Characterization of Bunyamwera virus S RNA that is transcribed and replicated by the L protein expressed from recombinant vaccinia virus.
AUTOR(ES)
Jin, H
RESUMO
Analysis of the 5' termini of Bunyamwera virus S segment mRNAs by cloning and sequence analysis revealed the presence of nonviral, heterogeneous sequences 12 to 17 bases long. This is similar to reports for other members of the family Bunyaviridae and is taken to indicate that mRNA transcription is primed by a "cap-snatching" mechanism. The 3' end of the Bunyamwera virus S mRNA was mapped, by using an RNase protection assay, to 100 to 110 nucleotides upstream of the 3' end of the template. Previously we reported expression of the Bunyamwera virus L (polymerase) protein by recombinant vaccinia virus and demonstrated that the recombinant L protein was functional in terms of RNA synthesis activity in a nucleocapsid transfection assay (H. Jin and R. M. Elliott, J. Virol. 65: 4182-4189, 1991). In the present study we further analyze the RNAs made by using this system and show that positive-sense RNAs contain 5' nonviral sequences. Hence the initiation of mRNA transcription by the recombinant L protein resembles that seen during authentic bunyavirus infection and suggests that the L protein has the endonuclease activity which generates the primers. Some of these positive-sense transcripts terminated at the mRNA termination site, but the majority read through to the end of the template. No primer sequences were found at the 5' terminal of negative-sense RNAs. The recombinant L protein was able to replicate negative-sense RNA supplied by transfected virion-derived nucleocapsids, and both positive- and negative-sense RNAs were synthesized. These results indicate that the recombinant L protein has both transcriptase and replicase activities.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=237509Documentos Relacionados
- Expression of functional Bunyamwera virus L protein by recombinant vaccinia viruses.
- Rapid and efficient purification of native histidine-tagged protein expressed by recombinant vaccinia virus.
- Hepatitis B virus large surface protein is not secreted but is immunogenic when selectively expressed by recombinant vaccinia virus.
- Immune responses to H-2Kd antigen expressed by recombinant vaccinia virus.
- Immunogenicity of the Plasmodium falciparum glutamate-rich protein expressed by vaccinia virus.