O-GlcNAcylation is an essential, nutrient-sensitive post-translational modification, but its biochemical and phenotypic effects remain incompletely understood. To address this knowledge gap, we investigated the global transcriptional response to perturbations in O-GlcNAcylation. Unexpectedly, many transcriptional effects of O-GlcNAc transferase (OGT) inhibition were due to the activation of NRF2, the master regulator of redox stress tolerance. Moreover, we found that a signature of low OGT activity strongly correlates with NRF2 activation in multiple tumor expression datasets. Guided by this information, we identified KEAP1 (also known as KLHL19), the primary negative regulator of NRF2, as a direct substrate of OGT. We show that O-GlcNAcylation of KEAP1 at serine 104 is required for the efficient ubiquitination and degradation of NRF2. Interestingly, O-GlcNAc levels and NRF2 activation co-vary in response to glucose fluctuations, indicating that KEAP1 O-GlcNAcylation links nutrient sensing to downstream stress resistance. Our results reveal a novel regulatory connection between nutrient-sensitive glycosylation and NRF2 signaling, and provide a blueprint for future approaches to discover functionally important O-GlcNAcylation events on other KLHL family proteins in various experimental and disease contexts.
Glycosylation of KEAP1 links nutrient sensing to redox stress signaling.
Specimen part, Cell line
View SamplesWe have reported more than a dozen microenvironmental factors whose signaling must be integrated in order to effect an organized, functional tissue morphology. In order to identify underlying commonalities in gene transcription associated with the phenotype, we compared the gene expression of organized and disorganized epithelial cells of the HMT-3522 breast cancer progression series: the non-malignant S1 cells that form polarized spheres (acini), the malignant T4-2 cells that form large tumor-like clusters, and the phenotypically reverted T4-2 cells that polarize as a result of correction of the microenvironmental signaling.
Inhibitors of Rho kinase (ROCK) signaling revert the malignant phenotype of breast cancer cells in 3D context.
Specimen part, Treatment
View SamplesNitric oxide being a versatile molecule inside biological systems, from being both a cell signaling molecule to a potent stress agent, has significant effect in the transcriptional response in fission yeast.
Global transcriptomic profiling of Schizosaccharomyces pombe in response to nitrosative stress.
No sample metadata fields
View SamplesThis study was designed to provide a genome-wide analysis of the effects of luteinizing hormone (LH) ablation/replacement versus steroid ablation/replacement on gene expression in the developed corpus luteum (CL) in primates during the menstrual cycle. Naturally cycling, female rhesus monkeys were left untreated (Control; n = 4) or received one of the following treatments for three days beginning on Day 9 of the luteal phase: daily injection of the gonadotropin-releasing hormone (GnRH) antagonist (Antide; n = 5), Antide + recombinant human LH (A+LH; n = 4), Antide + LH + the 3b-HSD antagonist Trilostane (A+LH+TRL; n = 4), and Antide + LH + TRL + progesterone replacement with a synthetic progestin R5020 (A+LH+TRL+ R5020; n = 5). On Day 12 of the luteal phase, CL were removed and samples of RNA from individual CL were fluorescently labeled and hybridized to Affymetrix rhesus macaque total genome microarrays. The greatest number of altered transcripts was associated with the ablation/replacement of LH, while ablation/replacement of progestin affected fewer transcripts. Replacement of LH during Antide treatment restored expression of most transcripts to control levels. Real-time PCR validation of a subset of transcripts revealed that most expression patterns were similar between microarray and real-time PCR. Analysis of protein levels were subsequently determined for 2 of the transcripts differentially expressed by real-time PCR. This is the first genome-wide analysis of LH and steroid regulation of gene transcription in the developed primate CL. Further analysis of novel transcripts identified in this data set can clarify the relative role for LH and steroids in CL maintenance and luteolysis.
The effects of luteinizing hormone ablation/replacement versus steroid ablation/replacement on gene expression in the primate corpus luteum.
No sample metadata fields
View SamplesTo obtain a genomic view of hepatocyte nuclear factor-4 (HNF-4) in the regulation of the inflammatory response, microarray analysis was used to probe the expression profile of an inflammatory response induced by cytokines in a model of knock-down HNF-4 HepG2 cells. The results indicate an extensive role for HNF-4 plays in the regulation of a large number of the liver-specific genes. Majority of genes (71%) affected by cytokine treatment are also affected by HNF-4 knock-down. This significant overlap suggests that HNF-4 may play a role in regulating the cytokine-induced inflammatory response.
Expression profile analysis of the inflammatory response regulated by hepatocyte nuclear factor 4α.
No sample metadata fields
View SamplesTo explore chorionic gonadotropin (CG)-regulated gene expression in the primate corpus luteum (CL), adult female rhesus macaques were treated with a model of simulated early pregnancy (SEP). Total RNA was isolated from individual CL and hybridized to Affymetrix GeneChip Rhesus Macaque Genome Arrays The level of 1192 transcripts changed expression > 2-fold (one-way ANOVA, FDR correction; P<0.05) during SEP when compared to Day 10 untreated controls, and the majority of changes occurred between Days 10 and 12 of SEP. To compare transcript levels between SEP rescued and regressing CL, previously banked rhesus GeneChip array data from the mid- to late and very late luteal phase were analyzed with time-matched intervals in SEP. Comparing RMA-normalized transcripts from the natural cycle with those from luteal rescue revealed 7677 transcripts changing in expression pattern >2 fold (one-way ANOVA, FDR correction; P<0.05) between the two groups. Clustering of samples revealed that the SEP samples possessed the most related transcript expression profiles. Regressed CL (days 18-19, around menses) were the most unlike all other CL. The most affected KEGG pathway was Steroid Biosynthesis, and most significantly absent pathways following SEP treatment includes groups of genes whose products promote cell-death. By further comparing the genome-wide changes in luteal gene expression during rescue in SEP, with those in CL during luteolysis in the natural menstrual cycle, it is possible to identify key regulatory pathways promoting fertility.
Microarray analysis of the primate luteal transcriptome during chorionic gonadotrophin administration simulating early pregnancy.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MGAT1 and Complex N-Glycans Regulate ERK Signaling During Spermatogenesis.
Age, Specimen part
View SamplesLoss of Mgat1 in spermatogonia was investigated in germ cells from 23 day males. Gene expression changes induced by deletion of Mgat1 were determined using the Affymetrix GeneChip Mouse Gene 2.0 ST Array.
MGAT1 and Complex N-Glycans Regulate ERK Signaling During Spermatogenesis.
Age, Specimen part
View SamplesMechanistic insights into MGAT1 loss during spermatogenesis were investigated in germ cells from 22 day males. Gene expression changes induced by deletion of Mgat 1in spermatogonia were determined using the Affymetrix GeneChip Whole Transcript Plus Reagent Kit.
MGAT1 and Complex N-Glycans Regulate ERK Signaling During Spermatogenesis.
Age, Specimen part
View SamplesSenescence in WI-38 cell context was induce by RASv12 over expression Cellular senescence is a permanent cell cycle arrest that is triggered by cancer- initiating or promoting events in mammalian cells and is now considered a major tumour suppressor mechanism. Here, we did a transcriptomic analysis and compared WI-38 contol wich is a human fibroblaste cell line and WI-38 that overexpressed RASv12 a G protein that induce senescence. The goal of our project is to compare transciptomic profile of human growing fibroblast (WI-38 control) and senescent human fibroblast (WI-38 OERAS)
Senescence is an endogenous trigger for microRNA-directed transcriptional gene silencing in human cells.
Specimen part
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