scholarly journals Primary microRNA transcript retention at sites of transcription leads to enhanced microRNA production

2008 ◽  
Vol 182 (1) ◽  
pp. 61-76 ◽  
Author(s):  
Jan M. Pawlicki ◽  
Joan A. Steitz
Keyword(s):  
Gene Expression ◽  
Noncoding Rnas ◽  
Mature Mirnas ◽  
Splicing Factor ◽  
Mirna Biogenesis ◽  
Nuclear Rna ◽  
Transcription Sites ◽  
Cleavage And Polyadenylation ◽  
Precursor Mirnas ◽  
Nuclear Levels

MicroRNAs (miRNAs) are noncoding RNAs with important roles in regulating gene expression. In studying the earliest nuclear steps of miRNA biogenesis, we observe that primary miRNA (pri-miRNA) transcripts retained at transcription sites due to the deletion of 3′-end processing signals are converted more efficiently into precursor miRNAs (pre-miRNAs) than pri-miRNAs that are cleaved, polyadenylated, and released. Flanking exons, which also increase retention at transcription sites, likewise contribute to increased levels of intronic pri-miRNAs. Consistently, efficiently processed endogenous pri-miRNAs are enriched in chromatin-associated nuclear fractions. In contrast, pri-miRNAs that accumulate to high nuclear levels after cleavage and polyadenylation because of the presence of a viral RNA element (the ENE of the Kaposi's sarcoma–associated herpes virus polyadenylated nuclear RNA) are not efficiently processed to precursor or mature miRNAs. Exogenous pri-miRNAs unexpectedly localize to nuclear foci containing splicing factor SC35; yet these foci are unlikely to represent sites of miRNA transcription or processing. Together, our results suggest that pri-miRNA processing is enhanced by coupling to transcription.

scholarly journals Coilin enhances phosphorylation and stability of DGCR8 and promotes miRNA biogenesis

2021 ◽  
pp. mbc.E21-05-0225
Author(s):  
Katheryn E. Lett ◽  
Madelyn K. Logan ◽  
Douglas M. McLaurin ◽  
Michael D. Hebert
Keyword(s):  
Noncoding Rnas ◽  
Mature Mirnas ◽  
Cajal Body ◽  
Mirna Biogenesis ◽  
Regulatory Interaction ◽  
Small Noncoding Rnas ◽  
Control Gene Expression ◽  
Processing Steps ◽  
Posttranscriptional Level

MicroRNAs (miRNAs) are ∼22 nt small noncoding RNAs that control gene expression at the posttranscriptional level through translational inhibition and destabilization of their target mRNAs. The biogenesis of miRNAs involves a series of processing steps beginning with cropping of the primary miRNA transcript by the Microprocessor complex, which is comprised of Drosha and DGCR8. Here we report a novel regulatory interaction between the Microprocessor components and coilin, the Cajal Body (CB) marker protein. Coilin knockdown causes alterations in the level of primary and mature miRNAs, let-7a and miR-34a, and their miRNA targets, HMGA2 and Notch1, respectively. We also found that coilin knockdown affects the levels of DGCR8 and Drosha in cells with (HeLa) and without (WI-38) CBs. To further explore the role of coilin in miRNA biogenesis, we conducted a series of co-immunoprecipitation experiments using coilin and DGCR8 constructs, which revealed that coilin and DGCR8 can form a complex. Additionally, our results indicate that phosphorylation of DGCR8, which has been shown to increase protein stability, is impacted by coilin knockdown. Collectively, our results implicate coilin as a member of the regulatory network governing miRNA biogenesis.

scholarly journals TRANSCRIPTION SITES IN SPREAD MEIOTIC PROPHASE CHROMOSOMES FROM MOUSE SPERMATOCYTES

1974 ◽  
Vol 63 (3) ◽  
pp. 923-935 ◽  
Author(s):  
A. L. Kierszenbaum ◽  
Laura L. Tres
Keyword(s):  
Gene Expression ◽  
Meiotic Prophase ◽  
Rna Synthesis ◽  
Sex Chromosome ◽  
Nucleolar Organizer ◽  
Structural Elements ◽  
Autosomal Bivalents ◽  
Whole Mount ◽  
Nuclear Rna ◽  
Transcription Sites

Mouse spermatocytes at pachytene stage have been examined by whole-mount electron microscope techniques complemented with autoradiography as an approach for visualizing their transcriptive activity. Structural elements of meiotic bivalents, such as synaptonemal complexes and chromatin fibers, have been satisfactorily displayed in the total set of autosomal and sexual bivalents in single spermatocytes. Adequate preservation of the entire set of bivalents has provided a basis for recognition of sites where presumptive preribosomal RNA and heterogeneous nuclear RNA species are being transcribed at different segments of autosomal bivalents. Nucleoli attached to the basal knob region where nucleolar organizer cistrons are assumed to be located and ribonucleoprotein fibrils associated with distinct chromatin loops have been recognized. These structural findings have been correlated with display of [3H]uridine incorporation sites in thin-section and whole-mount electron microscopy autoradiographic preparations. A low transcriptive activity of the sexual bivalent contrasted with extensive gene expression in autosomal bivalents. Each sex chromosome shows a double axial core. A short region of pairing with a synaptonemal complex joins the two chromosomes at one end. We conclude that variations in the rate of RNA synthesis throughout meiotic prophase stages in the mouse are expressed as fluctuations in the amount and distribution of distinct RNA species at specific segments of the bivalents.

Long noncoding RNAs transcribed downstream of the human β-globin locus regulate β-globin gene expression

2021 ◽  
Author(s):  
Miki Higashi ◽  
Tsuyoshi Ikehara ◽  
Takeya Nakagawa ◽  
Mitsuhiro Yoneda ◽  
Naoko Hattori ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Locus ◽  
Globin Gene ◽  
Noncoding Rnas ◽  
K562 Cells ◽  
In Vitro Transcription ◽  
Long Noncoding Rnas ◽  
Transcription Assay ◽  
Nuclear Rna

Abstract The five β-like globin genes (ε, Gγ, Aγ, δ, and β) at the human β-globin gene locus are known to be expressed at specific developmental stages, although details of the underlying mechanism remain to be uncovered. Here we used an in vitro transcription assay to clarify the mechanisms that control this gene expression. We first tested nuclear RNA from HeLa cells using RT-qPCR and discovered a long noncoding RNAs (lncRNAs) within a 5.2-kb region beginning 4.4 kb downstream of the β-globin gene coding region. We investigated nuclear RNA from K562 cells using a primer-extension assay and determined the transcription start sites (TSSs) of these lncRNAs. To clarify their functional role, we performed knockdown (KD) of these lncRNAs in K562 cells. Hydroxyurea, which induces differentiation of K562 cells, increased hemoglobin peptide production, and the effect was enhanced by KD of these lncRNAs, which also enhanced upregulation of the γ-globin expression induced by hydroxyurea. To confirm these results, we performed an in vitro transcription assay. Noncoding single-stranded RNAs inhibited β-globin expression, which was upregulated by GATA1. Furthermore, lncRNAs interacted with GATA1 without sequence specificity and inhibited its binding to its target DNA response element in vitro. Our results suggest that lncRNAs downstream of the β-globin gene locus are key factors regulating globin gene ex pression.

scholarly journals MAC5, an RNA-binding protein, protects pri-miRNAs from SERRATE-dependent exoribonuclease activities

2020 ◽  
Vol 117 (38) ◽  
pp. 23982-23990 ◽  
Author(s):  
Shengjun Li ◽  
Mu Li ◽  
Kan Liu ◽  
Huimin Zhang ◽  
Shuxin Zhang ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Protein ◽  
Dual Role ◽  
Mirna Biogenesis ◽  
Core Component ◽  
Stem Loop ◽  
Loop Region ◽  
Nuclear Rna ◽  
Efficient Processing ◽  
The Stability

MAC5 is a component of the conserved MOS4-associated complex. It plays critical roles in development and immunity. Here we report that MAC5 is required for microRNA (miRNA) biogenesis. MAC5 interacts with Serrate (SE), which is a core component of the microprocessor that processes primary miRNA transcripts (pri-miRNAs) into miRNAs and binds the stem-loop region of pri-miRNAs. MAC5 is essential for both the efficient processing and the stability of pri-miRNAs. Interestingly, the reduction of pri-miRNA levels inmac5is partially caused by XRN2/XRN3, the nuclear-localized 5′-to-3′ exoribonucleases, and depends on SE. These results reveal that MAC5 plays a dual role in promoting pri-miRNA processing and stability through its interaction with SE and/or pri-miRNAs. This study also uncovers that pri-miRNAs need to be protected from nuclear RNA decay machinery, which is connected to the microprocessor.

scholarly journals Publisher Correction: Exogenously overexpressed intronic long noncoding RNAs activate host gene expression by affecting histone modification in Arabidopsis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhang-Wei Liu ◽  
Nan Zhao ◽  
Yin-Na Su ◽  
Shan-Shan Chen ◽  
Xin-Jian He
Keyword(s):  
Gene Expression ◽  
Histone Modification ◽  
Noncoding Rnas ◽  
Long Noncoding Rnas ◽  
Host Gene ◽  
Host Gene Expression

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

scholarly journals A hybrid CNN-LSTM model for pre-miRNA classification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdulkadir Tasdelen ◽  
Baha Sen
Keyword(s):  
Evaluation Criteria ◽  
Mature Mirnas ◽  
Structural Features ◽  
Linear Discriminant ◽  
Sequential Structure ◽  
Precursor Mirnas ◽  
Lstm Network ◽  
Future Work ◽  
Cumulative Evidence

AbstractmiRNAs (or microRNAs) are small, endogenous, and noncoding RNAs construct of about 22 nucleotides. Cumulative evidence from biological experiments shows that miRNAs play a fundamental and important role in various biological processes. Therefore, the classification of miRNA is a critical problem in computational biology. Due to the short length of mature miRNAs, many researchers are working on precursor miRNAs (pre-miRNAs) with longer sequences and more structural features. Pre-miRNAs can be divided into two groups as mirtrons and canonical miRNAs in terms of biogenesis differences. Compared to mirtrons, canonical miRNAs are more conserved and easier to be identified. Many existing pre-miRNA classification methods rely on manual feature extraction. Moreover, these methods focus on either sequential structure or spatial structure of pre-miRNAs. To overcome the limitations of previous models, we propose a nucleotide-level hybrid deep learning method based on a CNN and LSTM network together. The prediction resulted in 0.943 (%95 CI ± 0.014) accuracy, 0.935 (%95 CI ± 0.016) sensitivity, 0.948 (%95 CI ± 0.029) specificity, 0.925 (%95 CI ± 0.016) F1 Score and 0.880 (%95 CI ± 0.028) Matthews Correlation Coefficient. When compared to the closest results, our proposed method revealed the best results for Acc., F1 Score, MCC. These were 2.51%, 1.00%, and 2.43% higher than the closest ones, respectively. The mean of sensitivity ranked first like Linear Discriminant Analysis. The results indicate that the hybrid CNN and LSTM networks can be employed to achieve better performance for pre-miRNA classification. In future work, we study on investigation of new classification models that deliver better performance in terms of all the evaluation criteria.

scholarly journals The Detection and Bioinformatic Analysis of Alternative 3′ UTR Isoforms as Potential Cancer Biomarkers

2021 ◽  
Vol 22 (10) ◽  
pp. 5322
Author(s):  
Nitika Kandhari ◽  
Calvin A. Kraupner-Taylor ◽  
Paul F. Harrison ◽  
David R. Powell ◽  
Traude H. Beilharz
Keyword(s):  
Gene Expression ◽  
Cell Transformation ◽  
Alternative Polyadenylation ◽  
Cancer Biomarkers ◽  
Bioinformatic Analysis ◽  
Alternative Transcript ◽  
Clinical Parameters ◽  
Transcript Cleavage ◽  
Cleavage And Polyadenylation ◽  
Potential Cancer

Alternative transcript cleavage and polyadenylation is linked to cancer cell transformation, proliferation and outcome. This has led researchers to develop methods to detect and bioinformatically analyse alternative polyadenylation as potential cancer biomarkers. If incorporated into standard prognostic measures such as gene expression and clinical parameters, these could advance cancer prognostic testing and possibly guide therapy. In this review, we focus on the existing methodologies, both experimental and computational, that have been applied to support the use of alternative polyadenylation as cancer biomarkers.

scholarly journals Study on the Relationship between the miRNA-centered ceRNA Regulatory Network and Fatigue

2021 ◽  
Author(s):  
Xingzhe Yang ◽  
Feng Li ◽  
Jie Ma ◽  
Yan Liu ◽  
Xuejiao Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Regulatory Network ◽  
Regulatory Network ◽  
Hot Spot ◽  
Genetic Research ◽  
Noncoding Rnas ◽  
Messenger Rnas ◽  
Effective Prevention ◽  
Gene Regulatory ◽  
The Relationship

AbstractIn recent years, the incidence of fatigue has been increasing, and the effective prevention and treatment of fatigue has become an urgent problem. As a result, the genetic research of fatigue has become a hot spot. Transcriptome-level regulation is the key link in the gene regulatory network. The transcriptome includes messenger RNAs (mRNAs) and noncoding RNAs (ncRNAs). MRNAs are common research targets in gene expression profiling. Noncoding RNAs, including miRNAs, lncRNAs, circRNAs and so on, have been developed rapidly. Studies have shown that miRNAs are closely related to the occurrence and development of fatigue. MiRNAs can regulate the immune inflammatory reaction in the central nervous system (CNS), regulate the transmission of nerve impulses and gene expression, regulate brain development and brain function, and participate in the occurrence and development of fatigue by regulating mitochondrial function and energy metabolism. LncRNAs can regulate dopaminergic neurons to participate in the occurrence and development of fatigue. This has certain value in the diagnosis of chronic fatigue syndrome (CFS). CircRNAs can participate in the occurrence and development of fatigue by regulating the NF-κB pathway, TNF-α and IL-1β. The ceRNA hypothesis posits that in addition to the function of miRNAs in unidirectional regulation, mRNAs, lncRNAs and circRNAs can regulate gene expression by competitive binding with miRNAs, forming a ceRNA regulatory network with miRNAs. Therefore, we suggest that the miRNA-centered ceRNA regulatory network is closely related to fatigue. At present, there are few studies on fatigue-related ncRNA genes, and most of these limited studies are on miRNAs in ncRNAs. However, there are a few studies on the relationship between lncRNAs, cirRNAs and fatigue. Less research is available on the pathogenesis of fatigue based on the ceRNA regulatory network. Therefore, exploring the complex mechanism of fatigue based on the ceRNA regulatory network is of great significance. In this review, we summarize the relationship between miRNAs, lncRNAs and circRNAs in ncRNAs and fatigue, and focus on exploring the regulatory role of the miRNA-centered ceRNA regulatory network in the occurrence and development of fatigue, in order to gain a comprehensive, in-depth and new understanding of the essence of the fatigue gene regulatory network.

scholarly journals MicroRNomics: a newly emerging approach for disease biology

2008 ◽  
Vol 33 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Chunxiang Zhang
Keyword(s):  
Gene Expression ◽  
Genomic Medicine ◽  
Noncoding Rnas ◽  
Cellular Tissue ◽  
Tissue Type ◽  
Regulation Of Expression ◽  
Protein Coding ◽  
Small Noncoding Rnas ◽  
Disease Biology ◽  
Genomic Scale

Genomic evidence reveals that gene expression in humans is precisely controlled in cellular, tissue-type, temporal, and condition-specific manners. Completely understanding the regulatory mechanisms of gene expression is therefore one of the most important issues in genomic medicine. Surprisingly, recent analyses of the human and animal genomes have demonstrated that the majority of RNA transcripts are relatively small, noncoding RNAs (sncRNAs), rather than large, protein coding message RNAs (mRNAs). Moreover, these sncRNAs may represent a novel important layer of regulation for gene expression. The most important breakthrough in this new area is the discovery of microRNAs (miRNAs). miRNAs comprise a novel class of endogenous, small, noncoding RNAs that negatively regulate gene expression via degradation or translational inhibition of their target mRNAs. As a group, miRNAs may directly regulate ∼30% of the genes in the human genome. In keeping with the nomenclature of RNomics, which is to study sncRNAs on the genomic scale, “microRNomics” is coined here to describe a novel subdiscipline of genomics that studies the identification, expression, biogenesis, structure, regulation of expression, targets, and biological functions of miRNAs on the genomic scale. A growing body of exciting evidence suggests that miRNAs are important regulators of cell differentiation, proliferation/growth, mobility, and apoptosis. These miRNAs therefore play important roles in development and physiology. Consequently, dysregulation of miRNA function may lead to human diseases such as cancer, cardiovascular disease, liver disease, immune dysfunction, and metabolic disorders. microRNomics may be a newly emerging approach for human disease biology.

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