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Viruses Aug 2020Rhabdoviruses, as single-stranded, negative-sense RNA viruses within the order , are characterised by bullet-shaped or bacteroid particles that contain a helical... (Review)
Review
Rhabdoviruses, as single-stranded, negative-sense RNA viruses within the order , are characterised by bullet-shaped or bacteroid particles that contain a helical ribonucleoprotein complex (RNP). Here, we review the components of the RNP and its higher-order structural assembly.
Topics: Nucleocapsid Proteins; Protein Conformation; Rhabdoviridae; Ribonucleoproteins; Viral Matrix Proteins; Viral Proteins; Viral Replicase Complex Proteins; Virion
PubMed: 32872471
DOI: 10.3390/v12090959 -
Nature Communications Nov 2015The L protein of mononegaviruses harbours all catalytic activities for genome replication and transcription. It contains six conserved domains (CR-I to -VI; Fig. 1a)....
The L protein of mononegaviruses harbours all catalytic activities for genome replication and transcription. It contains six conserved domains (CR-I to -VI; Fig. 1a). CR-III has been linked to polymerase and polyadenylation activity, CR-V to mRNA capping and CR-VI to cap methylation. However, how these activities are choreographed is poorly understood. Here we present the 2.2-Å X-ray structure and activities of CR-VI+, a portion of human Metapneumovirus L consisting of CR-VI and the poorly conserved region at its C terminus, the +domain. The CR-VI domain has a methyltransferase fold, which besides the typical S-adenosylmethionine-binding site ((SAM)P) also contains a novel pocket ((NS)P) that can accommodate a nucleoside. CR-VI lacks an obvious cap-binding site, and the (SAM)P-adjoining site holding the nucleotides undergoing methylation ((SUB)P) is unusually narrow because of the overhanging +domain. CR-VI+ sequentially methylates caps at their 2'O and N7 positions, and also displays nucleotide triphosphatase activity.
Topics: Animals; Binding Sites; Chromatography, Thin Layer; Crystallization; Crystallography, X-Ray; Metapneumovirus; Methylation; Mononegavirales; Protein Structure, Tertiary; RNA; RNA Caps; RNA-Dependent RNA Polymerase; S-Adenosylmethionine; Sf9 Cells; Spodoptera; Viral Proteins
PubMed: 26549102
DOI: 10.1038/ncomms9749 -
Archives of Virology Aug 2018In 2018, the order Mononegavirales was expanded by inclusion of 1 new genus and 12 novel species. This article presents the updated taxonomy of the order Mononegavirales...
In 2018, the order Mononegavirales was expanded by inclusion of 1 new genus and 12 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV) and summarizes additional taxonomic proposals that may affect the order in the near future.
Topics: Animals; Humans; Mononegavirales; Mononegavirales Infections; Phylogeny
PubMed: 29637429
DOI: 10.1007/s00705-018-3814-x -
Archives of Virology Aug 2016In 2016, the order Mononegavirales was emended through the addition of two new families (Mymonaviridae and Sunviridae), the elevation of the paramyxoviral subfamily...
In 2016, the order Mononegavirales was emended through the addition of two new families (Mymonaviridae and Sunviridae), the elevation of the paramyxoviral subfamily Pneumovirinae to family status (Pneumoviridae), the addition of five free-floating genera (Anphevirus, Arlivirus, Chengtivirus, Crustavirus, and Wastrivirus), and several other changes at the genus and species levels. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).
Topics: Genome, Viral; Mononegavirales; Phylogeny
PubMed: 27216929
DOI: 10.1007/s00705-016-2880-1 -
Antiviral Research Mar 2014Reverse genetics allows the generation of recombinant viruses entirely from cDNA. One application of this technology is the creation of reporter-expressing viruses,... (Review)
Review
Reverse genetics allows the generation of recombinant viruses entirely from cDNA. One application of this technology is the creation of reporter-expressing viruses, which greatly increase the detail and ease with which these viruses can be studied. However, there are a number of challenges when working with reporter-expressing viruses. Both the reporter protein itself as well as the genetic manipulations within the viral genome required for expression of this reporter can result in altered biological properties of the recombinant virus, and lead to attenuation in vitro and/or in vivo. Further, instability of reporter expression and purging of the genetic information encoding for the reporter from the viral genome can be an issue. Finally, a practical challenge for in vivo studies lies in the attenuation of light signals when traversing tissues. Novel expression strategies and the continued development of brighter, red and far-red shifted reporters and the increased use of bioluminescent reporters for in vivo applications promise to overcome some of these limitations in future. However, a "one size fits all" approach to the design of reporter-expressing viruses has thus far not been possible. Rather, a reporter suited to the intended application must be selected and an appropriate expression strategy and location for the reporter in the viral genome chosen. Still, attenuating effects of the reporter on viral fitness are difficult to predict and have to be carefully assessed with respect to the intended application. Despite these limitations the generation of suitable reporter-expressing viruses will become more common as technology and our understanding of the intricacies of viral gene expression and regulation improves, allowing deeper insight into virus biology both in living cells and in animals.
Topics: Animals; Gene Expression; Genes, Reporter; Humans; Mononegavirales; Reverse Genetics; Staining and Labeling; Virology
PubMed: 24462694
DOI: 10.1016/j.antiviral.2014.01.003 -
Viruses Jun 2019Canine distemper virus (CDV) is a worldwide distributed virus which belongs to the genus within the family. CDV spreads through the lymphatic, epithelial, and nervous... (Review)
Review
Canine distemper virus (CDV) is a worldwide distributed virus which belongs to the genus within the family. CDV spreads through the lymphatic, epithelial, and nervous systems of domestic dogs and wildlife, in at least six orders and over 20 families of mammals. Due to the high morbidity and mortality rates and broad host range, understanding the epidemiology of CDV is not only important for its control in domestic animals, but also for the development of reliable wildlife conservation strategies. The present review aims to give an outlook of the multiple evolutionary landscapes and factors involved in the transmission of CDV by including epidemiological data from multiple species in urban, wild and peri-urban settings, not only in domestic animal populations but at the wildlife interface. It is clear that different epidemiological scenarios can lead to the presence of CDV in wildlife even in the absence of infection in domestic populations, highlighting the role of CDV in different domestic or wild species without clinical signs of disease mainly acting as reservoirs (peridomestic and mesocarnivores) that are often found in peridomestic habits triggering CDV epidemics. Another scenario is driven by mutations, which generate genetic variation on which random drift and natural selection can act, shaping the genetic structure of CDV populations leading to some fitness compensations between hosts and driving the evolution of specialist and generalist traits in CDV populations. In this scenario, the highly variable protein hemagglutinin (H) determines the cellular and host tropism by binding to signaling lymphocytic activation molecule (SLAM) and nectin-4 receptors of the host; however, the multiple evolutionary events that may have facilitated CDV adaptation to different hosts must be evaluated by complete genome sequencing. This review is focused on the study of CDV interspecies transmission by examining molecular and epidemiological reports based on sequences of the hemagglutinin gene and the growing body of studies of the complete genome; emphasizing the importance of long-term multidisciplinary research that tracks CDV in the presence or absence of clinical signs in wild species, and helping to implement strategies to mitigate the infection. Integrated research incorporating the experience of wildlife managers, behavioral and conservation biologists, veterinarians, virologists, and immunologists (among other scientific areas) and the inclusion of several wild and domestic species is essential for understanding the intricate epidemiological dynamics of CDV in its multiple host infections.
Topics: Animals; Animals, Wild; Distemper; Distemper Virus, Canine; Dogs; Evolution, Molecular; Host Specificity; Phylogeny
PubMed: 31247987
DOI: 10.3390/v11070582 -
Revista Chilena de Infectologia :... 2018With the apparition of the crazy cows disease at the end of twentieth century, great was the temptation for denominate "crazy horses disease" an ancient enzootic...
With the apparition of the crazy cows disease at the end of twentieth century, great was the temptation for denominate "crazy horses disease" an ancient enzootic encephalo-myelitis, known from the 17th century and now named "Borna disease" in 1970, because severe outbreaks affecting horses in this city of Germany since 1885. But the sickness was not a prion disease but a viral one, causing also encephalopathy in several other animal species. After seventy years of investigation, the finding of the virus in human patients with psychiatric pathology in the eighties gave an incentive to work harder, and the genome structure of the so called Bornavirus was completely described. Recently, japanese investigators found that elements homologous to the nucleoprotein (N) gene of Bornavirus exist in the genomes of several mammalian species, including humans, in which these sequences have been designated endogenous Borna-like N (EBLN) elements. And now the question is what they are doing there since their integration two million years ago.
Topics: Animals; Bornaviridae; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; Horse Diseases; Horses; Mononegavirales Infections
PubMed: 31095192
DOI: 10.4067/S0716-10182018000600700 -
Archives of Virology Aug 2017In 2017, the order Mononegavirales was expanded by the inclusion of a total of 69 novel species. Five new rhabdovirus genera and one new nyamivirus genus were...
In 2017, the order Mononegavirales was expanded by the inclusion of a total of 69 novel species. Five new rhabdovirus genera and one new nyamivirus genus were established to harbor 41 of these species, whereas the remaining new species were assigned to already established genera. Furthermore, non-Latinized binomial species names replaced all paramyxovirus and pneumovirus species names, thereby accomplishing application of binomial species names throughout the entire order. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).
Topics: Gene Order; Genome, Viral; Mononegavirales; Phylogeny; Species Specificity
PubMed: 28389807
DOI: 10.1007/s00705-017-3311-7 -
Microbiology and Molecular Biology... Sep 2011The discovery of a new class of cytosolic receptors recognizing viral RNA, called the RIG-like receptors (RLRs), has revolutionized our understanding of the interplay... (Review)
Review
The discovery of a new class of cytosolic receptors recognizing viral RNA, called the RIG-like receptors (RLRs), has revolutionized our understanding of the interplay between viruses and host cells. A tremendous amount of work has been accumulating to decipher the RNA moieties required for an RLR agonist, the signal transduction pathway leading to activation of the innate immunity orchestrated by type I interferon (IFN), the cellular and viral regulators of this pathway, and the viral inhibitors of the innate immune response. Previous reviews have focused on the RLR signaling pathway and on the negative regulation of the interferon response by viral proteins. The focus of this review is to put this knowledge in the context of the virus replication cycle within a cell. Likewise, there has been an expansion of knowledge about the role of innate immunity in the pathophysiology of viral infection. As a consequence, some discrepancies have arisen between the current models of cell-intrinsic innate immunity and current knowledge of virus biology. This holds particularly true for the nonsegmented negative-strand viruses (Mononegavirales), which paradoxically have been largely used to build presently available models. The aim of this review is to bridge the gap between the virology and innate immunity to favor the rational building of a relevant model(s) describing the interplay between Mononegavirales and the innate immune system.
Topics: Animals; Cytosol; Host-Pathogen Interactions; Humans; Immune Tolerance; Immunity, Innate; Interferons; Models, Biological; Mononegavirales; Mononegavirales Infections; RNA, Viral; Receptors, Cytoplasmic and Nuclear; Receptors, Pattern Recognition; Signal Transduction
PubMed: 21885681
DOI: 10.1128/MMBR.00007-11 -
Journal of Molecular Biology Aug 2016The host innate immune system serves as the first line of defense against viral infections. Germline-encoded pattern recognition receptors detect molecular patterns... (Review)
Review
The host innate immune system serves as the first line of defense against viral infections. Germline-encoded pattern recognition receptors detect molecular patterns associated with pathogens and activate innate immune responses. Of particular relevance to viral infections are those pattern recognition receptors that activate type I interferon responses, which establish an antiviral state. The order Mononegavirales is composed of viruses that possess single-stranded, non-segmented negative-sense (NNS) RNA genomes and are important human pathogens that consistently antagonize signaling related to type I interferon responses. NNS viruses have limited encoding capacity compared to many DNA viruses, and as a likely consequence, most open reading frames encode multifunctional viral proteins that interact with host factors in order to evade host cell defenses while promoting viral replication. In this review, we will discuss the molecular mechanisms of innate immune evasion by select NNS viruses. A greater understanding of these interactions will be critical in facilitating the development of effective therapeutics and viral countermeasures.
Topics: Animals; Host-Pathogen Interactions; Humans; Immune Evasion; Immune Tolerance; Immunity, Innate; Models, Biological; Models, Molecular; Mononegavirales
PubMed: 27487481
DOI: 10.1016/j.jmb.2016.07.017