In higher eukaryotes, an important mechanism to tune translation in different tissues and conditions is mTORC1-dependent regulation of tRNAs transcription by RNA polymerase III (Pol III), as the relative amount of tRNAs tightly coordinates with the translational needs of the cell. mTORC1 contributes to regulate protein synthesis through its direct substrate MAF1, which functions as a negative regulator of Pol III transcription in response to stimuli such as serum starvation or rapamycin treatment. Here, we applied ChIP-seq to examine the Pol III occupancy profile in human fibroblasts and report evidence of a genome wide, MAF1-dependent coordinated response to favorable or stress growth conditions. Strikingly, while a set of genes is extremely responsive in terms of Pol III binding, other genes are mostly unperturbed, yet associated with transcriptionally engaged polymerases as revealed by nascent EU-labeled RNA-seq (neuRNA-seq). As shown by DamIP-seq, the responsiveness of a subset of genes is tightly connected to the rapid and transient interaction of MAF1 with DNA-bound Pol III. Overall design: We performed duplicate ChIP-seq experiments for the Rpc4 (POLR3D) subunit of RNA polymerase III in IMR90hTert cells grown in the presence of fetal bovine serum (FBS), serum starved (SS), serum starved and treated with insulin (SS+I), serum starved and treated with insulin and rapamycin (SS+R+I). Additional ChIP-seq profiles were generated in cells treated with MAF1 siRNAs and serum starved. MAF1 binding was addressed by DamIP-seq, using two replicates per clone of IMR90hTert cells expressing HA-tagged MAF1-DamK9A (2 different clones) or EGFP-DamK9A (2 different clones). To monitor dynamic transcription profiles we did neusRNA-seq in IMR90hTert cells EU-labeled or mock (DMSO)-labeled. For both DamIP-seq and neusRNA-seq, cells were either unperturbed or serum starved.
Human MAF1 targets and represses active RNA polymerase III genes by preventing recruitment rather than inducing long-term transcriptional arrest.
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View SamplesTLRs are considered important for innate immune responses that combat bacterial infections. Here, the role of TLRs in severe septic peritonitis using the colon ascendens stent peritonitis (CASP) model was examined. We demonstrate that mice deficient for MyD88 and TRIF had markedly reduced bacterial numbers both in peritoneal cavity and peripheral blood, indicating that bacterial clearance in this model is inhibited by TLR signals. Moreover, survival of Myd88-/-;TrifLps2/Lps2 mice was significantly improved. The lack of TLR signals prevented the excessive induction of inflammatory cytokines and of IL 10. Notably, the expression of IFN-gamma, which has an essential protective role in septic peritonitis, and of IFN-regulated genes including several p47 and p65 GTPases as well as IP 10 was independent of TLR signaling. These results provide evidence that, in severe septic peritonitis, TLR deficiency balances the innate immune response in a favorable manner by attenuating deleterious responses such as excessive cytokine release, while leaving intact protective IFN-gamma production.
Improved host defense against septic peritonitis in mice lacking MyD88 and TRIF is linked to a normal interferon response.
Specimen part, Treatment
View Samples[original title] Tissue-specific silencing of C2TA reveals the autonomous role of medullary thymic epithelial cells in central CD4 T cell tolerance.
Autonomous role of medullary thymic epithelial cells in central CD4(+) T cell tolerance.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Diurnal regulation of RNA polymerase III transcription is under the control of both the feeding-fasting response and the circadian clock.
Specimen part
View SamplesRNA polymerase III (pol III) synthesizes short non-coding RNAs, many of which, including tRNAs, Rpph1 RNA, Rn5s rRNA, and Rmrp RNA, are essential for translation. Accordingly, pol III activity is tightly regulated with cell growth and proliferation by factors such as MYC, RB1, TRP53, and MAF1. MAF1 is a repressor of pol III transcription whose activity is controlled by phosphorylation; in particular, it is inactivated through phosphorylation by mTORC1 kinase, a sensor of nutrient availability. Pol III regulation is thus sensitive to environmental cues, yet a diurnal profile of pol III transcription activity is so far lacking. Here we document pol III occupancy of its target genes in mouse liver during the diurnal cycle and show that pol III occupancy rises before the onset of the night, stays high during the night, when mice normally ingest food and when translation is increased, and decreases in daytime. By comparing diurnal pol III occupancy in wild-type mice, arrhythmic mice owing to inactivation of the Arntl gene, mice fed at regular intervals during both night and day, and mice lacking the Maf1 gene, we show that whereas higher pol III occupancy during the night reflects a MAF1-dependent response to feeding, the rise of pol III occupancy before the onset of the night reflects a circadian clock-dependent response. Thus, pol III transcription during the diurnal cycle is regulated both in response to nutrients and by the circadian clock, which allows anticipatory pol III transcription.
Diurnal regulation of RNA polymerase III transcription is under the control of both the feeding-fasting response and the circadian clock.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
HCFC1 is a common component of active human CpG-island promoters and coincides with ZNF143, THAP11, YY1, and GABP transcription factor occupancy.
Cell line, Treatment
View SamplesWe compared in triplicate mRNA levels from cells treated with siRNA against either HCF-1 or, as a negative control, luciferase. We observed that 19% of Refseq annotated genes are differentially expressed (either up or down regulated with a multiple testing corrected p value of 0.05) upon depletion of HCF-1. This large number of differentially expressed genes upon HCF-1 depletion demonstrates a broad role of HCF-1 in the regulation of gene expression.
HCFC1 is a common component of active human CpG-island promoters and coincides with ZNF143, THAP11, YY1, and GABP transcription factor occupancy.
Cell line, Treatment
View SamplesBy investigating the germinal center (GC) formation in STAT6ko/WT bone marrow-mixed chimera we found that GC formation in type 2 immune responses is dependent on B cell intrinsic expression of IL-4/IL-13-induced genes. We therefore used microarrays to find Stat6 dependent genes that are important for germinal center formation and/or organization after infection with the nematode Nippostrongylus brasiliensis (N. brasiliensis).
B-cell-intrinsic STAT6 signaling controls germinal center formation.
Specimen part
View SamplesTranscriptome analysis of control and MALAT1 lncRNA-depleted RNA samples from human diploid lung fibroblasts [WI38]
Long noncoding RNA MALAT1 controls cell cycle progression by regulating the expression of oncogenic transcription factor B-MYB.
Specimen part, Cell line
View SamplesVAChT KDHOM mice have a 70% decrease in the vesicular acetylcholine transporter (VAChT) and this leads to a systemic decrease in ACh release and cardiac dysfunction.
An analysis of the myocardial transcriptome in a mouse model of cardiac dysfunction with decreased cholinergic neurotransmission.
Sex, Age, Specimen part
View Samples