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.
Competition between pre-mRNAs for the splicing machinery drives global regulation of splicing.
Treatment, Subject
View SamplesSR proteins are well-characterized RNA binding proteins that promote exon inclusion by binding to exonic splicing enhancers (ESEs). However, it has been unclear whether regulatory rules deduced on model genes apply generally to activities of SR proteins in the cell. Here, we report global analyses of two prototypical SR proteins SRSF1 (SF2/ASF) and SRSF2 (SC35) using splicing-sensitive arrays and CLIP-seq on mouse embryo fibroblasts (MEFs). Unexpectedly, we find that these SR proteins promote both inclusion and skipping of exons in vivo, but their binding patterns do not explain such opposite responses. Further analyses reveal that loss of one SR protein is accompanied by coordinated loss or compensatory gain in the interaction of other SR proteins at the affected exons. Therefore, specific effects on regulated splicing by one SR protein actually depend on a complex set of relationships with multiple other SR proteins in mammalian genomes. Overall design: SRSF1 and SRSF2 CLIP-seq
Genome-wide analysis reveals SR protein cooperation and competition in regulated splicing.
Specimen part, Subject
View SamplesHere we report that Nono instead functions as a chromatin regulator cooperating with Erk to regulate mESC pluripotency. We demonstrate that Nono loss leads to robust self-renewing mESCs with enhanced expression of Nanog and Klf4, epigenome and transcriptome re-patterning to a “ground-like state” with global reduction of H3K27me3 and DNA methylation resembling the Erk inhibitor PD03 treated mESCs and 2i (both GSK and Erk kinase inhibitors)-induced “ground state”. Mechanistically, Nono and Erk co-bind at a subset of development-related, bivalent genes. Ablation of Nono compromises Erk activation and RNA polymerase II C-terminal Domain serine 5 phosphorylation, and while inactivation of Erk evicts Nono from chromatin, revealing reciprocal regulation. Furthermore, Nono loss results in a compromised activation of its target bivalent genes upon differentiation and the differentiation itself. These findings reveal an unanticipated role of Nono in collaborating with Erk signaling to regulate the integrity of bivalent domain and mESC pluripotency. Overall design: mRNA-seq of parental and Nono-KO mES cells
Nono, a Bivalent Domain Factor, Regulates Erk Signaling and Mouse Embryonic Stem Cell Pluripotency.
Specimen part, Subject
View SamplesWe conditionally inactivated mouse Cdx2, a dominant regulator of intestinal development, and mapped its genome occupancy in adult intestinal villi. Although homeotic transformation, observed in Cdx2-null embryos, was absent in mutant adults, gene expression and cell morphology were vitally compromised. Lethality was accelerated in mice lacking both Cdx2 and its homolog Cdx1, with exaggeration of defects in crypt cell replication and enterocyte differentiation. Cdx2 occupancy correlated with hundreds of transcripts that fell but not with equal numbers that rose with Cdx loss, indicating a predominantly activating role at intestinal cis-regulatory regions. Integrated consideration of a mutant phenotype and cistrome hence reveals the continued and distinct requirement in adults of a master developmental regulator that activates tissue-specific genes.
Essential and redundant functions of caudal family proteins in activating adult intestinal genes.
Specimen part
View SamplesAs Trypanosoma cruzi, the etiological agent of Chagas disease, multiplies in the cytoplasm of nucleated host cells, infection with this parasite is highly likely to affect host cells. We performed an exhaustive transcriptome analysis of T. cruzi-infected HeLa cells using an oligonucleotide microarray containing probes for greater than 47,000 human gene transcripts. In comparison with uninfected cells, those infected with T. cruzi showed greater than threefold up-regulation of 41 genes and greater than threefold down-regulation of 23 genes. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of selected, differentially expressed genes confirmed the microarray data. Many of these up- and down-regulated genes were related to cellular proliferation, including seven up-regulated genes encoding proliferation inhibitors and three down-regulated genes encoding proliferation promoters, strongly suggesting that T. cruzi infection inhibits host cell proliferation, which may allow more time for T. cruzi to replicate and produce its intracellular nests. These findings provide new insight into the molecular mechanisms by which intracellular T. cruzi infection influences the host cell, leading to pathogenicity.
Transcriptome profile of Trypanosoma cruzi-infected cells: simultaneous up- and down-regulation of proliferation inhibitors and promoters.
No sample metadata fields
View SamplesOur previous investigation indicated that high-virulence C. gattii (C. gattii TIMM 4097) tend to reside in the alveoli, whereas low-virulence C. gattii (C. gattii TIMM 4903) tend to be washed out from the alveoli and move into the central side of the respiratory system. To test this hypothesis, we performed microarray assay.
How histopathology can contribute to an understanding of defense mechanisms against cryptococci.
Sex, Specimen part
View SamplesRNA interference (RNAi) is a potent mechanism for down-regulating gene expression. Conserved RNAi pathway components are found in animals, plants, fungi and other eukaryotes. In C. elegans, the RNAi response is greatly amplified by the synthesis of abundant secondary siRNAs. Exogenous double stranded RNA is processed by Dicer and RDE-1/Argonaute into primary siRNA that guides target mRNA recognition. The RDE-10/RDE-11 complex and the RNA dependent RNA polymerase RRF-1 then engage the target mRNA for secondary siRNA synthesis. However, the molecular link between primary siRNA production and secondary siRNA synthesis remains largely unknown. Furthermore, it is unclear if the sub-cellular sites for target mRNA recognition and degradation coincide with sites where siRNA synthesis and amplification occur. In the C. elegans germline, cytoplasmic P granules at the nuclear pores and perinuclear Mutator foci contribute to target mRNA surveillance and siRNA amplification, respectively. We report that RDE-12, a conserved FG domain containing DEAD-box helicase, localizes in P-granules and cytoplasmic foci that are enriched in RSD-6 but are excluded from the Mutator foci. Our results suggest that RDE-12 promotes secondary siRNA synthesis by orchestrating the recruitment of RDE-10 and RRF-1 to primary siRNA targeted mRNA in distinct cytoplasmic compartments. Overall design: Examination of exogenous dsRNA trigger derived siRNA in wildtype and rde-12 mutant animals
The DEAD box helicase RDE-12 promotes amplification of RNAi in cytoplasmic foci in C. elegans.
Subject
View SamplesThe agonistic anti-human CD3 antibody , OKT-3, has been used to control acute transplant rejection. The in vivo administration of OKT-3 was previously shown to induce the partial depletion of T cells and anergy in the remaining CD4+ T cells. However, this therapy is also associated with the systemic release of several cytokines, which leads to a series of adverse side effects. We established a novel anti-human CD3 Ab, 20-2b2 (#1 abs), which recognized a close, but different determinant on the CD3 molecule from that recognized by OKT3. 20-2b2 was non-mitogenic for human CD4+ T cells, could inhibit the activation of T cells in vitro, and induced T cell anergy in in vivo experiments using humanized mice. Cytokine release in humanized mice induced by the administration of 20-2b2 was significantly less than that induced by OKT-3. Our results indicated that the CD3 molecule is still an attractive, effective, and useful target for the modulation of T cell responses. The establishment of other Abs that recognize CD3, even though the determinant recognized by those Abs may be close to or different from that recognized by OKT-3, may represent a novel approach for the development of safer Ab therapies using anti-CD3 Abs, in addition to the modification of OKT-3 in terms of the induction of cytokine production.
Modulation of the human T cell response by a novel non-mitogenic anti-CD3 antibody.
Specimen part, Disease, Disease stage
View SamplesGIST is considered to invariably arise through gain-of-function KIT or PDGFRA mutation of the interstitial cells of Cajal (ICC). However, the genetic basis of the malignant progression of GIST is poorly understood.
Distinct gene expression-defined classes of gastrointestinal stromal tumor.
Sex, Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Intestinal master transcription factor CDX2 controls chromatin access for partner transcription factor binding.
Specimen part
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