The New World arenavirus Junin virus (JUNV) is the causative agent of Argentine hemorrhagic fever (AHF), which is associated with high morbidity and significant mortality. Several pathogenic strains of JUNV have been documented, and a highly attenuated vaccine strain (Candid #1) was generated and used to vaccinate the human population at risk. The identification and functional characterization ...

The New World arenaviruses, Junin, Machupo, Guanarito, Sabia, and Chapare, are associated with rapidly progressing severe hemorrhagic fever with a high rate of case fatality in various regions of South America. The threat of natural or deliberate outbreaks associated with these viruses makes the development of preventive or therapeutic measures important. Here we describe a Junin virus function...

The viral RNA-dependent RNA polymerase (RdRp; L protein) of Rift Valley fever virus (RVFV; family Bunyaviridae) is a 238 kDa protein that is crucial for the life cycle of the virus, as it catalyses both transcription of viral mRNAs and replication of the tripartite genome. Despite its importance, little is known about the intracellular distribution of the polymerase or its other roles during in...

Avian pneumovirus (APV) is a member of the genus Metapneumovirus of the subfamily Pneumovirinae. This study describes the development of a reverse-genetics system for APV. A minigenome system was used to optimize the expression of the nucleoprotein, phosphoprotein, M2 and large polymerase proteins when transfected into Vero cells under the control of the bacteriophage T7 promoter. Subsequently,...

We have used a reverse genetic approach to identify the viral proteins required for packaging and assembly of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV). Plasmids encoding individual LCMV proteins under the control of an RNA polymerase II promoter were cotransfected with a plasmid containing an LCMV minigenome (MG). Intracellular synthesis of the LCMV MG was driven by T...

Some Newcastle disease virus (NDV) variants isolated from pigeons (pigeon paramyxovirus type 1; PPMV-1) do not show their full virulence potential for domestic chickens but may become virulent upon spread in these animals. In this study we examined the molecular changes responsible for this gain of virulence by passaging a low-pathogenic PPMV-1 isolate in chickens. Complete genome sequencing of...

The two enteroviral proteinases, 2A proteinase (2A(pro)) and 3C proteinase (3C(pro)), induce host cell translation shutoff in enterovirus-infected cells by cleaving canonical translation initiation factors. Cleavage of poly(A)-binding protein (PABP) by 3C(pro) has been shown to be a necessary component for host translation shutoff. Here we show that 3C(pro) inhibits cap-independent translation ...

The phosphoprotein (P) of vesicular stomatitis virus (VSV) plays essential roles in viral RNA synthesis. It associates with nascent nucleoprotein (N) to form N(0)-P (free of RNAs), thereby preventing the N from binding to cellular RNAs and maintaining the N in a viral genomic RNA encapsidation-competent form for transcription and replication. The contributions of phosphorylation of P to transcr...