scholarly journals Emerging Data on the Diversity of Molecular Mechanisms Involving C/D snoRNAs

2021 ◽  
Vol 7 (2) ◽  
pp. 30
Author(s):  
Laeya Baldini ◽  
Bruno Charpentier ◽  
Stéphane Labialle
Keyword(s):  
Ribosomal Rna ◽  
Molecular Mechanisms ◽  
Molecular Level ◽  
Accurate Description ◽  
Small Nucleolar Rnas ◽  
Age Of Maturity ◽  
Non Coding Rnas ◽  
And Function ◽  
Nucleolar Rnas

Box C/D small nucleolar RNAs (C/D snoRNAs) represent an ancient family of small non-coding RNAs that are classically viewed as housekeeping guides for the 2′-O-methylation of ribosomal RNA in Archaea and Eukaryotes. However, an extensive set of studies now argues that they are involved in mechanisms that go well beyond this function. Here, we present these pieces of evidence in light of the current comprehension of the molecular mechanisms that control C/D snoRNA expression and function. From this inventory emerges that an accurate description of these activities at a molecular level is required to let the snoRNA field enter in a second age of maturity.

scholarly journals Structure and biogenesis of small nucleolar RNAs acting as guides for ribosomal RNA modification.

1999 ◽  
Vol 46 (2) ◽  
pp. 377-389 ◽  
Author(s):  
W Filipowicz ◽  
P Pelczar ◽  
V Pogacic ◽  
F Dragon
Keyword(s):  
Ribosomal Rna ◽  
Structure And Function ◽  
Hydroxyl Group ◽  
Rna Modification ◽  
Small Nucleolar Rnas ◽  
Yeast Saccharomyces Cerevisiae ◽  
Site Specific ◽  
Alternative Pathways ◽  
And Function ◽  
Nucleolar Rnas

Maturation of pre-ribosomal RNA (pre-rRNA) in eukaryotic cells takes place in the nucleolus and involves a large number of cleavage events, which frequently follow alternative pathways. In addition, rRNAs are extensively modified, with the methylation of the 2'-hydroxyl group of sugar residues and conversion of uridines to pseudouridines being the most frequent modifications. Both cleavage and modification reactions of pre-rRNAs are assisted by a variety of small nucleolar RNAs (snoRNAs), which function in the form of ribonucleoprotein particles (snoRNPs). The majority of snoRNAs acts as guides directing site-specific 2'-O-ribose methylation or pseudouridine formation. Over one hundred RNAs of this type have been identified to date in vertebrates and the yeast Saccharomyces cerevisiae. This number is readily explained by the findings that one snoRNA acts as a guide usually for one or at most two modifications, and human rRNAs contain 91 pseudouridines and 106 2'-O-methyl residues. In this article we review information about the biogenesis, structure and function of guide snoRNAs.

Small nucleolar RNAs and RNA-guided post-transcriptional modification

2013 ◽  
Vol 54 ◽  
pp. 53-77 ◽  
Author(s):  
Lauren Lui ◽  
Todd Lowe
Keyword(s):  
Rna Processing ◽  
High Throughput Sequencing ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Small Nucleolar Rnas ◽  
Ribonucleoprotein Complexes ◽  
Associated Proteins ◽  
Non Coding Rnas ◽  
And Function ◽  
Nucleolar Rnas

snoRNAs (small nucleolar RNAs) constitute one of the largest and best-studied classes of non-coding RNAs that confer enzymatic specificity. With associated proteins, these snoRNAs form ribonucleoprotein complexes that can direct 2′-O-methylation or pseudouridylation of target non-coding RNAs. Aided by computational methods and high-throughput sequencing, new studies have expanded the diversity of known snoRNA functions. Complexes incorporating snoRNAs have dynamic specificity, and include diverse roles in RNA silencing, telomerase maintenance and regulation of alternative splicing. Evidence that dysregulation of snoRNAs can cause human disease, including cancer, indicates that the full scope of snoRNA roles remains an unfinished story. The diversity in structure, genomic origin and function between snoRNAs found in different complexes and among different phyla illustrates the surprising plasticity of snoRNAs in evolution. The ability of snoRNAs to direct highly specific interactions with other RNAs is a consistent thread in their newly discovered functions. Because they are ubiquitous throughout Eukarya and Archaea, it is likely they were a feature of the last common ancestor of these two domains, placing their origin over two billion years ago. In the present chapter, we focus on recent advances in our understanding of these ancient, but functionally dynamic RNA-processing machines.

scholarly journals Biogenesis and Function of Small Non-Coding RNAs Derived from Eukaryotic Ribosomal RNA

2018 ◽  
Author(s):  
Marine Lambert ◽  
Abderrahim Benmoussa ◽  
Patrick Provost
Keyword(s):  
Ribosomal Rna ◽  
Potential Role ◽  
A Priori ◽  
Biological Significance ◽  
Rna Seq ◽  
New Class ◽  
Scientific Mind ◽  
Non Coding Rnas ◽  
And Function ◽  
Rrna Sequences

The advent of RNA-sequencing (RNA-Seq) technologies has markedly improved our knowledge and expanded the compendium of small non-coding RNAs, most of which derive from the processing of longer RNA precursors. In this review article, we will discuss about the biogenesis and function of small non-coding RNAs derived from eukaryotic ribosomal RNA (rRNA), called rRNA fragments (rRFs), and their potential role(s) as regulator of gene expression. This relatively new class of ncRNAs remained poorly investigated and underappreciated until recently, due mainly to the a priori exclusion of rRNA sequences—because of their overabundance—from RNA-Seq datasets. The situation surrounding rRFs resembles that of microRNAs (miRNAs), which used to be readily discarded from further analyses, for more than five decades, because we could not believe that RNA of such a short length could bear biological significance. As if we had not yet learned our lesson not to restrain our investigative, scientific mind from challenging widely accepted beliefs or dogmas, and from looking for the hidden treasures in the most unexpected places.

scholarly journals Emerging Roles and Potential Applications of Non-Coding RNAs in Glioblastoma

2020 ◽  
Vol 21 (7) ◽  
pp. 2611 ◽  
Author(s):  
Carlos DeOcesano-Pereira ◽  
Raquel A. C. Machado ◽  
Ana Marisa Chudzinski-Tavassi ◽  
Mari Cleide Sogayar
Keyword(s):  
Cancer Type ◽  
Biological Processes ◽  
Small Nucleolar Rnas ◽  
Physiological Conditions ◽  
Master Regulators ◽  
Potential Applications ◽  
Non Coding Rnas ◽  
Regulatory Rnas ◽  
Nucleolar Rnas ◽  
Substantial Effort

Non-coding RNAs (ncRNAs) comprise a diversity of RNA species, which do not have the potential to encode proteins. Non-coding RNAs include two classes of RNAs, namely: short regulatory ncRNAs and long non-coding RNAs (lncRNAs). The short regulatory RNAs, containing up to 200 nucleotides, include small RNAs, such as microRNAs (miRNA), short interfering RNAs (siRNAs), piwi-interacting RNAs (piRNAs), and small nucleolar RNAs (snoRNAs). The lncRNAs include long antisense RNAs and long intergenic RNAs (lincRNAs). Non-coding RNAs have been implicated as master regulators of several biological processes, their expression being strictly regulated under physiological conditions. In recent years, particularly in the last decade, substantial effort has been made to investigate the function of ncRNAs in several human diseases, including cancer. Glioblastoma is the most common and aggressive type of brain cancer in adults, with deregulated expression of small and long ncRNAs having been implicated in onset, progression, invasiveness, and recurrence of this tumor. The aim of this review is to guide the reader through important aspects of miRNA and lncRNA biology, focusing on the molecular mechanism associated with the progression of this highly malignant cancer type.

scholarly journals Epigenetic Regulation of the Hippocampus, with Special Reference to Radiation Exposure

2020 ◽  
Vol 21 (24) ◽  
pp. 9514
Author(s):  
Genevieve Saw ◽  
Feng Ru Tang
Keyword(s):  
Epigenetic Regulation ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Epigenetic Changes ◽  
Epigenetic Factors ◽  
Hippocampal Function ◽  
Neuropsychological Disorders ◽  
Radiation Induced ◽  
Non Coding Rnas ◽  
And Function

The hippocampus is crucial in learning, memory and emotion processing, and is involved in the development of different neurological and neuropsychological disorders. Several epigenetic factors, including DNA methylation, histone modifications and non-coding RNAs, have been shown to regulate the development and function of the hippocampus, and the alteration of epigenetic regulation may play important roles in the development of neurocognitive and neurodegenerative diseases. This review summarizes the epigenetic modifications of various cell types and processes within the hippocampus and their resulting effects on cognition, memory and overall hippocampal function. In addition, the effects of exposure to radiation that may induce a myriad of epigenetic changes in the hippocampus are reviewed. By assessing and evaluating the current literature, we hope to prompt a more thorough understanding of the molecular mechanisms that underlie radiation-induced epigenetic changes, an area which can be further explored.

scholarly journals Ribosomal RNA: Small nucleolar RNAs make their mark

1996 ◽  
Vol 6 (11) ◽  
pp. 1413-1415 ◽  
Author(s):  
Brenda A. Peculis ◽  
Stephen M. Mount
Keyword(s):  
Ribosomal Rna ◽  
Small Nucleolar Rnas ◽  
Nucleolar Rnas

scholarly journals jouvence, a new human H/ACA snoRNA involves in the control of cell proliferation and differentiation

2020 ◽  
Author(s):  
Flaria El-Khoury ◽  
Jérôme Bignon ◽  
Jean-René Martin
Keyword(s):  
Cell Proliferation ◽  
Small Nucleolar Rnas ◽  
Primary Cells ◽  
Cell Proliferation And Differentiation ◽  
Cancerous Cell ◽  
Proliferation And Differentiation ◽  
Non Coding Rnas ◽  
Nucleolar Rnas

AbstractSmall nucleolar RNAs (snoRNAs) are non-coding RNAs conserved from archeobacteria to mammals. In humans, various snoRNAs have been associated with pathologies as well as with cancer. Recently in Drosophila, a new snoRNA named jouvence has been involved in lifespan. Since snoRNAs are well conserved through evolution, both structurally and functionally, jouvence orthologue has been identified in human, allowing hypothesizing that jouvence could display a similar function (increasing healthy lifespan) in human. Here, we report the characterization of the human snoRNA-jouvence, which was not yet annotated in the genome. We show, both in stably cancerous cell lines and in primary cells, that its overexpression stimulates the cell proliferation. In contrast, its knockdown, by siRNA leads to an opposite phenotype, a decrease in cell proliferation. Transcriptomic analysis reveals that overexpression of jouvence leads to a dedifferentiation signature of the cells, a cellular effect comparable to rejuvenation. Inversely, the knockdown of jouvence leads to a decrease of genes involved in ribosomes biogenesis and spliceosome in agreement with the canonical role of a H/ACA box snoRNA. In this context, jouvence could represent a now tool to fight against the deleterious effect of aging, as well as a new target in cancer therapy.

scholarly journals A Novel Regulatory Player in the Innate Immune System: Long Non-Coding RNAs

2021 ◽  
Vol 22 (17) ◽  
pp. 9535
Author(s):  
Yuhuai Xie ◽  
Yuanyuan Wei
Keyword(s):  
Immune System ◽  
Immune Cells ◽  
Innate Immune System ◽  
Molecular Mechanisms ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Immune Mediated ◽  
Development And Differentiation ◽  
Non Coding Rnas ◽  
And Function

Long non-coding RNAs (lncRNAs) represent crucial transcriptional and post-transcriptional gene regulators during antimicrobial responses in the host innate immune system. Studies have shown that lncRNAs are expressed in a highly tissue- and cell-specific- manner and are involved in the differentiation and function of innate immune cells, as well as inflammatory and antiviral processes, through versatile molecular mechanisms. These lncRNAs function via the interactions with DNA, RNA, or protein in either cis or trans pattern, relying on their specific sequences or their transcriptions and processing. The dysregulation of lncRNA function is associated with various human non-infectious diseases, such as inflammatory bowel disease, cardiovascular diseases, and diabetes mellitus. Here, we provide an overview of the regulation and mechanisms of lncRNA function in the development and differentiation of innate immune cells, and during the activation or repression of innate immune responses. These elucidations might be beneficial for the development of therapeutic strategies targeting inflammatory and innate immune-mediated diseases.

scholarly journals The Arabidopsis 2′-O-Ribose-Methylation and Pseudouridylation Landscape of rRNA in Comparison to Human and Yeast

2021 ◽  
Vol 12 ◽  
Author(s):  
Deniz Streit ◽  
Enrico Schleiff
Keyword(s):  
Arabidopsis Thaliana ◽  
Ribosomal Rna ◽  
Ribosomal Dna ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Ribosome Assembly ◽  
Small Nucleolar Rnas ◽  
General Process ◽  
Specific Factors ◽  
Nucleolar Rnas

Eukaryotic ribosome assembly starts in the nucleolus, where the ribosomal DNA (rDNA) is transcribed into the 35S pre-ribosomal RNA (pre-rRNA). More than two-hundred ribosome biogenesis factors (RBFs) and more than two-hundred small nucleolar RNAs (snoRNA) catalyze the processing, folding and modification of the rRNA in Arabidopsis thaliana. The initial pre-ribosomal 90S complex is formed already during transcription by association of ribosomal proteins (RPs) and RBFs. In addition, small nucleolar ribonucleoprotein particles (snoRNPs) composed of snoRNAs and RBFs catalyze the two major rRNA modification types, 2′-O-ribose-methylation and pseudouridylation. Besides these two modifications, rRNAs can also undergo base methylations and acetylation. However, the latter two modifications have not yet been systematically explored in plants. The snoRNAs of these snoRNPs serve as targeting factors to direct modifications to specific rRNA regions by antisense elements. Today, hundreds of different sites of modifications in the rRNA have been described for eukaryotic ribosomes in general. While our understanding of the general process of ribosome biogenesis has advanced rapidly, the diversities appearing during plant ribosome biogenesis is beginning to emerge. Today, more than two-hundred RBFs were identified by bioinformatics or biochemical approaches, including several plant specific factors. Similarly, more than two hundred snoRNA were predicted based on RNA sequencing experiments. Here, we discuss the predicted and verified rRNA modification sites and the corresponding identified snoRNAs on the example of the model plant Arabidopsis thaliana. Our summary uncovers the plant modification sites in comparison to the human and yeast modification sites.

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