Mediator Complex Regulates Alternative mRNA Processing via the Med23 Subunit
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE33887 | GEO | 2012/02/24
SECONDARY ACCESSION(S): PRJNA148321
REPOSITORIES: GEO
Similar Datasets
Project description:Mediator complex is an integrative hub for transcriptional regulation. Here we show that Mediator regulates alternative mRNA processing via its Med23 subunit. Combining tandem affinity purification and mass spectrometry, we identified a number of mRNA processing factors that bind to a soluble recombinant Mediator subunit MED23 but not to several other Mediator components. One of these factors, hnRNP L, specifically interacts with MED23 in vitro and in vivo. Consistently, Mediator partially colocalizes with hnRNP L and the splicing machinery in the cell. Functionally Med23 regulates a subset of hnRNP L-targeted alternative splicing (AS) and alternative cleavage and polyadenylation (APA) events as shown by minigene reporters and exon array analysis. ChIP-seq analysis revealed that Med23 can regulate hnRNP L occupancy at their co-regulated genes. Taken together, these results demonstrate a crosstalk between Mediator and the splicing machinery, suggesting a novel mechanism for coupling mRNA processing to transcription. Examination of hnRNP L and H3K36me3 enrichment in sictrl and si23 Hela cells
2012-02-24 | E-GEOD-33887 | biostudies-arrayexpress
Project description:Mediator complex is an integrative hub for transcriptional regulation. Here we show that Mediator regulates alternative mRNA processing via its Med23 subunit. Combining tandem affinity purification and mass spectrometry, we identified a number of mRNA processing factors that bind to a soluble recombinant Mediator subunit MED23 but not to several other Mediator components. One of these factors, hnRNP L, specifically interacts with MED23 in vitro and in vivo. Consistently, Mediator partially colocalizes with hnRNP L and the splicing machinery in the cell. Functionally Med23 regulates a subset of hnRNP L-targeted alternative splicing (AS) and alternative cleavage and polyadenylation (APA) events as shown by minigene reporters and exon array analysis. ChIP-seq analysis revealed that Med23 can regulate hnRNP L occupancy at their co-regulated genes. Taken together, these results demonstrate a crosstalk between Mediator and the splicing machinery, suggesting a novel mechanism for coupling mRNA processing to transcription. We performed an exon array experiment using HeLa cells expressing Med23, hnRNP L or control siRNAs which were established by a virus-mediated siRNA technology. Each sample was done in three biological replicates. Total RNA of these cell lines was processed and hybridized to the Affymetrix human exon array.
2012-02-24 | E-GEOD-33771 | biostudies-arrayexpress
Project description:Mediator complex is an integrative hub for transcriptional regulation. Here we show that Mediator regulates alternative mRNA processing via its Med23 subunit. Combining tandem affinity purification and mass spectrometry, we identified a number of mRNA processing factors that bind to a soluble recombinant Mediator subunit MED23 but not to several other Mediator components. One of these factors, hnRNP L, specifically interacts with MED23 in vitro and in vivo. Consistently, Mediator partially colocalizes with hnRNP L and the splicing machinery in the cell. Functionally Med23 regulates a subset of hnRNP L-targeted alternative splicing (AS) and alternative cleavage and polyadenylation (APA) events as shown by minigene reporters and exon array analysis. ChIP-seq analysis revealed that Med23 can regulate hnRNP L occupancy at their co-regulated genes. Taken together, these results demonstrate a crosstalk between Mediator and the splicing machinery, suggesting a novel mechanism for coupling mRNA processing to transcription.
2012-02-24 | GSE33771 | GEO
Project description:Mediator Complex Regulates Alternative mRNA Processing via the Med23 Subunit
| PRJNA148321 | ENA
Project description:Mediator Complex Regulates Alternative mRNA Processing via the Med23 Subunit
| PRJNA148383 | ENA
Project description:We developed a high-throughput mutagenesis screen to comprehensively identify the cis-regulatory elements that control a target splicing event from the MST1R gene that codes for the RON receptor tyrosine kinase. Skipping of alternative exon 11 results in a constitutively active isoform that promotes epithelial to mesenchymal transition and thereby contributes to the invasive phenotype of tumors. We identified the RNA binding protein hnRNP H as an important regulator of RON exon 11 splicing. To map hnRNP H binding sites on the RON minigene with either wildtype or hnRNP H binding site mutant background, we performed hnRNP H iCLIP with RON wildtype or mutant minigene transfected HEK293T cells. iCLIP was performed according to a previously published protocol (PMID: 26463384). The iCLIP libraries were made from two (G331C and G348C) or three replicates (wildtype and G305A) of HEK293T cells at 24 h after RON minigene transfection. The cells were irradiated with 150 mJ/cm2 UV light at 254 nm. For the immunoprecipitation step, we used 7.5 µg of a polyclonal rabbit anti-HNRNPH antibody from Abcam (AB10374). RNase digestion was performed by adding 10 µl of 1/100 diluted RNase I (Ambion) to each sample. We performed the sequencing on an Illumina MiSeq or NextSeq500 with 75-nt single-end reads.
2018-06-27 | E-MTAB-6221 | biostudies-arrayexpress
Project description:We developed a high-throughput mutagenesis screen to comprehensively identify the cis-regulatory elements that control a target splicing event from the MST1R gene that codes for the RON receptor tyrosine kinase. Skipping of alternative exon 11 results in a constitutively active isoform that promotes epithelial to mesenchymal transition and thereby contributes to the invasive phenotype of tumors. We identified the RNA binding protein hnRNP H as an important regulator of RON exon 11 splicing. To map hnRNP H binding sites on the RON minigene, we performed hnRNP H iCLIP with RON wildtype minigene transfected HEK293T cells. iCLIP was performed according to a previously published protocol (PMID: 26463384). The iCLIP libraries were made from two replicates of HEK293T cells at 24 h after RON minigene transfection. The cells were irradiated with 150 mJ/cm2 UV light at 254 nm. For the immunoprecipitation step, we used 7.5 µg of a polyclonal rabbit anti-HNRNPH antibody from Abcam (AB10374). RNase digestion was performed by adding 10 µl of 1/100 diluted RNase I (Ambion) to each sample. We performed the sequencing on an Illumina HiSeq2000 (75-nt single-end reads).
2018-06-27 | E-MTAB-6220 | biostudies-arrayexpress
Project description:We developed a high-throughput mutagenesis screen to comprehensively identify the cis-regulatory elements that control a target splicing event from the MST1R gene that codes for the RON receptor tyrosine kinase. Skipping of alternative exon 11 results in a constitutively active isoform that promotes epithelial to mesenchymal transition and thereby contributes to the invasive phenotype of tumors. First, we created a library of mutated minigenes via mutagenic PCR. Importantly, the reverse primer introduced a random barcode sequence, which labels the associated mutations. Next, the plasmid library was transfected as a pool and depending on the mutations, the transcripts exhibit changes in alternative splicing. The minigene library and the splicing outcome were analyzed by next-generation sequencing and subsequent integration of the datasets resulted in a map of splicing regulatory sites. The RNA binding protein hnRNP H was identified as an important regulator of RON exon 11 splicing. Thus, we performed RNA-seq experiments from minigene library transfected MCF7 cells under control and hnRNP H knockdown conditions in order to quantify the transcript isoforms originating from the minigene library. For preparation of high-throughput RNA sequencing (RNA-seq) libraries, MCF7 cells were first treated with single small interfering RNA (siRNA) against HNRNPH (5′-GGAGCUGGCUUUGAGAGGA[dT][dT] -3′, PMID: 21512137, Sigma-Aldrich) or non-targeting control siRNA (5′-UGGUUUACAUGUCGACUAA[dT][dT]-3′, Sigma-Aldrich) at a final concentration of 20 nM. Next, cells were transfected with the minigene library the day after. A day later, RNA was extracted and subsequently enriched for mRNA by performing polyA selection of 20 µg of total RNA using Dynabeads® Oligo (dT)25 beads (Invitrogen) according to the manufacturer’s protocol. Reverse transcription was carried out using 500 ng of enriched mRNA under the abovementioned conditions. To prevent the formation of chimeric amplicons, the libraries were amplified using emulsion PCR (PMID: 16791213), with Phusion DNA Polymerase (NEB) and cDNA derived from polyA-selected RNA. To amplify fragments for RNA-seq, the following primers containing Illumina sequencing adaptors were used: 5′-CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNGTTCCACTGAAGCCTGAG-3′ (forward primer) and 5′-AATGATACGGCGACCACCGAGATCTACACTCTTTCCCTACACGACGCTCTTCCGATCTNNNNNNNNNNATAGAATAGGGCCCTCTAGA-3′ (reverse primer). PCR products were purified using Agencourt AMPure XP beads (Beckman Coulter). Purified products were first analysed with the TapeStation 2200 capillary gel electrophoresis instrument (Agilent) and then fluorimetrically quantified using a Qubit fluorimeter (Thermo Scientific). Sequencing was carried out on the Illumina MiSeq platform using paired-end reads of 300 nt length and a 10% PhiX spike-in to increase sequence complexity.
2018-06-27 | E-MTAB-6217 | biostudies-arrayexpress
Project description:Unraveling the mechanisms underlying early neural differentiation of ESCs is crucial to the cell-based therapies of neurodegenerate diseases. Neural fate acquisition is proposed to be controlled by a âdefaultâ mechanism, for which the molecular regulation is not well understood. In this study, we investigated the functional roles of Mediator Med23 in pluripotency and lineage commitment of embryonic stem cells (ESCs). Unexpectedly we found that, despite the largely unchanged pluripotency and self-renewal of ESCs, Med23-depletion rendered the cells prone to neural differentiation in different differentiation assays. Knockdown of other Mediator subunit, Med1 or Med15, did not alter the neural differentiation of ESCs; and Med15 knockdown selectively inhibited endoderm differentiation, suggesting the specificity of cell fate control by distinctive Mediator subunits. Gene profiling revealed that Med23-depletion attenuated the BMP signaling in ESCs. Mechanistically, MED23 modulated Bmp4 expression by controlling the activity of ETS1 that is involved in the Bmp4 promoter-enhancer communication. Interestingly, Med23 knockdown in zebrafish embryos also enhanced the neural development at early embryogenesis, which could be reversible by coinjection of bmp4 mRNA. Taken together, our study reveals an intrinsic, restrictive role of MED23 in early neural development, thus providing new molecular insights for neural fate determination. We used microarrays to detail the global gene expression after MED23 knockout We examined the gene expression level in WT and MED23 knockout ES cells in steady culture condition.
2015-03-05 | E-GEOD-64500 | biostudies-arrayexpress
Project description:Mediator complex function as an integrative hub for transcriptional regulation. Here we show that Mediator subunit MED23 regulate glucose and lipid metabolism via FOXO1 in liver. Here, we have generated a liver-specific Med23-knockout (LMKO) mouse and found that Med23-deletion in liver improved glucose and lipid metabolism, as well as insulin responsiveness, and prevented diet-induced obesity. Mechanistically, MED23 participated in gluconeogenesis and cholesterol synthesis by interacting with FOXO1. Disruption of this interaction by hepatic Med23-deletion impaired the Mediator and RNAP II recruitment and partially reduced the expression of the FOXO1 target genes. Remarkably, acute hepatic Med23 knockdown in db/db mice significantly improved insulin sensitivity. Overall, our data revealed Mediator MED23 as a critical regulator of glucose and lipid metabolism, suggesting novel therapeutic strategies against metabolic diseases.
2015-03-16 | GSE48966 | GEO