N6-methyladenosine (m6A) is the most ubiquitous mRNA base modification, but little is known about its precise location, temporal dynamics, and regulation. Here, we generated genomic maps of m6A sites in meiotic yeast transcripts at nearly single-nucleotide resolution, identifying 1,308 putatively methylated sites within 1,183 transcripts. We validated 8/8 methylation sites in different genes with direct genetic analysis, demonstrated that methylated sites are significantly conserved in a related species, and built a model that predicts methylated sites directly from sequence. Sites vary in their methylation profiles along a dense meiotic time-course, and are regulated both locally, via predictable methylatability of each site, and globally, through the core meiotic circuitry. The methyltransferase complex components localize to the yeast nucleolus, and this localization is essential for mRNA methylation. Our data illuminates a conserved, dynamically regulated methylation program in yeast meiosis, and provides an important resource for studying the function of this epitranscriptomic modification. Overall design: Examination of m6A methylation under various conditions
High-resolution mapping reveals a conserved, widespread, dynamic mRNA methylation program in yeast meiosis.
Cell line, Subject
View SamplesProtein expression is regulated by production and degradation of mRNAs and proteins, but their specific relationships remain unknown. We combine measurements of protein production and degradation and mRNA dynamics to build a quantitative genomic model of the differential regulation of gene expression in LPS stimulated mouse dendritic cells. Changes in mRNA abundance play a dominant role in determining most dynamic fold changes in protein levels. Conversely, the preexisting proteome of proteins performing basic cellular functions is remodeled primarily through changes in protein production or degradation, accounting for over half of the absolute change in protein molecules in the cell. Thus, the proteome is regulated by transcriptional induction of novel cellular functions and remodeling of preexisting functions through the protein life cycle. Overall design: Mouse primary dendritic cells were treated with LPS or mock stimulus and profiled over a 12-hour time course. Cells were grown in M-labeled SILAC media, which was replaced with H-labeled SILAC media at time 0. Aliquots were taken at 0, 0.5, 1, 2, 3, 4, 5, 6, 9, and 12 hours post-stimulation and added to equal volumes of a master mix of unlabeled (L) cells for the purpose of normalization. RNA-Seq was performed at 0, 1, 2, 4, 6, 9, and 12 hours post-stimulation.
Immunogenetics. Dynamic profiling of the protein life cycle in response to pathogens.
No sample metadata fields
View SamplesN6-methyladenosine (m6A) is a common modification of mRNA, with potential roles in fine-tuning the RNA life cycle, but little is known about the pathways regulating this process and its physiological role. Here, we used mass-spectrometry to identify a dense network of proteins physically interacting with METTL3, a core component of the methyltransferase complex, and show that two of them, WTAP and KIAA1429, are required for methylation. Combining high resolution m6A-Seq with knockdown of WTAP allowed us to define accurate maps, at near single-nucleotide resolution, of sites of mRNA methylation across four dynamic programs in human and mouse, including development, differentiation, reprogramming and immune response. Internal WTAP-dependent methylation sites were largely static across the different surveyed conditions and present in the majority of mRNAs. However, methylations were found at much lower levels within highly expressed mRNAs, and methylation is inversely correlated with mRNA stability, consistent with a role in establishing an overall basal, cell-type invariant, distribution of degradation rates. In addition, we identify thousands of WTAP-independent methylation sites at transcription initiation sites, forming part of the mRNA cap structure. We show that the methylations occur at the first transcribed nucleotide, and find that thousands of transcripts are present in different isoforms differing in the methylation state of the first transcribed nucleotide, a previously unappreciated complexity of the transcriptome. Together, our data sheds new light on the proteomic and transcriptional underpinnings of this epitranscriptomic modification in mammals. Overall design: Examination of m6A methylation in human Hek293 and A549 cell lines, in human embryonic stem cells (ESCs) undergoing differentiation to neural progenitor cells (NPCs), in OKMS inducible fibroblasts reprogrammed into iPSC, and upon knockdown of factors using siRNAs or shRNAs.
Perturbation of m6A writers reveals two distinct classes of mRNA methylation at internal and 5' sites.
No sample metadata fields
View SamplesN6-methyladenosine (m6A) is a common modification of mRNA, with potential roles in fine-tuning the RNA life cycle, but little is known about the pathways regulating this process and its physiological role. Here, we used mass-spectrometry to identify a dense network of proteins physically interacting with METTL3, a core component of the methyltransferase complex, and show that two of them, WTAP and KIAA1429, are required for methylation. Combining high resolution m6A-Seq with knockdown of WTAP allowed us to define accurate maps, at near single-nucleotide resolution, of sites of mRNA methylation across four dynamic programs in human and mouse, including development, differentiation, reprogramming and immune response. Internal WTAP-dependent methylation sites were largely static across the different surveyed conditions and present in the majority of mRNAs. However, methylations were found at much lower levels within highly expressed mRNAs, and methylation is inversely correlated with mRNA stability, consistent with a role in establishing an overall basal, cell-type invariant, distribution of degradation rates. In addition, we identify thousands of WTAP-independent methylation sites at transcription initiation sites, forming part of the mRNA cap structure. We show that the methylations occur at the first transcribed nucleotide, and find that thousands of transcripts are present in different isoforms differing in the methylation state of the first transcribed nucleotide, a previously unappreciated complexity of the transcriptome. Together, our data sheds new light on the proteomic and transcriptional underpinnings of this epitranscriptomic modification in mammals. Overall design: Examination of m6A methylation across different knockdowns using shRNAs in mouse embryonic fibroblasts, in embyronic and adult brains, and in dendritic cell stimulated with LPS.
Perturbation of m6A writers reveals two distinct classes of mRNA methylation at internal and 5' sites.
No sample metadata fields
View SamplesWe used microarrays to assess gene expression changes in cells with siRNA-mediated knockdown of OPG compared to normal cells. Furthermore, we used microarrays to assess gene expression in cells treated with either RANKL or TRAIL compared to vehicle-treated cells.
No influence of OPG and its ligands, RANKL and TRAIL, on proliferation and regulation of the calcification process in primary human vascular smooth muscle cells.
Specimen part, Treatment
View SamplesThe present research aimed to study the interaction of three chemicals, methyl mercury, benzene and trichloroethylene, on mRNA expression alterations in rat liver and kidney measured by microarray analysis. These compounds were selected on presumed different modes of action. The chemicals were administered daily for 14 days at the Lowest-Observed-Adverse-Effect-Level (LOAEL) or at a two- or three-fold lower concentration individually or in binary or ternary mixtures. The compounds had strong antagonistic effects on each others gene expression changes, which included several genes encoding Phase I and II metabolizing enzymes. On the other hand, the mixtures affected the expression of “novel” genes that were not or little affected by the individual compounds. Based on gene expression changes, the three compounds exhibited a synergistic interaction at the LOAEL in the liver and both at the sub-LOAEL and LOAEL in the kidney. Many of the genes induced by mixtures but not by single compounds, such as Id2, Nr2f6, Tnfrsf1a, Ccng1, Mdm2 and Nfkb1 in the liver, are known to affect cellular proliferation, apoptosis and function. This indicates a shift from compound specific response on exposure to individual compounds to a more generic stress response to mixtures. Most of the effects on cell viability as concluded from transcriptomics were not detected by classical toxicological research illustrating the difference in sensitivity of these techniques. These results emphasize the benefit of applying toxicogenomics in mixture interaction studies, which yields biomarkers for joint toxicity and eventually can result in an interaction model for most known toxins.
Transcriptomics analysis of interactive effects of benzene, trichloroethylene and methyl mercury within binary and ternary mixtures on the liver and kidney following subchronic exposure in the rat.
Sex, Age, Specimen part, Treatment, Compound
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Differentiation-Defective Human Induced Pluripotent Stem Cells Reveal Strengths and Limitations of the Teratoma Assay and In Vitro Pluripotency Assays.
Specimen part
View SamplesHere we perfomed the Teratoma assay for a normal human embryonic stem cell line (H9(+Dox)), a human embryonic stem cell line with a mesendodermal differentiation bias (H9Hyb), a normal human induced pluripotent stem cell line (LU07), a human induced pluripotent stem cell line with reactivated transgenes (LU07+Dox) and a human embryonal carcinoma cell line (EC) and anayzed their gene expression.
Differentiation-Defective Human Induced Pluripotent Stem Cells Reveal Strengths and Limitations of the Teratoma Assay and In Vitro Pluripotency Assays.
No sample metadata fields
View SamplesBackground: Cancer stem cells are presumed to have virtually unlimited proliferative and self-renewal abilities and to be highly resistant to chemotherapy, a feature that is associated with overexpression of ATP-binding cassette transporters. We investigated whether prolonged continuous selection of cells for drug resistance enriches cultures for cancer stem-like cells.
Prolonged drug selection of breast cancer cells and enrichment of cancer stem cell characteristics.
Cell line, Treatment
View SamplesThis study compares the transcripts bound to BORIS in neural progenitor cells and cells differentiated for 6 days into young neurons
BORIS/CTCFL is an RNA-binding protein that associates with polysomes.
Specimen part
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