The causative agent of myonecrosis affecting cultured Penaeus vannamei in Brazil was demonstrated to be a virus after purification of the agent from infected shrimp tissues. Purified viral particles were injected into specific pathogen-free P. vannamei, resulting in a disease that displayed the same characteristics as those found in the original shrimp used for purification. The virus was named...

Bluetongue virus (BTV) is transmitted by blood-feeding insects (Culicoides sp.) and causes hemorrhagic diseases in livestock. BTV is a nonenveloped, double-stranded RNA (dsRNA) virus with two capsids: a well-studied, stable core enclosing the dsRNA genome and a highly unstable, poorly studied coat responsible for host cell attachment and entry. Here, based on cryo-electron microscopy (cryoEM), ...

Coronaviruses are positive-sense RNA viruses that generate double-stranded RNA (dsRNA) intermediates during replication, yet evade detection by host innate immune sensors. Here we report that coronavirus nonstructural protein 15 (nsp15), an endoribonuclease, is required for evasion of dsRNA sensors. We evaluated two independent nsp15 mutant mouse coronaviruses, designated N15m1 and N15m3, and f...

Double-stranded RNA (dsRNA) is a common by-product of viral infections and a potent inducer of innate antiviral immune responses in vertebrates. In the marine shrimp Litopenaeus vannamei, innate antiviral immunity is also induced by dsRNA in a sequence-independent manner. In this study, the hypothesis that dsRNA can evoke not only innate antiviral immunity but also a sequence-specific antiviral...

Double-stranded (ds) RNA viruses face two major challenges when infecting a cell: the cellular replicative machinery does not operate on dsRNA genomes, and dsRNA provokes a strong apoptotic response. To overcome these problems, dsRNA viruses conceal their genomes from the host cell in an enclosed icosahedral viral core, but then need to carry with them all the necessary enzymatic requirements f...

Wine Torulaspora delbrueckii strains producing a new killer toxin (Kbarr-1) were isolated and selected for wine making. They killed all the previously known Saccharomyces cerevisiae killer strains, in addition to other non-Saccharomyces yeasts. The Kbarr-1 phenotype is encoded by a medium-size 1.7 kb dsRNA, TdV-Mbarr-1, which seems to depend on a large-size 4.6 kb dsRNA virus (TdV-LAbarr) for s...

The dsRNA binding proteins (DRBPs) comprise a growing family of eukaryotic, prokaryotic, and viral-encoded products that share a common evolutionarily conserved motif specifically facilitating interaction with dsRNA. Proteins harboring dsRNA binding domains (DRBDs) have been reported to interact with as little as 11 bp of dsRNA, an event that is independent of nucleotide sequence arrangement. M...

Mosquito-borne viruses encompass a range of virus families, comprising a number of significant human pathogens (e.g., dengue viruses, West Nile virus, Chikungunya virus). Virulent strains of these viruses are continually evolving and expanding their geographic range, thus rapid and sensitive screening assays are required to detect emerging viruses and monitor their prevalence and spread in mosq...

Induction of interferon-alpha (IFNalpha) gene expression in virus-infected cells requires phosphorylation-induced activation of the transcription factors IRF3 and IRF7. However, the kinase(s) that targets these proteins has not been identified. Using a combined pharmacological and genetic approach, we found that none of the kinases tested was responsible for IRF phosphorylation in cells infecte...