Subject(s)
Mentors , Science/education , Volunteers , Biomedical Research , Budgets , Financial Support , Humans , Missouri , Teaching , UniversitiesABSTRACT
The virion host shutoff (vhs) protein of herpes simplex virus type 1 causes the degradation of host and viral mRNA immediately upon infection of permissive cells. vhs can interact with VP16 through a 20-amino-acid binding domain, and viruses containing a deletion of this VP16-binding domain of vhs (Delta20) and a corresponding marker rescue (Delta20R) were constructed and characterized. Transient-transfection assays showed that this domain was dispensable for vhs activity. The Delta20 recombinant virus, however, was unable to induce mRNA degradation in the presence of actinomycin D, while degradation induced by Delta20R was equivalent to that for wild-type virus. Delta20, Delta20R, and KOS caused comparable RNA degradation in the absence of actinomycin D. Western blot analysis of infected cells indicated that comparable levels of vhs were expressed by Delta20, Delta20R, and KOS, and there was only a modest reduction of vhs packaging in Delta20. Immunoprecipitation of protein from cells infected with Delta20 and Delta20R showed equivalent coprecipitation of vhs and VP16. Pathogenesis studies with Delta20 showed a significant decrease in replication in the corneas, trigeminal ganglia, and brains, as well as a significant reduction in clinical disease and lethality, but no significant difference in the establishment of, or reactivation from, latency compared to results with KOS and Delta20R. These results suggest that the previously described VP16-binding domain is not required for vhs packaging or for binding to VP16. It is required, however, for RNA degradation activity of tegument-derived vhs and wild-type replication and virulence in mice.
Subject(s)
Herpes Simplex Virus Protein Vmw65/metabolism , Herpesvirus 1, Human/physiology , Herpesvirus 1, Human/pathogenicity , Viral Proteins/chemistry , Viral Proteins/metabolism , Animals , Animals, Outbred Strains , Chlorocebus aethiops , Female , Herpes Simplex/physiopathology , Herpes Simplex/virology , Herpesvirus 1, Human/genetics , Mice , Ribonucleases , Vero Cells , Viral Proteins/genetics , Virus LatencyABSTRACT
The virion host shutoff protein (Vhs) of herpes simplex virus type 1 induces destabilization of mRNA following infection. Our study of primary neurons from CD-1 mice demonstrates that vhs is functional in neurons but that more Vhs is required to mediate RNA degradation in neurons than in other susceptible cells.