Single cut products of Microprocessor on pri-miRNAs
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ABSTRACT:
PROVIDER: PRJNA577891 | ENA |
REPOSITORIES: ENA
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Project description:The human Microprocessor complex cleaves primary microRNA (miRNA) transcripts (pri-miRNAs) to initiate miRNA synthesis. Microprocessor consists of DROSHA (an RNase III enzyme), and DGCR8. DROSHA has two conserved RNase III domains, which make double cuts on each of pri-miRNA strands. In this study, we show that Microprocessor has an unexpected single-cut activity, which creates a single cut on just one of the pri-miRNA strands using one of the two RNase III domains of DROSHA. This cleavage does not lead to the production of miRNA but instead it downregulates miRNA expression. We also demonstrate that certain RNA elements facilitate the single-cut activity of Microprocessor, and by manipulating these elements, we can regulate the ratio of single-cut to double-cut activities, thus controlling miRNA production both in vitro and in vivo.
2020-01-24 | GSE138950 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. MicroRNAs are predicted to regulate the expression of more than 60% of mammalian genes and play fundamental roles in most biological processes. Deregulation of miRNA expression is a hallmark of most cancers and further investigation of mechanisms controlling miRNA biogenesis is needed. The dsRNA-binding protein, NF90 has been shown to act as a competitor of Microprocessor for a limited number of pri-miRNAs. Here, we show that NF90 has a more widespread effect on pri-miRNA biogenesis than previously thought. Genome-wide approaches revealed that NF90 is associated with the stem region of 38 pri-miRNAs, in a manner that is largely exclusive of Microprocessor. Following loss of NF90, 25 NF90-bound pri-miRNAs showed increased abundance of mature miRNA products. NF90-targeted pri-miRNAs are highly stable, having a lower free energy and fewer mismatches compared to all pri-miRNAs. Mutations leading to less stable structures reduced NF90 binding while increasing pri-miRNA stability led to ac quisition of NF90 association, as determined by RNA EMSA. NF90-bound and modulated pri-miRNAs are embedded in introns of host genes and expression of several is concomitantly modulated, including an oncogene implicated in metastasis of hepatocellular carcinoma, TIAM2. These data suggest that NF90 controls the processing of a subset of highly stable, intronic miRNAs.
2020-05-01 | GSE132341 | GEO
Project description:Targeted sequencing at Microprocessor cleavage sites in pri-miRNAs to determine processing efficiency of several pri-miRNAs in vivo in one experiment
2020-05-01 | GSE149631 | GEO
Project description:Targeted sequencing at Microprocessor cleavage sites in pri-miRNAs to determine processing efficiency of several pri-miRNAs in vivo in one experiment
2020-04-17 | GSE148756 | GEO
Project description:Human Microprocessor cleaves pri-miRNAs to initiate miRNA biogenesis. The accuracy and efficiency of Microprocessor cleavage ensure appropriate miRNA sequence and expression and thus its proper gene regulation. However, Microprocessor cleaves many pri-miRNAs incorrectly, so it requires assistance from its many cofactors. For example, SRSF3 enhances Microprocessor cleavage by interacting with the CNNC motif in pri-miRNAs. However, whether SRSF3 can function with other motifs and/or requires the motifs in a certain secondary structure is unknown. In addition, the function of SRSF7 (a paralog of SRSF3) in miRNA biogenesis still needs to be discovered. Here, we demonstrated that SRSF7 could stimulate Microprocessor cleavage. In addition, by conducting high-throughput pri-miRNA cleavage assays for Microprocessor and SRSF7 or SRSF3, we demonstrated that SRSF7 and SRSF3 function with the CRC and CNNC motifs, adopting certain secondary structures. In addition, SRSF7 and SRSF3 affect the Microprocessor cleavage sites in human cells. Our findings demonstrate the roles of SRSF7 in miRNA biogenesis and provide a comprehensive view of the molecular mechanism of SRSF7 and SRSF3 in enhancing Microprocessor cleavage.
2023-01-23 | GSE215790 | GEO
Project description:MicroRNA biogenesis is known to be modulated by a variety of RNA binding proteins (RBPs), but in most cases, individual RBPs appear to influence the processing of a small number of selective targets. We herein report binding of the NONO/PSF heterodimer to hundreds of expressed pri-miRNAs in HeLa cells to globally enhance pri-miRNA processing by the Drosha/DGCR8 Microprocessor. As NONO/PSF are key components of paraspeckles organized by the lncRNA NEAT1, we find that NEAT1 also has profound effects on global pri-miRNA processing. Mechanistic dissection reveals that NEAT1 broadly interacts with NONO/PSF as well as many other RBPs, and that multiple RNA segments in NEAT1, including a “pseudo pri-miRNA” near its 3’ end, help attract the Microprocessor. These findings suggest a bird nest model for a large lncRNA to orchestrate efficient processing of an entire class of small RNAs in the nucleus.we used small RNA-seq to identify miRNA level in response to secific knockdowns relative to siGFP treatment control
2017-07-26 | GSE90650 | GEO
Project description:The cellular abundance of mature microRNAs (miRNAs) is dictated by the efficiency of nuclear processing of primary miRNA transcripts (pri-miRNAs) into pre-miRNA intermediates. The Microprocessor complex of Drosha and DGCR8 carries this out, but it has been unclear what controls Microprocessor's differential processing of various pri-miRNAs. Here, we show that Drosophila DGCR8 (Pasha) directly associates with the C terminal domain of the RNA polymerase II elongation complex when it is phosphorylated by the Cdk9 kinase (pTEFb). When association is blocked by loss of Cdk9 activity, a global change in pri-miRNA processing is detected. Processing of pri-miRNAs with a UGU sequence motif in their apical junction domain increases, while processing of pri-miRNAs lacking this motif decreases. Therefore, phosphorylation of RNA polymerase II recruits Microprocessor for co-transcriptional processing of non-UGU pri-miRNAs that would otherwise be poorly processed. In contrast, UGU-positive pri-miRNAs are robustly processed by Microprocessor independent of RNA polymerase association.
2017-09-15 | GSE103234 | GEO
Project description:Microprocessor, which consists of a ribonuclease III DROSHA and its cofactor DGCR8, initiates microRNA (miRNA) maturation by cleaving primary miRNA transcripts (pri-miRNAs). We recently demonstrated that the DGCR8 dimer recognizes the apical elements of pri-miRNAs, including the UGU motif, to accurately locate and orient Microprocessor on pri-miRNAs. However, the mechanism underlying the selective RNA binding remains unknown. In this study, we find that hemin, a ferric ion-containing porphyrin, enhances the specific interaction between the apical UGU motif and the DGCR8 dimer, allowing Microprocessor to achieve high efficiency and fidelity of pri-miRNA processing in vitro. Furthermore, by generating a DGCR8 mutant cell line and carrying out rescue experiments, we discover that hemin preferentially stimulates the expression of miRNAs possessing the UGU motif, thereby conferring differential regulation of miRNA maturation. Our findings reveal the molecular action mechanism of hemin in pri-miRNA processing and establish a novel function of hemin in inducing specific RNA-protein interaction.
2018-03-26 | GSE111431 | GEO
Project description:The microRNA (miRNA) biogenesis is responsible for the production of miRNAs that play critical roles in gene expression and numerous human diseases. The adequate biogenesis of miRNAs is largely determined by the efficiency and fidelity of primary microRNA (pri-miRNA) processing by Microprocessor. Here, we investigated the roles of a secondary RNA element, an RNA bulge, in pri-miRNA processing. We discovered that the 3p-strand bulges in positions 7-9 from the Microprocessor cleavage sites (midB_7-9) contributes to determining the cleavage sites of Microprocessor, the 5p- and 3p-strand bugles in positions 10-12 (midB_10-12) blocked the unproductive cleavage, and the 3p-strand bulges in positions 6-7 (seedB) inhibited the productive cleavage of Microprocessor. The 5p-strand midB_10-12 was found enriched and conserved in many pri-miRNAs of humans and other organisms. In addition, by analyzing the published Microprocessor-RNA structure and doing mutagenesis, we identified several amino acid residues of Microprocessor that explains a structure basis for the processing inhibition caused by seedB. The revealed functions of bulges in our study improves our understanding of the pri-miRNA processing by Microprocessor and implies their roles in regulating miRNA expression.
2021-08-23 | GSE158060 | GEO
Project description:Microprocessor (MP), cleaving primary microRNAs (pri-miRNAs) to initiate the biogenesis of thousands of miRNAs, was discovered in animals in 2004. Understanding the molecular mechanism of MP is critical for interpreting the gene-silencing roles of miRNAs in various cellular processes and human diseases. Though the molecular mechanism of human MP (hMP) has been comprehensively investigated for nearly two decades and is well understood, that of Caenorhabditis elegans MP (cMP, cDrosha-Pasha complex) is still unknown. In this study, we revealed a comprehensive molecular mechanism of cMP, distinctively from that of hMP. In the proposed mechanism, cDrosha and Pasha (DGCR8 in humans) measure ~16 bp and ~25 bp of the pri-miRNA stem, respectively, and they are coordinated in determining cleavage sites of cMP in pri-miRNAs. In addition, we also demonstrated the molecular basis for their substrate measurement. Our findings illustrate an unknown molecular mechanism of cMP, clarify differences between the mechanism of hMP and cMP, and provide a foundation for understanding multiple mechanisms regulating miRNA expression acting on cMP.
2023-01-23 | GSE212229 | GEO