The unfolded protein response in fission yeast modulates stability of select mRNAs to maintain protein homeostasis
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ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE40298 | GEO | 2012/11/21
SECONDARY ACCESSION(S): PRJNA173435
REPOSITORIES: GEO
Similar Datasets
Project description:Homeostatic control mechanisms are essentil to life. One such mechanism, the unfolded protein response (UPR) operates in all eukarytic cells to adjust protein folding capacity of the endoplasmic reticulum (ER) according to need. UPR induction in all eurkarytic cells to date involves Ire1 (kinase/endonuclease transmembrane protein) mediated a non-convential splicing of Hac1/XBP1 mRNA, encoding for a potent transcription factor. UPR induction causes a comprehensive transcriptional upregulation of the folding capacity in the ER. Here we studied the global transcriptional profile of the UPR in fission yeast. Fission yeast lacks a clear homolog of Hac1/XBP1. Instead Ire1 maintains ER homeostasis through two post-transciptional programs: selective mRNA decay and processing of Bip1 mRNA (encoding for a major HS70-familiy member in the ER) thereby stabilizing it. S. pombe cells were grown in liquid medium (YE5S) to OD600=0.25. Cells were treated with or without 2 mM DTT (Dithiothreitol, impairs disulfid bond formation) for 60 min at 30℃. Total RNA was extracted from cells using hot phenol method. PolyA+ mRNA were enriched by two sequential rounds of oligo-dT (Invitrogen) selection. rRNA depletion was performed by depletion of ll RNA smaller than 200nt (mirVana miRNA Purification Kit (Ambion) followed by two rounds of subtractive hybridization using Ribominus EukaryoteKit for RNA-seq (Invitrogen). To sequence 2',3'-cyclic phosphate cleavage products tRNA ligase was used to selectively ligate an RNA linker to all 2',3'-cyclic phosphatesin total RNA. (described in Schutz et al., 2010). Two biological repeats were performed for the following samples with different conditions and yeast strains: poly A+ mRNA sample and mRNA enriched (ribosome depletion). On replicate was performed for RNA 3' end mapping carrying a 2',3'-cyclic phosphate: 1 replicate
2012-11-21 | E-GEOD-40298 | biostudies-arrayexpress
Project description:The Unfolded Protein Response (UPR) is an adaptive pathway that restores cellular homeostasis after endoplasmic reticulum (ER) stress caused by an impairment of its protein folding capacity. The ER-resident kinase/ribonuclease Ire1 is the only UPR sensor that has been conserved during evolution from yeast to mammals; in these organisms, Ire1 transmits information from the ER to the nucleus trough the non-conventional splicing of Hac1 (yeast)/Xbp1 (metazoans) mRNA. We described the Dictyostelium discoideum ER-stress response and characterized its single bonafide Ire1 orthologue, IreA. We found that tunicamycin (TN) triggers a gene-expression program that increases the protein folding capacity of the ER and that alleviates ER protein load. Further, IreA resulted essential not only for cell-survival after TN-induced ER-stress, but also to accomplish about nearly 40% of the transcriptional changes induced upon a TN treatment. In addition, we described that autophagy is activated in Dictyostelium cells after a TN treatment and that autophagy-defective mutants exhibited increased sensitivity to this drug. The response of Dictyostelium cells to ER-stress involves the combined activation of an IreA-dependent gene expression program and the autophagy pathway.
2018-04-28 | GSE104409 | GEO
Project description:The unfolded protein response (UPR) aims to restore ER homeostasis under conditions of high protein folding load, a function primarily serving secretory cells. Additional, non-canonical UPR functions have recently been unraveled in immune cells. We addressed the function of the inositol-requiring-enzyme 1 (IRE1) signaling branch of the UPR in NK cells in homeostasis and microbial challenge. Cell-intrinsic compound deficiency (DKO) of IRE1 and its downstream transcription factor XBP1 in NKp46 + NK cells, did not affect basal NK cell homeostasis, or overall outcome of viral MCMV infection. However, mixed bone marrow chimeras revealed a competitive advantage in the proliferation of IRE1 sufficient Ly49H + NK cells after viral infection. CITE-Seq analysis confirmed strong induction of IRE1 early upon infection, concomitant with the activation of a canonical UPR signature. Therefore, we conclude that cell-intrinsic IRE1/XBP1 activation is required for NK cell proliferation early upon viral infection, as part of a canonical UPR response.
2023-10-27 | GSE236820 | GEO
Project description:The unfolded protein response (UPR) aims to restore ER homeostasis under conditions of high protein folding load, a function primarily serving secretory cells. Additional, non-canonical UPR functions have recently been unraveled in immune cells. We addressed the function of the inositol-requiring-enzyme 1 (IRE1) signaling branch of the UPR in NK cells in homeostasis and microbial challenge. Cell-intrinsic compound deficiency (DKO) of IRE1 and its downstream transcription factor XBP1 in NKp46 + NK cells, did not affect basal NK cell homeostasis, or overall outcome of viral MCMV infection. However, mixed bone marrow chimeras revealed a competitive advantage in the proliferation of IRE1 sufficient Ly49H + NK cells after viral infection. CITE-Seq analysis confirmed strong induction of IRE1 early upon infection, concomitant with the activation of a canonical UPR signature. Therefore, we conclude that cell-intrinsic IRE1/XBP1 activation is required for NK cell proliferation early upon viral infection, as part of a canonical UPR response.
2023-10-27 | GSE236819 | GEO
Project description:The ARV1-encoded protein mediates sterol transport from the endoplasmic reticulum (ER) to the plasma membrane. Yeast ARV1 mutants accumulate multiple lipids in the ER and are sensitive to pharmacological modulators of both sterol and sphingolipid metabolism. Using fluorescent and electron microscopy, we demonstrate sterol accumulation, subcellular membrane expansion, elevated lipid droplet formation and vacuolar fragmentation in ARV1 mutants. Motif-based regression analysis of ARV1 deletion transcription profiles indicates activation of Hac1p, an integral component of the UPR. Accordingly, we show constitutive splicing of HAC1 transcripts, induction of a UPR reporter and elevated expression of UPR targets in ARV1 mutants. IRE1, encoding the unfolded protein sensor in the ER lumen, exhibits a lethal genetic interaction with ARV1, indicating a viability requirement for the UPR in cells lacking ARV1. Surprisingly, ARV1 mutants expressing a variant of Ire1p defective in sensing unfolded proteins are viable. Moreover these strains also exhibit constitutive HAC1 splicing that interacts with DTT-mediated perturbation of protein folding. These data suggest a component of UPR induction in arv1? strains is distinct from protein misfolding. Decreased ARV1 expression in murine macrophages also results in UPR induction, particularly up-regulation of activating transcription factor-4, C/EBP homologous protein (CHOP) and apoptosis. Cholesterol loading or inhibition of cholesterol esterification further elevated CHOP expression in ARV1 knockdown cells. Thus, loss or down-regulation of ARV1 disturbs membrane and lipid homeostasis resulting in a disruption of ER integrity, one consequence of which is induction of the UPR. Yeast strains were grown to mid-logarithmic stage (A600=0.5-0.6) for RNA extraction and hybridization on Ye6100 or S98 Affymetrix gene chips. The control array (sample name C) was carried out in duplicate. The ARV1 mutant array (sample name A) was carried out in triplicate. Both ARV1 mutants Ye6100 arrays were compared to the same control Ye6100 array. Strains represent different isolates of the same genotype, mating type and genetic background (w303). Sturley lab collection (SCY) strains include SCY328 and SCY2004 for controls and SCY820 and SCY840 for ARV1 mutants.
2011-02-17 | E-GEOD-26801 | biostudies-arrayexpress
Project description:eIF2α phosphorylation-mediated translational regulation is crucial for global translation repression by various stresses, including the unfolded protein response (UPR). However, translational control during UPR has not been demonstrated in yeast. This study investigated ribosome ubiquitination-mediated translational controls during UPR. Tunicamycin-induced ER stress enhanced the levels of ubiquitination of the ribosomal proteins uS10, uS3 and eS7. Not4-mediated monoubiquitination of eS7A was required for resistance to tunicamycin, whereas E3 ligase Hel2-mediated ubiquitination of uS10 was not. Ribosome profiling showed that the monoubiquitination of eS7A was crucial for translational regulation, including the upregulation of the spliced form of HAC1 (HAC1i) mRNA and the downregulation of Histidine triad NucleoTide-binding 1 (HNT1) mRNA. Downregulation of the deubiquitinating enzyme complex Upb3-Bre5 increased the levels of ubiquitinated eS7A during UPR in an Ire1-independent manner. These findings suggest that the monoubiquitination of ribosomal protein eS7A plays a crucial role in translational controls during the ER stress response in yeast.
2020-11-12 | GSE128578 | GEO
Project description:The ARV1-encoded protein mediates sterol transport from the endoplasmic reticulum (ER) to the plasma membrane. Yeast ARV1 mutants accumulate multiple lipids in the ER and are sensitive to pharmacological modulators of both sterol and sphingolipid metabolism. Using fluorescent and electron microscopy, we demonstrate sterol accumulation, subcellular membrane expansion, elevated lipid droplet formation and vacuolar fragmentation in ARV1 mutants. Motif-based regression analysis of ARV1 deletion transcription profiles indicates activation of Hac1p, an integral component of the UPR. Accordingly, we show constitutive splicing of HAC1 transcripts, induction of a UPR reporter and elevated expression of UPR targets in ARV1 mutants. IRE1, encoding the unfolded protein sensor in the ER lumen, exhibits a lethal genetic interaction with ARV1, indicating a viability requirement for the UPR in cells lacking ARV1. Surprisingly, ARV1 mutants expressing a variant of Ire1p defective in sensing unfolded proteins are viable. Moreover these strains also exhibit constitutive HAC1 splicing that interacts with DTT-mediated perturbation of protein folding. These data suggest a component of UPR induction in arv1? strains is distinct from protein misfolding. Decreased ARV1 expression in murine macrophages also results in UPR induction, particularly up-regulation of activating transcription factor-4, C/EBP homologous protein (CHOP) and apoptosis. Cholesterol loading or inhibition of cholesterol esterification further elevated CHOP expression in ARV1 knockdown cells. Thus, loss or down-regulation of ARV1 disturbs membrane and lipid homeostasis resulting in a disruption of ER integrity, one consequence of which is induction of the UPR.
2011-02-17 | GSE26801 | GEO
Project description:Sse1, yeast cytosolic Hsp110 chaperone, is a wellknown Nucleotide Exchange Factor (NEF), a protein-disaggregase and a Chaperone linked to Protein Synthesis (CLIPS). Here we demonstrate SSE1’s genetic interaction with IRE1 and HAC1, the Endoplasmic Reticulum-Unfolded Protein Response (ER-UPR) sensors. sse1Δ strain exhibits an ER-UPR signalling-dependent resistance to tunicamycin-induced ER stress. Importantly, ER-stress-responsive reorganization of translating ribosomes from polysomes to monosomes is inefficient in SSE1 deleted strain leading to uninterrupted protein translation and starkly different ER-UPR kinetics. sse1Δ exhibits faster ER-UPR induction and quicker reversal to basal state compared to wildtype (WT) cells. Interestingly, ER-stress mediated yeast cell division arrest is escaped in sse1Δ strain during long term tunicamycin stress indicating important role of this chaperone in controlling cell division during ER stress. Furthermore, sse1Δ strain shows significantly higher cell viability in comparison to WT yeast, following short-term as well as long-term tunicamycin stress. In summary, we show that cytosolic chaperone Sse1 genetically interacts with ER-UPR pathway, controls the kinetics of ER-UPR, stress-induced cell division arrest and cell viability during global ER stress by tunicamycin.
2024-04-19 | PXD045382 | Pride
Project description:The unfolded protein response (UPR) allows the endoplasmic reticulum (ER) to recover from the accumulation of misfolded proteins, in part by increasing its folding capacity. IRE1 promotes this remodeling by detecting misfolded ER proteins and activating a transcription factor, XBP-1, through endonucleolytic cleavage of its mRNA. We found that IRE1 independently mediated the rapid degradation of a specific subset of mRNAs. The arrays deposited here show the effects of depletion of IRE1 and XBP-1 on UPR induction in S2 cells. We have characterized the IRE1-dependent repressive branch of this response. Keywords: stress response, RNAi, DTT
2006-05-20 | GSE4867 | GEO
Project description:The accumulation of unfolded proteins in the lumen of the endoplasmic reticulum (ER) causes stress and induces the unfolded protein response (UPR) which is characterised in part by the transcriptional induction of genes involved in assisting protein folding. Translational responses to ER stress have been less well described and here we report on a genome-wide analysis of translational regulation in the response to the ER stress-inducing agent dithiothreitol (DTT) in Saccharomyces cerevisiae. Although the observed polysome profiles were similar under control and ER stress conditions microarray analysis identified transcipt-specific translational regulation. Genes with functions in ribosomal biogenesis and assembly were translationally repressed under ER stress. In contrast mRNAs for known UPR genes, including the UPR transcription factor HAC1, the ER-oxidoreductase ERO1 and the ER-associated protein degradation (ERAD) gene DER1 were enriched in polysomal fractions under ER stress conditions. In addition, we show that splicing of HAC1 mRNA is required for efficient ribosomal loading and that Gcn2p is required for normal HAC1 splicing, so shedding light on the role of this protein kinase in the UPR pathway. Experiment Overall Design: Polyribosomes were extracted from S. cerevisiae cells treated with 2 mM DTT or water (control), and fractionated according to ribosome loading. Following RNA purification from these fractions, for each sub-polysomal and polysomal RNA sample, fractions from three independent extracts per treatment (DTT/control) were pooled.
2008-06-11 | E-GEOD-10091 | biostudies-arrayexpress