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Saccharomyces cerevisiae
6 Downloadable Samples
Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
The basic unit of genome packaging is the nucleosome, and nucleosomes have long been proposed to restrict DNA accessibility both to damage and to transcription. However, nucleosome number in cells was considered fixed, and no condition was described where nucleosome number was reduced. We show here that mammalian cells lacking High Mobility Group Box 1 protein (HMGB1) contain a reduced amount of core, linker and variant histones, and a correspondingly reduced number of nucleosomes. Yeast nhp6 mutants lacking NHP6A and B proteins, which are related to HMGB1, also have a reduced amount of histones and fewer nucleosomes. Nucleosome limitation in both mammalian and yeast cells increases the sensitivity of DNA to damage, increases transcription globally, and the relative expression of about 10% of genes. In yeast nhp6 cells the loss of more than one nucleosome in four does not affect the location of nucleosomes and their spacing, but nucleosomal occupancy. The decrease in nucleosomal occupancy is non-uniform, and our results can be modelled assuming that different nucleosomal sites compete for the available histones: sites with high affinity are almost always packaged into nucleosomes both in wt and nucleosome-depleted cells, whereas sites with low affinity are less frequently packaged in nucleosome-depleted cells. We suggest that by modulating the occupancy of nucleosomes histone availability may constitute a novel layer of epigenetic regulation.
Publication Title
Substantial histone reduction modulates genomewide nucleosomal occupancy and global transcriptional output.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 8 Downloadable Samples
Illumina HiSeq 2000
Description
Male germ cells express the widest repertoire of transcript variants in mammalian tissues. Nevertheless, factors and mechanisms underlying such pronounced diversity are largely unknown. The splicing regulator Sam68 is highly expressed in meiotic cells and its ablation results in defective spermatogenesis. Herein, we uncover an extensive splicing program operated by Sam68 across meiosis, primarily characterized by alternative last exon (ALE) regulation in genes of functional relevance for spermatogenesis. Lack of Sam68 preferentially causes premature transcript termination at internal polyadenylation sites. Overall design: RNA-Seq data for purified spermatocytes and spermatids isolated from Sam68+/+ and Sam68-/- mice.
Publication Title
Functional Interaction between U1snRNP and Sam68 Insures Proper 3' End Pre-mRNA Processing during Germ Cell Differentiation.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Homo sapiens
- 8 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Genome-wide analysis reveals a role for BRCA1 and PALB2 in transcriptional co-activation.
Sample Metadata Fields
Specimen part, Disease, Cell line
View Samples- Homo sapiens
- 4 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
Breast and ovarian cancer susceptibility genes, BRCA1 and PALB2 have enigmatic roles in cellular growth and mammalian development. While these genes are essential for growth during early developmental programs, inactivation later in adulthood leads to increased growth and formation of tumors, leading to their designation as tumor suppressors. We performed genome-wide analysis assessing their chromatin residence and gene expression responsiveness using high throughput sequencing in breast epithelial cells. These experiments revealed a critical role for BRCA1 and PALB2 in transcriptional responsiveness to NF-kB, a crucial mediator of growth and inflammatory response during development and cancer. Importantly, we also uncovered a vital role for these proteins in response to retinoic acid (RA), a growth inhibitory signal in breast cancer cells, which may constitute the basis for their tumor suppressor activity.
Publication Title
Genome-wide analysis reveals a role for BRCA1 and PALB2 in transcriptional co-activation.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 4 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
Breast and ovarian cancer susceptibility genes, BRCA1 and PALB2 have enigmatic roles in cellular growth and mammalian development. While these genes are essential for growth during early developmental programs, inactivation later in adulthood leads to increased growth and formation of tumors, leading to their designation as tumor suppressors. We performed genome-wide analysis assessing their chromatin residence and gene expression responsiveness using high throughput sequencing in breast epithelial cells. These experiments revealed a critical role for BRCA1 and PALB2 in transcriptional responsiveness to NF-kB, a crucial mediator of growth and inflammatory response during development and cancer. Importantly, we also uncovered a vital role for these proteins in response to retinoic acid (RA), a growth inhibitory signal in breast cancer cells, which may constitute the basis for their tumor suppressor activity.
Publication Title
Genome-wide analysis reveals a role for BRCA1 and PALB2 in transcriptional co-activation.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 12 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Requirement for SNAPC1 in transcriptional responsiveness to diverse extracellular signals.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 12 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
The small nuclear RNA (snRNA)-activating protein complex (SNAPc) is a basal transcription factor that mediates the transcriptional activation of snRNAs. Here, we describe the genome-wide occupancy of the SNAPC1_and SNAPC4 subunits of SNAPc. While the SNAPC4 occupancy was in accord with the role for SNAPc in snRNA transcription, SNAPC1_displayed a broader genomic profile mirroring that of RNA polymerase II at highly active protein-coding genes. Our functional analysis revealed a role for SNAPC1_in regulation of both basal and activator-induced transcription of protein-coding genes. These studies expand the role for SNAPC1_beyond its regulation of snRNA transcription.
Publication Title
Requirement for SNAPC1 in transcriptional responsiveness to diverse extracellular signals.
Sample Metadata Fields
Cell line, Treatment
View Samples
GSE6460- Homo sapiens
- 7 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The identity of cells that establish the hematopoietic microenvironment (HME) in human bone marrow (BM), and of skeletal ("mesenchymal") stem cells (SSCs) found in BM stroma, have long remained elusive. We show that MCAM/CD146-expressing, subendothelial cells in human BM stroma are both the self-renewing SSCs and the cells that transfer the HME at heterotopic sites upon transplantation.
Publication Title
Self-renewing osteoprogenitors in bone marrow sinusoids can organize a hematopoietic microenvironment.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 1 Downloadable Sample
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Microarray based mRNA profiling was used to identify the mechanism of action for the small molecule b-AP15.
Publication Title
Inhibition of proteasome deubiquitinating activity as a new cancer therapy.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 9 Downloadable Samples
- IlluminaGenomeAnalyzer
Description
Post-translational modifications, such as poly(ADP-ribosyl)ation (PARylation), regulate chromatin-modifying enzymes, ultimately affecting gene expression. This study explores the role of poly(ADP-ribose) polymerase (PARP) on global gene expression in a lymphoblastoid B cell line. We found that inhibition of PARP catalytic activity with olaparib resulted in global gene deregulation, affecting approximately 11% of genes expressed. Gene ontology analysis revealed that PARP could exert these effects through transcription factors and chromatin-remodeling enzymes, including the Polycomb Repressive Complex 2 (PRC2) member EZH2. EZH2 mediates the trimethylation of histone H3 at lysine 27 (H3K27me3), a modification associated with chromatin compaction and gene silencing. Both pharmacological inhibition of PARP and knockdown of PARP1 induced the expression of EZH2 that resulted in increased global H3K27me3. Chromatin immunoprecipitation confirmed that PARP1 inhibition led to H3K27me3 deposition at EZH2-target genes, which resulted in gene silencing. Moreover, increased EZH2 expression is attributed to occupancy loss of the transcription repressor E2F4 at the EZH2 promoter following PARP inhibition. Together, these data show that PARP plays an important role in global gene regulation and identifies for the first time a direct role of PARP1 in regulating the expression and function of EZH2. Overall design: Examination of the effect of PARP inhibition on global gene expression in LCLs cell lines. mRNA profiles of LCLs cells lines treated at different time points with olaparib were generated by deep sequencing, in triplicate, using Illumina GAIIx.
Publication Title
Global Transcriptome Analysis Reveals That Poly(ADP-Ribose) Polymerase 1 Regulates Gene Expression through EZH2.
Sample Metadata Fields
No sample metadata fields
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