Cytoplasmic Location of Translation Controls Protein Output [RNA-seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE215768 | GEO | 2022/11/15
REPOSITORIES: GEO
Similar Datasets
Project description:The cytoplasm contains membrane-bound organelles and membraneless compartments. The TIS granule network is formed through assembly of the RNA-binding protein TIS11B together with its bound mRNAs and associates with a portion of the rough endoplasmic reticulum (ER) – one of the major sites of protein synthesis. Subcellular mRNA localization is widespread in polarized cells. However, it is largely unknown if mRNA localization is also widespread in non-polarized cells and if the location of protein synthesis has biological consequences. To identify compartment-specific cellular functions, we used fluorescent particle sorting to isolate TIS granules, the ER surface, and the cytosol and determined their mRNA contents.
2022-11-15 | GSE215769 | GEO
Project description:In eukaryotic cells, the spatial regulation of protein expression is frequently conferred through the coupling of mRNA localization and the local control of translation. mRNA localization to the endoplasmic reticulum (ER) is a prominent example of such regulation and serves a ubiquitous role in segregating the synthesis of secretory and integral membrane proteins to the ER. Recent genomic and biochemical studies have now expanded this view to suggest a role for the ER in global protein synthesis. We have utilized cell fractionation and ribosome profiling to obtain a genomic survey of the subcellular organization of mRNA translation and report that ribosomal loading of mRNAs, a proxy for mRNA translation, is biased to the ER. Notably, ER-associated mRNAs encoding both cytosolic and topogenic signal-encoding proteins display similar ribosome loading densities, suggesting that ER-associated ribosomes serve a global role in mRNA translation. We propose that the partitioning of mRNAs and their translation between the cytosol and ER compartments may represent a novel mechanism for the post-transcriptional regulation of gene expression. HEK293 cells were fractionated between the cytosol and endoplasmic reticulum. Within each fraction, ribosome footprints were generated and sequenced. In parallel, total mRNA was sequenced.
2011-12-20 | E-GEOD-31539 | biostudies-arrayexpress
Project description:In eukaryotic cells, the spatial regulation of protein expression is frequently conferred through the coupling of mRNA localization and the local control of translation. mRNA localization to the endoplasmic reticulum (ER) is a prominent example of such regulation and serves a ubiquitous role in segregating the synthesis of secretory and integral membrane proteins to the ER. Recent genomic and biochemical studies have now expanded this view to suggest a role for the ER in global protein synthesis. We have utilized cell fractionation and ribosome profiling to obtain a genomic survey of the subcellular organization of mRNA translation and report that ribosomal loading of mRNAs, a proxy for mRNA translation, is biased to the ER. Notably, ER-associated mRNAs encoding both cytosolic and topogenic signal-encoding proteins display similar ribosome loading densities, suggesting that ER-associated ribosomes serve a global role in mRNA translation. We propose that the partitioning of mRNAs and their translation between the cytosol and ER compartments may represent a novel mechanism for the post-transcriptional regulation of gene expression.
2011-12-20 | GSE31539 | GEO
Project description:While previous studies suggest that many mRNAs containing more than one translation initiation site (TIS), the biological significance of most alternative TISs and their protein isoform (proteoform) products remains undetermined. Here we show that alternative translation initiation at a CUG and an AUG TIS in neuronal pentraxin receptor (NPR) mRNA produces two proteoforms, and their relative abundance is regulated by both neuronal activity as well as an adjacent RNA secondary structure. Downstream AUG initiation transformed the N-terminal transmembrane domain into a signal peptide, thereby converting NPR to a secreted factor sufficient to promote synaptic clustering of AMPA-type glutamate receptors. Changing the relative proteoform ratio, but not the overall NPR abundance reduces AMPA receptor in parvalbumin (PV)-positive interneurons and induces changes in learning behaviors in mice. In addition to NPR, N-terminal extensions of C1q-like synaptic organizers, mediated by upstream AUU start codons, anchor these otherwise secreted factors to the membrane. Thus, our results uncovered the plasticity of N-terminal signal sequences regulated by alternative TIS usage as a widespread mechanism to diversify protein localization and functions.
2024-09-23 | GSE255191 | GEO
Project description:Protein synthesis belongs to the most energy consuming processes in the cell. Lowering oxygen tension below normal (hypoxia) causes a rapid inhibition of global mRNA translation due to the decreased availability of energy. Interestingly, subsets of mRNAs pursue active translation under such circumstances. In human fibrosarcoma cells (HT1080) exposed to prolonged hypoxia (36 h, 1% oxygen) we observed that transcripts are either increasingly or decreasingly associated with ribosomes localized at the endoplasmic reticulum (ER). In a global setting it turned out that only 31% of transcripts showing elevated total-RNA levels were also increasingly present at the ER in hypoxia. These genes, regulated by its expression as well as its ER-localization, belong to the gene ontology’s “hypoxia response”, “glycolysis” and “HIF-1 transcription factor network” supporting the view of active mRNA translation at the ER during hypoxia. Interestingly, a large group of RNAs was found to be unchanged at the expression level, but translocate to the ER in hypoxia. Among these are transcripts encoding translation factors and >180 ncRNAs. In summary, we provide evidence that protein synthesis is favoured at the ER and, thus, partitioning of the transcriptome between cytoplasmic and ER associated ribosomes mediates adaptation of gene expression in hypoxia. Human fibrosarcoma HT1080 cells were cultured for 36 h under control/atmospheric (21% O2, 5% CO2, 37 °C) or hypoxic (1% O2, 5% CO2, 37°C) conditions. Total RNA (representing expression level) and ER (endoplasmatic reticulum)-RNA (representing transcript localization at ER) was isolated for both conditions. Pooled RNA samples from 5 independent biological experiments were used for microarray analysis.
2015-04-01 | E-GEOD-49029 | biostudies-arrayexpress
Project description:The unfolded protein response (UPR) couples cellular translation rates and gene expression to the protein folding status of the endoplasmic reticulum (ER). Upon activation, the UPR machinery elicits a general suppression of protein synthesis and activation of stress gene expression, which act coordinately to restore protein folding homeostasis. We report here that UPR activation promotes the release of signal sequence-encoding mRNAs from the ER to the cytosol as a mechanism to decrease protein influx into the ER. This release of mRNA begins rapidly, then gradually recovers with ongoing stress. Upon release into the cytosol, these mRNAs have divergent fates: some synthesize full-length proteins, while others are translationally inactive and retain nascent protein chains. Together, these findings identify the dynamic subcellular localization of mRNAs and translation as a regulatory feature of the cellular response to protein folding stress. Cells were treated with a timecourse of Thapsigargin or DTT, then fractionated and analyzed by mRNA-seq or ribosome profiling
2014-08-28 | E-GEOD-53743 | biostudies-arrayexpress
Project description:Signal recognition particle (SRP) pathway function in secretory/membrane protein translocation across the endoplasmic reticulum (ER) is well-established; its role in mRNA localization to the ER in mammalian cells remains largely unexplored. We address this question in SRP receptor (SR) knockout mammalian cell lines. SRPRB KO cells were generated by CRISPR editing. SRPRB KO resulted in profound destabilization of SRα with siRNA silencing of SRPRA in SRPRB KO cells yielding SR KO. Steady-state mRNA composition and ER-enrichments were not disrupted by loss of SR. SR function in the ER localization of newly exported mRNAs was examined by 4-thiouridine (4SU) pulse-chase/4SU-seq and found to be SR-independent. Under conditions of translation initiation inhibition, the ER was the default localization site for newly exported mRNAs. These data demonstrate that mRNA localization to the ER can be uncoupled from SRP pathway function and reopen questions regarding the mechanism of mRNA localization to the ER.
2023-09-01 | GSE164330 | GEO
Project description:Accumulation of misfolded proteins in the endoplasmic reticulum (ER) triggers the unfolded protein response (UPR), which results in the increased phosphorylation of the eukaryotic initiation factor, eIF2a, and widespread translational repression. Protein synthesis is subsequently restored following the stress-induced transcriptional upregulation of GADD34 (growth arrest and DNA damage transcript 34) protein, a regulator of an eIF2a phosphatase. Genome-wide ribosome foot-printing in WT and GADD34-/- MEFs established that GADD34 mRNA is translated in unstressed cells and identified numerous mRNAs, whose translation was dependent on GADD34 even in the absence of ER stress. Following UPR activation, temporal analyses showed that the translational profile in GADD34-/- MEFs was stalled, displaying a pattern that mirrors the early response to UPR in WT MEFs. Basal GADD34 expression is also required for de-repression of translation and displacement of ER-bound polysomes that occur in early UPR. Thus, the overall UPR response is delayed in the GADD34-/- MEFs, gradually recovering as CReP expression increased. These studies reveal a critical role for basal GADD34 in the propagation of UPR signals in MEFs and mice and suggest that delayed UPR signaling protects GADD34-/- mice from tunicamycin-induced renal toxicity.
2015-10-01 | GSE69800 | GEO
Project description:Protein synthesis belongs to the most energy consuming processes in the cell. Lowering oxygen tension below normal (hypoxia) causes a rapid inhibition of global mRNA translation due to the decreased availability of energy. Interestingly, subsets of mRNAs pursue active translation under such circumstances. In human fibrosarcoma cells (HT1080) exposed to prolonged hypoxia (36 h, 1% oxygen) we observed that transcripts are either increasingly or decreasingly associated with ribosomes localized at the endoplasmic reticulum (ER). In a global setting it turned out that only 31% of transcripts showing elevated total-RNA levels were also increasingly present at the ER in hypoxia. These genes, regulated by its expression as well as its ER-localization, belong to the gene ontology’s “hypoxia response”, “glycolysis” and “HIF-1 transcription factor network” supporting the view of active mRNA translation at the ER during hypoxia. Interestingly, a large group of RNAs was found to be unchanged at the expression level, but translocate to the ER in hypoxia. Among these are transcripts encoding translation factors and >180 ncRNAs. In summary, we provide evidence that protein synthesis is favoured at the ER and, thus, partitioning of the transcriptome between cytoplasmic and ER associated ribosomes mediates adaptation of gene expression in hypoxia.
2015-04-01 | GSE49029 | GEO
Project description:The unfolded protein response (UPR) couples cellular translation rates and gene expression to the protein folding status of the endoplasmic reticulum (ER). Upon activation, the UPR machinery elicits a general suppression of protein synthesis and activation of stress gene expression, which act coordinately to restore protein folding homeostasis. We report here that UPR activation promotes the release of signal sequence-encoding mRNAs from the ER to the cytosol as a mechanism to decrease protein influx into the ER. This release of mRNA begins rapidly, then gradually recovers with ongoing stress. Upon release into the cytosol, these mRNAs have divergent fates: some synthesize full-length proteins, while others are translationally inactive and retain nascent protein chains. Together, these findings identify the dynamic subcellular localization of mRNAs and translation as a regulatory feature of the cellular response to protein folding stress.
2014-08-28 | GSE53743 | GEO