scholarly journals Small RNA Plays Important Roles in Virus–Host Interactions

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1271
Author(s):  
Hui Dai ◽  
Weifeng Gu
Keyword(s):  
Influenza Virus ◽  
Small Rna ◽  
Small Rnas ◽  
Viral Transcription ◽  
Host Interactions ◽  
Recent Advances ◽  
Transcription And Replication

Non-coding small RNAs play important roles in virus–host interactions. For hosts, small RNAs can serve as sensors in antiviral pathways including RNAi and CRISPR; for viruses, small RNAs can be involved in viral transcription and replication. This paper covers several recent discoveries on small RNA mediated virus–host interactions, and focuses on influenza virus cap-snatching and a few important virus sensors including PIR-1, RIG-I like protein DRH-1 and piRNAs. The paper also discusses recent advances in mammalian antiviral RNAi.

scholarly journals Endogenous Retroviruses Walk a Fine Line between Priming and Silencing

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 792 ◽  
Author(s):  
Harrison Cullen ◽  
Andrea J. Schorn
Keyword(s):  
Small Rna ◽  
Binding Sites ◽  
Small Rnas ◽  
Genome Stability ◽  
Sequence Variation ◽  
Endogenous Retroviruses ◽  
Highly Active ◽  
Trna Primer ◽  
Ltr Retroelements ◽  
Transcription And Replication

Endogenous retroviruses (ERVs) in mammals are closely related to infectious retroviruses and utilize host tRNAs as a primer for reverse transcription and replication, a hallmark of long terminal repeat (LTR) retroelements. Their dependency on tRNA makes these elements vulnerable to targeting by small RNAs derived from the 3′-end of mature tRNAs (3′-tRFs), which are highly expressed during epigenetic reprogramming and potentially protect many tissues in eukaryotes. Here, we review some key functions of ERV reprogramming during mouse and human development and discuss how small RNA-mediated silencing maintains genome stability when ERVs are temporarily released from heterochromatin repression. In particular, we take a closer look at the tRNA primer binding sites (PBS) of two highly active ERV families in mice and their sequence variation that is shaped by the conflict of successful tRNA priming for replication versus evasion of silencing by 3′-tRFs.

scholarly journals NS2/NEP protein regulates transcription and replication of the influenza virus RNA genome

2009 ◽  
Vol 90 (6) ◽  
pp. 1398-1407 ◽  
Author(s):  
Nicole C. Robb ◽  
Matt Smith ◽  
Frank T. Vreede ◽  
Ervin Fodor
Keyword(s):  
Influenza Virus ◽  
Rna Polymerase ◽  
Nuclear Export ◽  
Influenza A ◽  
Viral Rna ◽  
Viral Transcription ◽  
Virus Rna ◽  
Specific Alteration ◽  
Transcription And Replication ◽  
Rna Levels

The influenza virus RNA polymerase transcribes the negative-sense viral RNA segments (vRNA) into mRNA and replicates them via complementary RNA (cRNA) intermediates into more copies of vRNA. It is not clear how the relative amounts of the three RNA products, mRNA, cRNA and vRNA, are regulated during the viral life cycle. We found that in viral ribonucleoprotein (vRNP) reconstitution assays involving only the minimal components required for viral transcription and replication (the RNA polymerase, the nucleoprotein and a vRNA template), the relative levels of accumulation of RNA products differed from those observed in infected cells, suggesting a regulatory role for additional viral proteins. Expression of the viral NS2/NEP protein in RNP reconstitution assays affected viral RNA levels by reducing the accumulation of transcription products and increasing the accumulation of replication products to more closely resemble those found during viral infection. This effect was functionally conserved in influenza A and B viruses and was influenza-virus-type-specific, demonstrating that the NS2/NEP protein changes RNA levels by specific alteration of the viral transcription and replication machinery, rather than through an indirect effect on the host cell. Although NS2/NEP has been shown previously to play a role in the nucleocytoplasmic export of viral RNPs, deletion of the nuclear export sequence region that is required for its transport function did not affect the ability of the protein to regulate RNA levels. A role for the NS2/NEP protein in the regulation of influenza virus transcription and replication that is independent of its viral RNP export function is proposed.

scholarly journals MicroRNAs: Biological Regulators in Pathogen–Host Interactions

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 113 ◽  
Author(s):  
Stephanie Maia Acuña ◽  
Lucile Maria Floeter-Winter ◽  
Sandra Marcia Muxel
Keyword(s):  
Immune Response ◽  
Infectious Diseases ◽  
Small Rnas ◽  
Immune Cell ◽  
Fine Tuning ◽  
Biological Processes ◽  
Host Interactions ◽  
The Past ◽  
Biological Aspects

An inflammatory response is essential for combating invading pathogens. Several effector components, as well as immune cell populations, are involved in mounting an immune response, thereby destroying pathogenic organisms such as bacteria, fungi, viruses, and parasites. In the past decade, microRNAs (miRNAs), a group of noncoding small RNAs, have emerged as functionally significant regulatory molecules with the significant capability of fine-tuning biological processes. The important role of miRNAs in inflammation and immune responses is highlighted by studies in which the regulation of miRNAs in the host was shown to be related to infectious diseases and associated with the eradication or susceptibility of the infection. Here, we review the biological aspects of microRNAs, focusing on their roles as regulators of gene expression during pathogen–host interactions and their implications in the immune response against Leishmania, Trypanosoma, Toxoplasma, and Plasmodium infectious diseases.

scholarly journals Mechanism of Stochastic Resonance in a Quorum Sensing Network Regulated by Small RNAs

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ya-nan Zhu ◽  
Jianwei Shen ◽  
Yong Xu
Keyword(s):  
Quorum Sensing ◽  
Stochastic Resonance ◽  
Small Rna ◽  
Small Rnas ◽  
Cell Communication ◽  
The Other ◽  
Important Process ◽  
Positive Role ◽  
Bacterial Quorum Sensing ◽  
Bacterial Quorum

Bacterial quorum sensing (QS) is an important process of cell communication and more and more attention is paid to it. Moreover, the noises are ubiquitous in nature and often play positive role. In this paper, we investigate how the noise enhances the QS though the stochastic resonance (SR) and explain the mechanism of SR in this quorum sensing network. In addition, we also discuss the interaction between the small RNA and the other genes in this network and discover the biological importance.

scholarly journals Intertissue small RNA communication mediates the acquisition and inheritance of hormesis in Caenorhabditis elegans

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Emiko Okabe ◽  
Masaharu Uno ◽  
Saya Kishimoto ◽  
Eisuke Nishida
Keyword(s):  
Caenorhabditis Elegans ◽  
Small Rna ◽  
Stress Resistance ◽  
Environmental Conditions ◽  
Production System ◽  
Small Rnas ◽  
Communication Systems ◽  
Rna Transport ◽  
Phenotypic Changes ◽  
Induced Stress

AbstractEnvironmental conditions can cause phenotypic changes, part of which can be inherited by subsequent generations via soma-to-germline communication. However, the signaling molecules or pathways that mediate intertissue communication remain unclear. Here, we show that intertissue small RNA communication systems play a key role in the acquisition and inheritance of hormesis effects – stress-induced stress resistance – in Caenorhabditis elegans. The miRNA-processing enzyme DRSH-1 is involved in both the acquisition and the inheritance of hormesis, whereas worm-specific Argonaute (WAGO) proteins, which function with endo-siRNAs, are involved only in its inheritance. Further analyses demonstrate that the miRNA production system in the neuron and the small RNA transport machinery in the intestine are both essential for its acquisition and that both the transport of small RNAs in the germline and the germline Argonaute HRDE-1 complex are required for its inheritance. Our results thus demonstrate that overlapping and distinct roles of small RNA systems in the acquisition and inheritance of hormesis effects.

scholarly journals Functional Analysis of PA Binding by Influenza A Virus PB1: Effects on Polymerase Activity and Viral Infectivity

2001 ◽  
Vol 75 (17) ◽  
pp. 8127-8136 ◽  
Author(s):  
Daniel R. Perez ◽  
Ruben O. Donis
Keyword(s):  
Amino Acids ◽  
Influenza Virus ◽  
Amino Acid ◽  
Viral Replication ◽  
Influenza A Virus ◽  
Influenza A ◽  
Amino Acid Sequences ◽  
Influenza Viruses ◽  
Virus Growth ◽  
Transcription And Replication

ABSTRACT Influenza A virus expresses three viral polymerase (P) subunits—PB1, PB2, and PA—all of which are essential for RNA and viral replication. The functions of P proteins in transcription and replication have been partially elucidated, yet some of these functions seem to be dependent on the formation of a heterotrimer for optimal viral RNA transcription and replication. Although it is conceivable that heterotrimer subunit interactions may allow a more efficient catalysis, direct evidence of their essentiality for viral replication is lacking. Biochemical studies addressing the molecular anatomy of the P complexes have revealed direct interactions between PB1 and PB2 as well as between PB1 and PA. Previous studies have shown that the N-terminal 48 amino acids of PB1, termed domain α, contain the residues required for binding PA. We report here the refined mapping of the amino acid sequences within this small region of PB1 that are indispensable for binding PA by deletion mutagenesis of PB1 in a two-hybrid assay. Subsequently, we used site-directed mutagenesis to identify the critical amino acid residues of PB1 for interaction with PA in vivo. The first 12 amino acids of PB1 were found to constitute the core of the interaction interface, thus narrowing the previous boundaries of domain α. The role of the minimal PB1 domain α in influenza virus gene expression and genome replication was subsequently analyzed by evaluating the activity of a set of PB1 mutants in a model reporter minigenome system. A strong correlation was observed between a functional PA binding site on PB1 and P activity. Influenza viruses bearing mutant PB1 genes were recovered using a plasmid-based influenza virus reverse genetics system. Interestingly, mutations that rendered PB1 unable to bind PA were either nonviable or severely growth impaired. These data are consistent with an essential role for the N terminus of PB1 in binding PA, P activity, and virus growth.

scholarly journals The Importance of the Small RNA Chaperone Hfq for Growth of Epidemic Yersinia pestis, but Not Yersinia pseudotuberculosis, with Implications for Plague Biology

2010 ◽  
Vol 192 (16) ◽  
pp. 4239-4245 ◽  
Author(s):  
Guangchun Bai ◽  
Andrey Golubov ◽  
Eric A. Smith ◽  
Kathleen A. McDonough
Keyword(s):  
Yersinia Pestis ◽  
Small Rna ◽  
Small Rnas ◽  
Yersinia Pseudotuberculosis ◽  
Etiologic Agent ◽  
Growth Restriction ◽  
Rna Chaperone ◽  
Unique Biology ◽  
Severe Growth

ABSTRACT Yersinia pestis, the etiologic agent of plague, has only recently evolved from Yersinia pseudotuberculosis. hfq deletion caused severe growth restriction at 37°C in Y. pestis but not in Y. pseudotuberculosis. Strains from all epidemic plague biovars were similarly affected, implicating Hfq, and likely small RNAs (sRNAs), in the unique biology of the plague bacillus.

scholarly journals Intergenerational metabolic priming by sperm piRNAs

2021 ◽  
Author(s):  
Adelheid Lempradl ◽  
Unn Kugelberg ◽  
Mary Iconomou ◽  
Ian Beddows ◽  
Daniel Nätt ◽  
...  
Keyword(s):  
Small Rna ◽  
Small Rnas ◽  
Target Gene ◽  
Epigenetic Inheritance ◽  
Mature Sperm ◽  
Transcriptional Reprogramming ◽  
Complementary Sequences ◽  
Specific Manner ◽  
Dietary Sugar ◽  
Pirna Pathway

Preconception parental environment can reproducibly program offspring phenotype without altering the DNA sequence, yet the mechanisms underpinning this epigenetic inheritance remains elusive. Here, we demonstrate the existence of an intact piRNA-pathway in mature Drosophila sperm and show that pathway modulation alters offspring gene transcription in a sequence-specific manner. We map a dynamic small RNA content in developing sperm and find that the mature sperm carry a highly distinct small RNA cargo. By biochemical pulldown, we identify a small RNA subset bound directly to piwi protein. And, we show that piRNA-pathway controlled sperm small RNAs are linked to target gene repression in offspring. Critically, we find that full piRNA-pathway dosage is necessary for the intergenerational metabolic and transcriptional reprogramming events triggered by high paternal dietary sugar. These data provide a direct link between regulation of endogenous mature sperm small RNAs and transcriptional programming of complementary sequences in offspring. Thus, we identify a novel mediator of paternal intergenerational epigenetic inheritance.

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