was that PARP1 activity in MCF7 cells plays a role in gene transcription. The results indicate that PARP1 inhibition does not significantly affect transcription after 6 hours of treatment.
Publication Title
Basal activity of a PARP1-NuA4 complex varies dramatically across cancer cell lines.
Sample Metadata Fields
Specimen part, Cell line
View Samples