scholarly journals Conservation of Small Regulatory RNAs in Vibrio parahaemolyticus: Possible role of RNA-OUT Encoded by the Pathogenicity Island (VPaI-7) of Pandemic Strains

2019 ◽  
Vol 20 (11) ◽  
pp. 2827
Author(s):  
Nicolás Plaza ◽  
Diliana Pérez-Reytor ◽  
Sebastián Ramírez-Araya ◽  
Alequis Pavón ◽  
Gino Corsini ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Regulation Of Gene Expression ◽  
Pathogenicity Island ◽  
Vibrio Species ◽  
Transcriptional Level ◽  
Adverse Conditions ◽  
Small Regulatory Rnas ◽  
Regulatory Rnas ◽  
Pandemic Strains

Small regulatory RNAs (sRNAs) are molecules that play an important role in the regulation of gene expression. sRNAs in bacteria can affect important processes, such as metabolism and virulence. Previous studies showed a significant role of sRNAs in the Vibrio species, but knowledge about Vibrio parahaemolyticus is limited. Here, we examined the conservation of sRNAs between V. parahaemolyticus and other human Vibrio species, in addition to investigating the conservation between V. parahaemolyticus strains differing in pandemic origin. Our results showed that only 7% of sRNAs were conserved between V. parahaemolyticus and other species, but 88% of sRNAs were highly conserved within species. Nonetheless, two sRNAs coding to RNA-OUT, a component of the Tn10/IS10 system, were exclusively present in pandemic strains. Subsequent analysis showed that both RNA-OUT were located in pathogenicity island-7 and would interact with transposase VPA1379, according to the model of pairing of IS10-encoded antisense RNAs. According to the location of RNA-OUT/VPA1379, we also investigated if they were expressed during infection. We observed that the transcriptional level of VPA1379 was significantly increased, while RNA-OUT was decreased at three hours post-infection. We suggest that IS10 transcription increases in pandemic strains during infection, probably to favor IS10 transposition and improve their fitness when they are facing adverse conditions.

scholarly journals Computational prediction of nonenzymatic RNA degradation patterns

2017 ◽  
Vol 63 (4) ◽  
Author(s):  
Agnieszka Rybarczyk ◽  
Paulina Jackowiak ◽  
Marek Figlerowicz ◽  
Jacek Blazewicz
Keyword(s):  
Regulation Of Gene Expression ◽  
Computational Prediction ◽  
Rna Degradation ◽  
Branch And Cut ◽  
Structural Factors ◽  
Rna Molecules ◽  
Small Regulatory Rnas ◽  
Rna Fragments ◽  
Regulatory Rnas

Since the beginning of XXI century, the increasing interest in the research of ribonucleic acids has been observed in response to a surprising discovery of the role that RNA molecules play in the biological systems. It was demonstrated that they do not only take part in the protein synthesis (mRNA, rRNA, tRNA) but also are involved in the regulation of gene expression. Several classes of small regulatory RNAs have been discovered (e.g. microRNA, small interfering RNA, piwiRNA). Most of them are excised from specific double-stranded RNA precursors by enzymes that belong to the RNaseIII family (Drosha, Dicer or Dicer-like proteins). More recently, it has been shown that small regulatory RNAs are also generated as stable intermediates of RNA degradation (so called RNA fragments originating from tRNA, snRNA, snoRNA etc.). Unfortunately, the mechanisms underlying biogenesis of the RNA fragments remain unclear. It is thought that several factors may be involved in the formation of the RNA fragments. The most important are specific RNases, RNA-protein interactions and RNA structure.  In this work, we focus on RNA primary and secondary structures as factors influencing RNA stability and consequently the pattern of RNA fragmentation. Earlier, we identified major structural factors affecting non-enzymatic RNA degradation. Now based on these data we developed a new branch-and-cut algorithm that is able to predict the products of large RNA molecules hydrolysis in vitro. We also present the experimental data that verify the results generated using this algorithm.

scholarly journals The Etiological Agent of Lyme Disease, Borrelia burgdorferi, Appears To Contain Only a Few Small RNA Molecules

2004 ◽  
Vol 186 (24) ◽  
pp. 8472-8477 ◽  
Author(s):  
Yngve Östberg ◽  
Ignas Bunikis ◽  
Sven Bergström ◽  
Jörgen Johansson
Keyword(s):  
Borrelia Burgdorferi ◽  
Small Rna ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Rnase E ◽  
Regulatory Pathways ◽  
Rna Molecules ◽  
Small Regulatory Rnas ◽  
Regulatory Rnas

ABSTRACT Small regulatory RNAs (sRNAs) have recently been shown to be the main controllers of several regulatory pathways. The function of sRNAs depends in many cases on the RNA-binding protein Hfq, especially for sRNAs with an antisense function. In this study, the genome of Borrelia burgdorferi was subjected to different searches for sRNAs, including direct homology and comparative genomics searches and ortholog- and annotation-based search strategies. Two new sRNAs were found, one of which showed complementarity to the rpoS region, which it possibly controls by an antisense mechanism. The role of the other sRNA is unknown, although observed complementarities against particular mRNA sequences suggest an antisense mechanism. We suggest that the low level of sRNAs observed in B. burgdorferi is at least partly due to the presumed lack of both functional Hfq protein and RNase E activity.

scholarly journals Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression

2016 ◽  
Vol 80 (4) ◽  
pp. 1029-1057 ◽  
Author(s):  
Ruben A. T. Mars ◽  
Pierre Nicolas ◽  
Emma L. Denham ◽  
Jan Maarten van Dijl
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Regulation Of Gene Expression ◽  
Regulatory Rna ◽  
Gram Positive ◽  
Content Type ◽  
Rna Molecules ◽  
Small Regulatory Rnas ◽  
Regulatory Rnas ◽  
The Stability

SUMMARYBacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules includetrans-acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5′ untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such asEscherichia coliandSalmonella. Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacteriumBacillus subtilis. A recent study identified 1,583 putative regulatory RNAs inB. subtilis, whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation inB. subtilis, and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation inB. subtilismostly involves elements at the 5′ ends of mRNA molecules. These can include 5′ secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs inB. subtilis. Altogether, the present survey provides many leads for the identification of new regulatory RNA functions inB. subtilis.

scholarly journals Cis- and Trans-Encoded Small Regulatory RNAs in Bacillus subtilis

2021 ◽  
Vol 9 (9) ◽  
pp. 1865
Author(s):  
Sabine Brantl ◽  
Peter Müller
Keyword(s):  
Potential Role ◽  
Bacterial Species ◽  
Model Organism ◽  
Physiological Role ◽  
Base Pairing ◽  
Small Regulatory Rnas ◽  
Regulatory Rnas ◽  
Rna Chaperones ◽  
Cis And Trans

Small regulatory RNAs (sRNAs) that act by base-pairing are the most abundant posttranscriptional regulators in all three kingdoms of life. Over the past 20 years, a variety of approaches have been employed to discover chromosome-encoded sRNAs in a multitude of bacterial species. However, although largely improved bioinformatics tools are available to predict potential targets of base-pairing sRNAs, it is still challenging to confirm these targets experimentally and to elucidate the mechanisms as well as the physiological role of their sRNA-mediated regulation. Here, we provide an overview of currently known cis- and trans-encoded sRNAs from B. subtilis with known targets and defined regulatory mechanisms and on the potential role of RNA chaperones that are or might be required to facilitate sRNA regulation in this important Gram-positive model organism.

scholarly journals An Inventory of CiaR-Dependent Small Regulatory RNAs in Streptococci

2021 ◽  
Vol 12 ◽  
Author(s):  
Nancy Jabbour ◽  
Marie-Frédérique Lartigue
Keyword(s):  
Farm Animals ◽  
Bacterial Survival ◽  
Rna Translation ◽  
Component Systems ◽  
Small Regulatory Rnas ◽  
Streptococcal Species ◽  
Two Component Systems ◽  
Regulatory Rnas ◽  
Physical And Chemical

Bacteria adapt to the different environments encountered by rapid and tightly controlled regulations involving complex networks. A first line of control is transcriptional with regulators such as two-component systems (TCSs) that respond to physical and chemical perturbations. It is followed by posttranscriptional regulations in which small regulatory RNAs (sRNAs) may affect RNA translation. Streptococci are opportunistic pathogens for humans and farm animals. The TCS CiaRH is highly conserved among this genus and crucial in bacterial survival under stressful conditions. In several streptococcal species, some sRNAs belong to the CiaRH regulon and are called csRNAs for cia-dependent sRNAs. In this review, we start by focusing on the Streptococcus species harboring a CiaRH TCS. Then the role of CiaRH in streptococcal pathogenesis is discussed in the context of recent studies. Finally, we give an overview of csRNAs and their functions in Streptococci with a focus on their importance in bacterial adaptation and virulence.

scholarly journals Identification of a DNA Methyltransferase Gene Carried on a Pathogenicity Island-Like Element (VPAI) in Vibrio parahaemolyticus and Its Prevalence among Clinical and Environmental Isolates

2006 ◽  
Vol 72 (6) ◽  
pp. 4455-4460 ◽  
Author(s):  
Hui-zhen Wang ◽  
Minnie M. L. Wong ◽  
Desmond O'Toole ◽  
Mandy M. H. Mak ◽  
Rudolf S. S. Wu ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Dna Methyltransferase ◽  
Pathogenicity Island ◽  
Environmental Isolates ◽  
Virulence Traits ◽  
Hemolysin Gene ◽  
Methyltransferase Gene ◽  
Thermostable Direct Hemolysin ◽  
Pandemic Strains

ABSTRACT In this study we identified a putative virulence-associated DNA methyltransferase (MTase) gene carried on a novel 22.79-kb pathogenicity island-like element (VPAI) in V. parahaemolyticus. The V. parahaemolyticus MTase gene was shown by PCR to be prevalent (>98%) in pandemic thermostable direct hemolysin gene-positive isolates, which suggests that VPAI may confer unique virulence traits to pandemic strains of V. parahaemolyticus.

Small Regulatory RNAs in Acidithiobacillus Ferrooxidans: Case Studies of 6S RNA and Frr

2009 ◽  
Vol 71-73 ◽  
pp. 191-194 ◽  
Author(s):  
Amir Shmaryahu ◽  
C. Lefimil ◽  
Eugenia Jedlicki ◽  
David S. Holmes
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Transcriptional Level ◽  
Global Regulator ◽  
Widespread Occurrence ◽  
Small Regulatory Rnas ◽  
Intergenic Regions ◽  
Bioinformatic Approaches ◽  
Regulatory Rnas ◽  
Regulatory Functions ◽  
Sigma 70

Bioinformatic approaches are described for the discovery of small regulatory RNAs (srRNAs) in the biomining microorganism Acidithiobacillus ferrooxidans. Intergenic regions of the annotated genome were extracted and computationally searched for srRNAs. Candidate srRNAs that were associated with predicted sigma 70 promoters and/or rho-independent terminators were chosen for further study. Experimental validation is presented for 6S srRNA and frr. srRNAs are known to control gene expression in a wide variety of microorganisms, usually at the post-transcriptional level, by acting as antisense RNAs that bind targeted mRNAs or by interacting with regulatory proteins. srRNAs are involved in the regulation of a large variety of processes. Frr is an RNA antisense to fur; the latter encodes a global regulator involved the control of a large number of genes involved in iron uptake and homeostasis. Because of the widespread occurrence and extensive repertoire of regulatory functions afforded by srRNAs, it is expected that their discovery functional analysis in biomining microorganisms will contribute to improving our understanding of the microbiology of bioleaching processes.

scholarly journals Neisseria meningitidis Uses Sibling Small Regulatory RNAs To Switch from Cataplerotic to Anaplerotic Metabolism

mBio ◽  
2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Yvonne Pannekoek ◽  
Robert A. G. Huis in ‘t Veld ◽  
Kim Schipper ◽  
Sandra Bovenkerk ◽  
Gertjan Kramer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Neisseria Meningitidis ◽  
Tricarboxylic Acid Cycle ◽  
Regulation Of Gene Expression ◽  
Stringent Response ◽  
Tricarboxylic Acid ◽  
Metabolic Adaptation ◽  
Acid Cycle ◽  
Small Regulatory Rnas ◽  
Regulatory Rnas

ABSTRACT Neisseria meningitidis (the meningococcus) is primarily a commensal of the human oropharynx that sporadically causes septicemia and meningitis. Meningococci adapt to diverse local host conditions differing in nutrient supply, like the nasopharynx, blood, and cerebrospinal fluid, by changing metabolism and protein repertoire. However, regulatory transcription factors and two-component systems in meningococci involved in adaptation to local nutrient variations are limited. We identified novel sibling small regulatory RNAs ( Neisseria metabolic switch regulators [NmsRs]) regulating switches between cataplerotic and anaplerotic metabolism in this pathogen. Overexpression of NmsRs was tolerated in blood but not in cerebrospinal fluid. Expression of six tricarboxylic acid cycle enzymes was downregulated by direct action of NmsRs. Expression of the NmsRs themselves was under the control of the stringent response through the action of RelA. Small sibling regulatory RNAs of meningococci, controlling general metabolic switches, add an exciting twist to their versatile repertoire in bacterial pathogens. IMPORTANCE Regulatory small RNAs (sRNAs) of pathogens are coming to be recognized as highly important components of riboregulatory networks, involved in the control of essential cellular processes. They play a prominent role in adaptation to physiological changes as represented by different host environments. They can function as posttranscriptional regulators of gene expression to orchestrate metabolic adaptation to nutrient stresses. Here, we identified highly conserved sibling sRNAs in Neisseria meningitidis which are functionally involved in the regulation of gene expression of components of the tricarboxylic acid cycle. These novel sibling sRNAs that function by antisense mechanisms extend the so-called stringent response which connects metabolic status to colonization and possibly virulence as well as pathogenesis in meningococci. IMPORTANCE Regulatory small RNAs (sRNAs) of pathogens are coming to be recognized as highly important components of riboregulatory networks, involved in the control of essential cellular processes. They play a prominent role in adaptation to physiological changes as represented by different host environments. They can function as posttranscriptional regulators of gene expression to orchestrate metabolic adaptation to nutrient stresses. Here, we identified highly conserved sibling sRNAs in Neisseria meningitidis which are functionally involved in the regulation of gene expression of components of the tricarboxylic acid cycle. These novel sibling sRNAs that function by antisense mechanisms extend the so-called stringent response which connects metabolic status to colonization and possibly virulence as well as pathogenesis in meningococci.

scholarly journals Insights into the Function of Regulatory RNAs in Bacteria and Archaea

2021 ◽  
Vol 1 (3) ◽  
pp. 403-423
Author(s):  
Elahe Soltani-Fard ◽  
Sina Taghvimi ◽  
Zahra Abedi Kichi ◽  
Christian Weber ◽  
Zahra Shabaninejad ◽  
...  
Keyword(s):  
Defense Mechanism ◽  
Regulation Of Gene Expression ◽  
Rna Molecules ◽  
Physiological Processes ◽  
Wide Range ◽  
Phage Dna ◽  
Small Molecule Ligands ◽  
Small Regulatory Rnas ◽  
Short Palindromic Repeat ◽  
Regulatory Rnas

Non-coding RNAs (ncRNAs) are functional RNA molecules that comprise about 80% of both mammals and prokaryotes genomes. Recent studies have identified a large number of small regulatory RNAs in Escherichia coli and other bacteria. In prokaryotes, RNA regulators are a diverse group of molecules that modulate a wide range of physiological responses through a variety of mechanisms. Similar to eukaryotes, bacterial microRNAs are an important class of ncRNAs that play an important role in the development and secretion of proteins and in the regulation of gene expression. Similarly, riboswitches are cis-regulatory structured RNA elements capable of directly controlling the expression of downstream genes in response to small molecule ligands. As a result, riboswitches detect and respond to the availability of various metabolic changes within cells. The most extensive and most widely studied set of small RNA regulators act through base pairing with RNAs. These types of RNAs are vital for prokaryotic life, activating or suppressing important physiological processes by modifying transcription or translation. The majority of these small RNAs control responses to changes in environmental conditions. Finally, clustered regularly interspaced short palindromic repeat (CRISPR) RNAs, a newly discovered RNA regulator group, contains short regions of homology to bacteriophage and plasmid sequences that bacteria use to splice phage DNA as a defense mechanism. The detailed mechanism is still unknown but devoted to target homologous foreign DNAs. Here, we review the known mechanisms and roles of non-coding regulatory RNAs, with particular attention to riboswitches and their functions, briefly introducing translational applications of CRISPR RNAs in mammals.

Epigenetic regulation mechanisms of microRNA expression

2017 ◽  
Vol 8 (5-6) ◽  
pp. 203-212 ◽  
Author(s):  
Sara Morales ◽  
Mariano Monzo ◽  
Alfons Navarro
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cell Proliferation ◽  
Epigenetic Regulation ◽  
Regulation Of Gene Expression ◽  
Transcriptional Level ◽  
Regulate Gene Expression ◽  
Regulation Mechanisms ◽  
Regulate Gene

AbstractMicroRNAs (miRNAs) are single-stranded RNAs of 18–25 nucleotides that regulate gene expression at the post-transcriptional level. They are involved in many physiological and pathological processes, including cell proliferation, apoptosis, development and carcinogenesis. Because of the central role of miRNAs in the regulation of gene expression, their expression needs to be tightly controlled. Here, we summarize the different mechanisms of epigenetic regulation of miRNAs, with a particular focus on DNA methylation and histone modification.

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