Disruptions of the endoplasmic reticulum (ER) that perturb protein folding cause ER stress and elicit an unfolded protein response (UPR) that involves translational and transcriptional changes in gene expression aimed at expanding the ER processing capacity and alleviating cellular injury. Three ER stress sensors PERK, ATF6, and IRE1 implement the UPR. PERK phosphorylation of eIF2 during ER stress represses protein synthesis, which prevents further influx of ER client proteins, along with preferential translation of ATF4, a transcription activator of the integrated stress response. In this study we show that the PERK/eIF2~P/ATF4 pathway is required not only for translational control, but also activation of ATF6 and its target genes. The PERK pathway facilitates both the synthesis of ATF6 and trafficking of ATF6 from the ER to the Golgi for intramembrane proteolysis and activation of ATF6. As a consequence, liver-specific depletion of PERK significantly reduces both the translational and transcriptional phases of the UPR, leading to reduced protein chaperone expression, disruptions of lipid metabolism, and enhanced apoptosis. These findings show that the regulatory networks of the UPR are fully integrated, and helps explain the diverse pathologies associated with loss of PERK.
The eIF2 kinase PERK and the integrated stress response facilitate activation of ATF6 during endoplasmic reticulum stress.
Specimen part, Treatment
View SamplesWe describe the preparation, evaluation, and application of an S100A12 protein-conjugated solid support, hereafter the “A12-resin,” that can remove 99% of Zn(II) from complex biological solutions without significantly perturbing the concentrations of other metal ions. The A12-resin can be applied to selectively deplete Zn(II) from diverse tissue culture media and from other biological fluids including human sera. To further demonstrate the utility of this approach, we investigated metabolic, transcriptomic, and metallomic responses of HEK293T cells cultured in medium depleted of Zn(II) using S100A12. Our data indicate that dividing cells can maintain a constant pool of free Zn(II), even under conditions of severe Zn(II) deprivation. We expect that the A12-resin will facilitate interrogation of disrupted Zn(II) homeostasis in biological settings, uncovering novel roles for Zn(II) in biology. Overall design: Defining the response of a cell line to Zn(II) starvation
A Method for Selective Depletion of Zn(II) Ions from Complex Biological Media and Evaluation of Cellular Consequences of Zn(II) Deficiency.
Cell line, Subject
View SamplesRNA-seq transcriptome profiling of human induced pluripotent stem cells to characterize gene expression variation across individuals and within multiple iPSC lines from the same individual Overall design: Donor erythroblast or activated T-cells were reprogrammed with a Sendai viral vector coding for reprogramming factors. IPSC lines were propagated for ~9 passages before RNA sequencing
Analysis of Transcriptional Variability in a Large Human iPSC Library Reveals Genetic and Non-genetic Determinants of Heterogeneity.
Sex, Age, Race, Subject
View SamplesIn fission yeast, the nuclear-localized Lsk1p-Lsc1p-Lsg1p cyclin dependent kinase complex is required for the reliable execution of cytokinesis and is also required for Ser-2 phosphorylation RNA pol II carboxy terminal domain.
Global gene expression analysis of fission yeast mutants impaired in Ser-2 phosphorylation of the RNA pol II carboxy terminal domain.
No sample metadata fields
View SamplesAnalysis of spleen samples taken throughout the acute phase of infection from mice infected with virulent P. chabaudi CB strain
Transcriptome analysis of blood and spleen in virulent and avirulent mouse malaria infection.
Sex, Specimen part, Time
View SamplesRodent malaria parasite RNA hybridized on Illumina Mouse WG-6 v2.0 Expression BeadChip
Transcriptome analysis of blood and spleen in virulent and avirulent mouse malaria infection.
Sex, Specimen part
View SamplesThis study assessed the transcriptional profile of SiHa cells. SiHa is a cervical cancer cell line with integrated HPV16, and was used as a model to study human gene expression in the context of integrated virus. Gene expression in SiHa, calculated by Cufflinks, was scored in windows around the locations of known viral integrations in patients or cell lines to determine if there was an association between gene expression and viral integration. We found that SiHa gene expression was higher near loci of integration for HPV18 vs. HPV16, cervical tissues vs. head and neck cancers, and cervical cancers vs. in vitro integrations. This study provides insight into the factors that may influence where viruses integrate in the human genome. Overall design: Gene Expression in untreated SiHa cells.
Meta-Analysis of DNA Tumor-Viral Integration Site Selection Indicates a Role for Repeats, Gene Expression and Epigenetics.
No sample metadata fields
View SamplesBeef cow adipose tissue transcriptome
Differential transcript abundance in adipose tissue of mature beef cows during feed restriction and realimentation.
Specimen part
View SamplesMitochondrial oxidative function is tightly controlled to maintain energy homeostasis in response to nutrient and hormonal signals. An important cellular component in the energy sensing response is the target of rapamycin (TOR) kinase pathway; however whether and how mTOR controls mitochondrial oxidative activity is unknown. Here, we show that mTOR kinase activity stimulates mitochondrial gene expression and oxidative function. In skeletal muscle cells and TSC2-/- MEFs, the mTOR inhibitor rapamycin largely decreased gene expression of mitochondrial transcriptional regulators such as PGC-1alpha and the transcription factors ERRalpha and NRFs. As a consequence, mitochondrial gene expression and oxygen consumption were reduced upon mTOR inhibition. Using computational genomics, we identified the transcription factor YY1 as a common target of mTOR and PGC-1alpha that controls mitochondrial gene expression. Inhibition of mTOR resulted in a failure of YY1 to interact and be coactivated by PGC-1alpha. Notably, knock-down of YY1 in skeletal muscle cells caused a significant decrease in mRNAs of mitochondrial regulators and mitochondrial genes that resulted in a decrease in respiration. Moreover, YY1 was required for rapamycin-dependent repression of mitochondrial genes. Thus, we have identified a novel mechanism in which a nutrient sensor (mTOR) balances energy metabolism via transcriptional control of mitochondrial oxidative function. These results have important implications for our understanding of how these pathways might be altered in metabolic diseases and cancer.
mTOR controls mitochondrial oxidative function through a YY1-PGC-1alpha transcriptional complex.
No sample metadata fields
View SamplesCraniosynostosis is a disease defined by premature fusion of one or more cranial sutures. The mechanistic pathology of isolated single-suture craniosynostosis is complex and while a number of genetic biomarkers and environmental predispositions have been identified, in many cases the causes remain controversial and inconclusive at best. After controlling for variables contributing to potential bias, FGF7, SFRP4, and VCAM1 emerged as potential genetic biomarkers for single-suture craniosynostosis due to their significantly large changes in gene expression compared to the control population. Furthermore, pathway analysis implicated focal adhesion and extracellular matrix (ECM)-receptor interaction as differentially regulated gene networks when comparing all cases of single-suture synostosis and controls. Lastly, overall gene expression was found to be highly conserved between coronal and metopic cases, as evidenced by the fact that WNT2 and IGFBP2 were the only differentially regulated genes identified in a direct comparison. These results not only confirm the roles of previously reported craniosynostosis-related targets but also introduce novel genetic biomarkers and pathways that may play critical roles in its pathogenesis.
Differential expression of extracellular matrix-mediated pathways in single-suture craniosynostosis.
Sex, Specimen part
View Samples