The roles of RNA-binding proteins as chaperones in the lifecycles of mRNAs are not well understood. The mammalian mitochondrial genome has been compressed over evolution to a size of just 16 kb, nevertheless the expression of its genes requires transcription, RNA processing, translation and RNA decay, much like the more complex chromosomal systems, providing an opportunity to use it as a model system to understand the fundamental aspects of gene expression. Here we combine RNase footprinting with PAR-CLIP at unprecedented depth to reveal the importance of RNA-protein interactions guided by the LRPPRC/SLIRP complex in dictating RNA folding within the mitochondrial transcriptome. We show that LRPPRC, in complex with its protein partner SLIRP, binds throughout the mitochondrial transcriptome, with a preference for mRNAs, and its loss affects the entire secondary structure and stability of the transcriptome. We demonstrate that the LRPPRC/SLIRP complex is a global RNA chaperone that stabilizes RNA structures to expose the required sites for translation, stabilization and polyadenylation. Our findings reveal a general mechanism where extensive RNA-protein interactions ensure that RNA is accessible for its biological functions. Overall design: RNase footprinting of LRPPRC and SLIRP knockout and control mice, in technical duplicate.
LRPPRC-mediated folding of the mitochondrial transcriptome.
Specimen part, Cell line, Subject
View SamplesFamilial hemophagocytic lymphohistiocytosis (FHL) is a rare, genetically heterogeneous autosomal recessive immune disorder that results when the critical regulatory pathways that mediate immune defense mechanisms and the natural termination of immune/inflammatory responses are disrupted or overwhelmed. In order to advance the understanding of FHL, we performed gene expression profiling of peripheral blood mononuclear cells (PBMCs) from 11 children with untreated FHL. Total RNA was isolated and gene expression levels were determined using microarray analysis. Comparisons between patients with FHL and normal pediatric controls (n = 30) identified 915 down-regulated and 550 up-regulated genes with 2.5-fold difference in expression (P = 0.05). The expression of genes associated with natural killer cell functions, innate and adaptive immune responses, pro-apoptotic proteins, and B- and T-cell differentiation were down-regulated in patients with FHL. Genes associated with the canonical pathways of IL-6, IL-10 IL-1, IL-8, TREM1, LXR/RXR activation, and PPAR signaling and genes encoding of anti-apoptotic proteins were overexpressed in patients with FHL. This, first study of genome-wide expression profiling in children with FHL demonstrates the complexity of gene expression patterns, which underly the immunobiology of FHL.
Gene expression profiling of peripheral blood mononuclear cells from children with active hemophagocytic lymphohistiocytosis.
Specimen part
View SamplesDifferential gene expression as a consequence of PTCD1 loss Overall design: We used RNA from control and PTCD1 knockout mice to investigate changes at the RNA level in response to PTCD1 loss
PTCD1 Is Required for 16S rRNA Maturation Complex Stability and Mitochondrial Ribosome Assembly.
Specimen part, Subject
View SamplesSkeletal muscle actin mice (Crawford et al., (2002) Mol Cell Biol 22, 5587) were crossed with cardiac actin transgenic mice (termed "ACTC^Coco" or "Coco" for short), to produce mice that had cardiac actin instead of skeletal muscle actin in their skeletal muscles (termed "ACTC^Co/KO" or for short "Coco/KO"). Microarray analysis using the Illumina mouse-6 v1.1 expression beadchip was performed on RNA extraced from the soleus muscle of Coco/KO mice and wildtype mice, to confirm the swith in actin isoform expression, and to determine what other differences might exist between wildtype mice and the Coco/KO mice.
Rescue of skeletal muscle alpha-actin-null mice by cardiac (fetal) alpha-actin.
No sample metadata fields
View SamplesDouble-stranded RNA (dsRNA) can enter different pathways in mammalian cells, including sequence-specific RNA interference, sequence-independent interferon response and editing by adenosine deaminases. To assess the potential of expressed dsRNA to induce interferon stimulated genes in somatic cells, we performed microarray analysis of HEK293 and HeLa cells transfected with a MosIR plasmid expressing an mRNA with a long inverted repeat structure in its 3UTR (MosIR) or with a parental MosIR plasmid (without inverted repeat) as a control.
dsRNA expression in the mouse elicits RNAi in oocytes and low adenosine deamination in somatic cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The mammalian TRIM-NHL protein TRIM71/LIN-41 is a repressor of mRNA function.
Specimen part, Cell line
View SamplesWe identify mammalian TRIM71 as repressor of mRNAs that inhibits translation and affects mRNA stability.
The mammalian TRIM-NHL protein TRIM71/LIN-41 is a repressor of mRNA function.
Cell line
View SamplesWe identify mammalian TRIM71 as repressor of mRNAs that inhibits translation and affects mRNA stability. In this data set we compare the expression profile of mouse ES upon Trim71 KD versus that of the parental cells.
The mammalian TRIM-NHL protein TRIM71/LIN-41 is a repressor of mRNA function.
Specimen part
View SamplesDuring early development, the correct establishment of the body axes is a critical step. The anterior pole of the mouse embryo is established when Distal Visceral Endoderm (DVE) cells migrate to form the Anterior Visceral Endoderm (AVE). Asymmetrical expression of Lefty1, Cerl and Dkk determines the direction of DVE migration and the future anterior side. Besides being implicated in the establishment of Anterior-Posterior axis the AVE has also been correlated with anterior neural specification. In order to better understand the role of the AVE in these processes, this cell population was isolated using a cerlP-EGFP transgenic mouse line, and a differential screening was performed using Affymetrix GeneChip technology. From this differential screening, 175 genes were found to be upregulated in the AVE, whereas 35 genes were upregulated in the Proximal-posterior sample. Using DAVID, here we characterize the AVE cell population regarding cellular component, molecular function and biological processes. Among the genes that were found to be upregulated in the AVE, several novel genes with expression in the AVE were identified. Four of the identified transcripts displaying high-fold change were further characterized by in situ hybridization in early stages of development in order to validate the screening. From those four selected genes, ADTK1 was chosen to be functionally characterized by targeted inactivation in ES cells. ADTK1 encodes for an unknown serine/threonine kinase. ADTK null mutants present short limbs and defects in the eye and ear. Taken together, these data point to the importance of reporting novel genes present in the AVE.
Identification and functional analysis of novel genes expressed in the Anterior Visceral Endoderm.
Specimen part
View SamplesHepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. The current standard therapy for chronic hepatitis C (CHC) consists of a combination of pegylated IFN alpha (pegIFN-alpha) and ribavirin. It achieves a sustained viral clearance in only 5060% of patients. To learn more about molecular mechanisms underlying treatment failure, we investigated IFN-induced signaling in paired liver biopsies collected from CHC patients before and after administration of pegIFN-alpha. In patients with a rapid virological response to treatment, pegIFN-alpha induced a strong up-regulation of IFN-stimulated genes (ISGs). As shown previously, nonresponders had high expression levels of ISGs before therapy. Analysis of posttreatment biopsies of these patients revealed that pegIFN-alpha did not induce expression of ISGs above the pretreatment levels. In accordance with ISG expression data, phosphorylation, DNA binding, and nuclear localization of STAT1 indicated that the IFN signaling pathway in nonresponsive patients is preactivated and refractory to further stimulation. Some features characteristic of nonresponders were more accentuated in patients infected with HCV genotypes 1 and 4 compared with genotypes 2 and 3, providing a possible explanation for the poor response of the former group to therapy. Taken together with previous findings, our data support the concept that activation of the endogenous IFN system in CHC not only is ineffective in clearing the infection but also may impede the response to therapy, most likely by inducing a refractory state of the IFN signaling pathway.
Interferon signaling and treatment outcome in chronic hepatitis C.
No sample metadata fields
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