Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Microprocessor depends on hemin to recognize the apical loop of primary microRNA

ABSTRACT: 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.

ORGANISM(S): Homo sapiens

PROVIDER: GSE111431 | GEO | 2018/03/26

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Shared Molecules

Only show the datasets with similarity scores above: 0.5

Threshold

0.5

Similar Datasets

The DGCR8-UGU interaction in microRNA biogenesis

Project description:Human Microprocessor is a trimeric complex composed of the RNase III enzyme, DROSHA, and a dimer of DGCR8 (its cofactor). Microprocessor initiates the biogenesis of microRNA by processing primary microRNAs (pri-miRNAs), during which, its cleavage efficiency and accuracy are enhanced because DGCR8 interacts with the apical UGU motif of pri-miRNAs. However, the mechanism of DGCR8-UGU interaction and influence of this interaction on the expression of cellular miRNA are still elusive. In this study, we demonstrated that the Rhed domain (i.e., the RNA-binding heme domain, amino acids 285-478) of DGCR8 is sufficient to recognize and interact with UGU. In addition, we identified three amino acid residues in Rhed (amino acids 361-363), which are critical for the UGU interaction, and we showed that these residues are essential for the Microprocessor complex to accurately and efficiently process pri-miRNAs in vitro. Furthermore, we found that within the DGCR8 dimer, the UGU-binding site from just one monomer is capable of discriminating between UGU- and non-UGU-containing pri-miRNAs. Finally, we showed that these amino acids are more important for the expression of UGU miRNAs than non-UGU miRNAs in human cells. This study improves our understanding of the substrate-recognizing mechanism of DGCR8, and implicates the roles of this recognition in differentiating miRNA expression in human cells.

2020-07-08 | GSE140209 | GEO

Microprocessor recruitment to elongating RNA Polymerase II is required for differential expression of microRNAs

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

Single cut products of Microprocessor on pri-miRNAs

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

The high-throughput human pri-miRNA processing assays

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

High-throughput in vitro DROSHA processing on artificial variants

Project description:MicroRNAs (miRNAs) are small RNAs that regulate gene expression. miRNAs are produced from primary miRNAs (pri-miRNAs), the cleavage of which is catalyzed by the Microprocessor complex. Microprocessor therefore plays a key role in determining the efficiency and precision of miRNA production, and thus the function of the final miRNA product. In this study, we utilized high-throughput sequencing-integrated enzymology with purified Microprocessor proteins and randomized pri-miRNA sequences to investigate the catalytic mechanism of Microprocessor. We identified multiple mismatches and wobble base pairs in the upper stem of pri-miRNAs, which determine the efficiency and accuracy of pri-miRNA processing. The existence of these RNA elements helps to explain the alternative cleavage mechanism of Microprocessor, which occurs for some human pri-miRNAs. We also showed that these RNA elements are targets of RNA-editing or single nucleotide polymorphisms (SNPs) for regulating miRNA biogenesis. These findings considerably improve our understanding of pri-miRNA processing mechanisms, and provide a foundation for interpreting differential miRNA expression by several mechanisms, such as RNA modifications and SNPs.

2020-02-28 | GSE131636 | GEO

QKI5-regulated miRNAs

Project description:microRNAs (miRNAs) accomplish a remarkable variety of biological functions. Their expression is tightly controlled, and the final production of a miRNA is dependent on the cooperation of multiple mechanisms and their net effect. Here we show that miR-124-1 is transcriptionally activated during erythroid differentiation by GATA-1, however its post-transcriptional processing is attenuated. We found that QKI5 binds to a distal QKI response element (QRE) embedded in the primary transcript of miR-124-1 (pri-124-1) and modulates Microprocessor function by direct association with DGCR8. Strikingly, Microprocessor recruitment to pri-124-1 is disrupted upon RNAi-mediated depletion of QKI5, consistent with the decrease in mature miR-124. Moreover, addition of QKI5 increases the conversion efficiency of pri-124-1 in cell-free extracts. For erythropoiesis, the decreased QKI5 leads to attenuated Microprocessor-mediated processing of pri-124-1, which confers the exquisite miRNA abundance necessary for development. This regulation also gives rise to a unique miRNA signature required for normal erythropoiesis. Thus, this QKI5-regulated miRNA processing may represent a common paradigm for erythroid development, and specifically, it may serve as a post-transcriptional fault security to prevent misexpression of certain miRNAs, that is essential for the establishment of particular gene expression patterns during development. Two samples are analyzed: K562 cells transduced with GFP lentivirus; and K562 cells transduced with QKI5-overexpressing lentivirus.

2015-05-06 | E-GEOD-57363 | biostudies-arrayexpress

Global microRNA expression analysis in HaCaT human keratinocytes transfected with siRNA(s) for p72, NF2/LATS2, DROSHA/DGCR8, or negative control

Project description:Global downregulation of microRNAs (miRNAs) is commonly observed in human cancers and can have a causative role in tumorigenesis. The mechanisms responsible for this phenomenon remain poorly understood. Here we show that YAP, the downstream target of the tumor-suppressive Hippo signaling pathway regulates miRNA biogenesis in a cell density-dependent manner. At low cell density, nuclear YAP binds and sequesters p72 (DDX17), a regulatory component of the miRNA processing machinery. At high cell density, Hippo-mediated cytoplasmic retention of YAP facilitates p72 association with Microprocessor and binding to a specific sequence motif in pri-miRNAs. Inactivation of the Hippo pathway or expression of constitutively active YAP causes widespread miRNA suppression in cells and tumors and a corresponding post-transcriptional induction of MYC expression. Thus, the Hippo pathway links contact-inhibition regulation to miRNA biogenesis and may be responsible for the widespread miRNA repression observed in cancer. Four conditions (siCtrl, si p72, siNF2/LATS2 and siDROSHA/DGCR8) were analyzed in duplicate.

2014-03-03 | E-GEOD-52186 | biostudies-arrayexpress

The LncRNA NEAT1 Nests RNA Binding Proteins and the Microprocessor to Globally Enhance Pri-miRNA Processing

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

Differential roles of human PUS10 in miRNA processing and tRNA pseudouridylation

Project description:Pseudouridine synthases (PUSs) are responsible for the installation of pseudouridine (Ψ) modification in RNA. However, the activity and function of the PUS enzymes remain largely unexplored. Here we focus on human PUS10 and find that it co-expresses with the microprocessor (DROSHA–DGCR8 complex). Depletion of PUS10 results in a marked reduction of the expression level of a large number of mature miRNAs and concomitant accumulation of unprocessed primary microRNAs (pri-miRNAs) in multiple human cells. Mechanistically, PUS10 directly binds to pri-miRNAs and interacts with the microprocessor to promote miRNA biogenesis. Unexpectedly, this process is independent of the catalytic activity of PUS10. Additionally, we develop a sequencing method to profile Ψ in the tRNAome and report PUS10-dependent Ψ sites in tRNA. Collectively, our findings reveal differential functions of PUS10 in nuclear miRNA processing and in cytoplasmic tRNA pseudouridylation.

2019-11-21 | GSE124558 | GEO

QKI5-regulated miRNAs

2015-05-06 | GSE57363 | GEO