Genome packaging of the Bunyavirales
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Paul J Wichgers Schreur, Richard Kormelink, Jeroen KortekaasThe order Bunyavirales comprises nine families of enveloped, negative-strand RNA viruses. Depending on the family and genus, bunyaviruses (i.e. now referring to all members of the Bunyavirales) contain genomes consisting of two to six segments. Each genome segment is encapsidated by multiple copies of the nucleocapsid (N) protein and one or a few molecules of the viral polymerase, forming so-called ribonucleoproteins (RNPs). Incorporation of RNPs into virions is mediated by the...
Source: Current Opinion in Virology - September 16, 2018 Category: Virology Source Type: research
Vector-transmission of plant viruses and constraints imposed by virus–vector interactions
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Romain Gallet, Yannis Michalakis, Stéphane BlancBecause plants are sessile and their cells protected by a cell wall, the contact transmission of plant viruses is very rare. Almost all plant viruses are transmitted by vectors, which can be insects, nematodes, mites or fungi. Although very efficient, this mode of transmission is not trivial and imposes numerous constraints on viruses. In this review we show that these constraints apply at all stages of the transmission process and at all scales, from the molecular to ecological interacti...
Source: Current Opinion in Virology - September 15, 2018 Category: Virology Source Type: research
Direct and indirect influences of virus–insect vector–plant interactions on non-circulative, semi-persistent virus transmission
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Jaclyn S Zhou, Martin Drucker, James CK NgPlant viruses that are transmitted in a non-circulative, semi-persistent (NCSP) manner have determinants on, and/or accessories to, their capsids that facilitate virion binding to specific retention sites in their insect vectors. Bilateral interactions and interactions occurring at the nexus of all three partners (virus, vector and plant) also contribute to transmission by influencing virus acquisition and inoculation. Vector feeding behavior lies at the core of this trio of virus transmission p...
Source: Current Opinion in Virology - September 11, 2018 Category: Virology Source Type: research
Long-distance movement of helical multipartite phytoviruses: keep connected or die?
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): David Gilmer, Claudio Ratti, Fabrice MichelAll living organisms have to preserve genome integrity to ensure the survival of progeny generations. Viruses, though often regarded as ‘non living’, protect their nucleic acids from biotic and abiotic stresses, ranging from nuclease action to radiation-induced adducts. When the viral genome is split into multiple segments, preservation of at least one copy of each segment is required. While segmented and monopartite viruses use an all-in-one strategy, multipartite viruses have to address i...
Source: Current Opinion in Virology - September 8, 2018 Category: Virology Source Type: research
All-atom virus simulations
Publication date: Available online 1 September 2018Source: Current Opinion in VirologyAuthor(s): Jodi A Hadden, Juan R PerillaThe constant threat of viral disease can be combated by the development of novel vaccines and therapeutics designed to disrupt key features of virus structure or infection cycle processes. Such development relies on high-resolution characterization of viruses and their dynamical behaviors, which are often challenging to obtain solely by experiment. In response, all-atom molecular dynamics simulations are widely leveraged to study the structural components of viruses, leading to some of the largest s...
Source: Current Opinion in Virology - September 2, 2018 Category: Virology Source Type: research
Molecular and biological factors regulating the genome packaging in single-strand positive-sense tripartite RNA plant viruses
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Sonali Chaturvedi, ALN RaoPlant pathogenic single strand positive-sense RNA viruses with the tripartite genome are classified into two families: Bromoviridae and Virgaviridae. Family Bromoviridae contains four genera Bromo, Cucumo, Alfamo, and Ilarviruses characterized by icosahedral particles. By contrast family Virgaviridae contains only one genus, Hordeivirus, with tripartite genome and characterized by helical particles. Unlike in monopartite plant viruses, packaging in tripartite RNA viruses requires a well-orchestrated process to ...
Source: Current Opinion in Virology - August 28, 2018 Category: Virology Source Type: research
Biology of viral satellites and their role in pathogenesis
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Prabu Gnanasekaran, Supriya ChakrabortyExtraviral components that can influence the accumulation and pathogenesis of their associated helper viruses are known as ‘satellites’. The maintenance of satellites requires their ability to associate with their helper viruses. Satellites can be categorized as either satellite viruses or satellite nucleic acids based on their ability to encode capsid proteins. Understanding the biology of satellites is important since they are pathogenic to a wide range of plant, animal, and yeast organisms. ...
Source: Current Opinion in Virology - August 24, 2018 Category: Virology Source Type: research
Genome packaging in multi-segmented dsRNA viruses: distinct mechanisms with similar outcomes
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Alexander Borodavka, Ulrich Desselberger, John T PattonSegmented double-stranded (ds)RNA viruses share remarkable similarities in their replication strategy and capsid structure. During virus replication, positive-sense single-stranded (+)RNAs are packaged into procapsids, where they serve as templates for dsRNA synthesis, forming progeny particles containing a complete equimolar set of genome segments. How the +RNAs are recognized and stoichiometrically packaged remains uncertain. Whereas bacteriophages of the Cystoviridae family rely ...
Source: Current Opinion in Virology - August 24, 2018 Category: Virology Source Type: research
Theoretical approaches to disclosing the emergence and adaptive advantages of multipartite viruses
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Adriana Lucía-Sanz, Jacobo Aguirre, Susanna ManrubiaMultipartite viruses have a segmented genome encapsidated in different viral particles that, in principle, propagate independently. Current empirical knowledge on the molecular, ecological and evolutionary features underlying the very existence of multipartitism is fragmented and puzzling. Although it is generally assumed that multipartitism is viable only when propagation occurs at high multiplicity of infection, evidence indicates that severe population bottlenecks are common. Mathe...
Source: Current Opinion in Virology - August 16, 2018 Category: Virology Source Type: research
Giant viruses and their mobile genetic elements: the molecular symbiosis hypothesis
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Jonathan FiléeAmong the virus world, Giant viruses (GVs) compose one of the most successful eukaryovirus families. By contrast with other eukaryoviruses, GV genomes contain a wide array of mobile genetic elements (MGEs) that encompass diverse, mostly prokaryotic-like, transposable element families, introns, inteins, restriction–modification systems and enigmatic classes of mobile elements having little similarities with known families. Interestingly, several of these MGEs may be beneficial to the GVs, fulfilling two kinds of function...
Source: Current Opinion in Virology - August 14, 2018 Category: Virology Source Type: research
The defective component of viral populations
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Veronica V Rezelj, Laura I Levi, Marco VignuzziParticles containing degenerate forms of the viral genome which interfere with virus replication and are non-replicative per se are known as defective interfering particles (DIPs). DIPs are likely to be produced upon infection by any virus in vitro and in nature. Until recently, roles of these non-viable particles as members of a multi-component viral system have been overlooked. In this review, we cover the most recent studies that shed light on critical roles of DIPs during the course of ...
Source: Current Opinion in Virology - August 10, 2018 Category: Virology Source Type: research
Brevipalpus-transmitted viruses: parallelism beyond a common vector or convergent evolution of distantly related pathogens?
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Juliana Freitas-Astúa, Pedro Luis Ramos-González, Gabriella Dias Arena, Aline Daniele Tassi, Elliot Watanabe KitajimaAlthough diseases caused by Brevipalpus-transmitted viruses (BTV) became relevant for agriculture a century ago, their causal agents have been only recently characterized and classified in two new genera of plant-infecting viruses: Cilevirus and Dichorhavirus. In this review, we highlight both similarities and differences between these viruses emphasizing their current taxonomy and historical classification, phylogeny, ...
Source: Current Opinion in Virology - August 4, 2018 Category: Virology Source Type: research
The biological attributes, genome architecture and packaging of diverse multi-component fungal viruses
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Yukiyo Sato, José R Castón, Nobuhiro SuzukiMany fungal viruses or mycoviruses have multi-segmented, rather than single-segmented, genomes. This multi-segment nature is frequently possessed by double-stranded RNA viruses, which include members of the Chrysoviridae, Quadriviridae, Megabirnaviridae, Partitiviridae, and Reoviridae families, and unassigned groups. Their genome segments are often packaged separately with the exception of mycoreoviruses, which are multi-segmented but mono-particulate viruses. These multi-segmented fungal dsR...
Source: Current Opinion in Virology - August 4, 2018 Category: Virology Source Type: research
A modelling paradigm for RNA virus assembly
Publication date: Available online 2 August 2018Source: Current Opinion in VirologyAuthor(s): Reidun Twarock, Richard J Bingham, Eric C Dykeman, Peter G StockleyVirus assembly, a key stage in any viral life cycle, had long been considered to be primarily driven by protein–protein interactions and nonspecific interactions between genomic RNA and capsid protein. We review here a modelling paradigm for RNA virus assembly that illustrates the crucial roles of multiple dispersed, specific interactions between viral genomes and coat proteins in capsid assembly. The model reveals how multiple sequence-structure motifs in the ge...
Source: Current Opinion in Virology - August 2, 2018 Category: Virology Source Type: research
Genetics and mechanisms underlying transmission of Wheat streak mosaic virus by the wheat curl mite
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Satyanarayana Tatineni, Gary L HeinWheat streak mosaic virus (WSMV, genus Tritimovirus; family Potyviridae) is the most economically important virus of wheat in the Great Plains region of the USA. WSMV is transmitted by the eriophyid wheat curl mite (WCM), Aceria tosichella Keifer. In contrast to Hemipteran-borne plant viruses, the mode and mechanism of eriophyid mite transmission of viruses have remained poorly understood, mostly due to difficulty of working with these ∼200 μm long microscopic creatures. Among eriophyid-transmitte...
Source: Current Opinion in Virology - August 2, 2018 Category: Virology Source Type: research
