The non-coding Xist RNA triggers silencing of one of the two female X chromosomes during X inactivation in mammals. Gene silencing by Xist is restricted to special developmental contexts found in cells of the early embryo and specific hematopoietic precursors. The absence of critical silencing factors might explain why Xist cannot silence outside these contexts. Here, we show that Xist can also initiate silencing in a lymphoma model. Using the tumor context we identify the special AT rich binding protein SATB1 as an essential silencing factor. We show that loss of SATB1 in tumor cells abrogates the silencing function of Xist. In normal female lymphocytes Xist localizes along SATB1 filaments and, importantly, forced Xist expression can relocalize SATB1 into the Xist cluster. This reciprocal influence on localization suggests a molecular interaction between Xist and SATB1. SATB1 and its close homologue SATB2 are expressed during the initiation window for X inactivation in embryonic stem cells and are recruited to surround the Xist cluster. Furthermore, ectopic expression SATB1 or SATB2 enables gene silencing by Xist in embryonic fibroblasts, which normally do not provide an initiation context. Thus, SATB1 functions as a crucial initiation factor and may act to organize genes for silencing by Xist during the initiation of X inactivation.
SATB1 defines the developmental context for gene silencing by Xist in lymphoma and embryonic cells.
Specimen part
View SamplesThe overall aim of this experiment was to identify specific genes and molecular pathways regulated by ML290, a small molecule agonist of the relaxin receptor, RXFP1, in the context of liver fibrosis. Overall design: Whole transcriptome mRNA sequencing of transformed LX-2 cells using HiSeq platforms with paired-end 150 bp (PE 150) sequencing strategy, with four biological replicates in each treatment group.
Therapeutic effects of a small molecule agonist of the relaxin receptor ML290 in liver fibrosis.
Specimen part, Cell line, Subject
View SamplesFifty six genes from DESeq were differentially expressed in the treated versus control samples. More than 20% were related to immune, defense, wounding and inflammatory responses Overall design: Downregulation of REST-003 using siRNAs in MDA-MB-231 cells; we used siRNA against REST-003, as REST-003 may control invasiveness. We transfected si-Control (scramble) or si-REST-003 in MDA-MB-231: duplicate of both (total 4 samples).
Non-coding RNAs derived from an alternatively spliced REST transcript (REST-003) regulate breast cancer invasiveness.
No sample metadata fields
View SamplesOne of the major players controlling RNA decay is the cytoplasmic 5'-to-3' exoribonuclease, which is conserved among eukaryotic organisms. In Arabidopsis, the 5'-to-3' exoribonuclease XRN4 is involved in disease resistance, the response to ethylene, RNAi, and miRNA-mediated RNA decay. Curiously, XRN4 appears to display selectivity among its substrates because certain 3' cleavage products formed by miRNA-mediated decay, such as from ARF10 mRNA, accumulate in the xrn4 mutant, whereas others, such as from AGO1, do not. To examine the nature of this selectivity, transcripts that differentially accumulate in xrn4 were identified by combining PARE and Affymetrix arrays. Certain functional categories, such as stamen-associated proteins and hydrolases, were over-represented among transcripts decreased in xrn4, whereas transcripts encoding nuclear-encoded chloroplast-targeted proteins and nucleic acid-binding proteins were over-represented in transcripts increased in xrn4. To ascertain if RNA sequence influences the apparent XRN4 selectivity, a series of chimeric constructs was generated in which the miRNA-complementary sites and different portions of the surrounding sequences from AGO1 and ARF10 were interchanged. Analysis of the resulting transgenic plants revealed that the presence of a 150 nucleotide sequence downstream from the ARF10 miRNA-complementary site conferred strong accumulation of the 3' cleavage products in xrn4. In addition, sequence analysis of differentially accumulating transcripts led to the identification of 27 hexamer motifs that were over-represented in transcripts or miRNA-cleavage products accumulating in xrn4. Taken together, the data indicate that specific mRNA sequences, like those in ARF10, and mRNAs from select functional categories are attractive targets for XRN4-mediated decay.
Evidence that XRN4, an Arabidopsis homolog of exoribonuclease XRN1, preferentially impacts transcripts with certain sequences or in particular functional categories.
Specimen part
View SamplesCertain neuron types fire spontaneously at high rates, an ability that is crucial for their function in brain circuits. The spontaneously active GABAergic neurons of the substantia nigra pars reticulata (SNr), a major output of the basal ganglia, provide tonic inhibition of downstream brain areas. A depolarizing "leak" current supports this firing pattern, but its molecular basis remains poorly understood. To understand how SNr neurons maintain tonic activity, we used single-cell RNA sequencing to determine the transcriptome of individual SNr neurons. We discovered that SNr neurons express the sodium leak current, NaLCN and that SNr neurons lacking NaLCN have impaired spontaneous firing. Overall design: RNA sequencing profiles from 87 GFP-positive GABAergic SNr neurons and 9 GFP-negative SNr cells were carried out. However only 80 samples that passed initial quality control and that were included in the data processing are represented in this record.
The leak channel NALCN controls tonic firing and glycolytic sensitivity of substantia nigra pars reticulata neurons.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of artifactual microarray probe signals constantly present in multiple sample types.
Specimen part
View SamplesThe correlation of the RNA profiles obtained by microarray analysis was compared with that obtained from RNA-Seq by using reduced complexity sperm datasets. This resolved as a series of discordant probes. The extent of discordancy among other datasets was then determined.
Identification of artifactual microarray probe signals constantly present in multiple sample types.
Specimen part
View SamplesTranscriptome analysis of depletion of DYRK1A in HeLa cells
DYRK1A phoshorylates histone H3 to differentially regulate the binding of HP1 isoforms and antagonize HP1-mediated transcriptional repression.
Specimen part, Cell line
View SamplesThe correlation of the RNA profiles obtained by microarray analysis was compared with that obtained from RNA-Seq by using reduced complexity sperm datasets. This resolved as a series of discordant probes. The extent of discordancy among other datasets was then determined. Overall design: A correlative study between probe’s signal intensity from Illumina bead arrays with its transcript level detected by next generation sequencing technique was performed. RNAs from sperm and testis samples were applied
Identification of artifactual microarray probe signals constantly present in multiple sample types.
Specimen part, Subject
View SamplesThe transcriptome is the complete set of all RNA transcripts produced by the genome in a cell and reflects the genes that are being actively expressed. Transcriptome analysis is essential for understanding the genetic mechanism controlling the phenotype of a cell.
Characterization of transcriptomes of cochlear inner and outer hair cells.
Specimen part
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