Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Gene expression data of human primary keratinocytes with control, EXOSC9 or EXOSC9+GRHL3 knockdown

ABSTRACT: Stem and progenitor cells maintain the tissue they reside in for life by regulating the balance between proliferation and differentiation. How this is done is not well understood. Here, we report that the human exosome maintains progenitor cell function. The expression of several subunits of the exosome were found to be enriched in epidermal progenitor cells, which were required to retain proliferative capacity and to prevent premature differentiation. Loss of PM/Scl-75 also known as EXOSC9, a key subunit of the exosome complex, resulted in loss of cells from the progenitor cell compartment, premature differentiation, and loss of epidermal tissue. EXOSC9 promotes self-renewal and prevents premature differentiation by maintaining transcript levels of a transcription factor necessary for epidermal differentiation, GRHL3, at low levels through mRNA degradation. These data demonstrate that control of differentiation specific transcription factors through mRNA degradation is required for progenitor cell maintenance in mammalian tissue. Refer to publication (Mistry et. Cell Stem Cell 2012) for more detail For gene expression profiling, cultured primary human keratinocytes were knocked down for EXOSC9, EXOSC9 and GRHL3, or control. RNA was harvested from the cells 5 days after knockdown. Microarray analysis using Affymetrix HG-U133 2.0 plus arrays was performed on duplicate samples. Significantly changed genes were identified as previously described(Sen et al., 2010).

ORGANISM(S): Homo sapiens

SUBMITTER: Devendra Mistry

PROVIDER: E-GEOD-37637 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:The first described feedback loop of the Arabidopsis circadian clock is based on reciprocal regulation between TOC1 and CCA1/LHY. CCA1 and LHY are MYB transcription factors that bind directly to the TOC1 promoter to negatively regulate its expression. Conversely, the activity of TOC1 has remained less well characterized. Genetic data supports that TOC1 is necessary for the reactivation of CCA1/LHY, but there is little description of its biochemical function. Here we show that TOC1 occupies specific genomic regions in the CCA1 and LHY promoters. Purified TOC1 binds directly to DNA through its CCT domain, which is similar to known DNA binding domains. Chemical induction and transient overexpression of TOC1 in Arabidopsis seedlings cause repression of CCA1/LHY expression demonstrating that TOC1 can repress direct targets, and mutation or deletion of the CCT domain prevents this repression showing that DNA binding is necessary for TOC1 action. Furthermore, we use the Gal4/UAS system in Arabidopsis to show that TOC1 acts as a general transcriptional repressor, and that repression activity is in the Pseudoreceiver (PR) domain of the protein. To identify the genes regulated by TOC1 on a genomic scale, we couple TOC1 chemical induction with microarray analysis and identify new potential TOC1 targets and output pathways. Together these results define the biochemical action of the core clock protein TOC1 and refine our perspective on how plant clocks function. Keywords: Expression profiling by array wild type (Col-0) and ALC::TOC1 were sown on Murashige-Skoog with 0.8% agar, stratified for 48 hours and grown in12:12 light:dark (LD) for 12 days and either left in LD or transferred to constant light (LL) and then grown for one more day before the start of the experiment. Tissue was submerged in Murashige-Skoog media supplemented with 2.5% ethanol or no ethanol (mock) and with 20mM MG132 for 3 hours and harvested at ZT1. Three replicates each of the seedlings were collected and frozen in liquid nitrogen.

Project description:Plasmodium and Toxoplasma are parasites of major medical importance that belong to the Apicomplexa phylum of protozoa. These parasites transform into various stages during their life cycle and express a specific set of proteins at each stage. Although still little is known of how gene expression is controlled in Apicomplexa, histone modifications, particularly acetylation, are emerging as key regulators of parasite differentiation and stage conversion. Here, we investigated the anti-Apicomplexa effect of FR235222, a histone deacetylase (HDAC) inhibitor. We show that FR235222 is active against a variety of Apicomplexa genera, including Plasmodium and Toxoplasma, and is more potent than other HDACi such as TSA and the clinically relevant compound, pyrimethamine. We identify TgHDAC3 as the target of FR235222 in Toxoplasma tachyzoites and demonstrate the crucial role of the conserved and Apicomplexa HDAC-specific residue TgHDAC3 T99 in the inhibitory activity of the drug. We also show that FR235222 induces differentiation of the tachyzoite (replicative) into the bradyzoite (non replicative) stage. Additionally, via its anti-TgHDAC3 activity, FR235222 influences the expression of ~370 genes, a third of which are stage-specifically expressed. These results identify FR235222 as a potent HDAC inhibitor of Apicomplexa, and establish HDAC3 as a central regulator of gene expression and stage conversion in Toxoplasma and likely other Apicomplexa. Freshly released tachyzoites were needle-passed, and filtered using a 3-Âµm nucleopore membrane. Parasites were resuspended into fresh DMEM supplemented with 10% (v/v) FBS and 25 mM HEPES buffer pH7.2. Parasites were incubated in the presence of FR235222 (40 nM) or DMSO (0.1%) for 4 h at 37Â°C with 5% CO2. For ChIP-chip experiments freshly released tachyzoites (~5 x 109 at ~12 x 107 parasites/mL) were fixed for 15 min in 1% formaldehyde. Increase in AcH4 signals was verified by immunoblot to verify that FR235222 treatment was effective. To prepare chromatin samples, fixed parasites were lysed in MNase buffer (0.32 M Sucrose, 50 mM Tris-HCl pH7.8, 4 mM MgCl2, 3 mM CaCl2, 100 mM NaCl, 0.25% (v/v) NP40, 5% (v/v) glycerol, protease inhibitor EDTA-free cocktail (Roche)) and DNA was digested for 4 min at 37Â°C by MNase (2 units/mL). Digestion was stopped with 20 mM EDTA and chromatin was recovered in the soluble fraction after centrifugation at 10,000 g at 4Â°C; this constituted the S1 fractions. Pelleted materials were resuspended in dialysis buffer (1mM Tris-HCl pH7.8, 0.2 mM EDTA) containing 1 mM PMSF and protease inhibitor cocktail (RocheÂ®) and dialyzed overnight at 4Â°C against the same solution. Then dialyzed materials were centrifuged and supernatant were harvested; this constitutes the S2 fractions. For chromatin immunoprecipitations, fractions S1 and S2 were pooled and DNA quality was verified by electrophoresis on 2% agarose gels; oligonucleosome ladder of 100-1000 bp were obtained. The histone-DNA complexes were immunoprecipitated with anti-acetyl histone H4 (UpstateÂ®, catalog # 06-866) antibodies according to NimbleGenâs protocol (http://www.genomecenter.ucdavis.edu/expression_analysis/documents).

Dataset Information

Gene expression data of human primary keratinocytes with control, EXOSC9 or EXOSC9+GRHL3 knockdown

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure