scholarly journals Negative-sense RNA viruses: An underexplored platform for examining virus–host lipid interactions

2021 ◽  
Vol 32 (20) ◽  
pp. pe1
Author(s):  
Monica L. Husby ◽  
Robert V. Stahelin
Keyword(s):  
Host Cell ◽  
Rna Viruses ◽  
Life Cycles ◽  
Diverse Range ◽  
Membrane Biology ◽  
Wide Range ◽  
Range Of Functions ◽  
Pathogenic Viruses ◽  
Pathogenic Agents ◽  
Negative Sense

Viruses are pathogenic agents that can infect all varieties of organisms, including plants, animals, and humans. These microscopic particles are genetically simple as they encode a limited number of proteins that undertake a wide range of functions. While structurally distinct, viruses often share common characteristics that have evolved to aid in their infectious life cycles. A commonly underappreciated characteristic of many deadly viruses is a lipid envelope that surrounds their protein and genetic contents. Notably, the lipid envelope is formed from the host cell the virus infects. Lipid-enveloped viruses comprise a diverse range of pathogenic viruses, which often lead to high fatality rates and many lack effective therapeutics and/or vaccines. This perspective primarily focuses on the negative-sense RNA viruses from the order Mononegavirales, which obtain their lipid envelope from the host plasma membrane. Specifically, the perspective highlights the common themes of host cell lipid and membrane biology necessary for virus replication, assembly, and budding.

Secretory Proteases of the Human Skin Microbiome

2021 ◽  
Author(s):  
Wisely Chua ◽  
Si En Poh ◽  
Hao Li
Keyword(s):  
Human Skin ◽  
Hydrolytic Enzymes ◽  
Microbial Interactions ◽  
Skin Microbiome ◽  
Protein Cleavage ◽  
Wide Range ◽  
Range Of Functions ◽  
Diverse Community ◽  
Secreted Proteases ◽  
Pathogenic Agents

The human skin is our outermost layer and serves as a protective barrier against external insults. Advances in next generation sequencing have enabled the discoveries of a rich and diverse community of microbes - bacteria, fungi and viruses that are residents of this surface. The genomes of these microbes also revealed the presence of many secretory enzymes. In particular, proteases which are hydrolytic enzymes capable of protein cleavage and degradation are of special interest in the skin environment which is enriched in proteins and lipids. In this minireview, we will focus on the roles of these skin-relevant microbial secreted proteases, both in terms of their widely studied roles as pathogenic agents in tissue invasion and host immune inactivation, and their recently discovered roles in inter-microbial interactions and modulation of virulence factors. From these studies, it has become apparent that while microbial proteases are capable of a wide range of functions, their expression is tightly regulated and highly responsive to the environments the microbes are in. With the introduction of new biochemical and bioinformatics tools to study protease functions, it will be important to understand the roles played by skin microbial secretory proteases in cutaneous health, especially the less studied commensal microbes with an emphasis on contextual relevance.

scholarly journals Extensive C->U transition biases in the genomes of a wide range of mammalian RNA viruses; potential associations with transcriptional mutations, damage- or host-mediated editing of viral RNA

2021 ◽  
Vol 17 (6) ◽  
pp. e1009596
Author(s):  
Peter Simmonds ◽  
M. Azim Ansari
Keyword(s):  
Rna Structure ◽  
Rna Viruses ◽  
Multivariable Analysis ◽  
Rapid Evolution ◽  
Structural Parameter ◽  
Coding Region ◽  
Association Index ◽  
Diverse Range ◽  
Wide Range ◽  
Genome Scale

The rapid evolution of RNA viruses has been long considered to result from a combination of high copying error frequencies during RNA replication, short generation times and the consequent extensive fixation of neutral or adaptive changes over short periods. While both the identities and sites of mutations are typically modelled as being random, recent investigations of sequence diversity of SARS coronavirus 2 (SARS-CoV-2) have identified a preponderance of C->U transitions, proposed to be driven by an APOBEC-like RNA editing process. The current study investigated whether this phenomenon could be observed in datasets of other RNA viruses. Using a 5% divergence filter to infer directionality, 18 from 36 datasets of aligned coding region sequences from a diverse range of mammalian RNA viruses (including Picornaviridae, Flaviviridae, Matonaviridae, Caliciviridae and Coronaviridae) showed a >2-fold base composition normalised excess of C->U transitions compared to U->C (range 2.1x–7.5x), with a consistently observed favoured 5’ U upstream context. The presence of genome scale RNA secondary structure (GORS) was the only other genomic or structural parameter significantly associated with C->U/U->C transition asymmetries by multivariable analysis (ANOVA), potentially reflecting RNA structure dependence of sites targeted for C->U mutations. Using the association index metric, C->U changes were specifically over-represented at phylogenetically uninformative sites, potentially paralleling extensive homoplasy of this transition reported in SARS-CoV-2. Although mechanisms remain to be functionally characterised, excess C->U substitutions accounted for 11–14% of standing sequence variability of structured viruses and may therefore represent a potent driver of their sequence diversification and longer-term evolution.

scholarly journals Mutation bias implicates RNA editing in a wide range of mammalian RNA viruses

2021 ◽  
Author(s):  
Peter Simmonds ◽  
M. Azim Ansari
Keyword(s):  
Rna Editing ◽  
Rna Viruses ◽  
Rna Virus ◽  
Structural Parameters ◽  
Rapid Evolution ◽  
Sequence Variability ◽  
Diverse Range ◽  
Mouth Disease Virus ◽  
Wide Range ◽  
Virus Sequence

ABSTRACTThe rapid evolution of RNA viruses has been long considered to result from a combination of high copying error frequencies during RNA replication, short generation times and the consequent extensive fixation of neutral or adaptive changes over short periods. While both the identities and sites of mutations are typically modelled as being random, recent investigations of sequence diversity of SARS coronavirus 2 (SARS-CoV-2) have identified a preponderance of C->U transitions, potentially driven by an APOBEC-like RNA editing process. The current study investigated whether this phenomenon could be observed in the more genetically diverse datasets of other RNA viruses. Using a 5% divergence filter to infer directionality, 18 from 32 datasets of aligned coding region sequences from a diverse range of mammalian RNA viruses (including Picornaviridae, Flaviviridae, Matonaviridae, Caliciviridae and Coronaviridae) showed a >2-fold base composition normalised excess of C->U transitions compared to U->C (range 2.1x–7.5x). C->U transitions showed a favoured 5’ U upstream context consistent with previous analyses of APOBEC-mediated RNA targeting. Amongst several genomic compositional and structural parameters, the presence of genome scale RNA secondary structure (GORS) was associated with C->U/U->C transition asymmetries (p < 0.001), potentially reflecting the documented structure dependence of APOBEC-mediated RNA editing. Using the association index metric, C->U changes were specifically over-represented at phylogenetically uninformative sites, consistent with extensive homoplasy documented in SARS-CoV-2. Excess C->U substitutions accounted for 15-20% of standing sequence variability of HCV and other RNA viruses; RNA editing may therefore represent a potent driver of RNA virus sequence diversification and longer term evolution.Author SummaryThe rapid evolution of RNA viruses is thought to arise from high mutation frequencies during replication and the rapid accumulation of genetic changes over time in response to its changing environments. This study describes an additional potent factor that contributes to the evolution of RNA infecting mammals, the deliberate mutation of the viral genome by host antiviral pathways active within the cell when it becomes infected. This so called “genome editing” by one or more APOBEC enzymes leads to characteristic C->U mutations that damage the virus’s ability to replicate. While this pathway is well characterised as an antiviral defence against HIV and other retroviruses, this study provides evidence for its activity against a wide range of human and veterinary viruses, including HCV and foot and mouth disease virus. APOBEC-driven mutations accounted for 15-20% of standing sequence variability of RNA virus groups, representing a potent driver of RNA virus sequence diversification.

scholarly journals High Prevalence of a Newly Discovered Wutai Mosquito Phasivirus in Mosquitoes from Rio de Janeiro, Brazil

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 135
Author(s):  
Mário Sérgio Ribeiro ◽  
Tania Ayllón ◽  
Viviana Malirat ◽  
Daniel Cardoso Portela Câmara ◽  
Cristina Maria Giordano Dias ◽  
...  
Keyword(s):  
Rio De Janeiro ◽  
Rna Viruses ◽  
Vector Competence ◽  
Blood Feeding ◽  
Life Cycles ◽  
Intrinsic Factors ◽  
Phlebotomine Sandflies ◽  
Wide Range ◽  
High Prevalence ◽  
The Impact

Many RNA viruses have recently emerged, threatening humans and causing harm to animals and plants. Bunyaviruses represent one of the largest groups of RNA viruses and are able to infect a wide range of hosts (invertebrates, vertebrates, and plants). Recently, new insect-specific viruses have been isolated from mosquitoes and phlebotomine sandflies worldwide. Little is known regarding the impact of these viruses on the vector life cycles and the stages of oviposition, breeding, blood feeding, and the mosquito’s lifespan. This study describes, for the first time in South America, the detection and characterization of a recently discovered bunyavirus corresponding to the Wutai mosquito phasivirus, confirming its high prevalence in the Culex spp. and Aedes spp. mosquitoes collected in the urban environment of Rio de Janeiro city, Brazil. The knowledge of the mosquito’s insect-specific virus infection can improve virus evolution studies and may contribute to the understanding of intrinsic factors that influence vector competence to transmit pathogenic viruses.

scholarly journals A Sister Lineage of Sampled Retroviruses Corroborates the Complex Evolution of Retroviruses

2020 ◽  
Author(s):  
Jianhua Wang ◽  
Guan-Zhu Han
Keyword(s):  
Evolutionary History ◽  
Rna Viruses ◽  
Phylogenetic Analyses ◽  
Ribonuclease H ◽  
Genome Architecture ◽  
Major Lineage ◽  
Wide Range ◽  
History Of ◽  
Negative Sense ◽  
Complex Evolutionary History

Abstract The origin and deep history of retroviruses remain mysterious and contentious, largely because the diversity of retroviruses is incompletely understood. Here, we report the discovery of lokiretroviruses, a novel major lineage of retroviruses, within the genomes of a wide range of vertebrates (at least 137 species), including lampreys, ray-finned fishes, lobe-finned fishes, amphibians, and reptiles. Lokiretroviruses share a similar genome architecture with known retroviruses, but display some unique features. Interestingly, lokiretrovirus Env proteins share detectable similarity with fusion glycoproteins of viruses within the Mononegavirales order, blurring the boundary between retroviruses and negative sense single-stranded RNA viruses. Phylogenetic analyses based on reverse transcriptase demonstrate that lokiretroviruses are sister to all the retroviruses sampled to date, providing a crucial nexus for studying the deep history of retroviruses. Comparing congruence between host and virus phylogenies suggests lokiretroviruses mainly underwent cross-species transmission. Moreover, we find that retroviruses replaced their ribonuclease H and integrase domains multiple times during their evolutionary course, revealing the importance of domain shuffling in the evolution of retroviruses. Overall, our findings greatly expand our views of the diversity of retroviruses, and provide novel insights into the origin and complex evolutionary history of retroviruses.

scholarly journals Symmetries among Multivariate Information Measures Explored Using Möbius Operators

2018 ◽  
Author(s):  
David J. Galas ◽  
Nikita A. Sakhanenko
Keyword(s):  
Data Analysis ◽  
Operator Algebra ◽  
Full Range ◽  
Direct Consequence ◽  
Biological Data ◽  
Diverse Range ◽  
Common Information ◽  
Information Measures ◽  
Wide Range ◽  
Range Of Functions

Information-related measures are useful tools for multi-variable data analysis, as measures of dependence among variables, and as descriptions of order and disorder in biological and physical systems. &nbsp;Measures, like marginal entropies, mutual / interaction / multi -information, have long been used in a number of fields including descriptions of systems complexity and biological data analysis.&nbsp; The mathematical relationships among these measures are therefore of significant inherent interest. &nbsp;Relations between common information measures include the duality relations based on M&ouml;bius inversion on lattices. &nbsp;These are the direct consequence of the symmetries of the lattices of the sets of variables (subsets ordered by inclusion). &nbsp;While these relationships are of significant interest there has been, to our knowledge, no systematic examination of the full range of relationships of this diverse range of functions into a unifying formalism as we do here. &nbsp;In this paper we define operators on functions on these lattices based on the M&ouml;bius inversions that map functions into one another (M&ouml;bius operators).&nbsp; We show that these operators form a simple group isomorphic to the symmetric group S3.&nbsp; Relations among the set of functions on the lattice are transparently expressed in terms of the operator algebra, and, applied to the information measures, can be used to derive a wide range of relationships among diverse information measures. &nbsp;The M&ouml;bius operator algebra is naturally generalized which yields extensive new relationships. &nbsp;This formalism now provides a fundamental unification of information-related measures, and the isomorphism of all distributive lattices with the subset lattice implies an even broader application of these results.

scholarly journals Methods for the targeted sequencing and analysis of integrons and their gene cassettes from complex microbial communities

2021 ◽  
Author(s):  
Timothy M. Ghaly ◽  
Anahit Penesyan ◽  
Alexander Pritchard ◽  
Qin Qi ◽  
Vaheesan Rajabal ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antibiotic Resistance Genes ◽  
Pcr Amplification ◽  
Gene Cassette ◽  
Human Pathogens ◽  
Diverse Range ◽  
Gene Cassettes ◽  
Wide Range ◽  
Class 1 ◽  
Range Of Functions

AbstractIntegrons are bacterial genetic elements that can integrate mobile gene cassettes. They are mostly known for spreading antibiotic resistance cassettes among human pathogens. However, beyond clinical settings, gene cassettes encode an extraordinarily diverse range of functions important for bacterial adaptation. The recovery and sequencing of cassettes has promising applications, including: surveillance of clinically important genes, particularly antibiotic resistance determinants; investigating the functional diversity of integron-carrying bacteria; and novel enzyme discovery. Although gene cassettes can be directly recovered using PCR, there are no standardised methods for their amplification and, importantly, for validating sequences as genuine integron gene cassettes. Here, we present reproducible methods for the PCR amplification, sequence processing, and validation of gene cassette amplicons from complex communities. We describe two different PCR assays that either amplify cassettes together with integron integrases, or gene cassettes together within cassette arrays. We compare the use of Nanopore and Illumina sequencing, and present bioinformatic pipelines that filter sequences to ensure that they represent amplicons from genuine integrons. Using a diverse set of environmental DNAs, we show that our approach can consistently recover thousands of unique cassettes per sample and up to hundreds of different integron integrases. Recovered cassettes confer a wide range of functions, including antibiotic resistance, with as many as 300 resistance cassettes found in a single sample. In particular, we show that class 1 integrons appear to be collecting and concentrating antibiotic resistance genes out of the broader diversity of cassette functions. The methods described here can be applied to any environmental or clinical microbiome sample.

Nine Centuries of Man

2017 ◽  
Keyword(s):  
Twentieth Century ◽  
Diverse Range ◽  
Gender Expectations ◽  
Court Records ◽  
The Past ◽  
Wide Range ◽  
Police Reports ◽  
Late Twentieth ◽  
Scottish History ◽  
Late Twentieth Century

What did it mean to be a man in Scotland over the past nine centuries? Scotland, with its stereotypes of the kilted warrior and the industrial ‘hard man’, has long been characterised in masculine terms, but there has been little historical exploration of masculinity in a wider context. This interdisciplinary collection examines a diverse range of the multiple and changing forms of masculinities from the late eleventh to the late twentieth century, exploring the ways in which Scottish society through the ages defined expectations for men and their behaviour. How men reacted to those expectations is examined through sources such as documentary materials, medieval seals, romances, poetry, begging letters, police reports and court records, charity records, oral histories and personal correspondence. Focusing upon the wide range of activities and roles undertaken by men – work, fatherhood and play, violence and war, sex and commerce – the book also illustrates the range of masculinities that affected or were internalised by men. Together, the chapters illustrate some of the ways Scotland’s gender expectations have changed over the centuries and how, more generally, masculinities have informed the path of Scottish history

Diversity and Integration in Private International Law

2019 ◽  
Keyword(s):  
South America ◽  
International Law ◽  
Value Systems ◽  
Private International Law ◽  
Diverse Range ◽  
Cross Border ◽  
Wide Range ◽  
Depth Analysis ◽  
And Shifts ◽  
Substantive Law

This book opens a cross-regional dialogue and shifts the Eurocentric discussion on diversity and integration to a more inclusive engagement with South America in private international law issues. It promotes a contemporary vision of private international law as a discipline enabling legal interconnectivity, with the potential to transcend its disciplinary boundaries to further promote the reality of cross-border integration, with its focus on the ever-increasing cross-border mobility of individuals. Private international law embraces legal diversity and pluralism. Different legal traditions continue to meet, interact and integrate in different forms, at the national, regional and international levels. Different systems of substantive law couple with divergent systems of private international law (designed to accommodate the former in cross-border situations). This complex legal landscape impacts individuals and families in cross-border scenarios, and international commerce broadly conceived. Private international law methodologies and techniques offer means for the coordination of this constellation of legal orders and value systems in cross-border situations. Bringing together world-renowned academics and experienced private international lawyers from a wide range of jurisdictions in Europe and South America, this edited collection focuses on the connective capabilities of private international law in bridging and balancing legal diversity as a corollary for the development of integration. The book provides in-depth analysis of the role of private international law in dealing with legal diversity across a diverse range of topics and jurisdictions.

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