scholarly journals Epigenetic Modulation of Chromatin States and Gene Expression by G-Quadruplex Structures

2020 ◽  
Vol 21 (11) ◽  
pp. 4172 ◽  
Author(s):  
Chiara Reina ◽  
Vincenzo Cavalieri
Keyword(s):  
Gene Expression ◽  
Noncoding Rna ◽  
Biological Activities ◽  
Regulation Of Gene Expression ◽  
Three Dimensional ◽  
Structural Features ◽  
Rna Molecules ◽  
Dna And Rna ◽  
G Quadruplex ◽  
Epigenetic Modulation

G-quadruplexes are four-stranded helical nucleic acid structures formed by guanine-rich sequences. A considerable number of studies have revealed that these noncanonical structural motifs are widespread throughout the genome and transcriptome of numerous organisms, including humans. In particular, G-quadruplexes occupy strategic locations in genomic DNA and both coding and noncoding RNA molecules, being involved in many essential cellular and organismal functions. In this review, we first outline the fundamental structural features of G-quadruplexes and then focus on the concept that these DNA and RNA structures convey a distinctive layer of epigenetic information that is critical for the complex regulation, either positive or negative, of biological activities in different contexts. In this framework, we summarize and discuss the proposed mechanisms underlying the functions of G-quadruplexes and their interacting factors. Furthermore, we give special emphasis to the interplay between G-quadruplex formation/disruption and other epigenetic marks, including biochemical modifications of DNA bases and histones, nucleosome positioning, and three-dimensional organization of chromatin. Finally, epigenetic roles of RNA G-quadruplexes in post-transcriptional regulation of gene expression are also discussed. Undoubtedly, the issues addressed in this review take on particular importance in the field of comparative epigenetics, as well as in translational research.

scholarly journals Small Molecule, Big Prospects: MicroRNA in Pregnancy and Its Complications

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Meng Cai ◽  
Gopi K. Kolluru ◽  
Asif Ahmed
Keyword(s):  
Gene Expression ◽  
Preterm Labor ◽  
Noncoding Rna ◽  
Molecular Mechanisms ◽  
Regulation Of Gene Expression ◽  
Disease Process ◽  
Rna Molecules ◽  
Small Noncoding Rna ◽  
Posttranscriptional Level ◽  
In Pregnancy

MicroRNAs are small, noncoding RNA molecules that regulate target gene expression in the posttranscriptional level. Unlike siRNA, microRNAs are “fine-tuners” rather than “switches” in the regulation of gene expression; thus they play key roles in maintaining tissue homeostasis. The aberrant microRNA expression is implicated in the disease process. To date, numerous studies have demonstrated the regulatory roles of microRNAs in various pathophysiological conditions. In contrast, the study of microRNA in pregnancy and its associated complications, such as preeclampsia (PE), fetal growth restriction (FGR), and preterm labor, is a young field. Over the last decade, the knowledge of pregnancy-related microRNAs has increased and the molecular mechanisms by which microRNAs regulate pregnancy or its associated complications are emerging. In this review, we focus on the recent advances in the research of pregnancy-related microRNAs, especially their function in pregnancy-associated complications and the potential clinical applications. Here microRNAs that associate with pregnancy are classified as placenta-specific, placenta-associated, placenta-derived circulating, and uterine microRNA according to their localization and origin. MicroRNAs offer a great potential for developing diagnostic and therapeutic targets in pregnancy-related disorders.

scholarly journals Arginine Methyltransferases as Regulators of RNA-Binding Protein Activities in Pathogenic Kinetoplastids

2021 ◽  
Vol 8 ◽  
Author(s):  
Gustavo D. Campagnaro ◽  
Edward Nay ◽  
Michael J. Plevin ◽  
Angela K. Cruz ◽  
Pegine B. Walrad
Keyword(s):  
Gene Expression ◽  
Transcriptional Control ◽  
Rna Binding ◽  
Methylation Status ◽  
Regulation Of Gene Expression ◽  
Structural Features ◽  
Arginine Methylation ◽  
Diverse Range ◽  
Host Interaction ◽  
Intronless Genes

A large number of eukaryotic proteins are processed by single or combinatorial post-translational covalent modifications that may alter their activity, interactions and fate. The set of modifications of each protein may be considered a “regulatory code”. Among the PTMs, arginine methylation, catalyzed by protein arginine methyltransferases (PRMTs), can affect how a protein interacts with other macromolecules such as nucleic acids or other proteins. In fact, many RNA-binding (RBPs) proteins are targets of PRMTs. The methylation status of RBPs may affect the expression of their bound RNAs and impact a diverse range of physiological and pathological cellular processes. Unlike most eukaryotes, Kinetoplastids have overwhelmingly intronless genes that are arranged within polycistronic units from which mature mRNAs are generated by trans-splicing. Gene expression in these organisms is thus highly dependent on post-transcriptional control, and therefore on the action of RBPs. These genetic features make trypanosomatids excellent models for the study of post-transcriptional regulation of gene expression. The roles of PRMTs in controlling the activity of RBPs in pathogenic kinetoplastids have now been studied for close to 2 decades with important advances achieved in recent years. These include the finding that about 10% of the Trypanosoma brucei proteome carries arginine methylation and that arginine methylation controls Leishmania:host interaction. Herein, we review how trypanosomatid PRMTs regulate the activity of RBPs, including by modulating interactions with RNA and/or protein complex formation, and discuss how this impacts cellular and biological processes. We further highlight unique structural features of trypanosomatid PRMTs and how it contributes to their singular functionality.

scholarly journals Repeat elements organize 3D genome structure and mediate transcription in the filamentous fungusEpichloë festucae

2018 ◽  
Author(s):  
David J Winter ◽  
Austen RD Ganley ◽  
Carolyn A Young ◽  
Ivan Liachko ◽  
Christopher L Schardl ◽  
...  
Keyword(s):  
Genome Structure ◽  
Regulation Of Gene Expression ◽  
Three Dimensional ◽  
Structural Features ◽  
Dimensional Structure ◽  
In Planta ◽  
Repeat Elements ◽  
Symbiotic Relationships ◽  
3D Genome ◽  
Transcriptional Changes

AbstractStructural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organization influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus,Epichloë festucae. Coupling it with RNAseq and HiC data, we investigate how the structure of the genome contributes to the suite of transcriptional changes that anEpichloëspecies needs to maintain symbiotic relationships with its grass host. Our results reveal a unique “patchwork” genome, in which repeat-rich blocks of DNA with discrete boundaries are interspersed by gene-rich sequences. In contrast to other species, the three-dimensional structure of the genome is anchored by these repeat blocks, which act to isolate transcription in neighbouring gene-rich regions. Genes that are differentially expressed in planta are enriched near the boundaries of these repeat-rich blocks, suggesting that their three-dimensional orientation partly encodes and regulates the symbiotic relationship formed by this organism.

Diagnostic, prognostic, and therapeutic value of miR-148b in human cancers

2021 ◽  
Vol 21 ◽  
Author(s):  
Afsane Bahrami ◽  
Gordon A. Ferns
Keyword(s):  
Gene Expression ◽  
Tumor Suppressor ◽  
Noncoding Rna ◽  
Clinical Importance ◽  
Aberrant Expression ◽  
Rna Molecules ◽  
Small Noncoding Rna ◽  
Human Cancers ◽  
Therapeutic Value ◽  
Cancer Types

: MicroRNAs (miRs) is a class of conserved, small, noncoding RNA molecules which modulate gene expression post-transcriptionally. miR-148b is a member of miR-148/152 family generally known to be a tumor suppressor via its affect on different signaling pathways and regulatory genes. Aberrant expression of miR-148b has recently been shown to be responsible for tumorigenesis for several different cancer types. This review discusses the current evidences regarding the involvement of miR-148b expression in human cancers and its potential clinical importance for tumor diagnosis, prognosis, and therapeutics.

scholarly journals Molecular Mechanisms, Diagnostic Aspects and Therapeutic Opportunities of Micro Ribonucleic Acids in Atrial Fibrillation

2020 ◽  
Vol 21 (8) ◽  
pp. 2742 ◽  
Author(s):  
Allan Böhm ◽  
Marianna Vachalcova ◽  
Peter Snopek ◽  
Ljuba Bacharova ◽  
Dominika Komarova ◽  
...  
Keyword(s):  
Gene Expression ◽  
Atrial Fibrillation ◽  
Molecular Mechanisms ◽  
Wide Spectrum ◽  
Regulation Of Gene Expression ◽  
Review Article ◽  
Ribonucleic Acids ◽  
Rna Molecules ◽  
Diagnostic Aspects ◽  
Non Coding Rna

Micro ribonucleic acids (miRNAs) are short non-coding RNA molecules responsible for regulation of gene expression. They are involved in many pathophysiological processes of a wide spectrum of diseases. Recent studies showed their involvement in atrial fibrillation. They seem to become potential screening biomarkers for atrial fibrillation and even treatment targets for this arrhythmia. The aim of this review article was to summarize the latest knowledge about miRNA and their molecular relation to the pathophysiology, diagnosis and treatment of atrial fibrillation.

scholarly journals The molecular dynamics of long noncoding RNA control of transcription in PTEN and its pseudogene

2017 ◽  
Vol 114 (37) ◽  
pp. 9942-9947 ◽  
Author(s):  
Nicholas Lister ◽  
Galina Shevchenko ◽  
James L. Walshe ◽  
Jessica Groen ◽  
Per Johnsson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Structure ◽  
Noncoding Rna ◽  
Dna Methyltransferase ◽  
Regulation Of Gene Expression ◽  
Control Of Gene Expression ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Sequence Components ◽  
Antisense Lncrnas

RNA has been found to interact with chromatin and modulate gene transcription. In human cells, little is known about how long noncoding RNAs (lncRNAs) interact with target loci in the context of chromatin. We find here, using the phosphatase and tensin homolog (PTEN) pseudogene as a model system, that antisense lncRNAs interact first with a 5′ UTR-containing promoter-spanning transcript, which is then followed by the recruitment of DNA methyltransferase 3a (DNMT3a), ultimately resulting in the transcriptional and epigenetic control of gene expression. Moreover, we find that the lncRNA and promoter-spanning transcript interaction are based on a combination of structural and sequence components of the antisense lncRNA. These observations suggest, on the basis of this one example, that evolutionary pressures may be placed on RNA structure more so than sequence conservation. Collectively, the observations presented here suggest a much more complex and vibrant RNA regulatory world may be operative in the regulation of gene expression.

scholarly journals Differential Expression of MicroRNAs between Eutopic and Ectopic Endometrium in Ovarian Endometriosis

2010 ◽  
Vol 2010 ◽  
pp. 1-29 ◽  
Author(s):  
Nicoletta Filigheddu ◽  
Ilaria Gregnanin ◽  
Paolo E. Porporato ◽  
Daniela Surico ◽  
Beatrice Perego ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Expression ◽  
Posttranscriptional Regulation ◽  
Noncoding Rna ◽  
Critical Role ◽  
Regulation Of Gene Expression ◽  
Differentially Expressed ◽  
Ovarian Endometriosis ◽  
Eutopic Endometrium ◽  
Ectopic Endometrium

Endometriosis, defined as the presence of endometrial tissue outside the uterus, is a common gynecological disease with poorly understood pathogenesis. MicroRNAs are members of a class of small noncoding RNA molecules that have a critical role in posttranscriptional regulation of gene expression by repression of target mRNAs translation. We assessed differentially expressed microRNAs in ectopic endometrium compared with eutopic endometrium in 3 patients through microarray analysis. We identified 50 microRNAs differentially expressed and the differential expression of five microRNAs was validated by real-time RT-PCR in other 13 patients. We identifiedin silicotheir predicted targets, several of which match the genes that have been identified to be differentially expressed in ectopicversuseutopic endometrium in studies of gene expression. A functional analysis of the predicted targets indicates that several of these are involved in molecular pathways implicated in endometriosis, thus strengthening the hypothesis of the role of microRNAs in this pathology.

Mammalian genome evolution as a result of epigenetic regulation of transposable elements

2014 ◽  
Vol 5 (3) ◽  
pp. 183-194 ◽  
Author(s):  
Reuben M. Buckley ◽  
David L. Adelson
Keyword(s):  
Gene Expression ◽  
Transposable Elements ◽  
Epigenetic Regulation ◽  
Dna Sequences ◽  
Defense Mechanisms ◽  
Regulatory Networks ◽  
Regulation Of Gene Expression ◽  
Epigenetic Marks ◽  
Rna Molecules ◽  
Mammalian Genomes

AbstractTransposable elements (TEs) make up a large proportion of mammalian genomes and are a strong evolutionary force capable of rewiring regulatory networks and causing genome rearrangements. Additionally, there are many eukaryotic epigenetic defense mechanisms able to transcriptionally silence TEs. Furthermore, small RNA molecules that target TE DNA sequences often mediate these epigenetic defense mechanisms. As a result, epigenetic marks associated with TE silencing can be reestablished after epigenetic reprogramming – an event during the mammalian life cycle that results in widespread loss of parental epigenetic marks. Furthermore, targeted epigenetic marks associated with TE silencing may have an impact on nearby gene expression. Therefore, TEs may have driven species evolution via their ability to heritably alter the epigenetic regulation of gene expression in mammals.

scholarly journals Long Noncoding RNA Plays a Key Role in Metastasis and Prognosis of Hepatocellular Carcinoma

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Guangbing Li ◽  
Haohai Zhang ◽  
Xueshuai Wan ◽  
Xiaobo Yang ◽  
Chengpei Zhu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hepatocellular Carcinoma ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Regulation Of Gene Expression ◽  
Noncoding Rnas ◽  
Long Noncoding Rnas ◽  
Comprehensive Review ◽  
Cellular Processes

Long noncoding RNAs (lncRNAs) have been attracting immense research interests. However, only a handful of lncRNAs had been thoroughly characterized. They were involved in fundamental cellular processes including regulation of gene expression at epigenetics as well as tumorogenesis. In this paper, we give a systematic and comprehensive review of existing literature about lncRNA involvement in hepatocellular carcinoma. This review exhibited that lncRNAs played important roles in tumorigenesis and subsequent prognosis and metastasis of hepatocellular carcinoma and elucidated the role of some specific lncRNAs such as MALAT1 and HOTAIR in the pathophysiology of hepatocellular carcinoma and their potential of being therapeutic targets.

scholarly journals Circular RNAs in Cardiovascular Disease: An Overview

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Ximin Fan ◽  
Xinyu Weng ◽  
Yifan Zhao ◽  
Wei Chen ◽  
Tianyi Gan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cardiovascular Disease ◽  
Cardiovascular Diseases ◽  
Noncoding Rna ◽  
Essential Role ◽  
Closed Loop ◽  
Regulation Of Gene Expression ◽  
Circular Rna ◽  
Circular Rnas ◽  
Mirna Sponges

Circular RNA (circRNA), a novel type of endogenous noncoding RNA (ncRNA), has become a research hotspot in recent years. CircRNAs are abundant and stably exist in creatures, and they are found with covalently closed loop structures in which they are quite different from linear RNAs. Nowadays, an increasing number of scientists have demonstrated that circRNAs may have played an essential role in the regulation of gene expression, especially acting as miRNA sponges, and have described the potential mechanisms of several circRNAs in diseases, hinting at their clinical therapeutic values. In this review, the authors summarized the current understandings of the biogenesis and properties of circRNAs and their functions and role as biomarkers in cardiovascular diseases.

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