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GSE81740
Homo sapiens
26 Downloadable Samples
Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
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.
Publication Title
Glycosylation of KEAP1 links nutrient sensing to redox stress signaling.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
The histone chaperone CAF-1 safeguards somatic cell identity.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
Cellular differentiation involves profound changes in the chromatic landscape, yet the mechanisms by which somatic cell identity is subsequently maintained remain incompletely understood. To further elucidate regulatory pathways that safeguard the somatic state, we performed two comprehensive RNAi screens targeting chromatin factors during transcription factor-mediated reprogramming of mouse fibroblasts to induced pluripotent stem cells (iPSCs). Remarkably, subunits of the chromatin assembly factor-1 (CAF-1) complex emerged as the most prominent hits from both screens, followed by modulators of lysine sumoylation and heterochromatin maintenance. Suppression of CAF-1 increased reprogramming efficiency by several orders of magnitude and facilitated iPSC formation in as little as 4 days. Mechanistically, CAF-1 suppression led to a more accessible chromatin structure at enhancer elements early during reprogramming. These changes were accompanied by a decrease in somatic heterochromatin domains, increased binding of Sox2 to pluripotency-specific targets and activation of associated genes. Notably, suppression of CAF-1 also enhanced the direct conversion of B cells into macrophages and fibroblasts into neurons. Together, our findings reveal the histone chaperone CAF-1 as a novel regulator of somatic cell identity during transcription factor-induced cell fate transitions and provide a potential strategy to modulate cellular plasticity in a regenerative setting.
Publication Title
The histone chaperone CAF-1 safeguards somatic cell identity.
Sample Metadata Fields
Specimen part, Time
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Dendritic cells (DC) serve a key function in host defense, linking innate detection of microbes to the activation of pathogen-specific adaptive immune responses. Whether there is cell-intrinsic recognition of HIV-1 by host innate pattern-recognition receptors and subsequent coupling to antiviral T cell responses is not yet known. DC are largely resistant to infection with HIV-1, but facilitate infection of co-cultured T-helper cells through a process of trans-enhancement. We show here that, when DC resistance to infection is circumvented, HIV-1 induces DC maturation, an antiviral type I interferon response and activation of T cells. This innate response is dependent on the interaction of newly-synthesized HIV-1 capsid (CA) with cellular cyclophilin A (CypA) and the subsequent activation of the transcription factor IRF3. Because the peptidyl-prolyl isomerase CypA also interacts with CA to promote HIV-1 infectivity, our results suggest that CA conformation has evolved under opposing selective pressures for infectivity versus furtiveness. Thus, a cell intrinsic sensor for HIV-1 exists in DC and mediates an antiviral immune response, but it is not typically engaged due to absence of DC infection. The virulence of HIV-1 may be related to evasion of this response, whose manipulation may be necessary to generate an effective HIV-1 vaccine.
Publication Title
A cryptic sensor for HIV-1 activates antiviral innate immunity in dendritic cells.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 16 Downloadable Samples
Illumina HiSeq 2500
Description
Thousands of long non-coding RNAs (lncRNAs) have been identified in the human genome, but specific biological functions and biochemical mechanisms have been discovered for only about a dozen lncRNAs. One specific lncRNA, Non-coding RNA Activated by DNA Damage (NORAD), has recently been shown by genetic deletion to be required for maintaining genomic stability, but its molecular mechanism is unknown. Here, we combine RNA antisense purification (RAP) and quantitative mass spectrometry to identify proteins that directly interact with NORAD in living cells. We show that NORAD interacts with proteins involved in DNA replication and repair in steady-state cells and localizes to the nucleus upon stimulation with replication stress or DNA damage. In particular, NORAD interacts with RBMX (an emerging component of the DNA-damage response) and encodes the strongest RBMX-binding site in the transcriptome. We demonstrate that NORAD controls the ability of RBMX to assemble a ribonucleoprotein complex, which we term NORAD-Activated Ribonucleoprotein Complex 1 (NARC1), containing known suppressors of genomic instability: topoisomerase I (TOP1), ALYREF and the PRPF19/CDC5L complex. Cells depleted of NORAD or RBMX display an increased frequency of chromosome segregation errors, reduced replication-fork velocity and altered cell cycle progression phenotypes that are mechanistically linked to TOP1 and PRPF19/CDC5L function. Expression of NORAD in trans can rescue defects caused by NORAD depletion, but rescue is significantly impaired when the RBMX-binding site in NORAD is deleted. Our results demonstrate that the interaction between NORAD and RBMX is important for NORAD function and that NORAD is required for the assembly of a previously unknown topoisomerase complex (NARC1) that contributes to maintaining genomic stability. Moreover, we uncover a novel function for lncRNAs in modulating the ability of an RNA-binding protein to assemble a higher-order ribonucleoprotein complex. Overall design: We examined gene expression changes and alternative splicing events in wildtype and NORAD depleted cells using RNA sequencing.
Publication Title
The NORAD lncRNA assembles a topoisomerase complex critical for genome stability.
Sample Metadata Fields
Cell line, Subject, Time
View Samples- Homo sapiens
- 8 Downloadable Samples
- IlluminaHiSeq2000
Description
RNA-seq analysis of human 293 Tet-off cells depleted of PTBP1 and UPF1 alone and in tandem with specific siRNAs. Overall design: siRNA-based depletion of PTBP1, UPF1, and PTBP1/UPF1 together, with a validated non-silencing siRNA as a control.
Publication Title
Polypyrimidine tract binding protein 1 protects mRNAs from recognition by the nonsense-mediated mRNA decay pathway.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 77 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
WIN 18,446/RA treatment of neonatal mice was used to synchronize the initial wave of spermatogenesis and identify novel messages expressed within either germ or Sertoli cells as spermatogonia enter meiosis.
Publication Title
Riding the spermatogenic wave: profiling gene expression within neonatal germ and sertoli cells during a synchronized initial wave of spermatogenesis in mice.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 23 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
Circadian profiling of total RNA collected from wildtype and NPY KO murine liver. Liver RNA collected every 4 hours in a 12hr light:12hr dark cycle.
Publication Title
Neural clocks and Neuropeptide F/Y regulate circadian gene expression in a peripheral metabolic tissue.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 15 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Positive selection occurs in the thymic cortex, but critical maturation events occur later in the medulla. We defined the precise stage at which T cells acquire competence to proliferate and emigrate. Transcriptome analysis of late gene changes suggested roles for NF-B and interferon signaling. Mice lacking the IKK kinase TAK1, showed normal positive selection, but a specific block in functional maturation. NF-B signaling provided protection from TNF, and was required for proliferation and emigration. Alternatively, the interferon signature was independent of NF-B, and IFNR deficient thymocytes showed reduced STAT1 levels and phenotypic abnormality, but were competent to proliferate. Thus, both NF-B and tonic IFN signals are involved in the final maturation of thymocytes into nave T cells.
Publication Title
Late stages of T cell maturation in the thymus involve NF-κB and tonic type I interferon signaling.
Sample Metadata Fields
Specimen part
View Samples- Saccharomyces cerevisiae
- 12 Downloadable Samples
- Illumina HiSeq 2000, Illumina Genome Analyzer II
Description
During translation elongation, the ribosome ratchets along its mRNA template, incorporating each new amino acid and translocating from one codon to the next. The elongation cycle requires dramatic structural rearrangements of the ribosome. We show here that deep sequencing of ribosome-protected mRNA fragments reveals not only the position of each ribosome but also, unexpectedly, its particular stage of the elongation cycle. Sequencing reveals two distinct populations of ribosome footprints, 28-30 nucleotides and 20-22 nucleotides long, representing translating ribosomes in distinct states, differentially stabilized by specific elongation inhibitors. We find that the balance of small and large footprints varies by codon and is correlated with translation speed. The ability to visualize conformational changes in the ribosome during elongation, at single-codon resolution, provides a new way to study the detailed kinetics of translation and a new probe with which to identify the factors that affect each step in the elongation cycle. Overall design: Ribosome profiling, or sequencing of ribosome-protected mRNA fragments, in yeast. We assay ribosome footprint sizes and positions in three conditions: untreated yeast (3 replicates) and yeast treated with translation inhibitors cycloheximide (2 replicates) and anisomycin (2 biological replicates, one technical replicate). We also treat yeast with 3-aminotriazole to measure the effect of limited histidine tRNAs on ribosome footprint size and distribution (two treatment durations).
Publication Title
Distinct stages of the translation elongation cycle revealed by sequencing ribosome-protected mRNA fragments.
Sample Metadata Fields
Cell line, Treatment, Subject
View Samples