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SRP149449
Homo sapiens
18 Downloadable Samples
Illumina HiSeq 2500
Description
Here, we present a systematic and quantitative test of the hypothesis that the composition and activities of the endoplasmic reticulum (ER) proteostasis network impact mutational tolerance of secretory pathway client proteins. We focus on influenza hemagluttinin (HA), a viral coat protein that folds in the host's ER via a complex but well-characterized pathway. By integrating chemical methods to modulate the unfolded protein response with deep mutational scanning to assess mutational tolerance, we discover that upregulation of ER chaperones broadly enhances HA mutational tolerance across numerous sites and secondary/tertiary structure elements, including sites targeted by host antibodies. Remarkably, this host chaperone-enhanced mutational tolerance is observed at the same HA sites where mutational tolerance is most reduced by propagation at a fever-like temperature. Thus, host ER proteostasis mechanisms and temperature modulate HA mutational tolerance in opposite directions. This finding has important implications for influenza evolution, because influenza immune escape is contingent on HA possessing sufficient mutational tolerance to acquire antibody resistance while still maintaining the capacity to fold and function. More broadly, this work provides the first experimental evidence that the composition and activities of the ER proteostasis network critically define the mutational tolerance and, therefore, the evolution of secretory pathway client proteins. Overall design: RNA-seq characterizing a clonal HEK293T-Rex cell line, expressing DHFR ATF6f, Tet XBP1s, and the tetracycline repressor. These cell lines were treated with small molecules for 24 hours (in triplicate) to modulate the proteostasis environment in a stress-independent manner, at either 37C or 39C. XBP1s was activated by treatment with 0.1 ug/mL Doxycycline; ATF6f/XBP1s were activated by treatment with 0.1 ug/mL Doxycycline and 1 uM TMP; basal cells were vehicle-treated (0.01% DMSO). These cells were previously characterized in Shoulders et al. Cell Reports, 2013.
Publication Title
Enhanced ER proteostasis and temperature differentially impact the mutational tolerance of influenza hemagglutinin.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Homo sapiens
- 9 Downloadable Samples
- Illumina HiSeq 2000
Description
We 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
Publication Title
A Method for Selective Depletion of Zn(II) Ions from Complex Biological Media and Evaluation of Cellular Consequences of Zn(II) Deficiency.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 15 Downloadable Samples
Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Stress-independent activation of XBP1s and/or ATF6 reveals three functionally diverse ER proteostasis environments.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The unfolded protein response (UPR) maintains endoplasmic reticulum (ER) proteostasis through the activation of transcription factors such as XBP1s and ATF6. The functional consequences of these transcription factors for ER proteostasis remain poorly defined. Here, we describe methodology that enables orthogonal, small molecule-mediated activation of the UPR-associated transcription factors XBP1s and/or ATF6 in the same cell independent of stress. We employ transcriptomics and quantitative proteomics to evaluate ER proteostasis network remodeling owing to the XBP1s and/or ATF6 transcriptional programs. Furthermore, we demonstrate that the three ER proteostasis environments accessible by activating XBP1s and/or ATF6 differentially influence the folding, trafficking, and degradation of destabilized ER client proteins without globally affecting the endogenous proteome. Our data reveal how the ER proteostasis network is remodeled by the XBP1s and/or ATF6 transcriptional programs at the molecular level and demonstrate the potential for selectively restoring aberrant ER proteostasis of pathologic, destabilized proteins through arm-selective UPR-activation.
Publication Title
Stress-independent activation of XBP1s and/or ATF6 reveals three functionally diverse ER proteostasis environments.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The unfolded protein response (UPR) maintains endoplasmic reticulum (ER) proteostasis through the activation of transcription factors such as XBP1s and ATF6. The functional consequences of these transcription factors for ER proteostasis remain poorly defined. Here, we describe methodology that enables orthogonal, small molecule-mediated activation of the UPR-associated transcription factors XBP1s and/or ATF6 in the same cell independent of stress. We employ transcriptomics and quantitative proteomics to evaluate ER proteostasis network remodeling owing to the XBP1s and/or ATF6 transcriptional programs. Furthermore, we demonstrate that the three ER proteostasis environments accessible by activating XBP1s and/or ATF6 differentially influence the folding, trafficking, and degradation of destabilized ER client proteins without globally affecting the endogenous proteome. Our data reveal how the ER proteostasis network is remodeled by the XBP1s and/or ATF6 transcriptional programs at the molecular level and demonstrate the potential for selectively restoring aberrant ER proteostasis of pathologic, destabilized proteins through arm-selective UPR-activation.
Publication Title
Stress-independent activation of XBP1s and/or ATF6 reveals three functionally diverse ER proteostasis environments.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Rattus norvegicus
- 25 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
The endoplasmic reticulum (ER) is the site of secretory lipoprotein production and de novo cholesterol synthesis, yet little is known about how these activities are coordinated with each other, or with the activity of the COPII machinery, which transports ER cargo to the Golgi. The Sar1B component of this machinery is mutated in Chylomicron Retention Disorder, establishing that this Sar1 isoform secures delivery of dietary lipids into the circulation.
Publication Title
The endoplasmic reticulum coat protein II transport machinery coordinates cellular lipid secretion and cholesterol biosynthesis.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 9 Downloadable Samples
- Illumina HiSeq 2000
Description
The unfolded protein response (UPR), as its name implies, safeguards secretory pathway proteostasis. The most ancient arm of the UPR, the IRE1-activated, XBP1s-mediated transcriptional response, has roles in secretory pathway maturation beyond resolving proteostatic stress. Understanding the consequences of XBP1s' transcriptional output for cellular processes is critical for elucidating mechanistic connections between XBP1s and development, immunity, and disease. Here, we show that a key functional consequence of XBP1s activation is a cell type-dependent shift in the distribution of N-glycan structures on endogenous membrane and secreted proteomes. XBP1s activity decreases sialylation of tri- and tetra-antennary N-glycans in the HEK293 membrane proteome and secretome, while substantially increasing the population of high mannose N-glycans only in the secretome. Related, but distinctive, signatures in the HEK293 N-glycome are observed when the entire UPR is activated in a stress-dependent manner using thapsigargin. In HeLa cells, stress-independent XBP1s activation increases the population of cell surface high mannose N-glycans and tetra-antennary N-glycans. mRNA profiling experiments suggest that the XBP1s-mediated remodeling of the N-glycome may re-flect a coordinated consequence of transcriptional resculpting of the N-glycan maturation pathway by XBP1s. The discovery of XBP1s-induced N-glycan structural remodeling on a glycome-wide scale suggests that XBP1s is a master regulator of N-glycan maturation. Moreover, because the sugars on cell surface proteins or on those proteins secreted from an XBP1s-activated cell can be molecularly distinct from those of an unactivated cell, these findings reveal a potential new mechanism for translating intracellular stress signaling pathways into al-tered interactions with the extracellular environment. Overall design: Three biological replicates of HeLaXBP1s cells treated with DMSO vehicle, 1 ug/ml dox or 750 nM Thapsigargin.
Publication Title
XBP1s activation can globally remodel N-glycan structure distribution patterns.
Sample Metadata Fields
Cell line, Treatment, Subject, Time
View Samples- Homo sapiens
- 120 Downloadable Samples
- Affymetrix Human Genome U95A Array (hgu95a)
Description
FCHL is a common, complex genetic lipid disorder with a largely unknown aetiology. Altered adipose tissue metabolism has been implicated as contributing to FCHL.
Publication Title
CDKN2B expression in adipose tissue of familial combined hyperlipidemia patients.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus, Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
MicroRNAs are transported in plasma and delivered to recipient cells by high-density lipoproteins.
Sample Metadata Fields
Sex, Age, Cell line, Treatment
View Samples- Oryza sativa
- 24 Downloadable Samples
- Affymetrix Rice Genome Array (rice)
Description
In response to bacterial infection, early transcriptional re-programming occurs in the host plant.
Publication Title
Antagonistic, overlapping and distinct responses to biotic stress in rice (Oryza sativa) and interactions with abiotic stress.
Sample Metadata Fields
Specimen part
View Samples