Homo sapiens
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PROVIDER: PRJNA308648 | ENA |
REPOSITORIES: ENA
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Project description:Stress granules are small RNA-protein granules that modify the translational landscape during cellular stress to promote survival. The RhoGTPase RhoA is implicated in the formation of RNA stress granules. Our data demonstrate that the cytokinetic proteins ECT2 and AurkB are localized to stress granules in human astrocytoma cells. AurkB and its downstream target histone-3 are phosphorylated during arsenite-induced stress. Chemical (AZD1152-HQPA) and siRNA inhibition of AurkB results in fewer and smaller stress granules when analyzed utilizing high throughput fluorescent based cellomics assays. RNA immunoprecipitation with the known stress granule aggregates TIAR and G3BP1 was performed on astrocytoma cells and subsequent analysis revealed that astrocytoma stress granules harbour unique mRNAs for various cellular pathways including cellular migration, metabolism, translation and transcriptional regulation. Human astrocytoma cell stress granules contain mRNA that are known to be involved in glioma signaling and the mTOR pathway. These data provide evidence that RNA stress granules are a novel form of epigenetic regulation in astrocytoma cells, which may be targetable by chemical inhibitors and enhance astrocytoma susceptiblity to conventional therapy such as radiation and chemotherapy. Astrocytoma cells were either untreated or treated with arsenite to induce stress granule formation and RNA immunoprecipitates were analyzed by exon array analysis. RNA species that were enriched in TIAR RIPs and G3BP1 RIPS, respectively were compared to compared to TIAR and G3BP1 RIPs from untreated cells and input controls. Ingenuity pathway analysis was performed on the stress granule enriched mRNAs from the TIAR and G3BP1 RIPs to identify significant functional biology networks.
2016-02-29 | E-GEOD-76814 | biostudies-arrayexpress
Project description:Stress granules are small RNA-protein granules that modify the translational landscape during cellular stress to promote survival. The RhoGTPase RhoA is implicated in the formation of RNA stress granules. Our data demonstrate that the cytokinetic proteins ECT2 and AurkB are localized to stress granules in human astrocytoma cells. AurkB and its downstream target histone-3 are phosphorylated during arsenite-induced stress. Chemical (AZD1152-HQPA) and siRNA inhibition of AurkB results in fewer and smaller stress granules when analyzed utilizing high throughput fluorescent based cellomics assays. RNA immunoprecipitation with the known stress granule aggregates TIAR and G3BP1 was performed on astrocytoma cells and subsequent analysis revealed that astrocytoma stress granules harbour unique mRNAs for various cellular pathways including cellular migration, metabolism, translation and transcriptional regulation. Human astrocytoma cell stress granules contain mRNA that are known to be involved in glioma signaling and the mTOR pathway. These data provide evidence that RNA stress granules are a novel form of epigenetic regulation in astrocytoma cells, which may be targetable by chemical inhibitors and enhance astrocytoma susceptiblity to conventional therapy such as radiation and chemotherapy.
2016-02-29 | GSE76814 | GEO
Project description:N6-methyladenosine (m6A) in mRNA is key to eukaryotic gene regulation. Many m6A functions involve RNA-binding proteins that recognize m6A via a YT521-B Homology (YTH) domain. YTH domain proteins contain long intrinsically disordered regions (IDRs) that may mediate phase separation and interaction with protein partners, but whose precise biochemical functions remain largely unknown. The Arabidopsis thaliana YTH domain proteins ECT2, ECT3 and ECT4 accelerate organogenesis through stimulation of cell division in organ primordia. Here, we use ECT2 to reveal molecular underpinnings of this function. We show that stimulation of leaf formation requires the long N-terminal IDR, and we identify two short IDR-elements required for ECT2-mediated organogenesis. Of these two, a 19-amino acid region containing a tyrosine-rich motif conserved in both plant and metazoan YTHDF proteins is necessary for binding to the major cytoplasmic poly(A)-binding proteins PAB2, PAB4 and PAB8. Remarkably, overexpression of PAB4 in leaf primordia partially rescues the delayed leaf formation in ect2 ect3 ect4 mutants, suggesting that the ECT2-PAB2/4/8 interaction on target mRNAs of organogenesis-related genes may overcome limiting PAB concentrations in primordial cells.
2023-11-28 | PXD045801 | Pride
Project description:Abstract : "A hallmark of the cellular response to environmental stress is the formation of stress granules. Stress granules are RNA-protein assemblies that provide an adaptive response to stress; however, the basis for their formation and how they contribute to the stress response remains incompletely understood. Here we show that the mRNA modification N6-methyladenosine (m6A) is a mark that targets mRNAs to stress granules. We find that m6A mRNAs are highly enriched in stress granules, and this is mediated by m6A-induced liquid-liquid phase separation of the YTHDF family of m6A-binding proteins. These proteins bind poly-methylated m6A mRNAs, causing them to form liquid droplets that partition into stress granules. Moreover, disrupting either m6A or YTHDF proteins prevents stress granule formation." The goal of this experiment is to understand how recruitment of m6A mRNA to stress granules influences the translational response to heat shock. Result: we found that m6A-containing mRNA are preferentially repressed during stress, and that m6A is required for translational recovery after heat shock
2021-01-15 | GSE109253 | GEO
Project description:Cells limit energy-consuming mRNA translation during stress to maintain metabolic homeostasis. Sequestration of mRNAs by RNA binding proteins (RBPs) into stress granules (SGs) reduces translation, but it remains unclear whether SGs also function in partitioning of specific transcripts to polysomes (PSs) to guide selective translation and stress-adaptation in cancer. Transcripts enriched in PSs, defined by polysome fractionation and RNAseq, were compared with mRNAs complexed with the SG-nucleator protein, G3BP1, defined by spatially-restricted enzymatic tagging. Short-term oxidative stress profoundly altered mRNA translation by promoting selective enrichment of transcripts within SGs or PSs. G3BP1 participates in this compartmentalisation by sequestering transcripts in SGs. Under stress, G3BP1-bound transcripts are PS-depleted and encode proteins involved in mRNA translation, pro-apoptosis, and mitochondrial function. In contrast, specific PS-enriched transcripts disassociate from G3BP1 under stress to encode proteins involved in diverse cellular cytoprotective pathways. Therefore, G3BP1 partitioning guides selective translation to support stress adaptation and cell survival.
2020-04-30 | PXD015491 | Pride
Project description:Epithelial Cell Transforming Sequence 2 (ECT2), a guanine nucleotide exchange factor (GEF) for Rho GTPases, is overexpressed in many cancers and is involved in signal transduction pathways that promote cancer cell proliferation, invasion and tumorigenesis. Recently, we demonstrated that a significant pool of ECT2 localizes to the nucleolus of non small cell lung cancer (NSCLC) cells where it binds the transcription factor Upstream Binding Factor 1 (UBF1) on the promoter regions of the ribosomal DNA (rDNA) and activates rDNA transcription, transformed growth and tumor formation. Here we investigate the mechanism by which ECT2 engages UBF1 on rDNA. Mutagenesis of ECT2 demonstrates that the tandem BRCT domain of ECT2 mediates binding to UBF1. Biochemical and mass spectrometry analysis reveals that Protein Kinase Ci (PKCi) directly phosphorylates UBF1 at Ser412 to generate a phosphopeptide binding epitope that binds the ECT2 BRCT domain. Lentiviral shRNA knockdown and reconstitution experiments demonstrate that both a functional ECT2 BRCT domain and the UBF1 Ser412 phosphorylation site are required for UBF1 mediated ECT2 recruitment to rDNA, elevated rRNA synthesis and transformed growth. Taken together, our study provides new molecular insight into ECT2 mediated regulation of rDNA transcription in cancer cells and provides a rationale for therapeutic targeting of UBF1 and ECT2 stimulated rDNA transcription for the treatment of NSCLC.
2020-04-10 | MSV000085269 | MassIVE
Project description:Alphaherpesviruses remodel the cellular transcriptome to deplete m6A-containing transcripts
| PRJNA827853 | ENA
Project description:Cells limit energy-consuming mRNA translation during stress to maintain metabolic homeostasis. Sequestration of mRNAs by RNA binding proteins (RBPs) into stress granules (SGs) reduces translation, but it remains unclear whether SGs also function in partitioning of specific transcripts to polysomes (PSs) to guide selective translation and stress-adaptation in cancer. Transcripts enriched in PSs, defined by polysome fractionation and RNAseq, were compared with mRNAs complexed with the SG-nucleator protein, G3BP1, defined by spatially-restricted enzymatic tagging. Short-term oxidative stress profoundly altered mRNA translation by promoting selective enrichment of transcripts within SGs or PSs. G3BP1 participates in this compartmentalisation by sequestering transcripts in SGs. Under stress, G3BP1-bound transcripts are PS-depleted and encode proteins involved in mRNA translation, pro-apoptosis, and mitochondrial function. In contrast, specific PS-enriched transcripts disassociate from G3BP1 under stress to encode proteins involved in diverse cellular cytoprotective pathways. Therefore, G3BP1 partitioning guides selective translation to support stress adaptation and cell survival.
2019-11-01 | GSE138058 | GEO
Project description:mRNA and microRNA expression was examined in global cellular fractions and in RNA-induced silencing complex (RISC)-immunoprecipitated cell fractions in cultured primary human astrocytes (ScienCell) and in cultured human U-87 MG astrocytoma cells (ATCC). ABSTRACT: Background: GW/P bodies are cytoplasmic ribonucleoprotein-rich foci that are involved in microRNA (miRNA)-mediated messenger RNA (mRNA) silencing and degradation. These mRNA regulatory functions within GW/P bodies are mediated by GW182 and its binding partner hAgo2 when bound to miRNA within the RNA-induced silencing complex (RISC). Although miRNAs and mRNAs are known to be localized to RISC in a variety of cells, to date no published study has examined the profile of specific miRNA and mRNA targeted to the RISC. Methodology/Principle Findings: In this study, RISC mRNA and miRNA components were profiled by microarray analysis of human U-87 astrocytoma cells and primary human astrocytes with total RNA extracted from the RISC as well as the global cellular fractions. The novel findings of this study were fourfold: (1) miRNAs are highly enriched in primary astrocyte RISC compared to U-87 astrocytoma RISC, (2) astrocytoma cells and primary astrocytes each contain unique RISC miRNA profiles as compared to their respective cellular miRNA profiles, (3) miR-195, 10b, 29b, 19b, 34a and 455-3p were upregulated and miR-181b was downregulated in U-87 astrocytoma RISC as compared to primary astrocyte RISC, and (4) RISC contain mostly downregulated mRNAs in primary astrocytes and U-87 astrocytoma cells. Conclusions/Significance: We show that in U-87 astrocytoma cells, miR-34a and miR-195 were upregulated in RISC suggesting an oncogenic role for these miRNAs. Three miR34a-targeted mRNAs and two miR-195-targeted mRNAs were downregulated. One miR-195-targeted mRNA was upregulated. Biological pathway analysis of RISC mRNA components suggests that the RISC plays a pivotal role in cancer, inflammatory disease, immunological disease, the cell cycle, cellular movement and numerous cell signaling pathways. This study points to the importance of the RISC and ultimately GW/P body composition and function and in miRNA and mRNA deregulation in astrocytoma cells and possibly for other brain tumors. Experiments outsourced to LC Sciences who are partnered with an AffymetrixM-BM-. Authorized Service Provider, SeqWright DNA Technology Services (Houston, TX). Using Affymetrix Human Genome U133A 2.0 Array, they analyzed 14,500 well-characterized human genes across 4 replicates in each of the 4 sample groups: (1) global cellular U-87 astrocytoma, (2) global cellular primary astrocyte, (3) RISC-IP U-87 astrocytoma, and (4) RISC-IP primary astrocyte. Experiments outsourced to LC Sciences (Houston, TX). Using M-BM-5Paraflo microfluidic chips, they analyzed 6211 target human miRNAs (Sanger miRBase version 11, http://microrna.sanger.ac.uk/sequences/) or control RNAs (array hybridization controls and single-base mismatch targets) and a polyethylene glycol spacer segment to extend the coding segment away from the substrate across 4 replicates in each of the 4 sample groups: (1) global cellular U-87 astrocytoma, (2) global cellular primary astrocyte, (3) RISC-IP U-87 astrocytoma, and (4) RISC-IP primary astrocyte.
2011-05-26 | E-GEOD-21514 | biostudies-arrayexpress
Project description:RNP granules are membrane-less compartments within cells, formed by phase separation, that function as regulatory hubs for diverse biological processes. However, the mechanisms by which RNAs and proteins interact to promote RNP granule assembly and function in vivo remain unclear. In Xenopus laevis oocytes, maternal mRNAs are transported as large RNPs to the vegetal hemisphere of the developing oocyte, where local translation is critical for proper embryonic patterning. Here, we demonstrate that vegetal transport RNPs represent a new class of cytoplasmic RNP granule, termed Localization-bodies (L-bodies). We show that L-bodies are multiphase RNP granules, containing a dynamic liquid-like protein-containing phase surrounding a non-dynamic RNA-containing substructure. Our results support a role for RNA as a critical scaffold component within these RNP granules and suggest that cis-elements within localized mRNAs may drive subcellular RNA localization through control over phase behavior.
2020-09-20 | GSE158246 | GEO