Feedback control by the human microRNA, let-7, regulates expression of the RNA sielncing enzyme, Dicer
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ABSTRACT:
ORGANISM(S): Mus musculus Homo sapiens
PROVIDER: GSE2918 | GEO | 2009/06/30
SECONDARY ACCESSION(S): PRJNA92605
REPOSITORIES: GEO
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Project description:DICER has a well-characterized role in the processing of microRNAs (miRNAs) and small interfering RNAs (siRNA) that are important for post-transcriptional gene regulation. Emerging evidence suggests that DICER also has several non-canonical functions beyond miRNA/siRNA biogenesis, for example in transcriptional gene silencing at the chromatin level, as well as in RNA degradation and maintenance of genomic integrity. We have shown that the function of DICER in germ cells is essential for normal spermatogenesis; male mice lacking DICER in postnatal male germ cells are infertile due to severe defects in haploid differentiation. To better understand the function of DICER in male germ cells, we immunoprecipitated DICER from juvenile mouse testes and performed mass spectrometric analysis to identify DICER-interacting proteins.
2020-06-03 | PXD017772 | Pride
Project description:Dicer is an essential ribonuclease involved in the biogenesis of miRNA. Previous studies have reported that Dicer is dysregulated in multiple types of cancers. To investigate the downstream phosphoproteome of Dicer, we carried out phosphotyrosine profiling of the liver of Dicer knockout of mice. We employed antibody-based enrichment of phosphotyrosine containing peptides coupled with spike-in SILAC-based quantitation. Over 400 phosphoisites were identified in each condition while 290 phosphosites were quantitated in common. Amongst these, several key signaling molecules like receptor tyrosine kinase MET, MET, PDGFR, EPHA2, EPHB4 and IGF1R/INSR were hyperphosphorylated. Also, non-receptor tyrosine kinases of Src family and their downstream effector signaling partners including IRS2 and STAT3were found to be hyperphosphorylated. Our study indicates that there is significant alteration in the signaling pathways upon ablation of Dicer.
2016-07-08 | PXD000927 | Pride
Project description:Feedback control by the human microRNA, let-7, regulates expression of the RNA sielncing enzyme, Dicer
| PRJNA92605 | ENA
Project description:We have used genome editing to generate inactivating deletion mutations in all three copies of the dicer (hdcr) gene present in the human cell line 293T. As previously shown in murine ES cells lacking Dicer function, hDcr-deficient 293T cells are severely impaired for the production of mature microRNAs (miRNAs). Nevertheless, RNA-induced silencing complexes (RISCs) present in these hDcr-deficient cells are readily programmed by transfected, synthetic miRNA duplexes to repress mRNAs bearing either fully or partially complementary targets, including targets bearing incomplete seed homology to the introduced miRNA. Using these hDcr-deficient 293T cells, we demonstrate that human pre-miRNA processing can be effectively rescued by ectopic expression of the Drosophila Dicer 1 protein, but only in the presence of the PB isoform of Loquacious (Loqs-PB), the fly homolog of the hDcr co-factor TRBP. In contrast, Drosophila Dicer 2, even in the presence of its co-factors Loqs-PD and R2D2, was unable to support human pre-miRNA processing. Interestingly, although ectopic Drosophila Dicer 1/Loqs-PB or hDcr both rescued pre-miRNA processing effectively in these hDcr-deficient cells, there were significant differences in the ratio of the miRNA isoforms that were produced, especially in the case of miR-30 family members, and we also noted differences in the relative expression level of miRNAs versus passenger strands for a subset of human miRNAs. These data demonstrate that the mechanisms underlying the accurate processing of pre-miRNAs are largely, but not entirely, conserved between mammalian and insect cells.
2014-04-17 | GSE56836 | GEO
Project description:As the biogenesis of miRNAs depends on the cleavage by the RNase III enzyme Dicer, miR-18a may change the miRNA expression profiles by targeting dicer. We then performed the miRNA array assay to investigate the miRNA profiles change caused by miR-18a.
2012-03-01 | GSE32680 | GEO
Project description:Biogenesis of canonical microRNAs (miRNAs) involves multiple steps: nuclear processing of primary miRNA (pri-miRNA) by DROSHA, nuclear export of precursor miRNA (pre-miRNA) by Exportin 5 (XPO5), and cytoplasmic processing of pre-miRNA by DICER. To gain a deeper understanding of the contribution of each of these maturation steps, we deleted DROSHA, XPO5, and DICER in the same human cell line, and analyzed their effects on miRNA biogenesis. Canonical miRNA production was completely abolished in DROSHA-deleted cells while we detected a few DROSHA-independent miRNAs including three previously unidentified noncanonical miRNAs (miR-7706, miR-3615, and miR-1254). In contrast to DROSHA knockout, many canonical miRNAs were still detected without DICER albeit at markedly reduced levels. In the absence of DICER, pre-miRNAs are loaded directly onto AGO and trimmed at the 3′ end, yielding miRNAs from the 5′ strand (5p miRNAs). Interestingly, in XPO5 knockout cells, most miRNAs are affected only modestly, suggesting that XPO5 is necessary but not critical for miRNA maturation. Our study demonstrates an essential role of DROSHA and an important contribution of DICER in the canonical miRNA pathway, and reveals that the function of XPO5 can be complemented by alternative mechanisms. Thus, this study allows us to understand differential contributions of key biogenesis factors, and provides with valuable resources for miRNA research.
2016-03-17 | GSE77989 | GEO
Project description:We have used genome editing to generate inactivating deletion mutations in all three copies of the dicer (hdcr) gene present in the human cell line 293T. As previously shown in murine ES cells lacking Dicer function, hDcr-deficient 293T cells are severely impaired for the production of mature microRNAs (miRNAs). Nevertheless, RNA-induced silencing complexes (RISCs) present in these hDcr-deficient cells are readily programmed by transfected, synthetic miRNA duplexes to repress mRNAs bearing either fully or partially complementary targets, including targets bearing incomplete seed homology to the introduced miRNA. Using these hDcr-deficient 293T cells, we demonstrate that human pre-miRNA processing can be effectively rescued by ectopic expression of the Drosophila Dicer 1 protein, but only in the presence of the PB isoform of Loquacious (Loqs-PB), the fly homolog of the hDcr co-factor TRBP. In contrast, Drosophila Dicer 2, even in the presence of its co-factors Loqs-PD and R2D2, was unable to support human pre-miRNA processing. Interestingly, although ectopic Drosophila Dicer 1/Loqs-PB or hDcr both rescued pre-miRNA processing effectively in these hDcr-deficient cells, there were significant differences in the ratio of the miRNA isoforms that were produced, especially in the case of miR-30 family members, and we also noted differences in the relative expression level of miRNAs versus passenger strands for a subset of human miRNAs. These data demonstrate that the mechanisms underlying the accurate processing of pre-miRNAs are largely, but not entirely, conserved between mammalian and insect cells. Series includes three datasets of total small RNA reads from wild type and Dicer negative 293T cells. Also included are total small RNA reads of the Dicer-negative cell line NoDice(4-25) transfected with a vector expressing human Dicer, Drosophila Dicer1, or mock transfected. RISC-associated small RNAs identified by ribonucleoprotein immunoprecipitation (RIP-Seq) in wild type 293T, Dicer-negative NoDice(4-25) line, and NoDice(4-25) transfected with either hsa-miR-155 or kshv-miR-K12-11 miRNA duplexes. The final data series are PAR-CLIP libraries which identified microRNA targets in untransfected NoDice(4-25) cells and NoDice(4-25) cells transfected with either hsa-miR-92a, hsa-miR-155, kshv-miR-K12-11 miRNA duplexes
2014-04-17 | E-GEOD-56836 | biostudies-arrayexpress
Project description:Ovarian cancer is a nearly uniform lethal disease and its highly aggressive metastatic phenotype portends a poor prognosis. Lack of a well-controlled, relevant experimental model has been a major obstacle to identifying key molecules causing metastasis. Here we describe the creation of a new isogenic model of spontaneous human ovarian cancer metastasis exhibiting opposite phenotypes - highly metastatic (HM) and non-metastatic (NM) - both in vitro and in vivo. HM was unique in its ability to metastasize consistently to the peritoneum, mimicking the major dissemination route of human ovarian cancer. In contrast, NM failed to form detectable metastases although it was equally tumorigenic. Using comparative label-free quantitative LC-MS/MS, we identified b-catenin which we demonstrated for the first time a direct role in the pathogenesis of ovarian cancer metastasis. Our studies also revealed a previously unrecognized role of b-catenin in the downregulation of multiple microRNAs (miRNAs) through attenuating miRNA biogenesis by targeting Dicer, a key component of the microRNA processing machinery. One such downregulated miRNAs was miR-29s involved in epithelial-to-mesenchymal transition and subsequent stem cell traits. Silencing b-catenin or overexpressing Dicer or miR-29 mimics in HM significantly reduced the ability of these cells to migrate. B-catenin knockdown cells also failed to metastasize in an orthotopic model of ovarian cancer. Meta-analysis revealed an increase in CTNNB1 and a decrease in DICER1 expression levels in the high-risk group. These results uncover b-catenin as a critical player in promoting ovarian cancer aggressiveness and a new mechanism linking between b-catenin and miRNA downregulation underlying this process.
2017-07-03 | PXD006327 | Pride
Project description:5’-isomiRs expand the repertoire of miRNA targets. However, how they are generated is not well understood. Here, we showed that, for some miRNAs in mammalian cells, 5’-isomiRs are generated by alternative Dicer processing by using miRNA offset RNAs (moRs) to determine Drosha cleavage sites in cells. In addition, we showed that in miR-203, alternative Dicer processing is regulated by a conserved sliding-bulge structure at the Dicer processing site, which allows the pre-miRNA molecule to fold into two different structures that are processed differently by Dicer. So far no RNA motif that slides to change conformation and alter a protein–RNA interaction has been reported. Thus, our study revealed a novel RNA motif that regulates 5’-isomiR generation in some miRNAs. It might also contribute to regulating protein–RNA interactions in other biological processes, since it takes only one point mutation to generate the sliding bulge, and there are a large number of different RNAs in the cell.
2016-09-01 | GSE80772 | GEO
Project description:As the biogenesis of miRNAs depends on the cleavage by the RNase III enzyme Dicer, miR-18a may change the miRNA expression profiles by targeting dicer. We then performed the miRNA array assay to investigate the miRNA profiles change caused by miR-18a. Total RNA obtained from two pairs,one is the miR-18a overexpression cell line compared to the miRNAs (control), the other is the over-expression miR-18a cell line transfected Dicer plasmid.
2012-03-01 | E-GEOD-32680 | biostudies-arrayexpress