An infectious clone of the West Nile flavivirus.
West Nile (WN) virus is the most widespread among flaviviruses, but until recently it was not known on the American continent. We describe here design of a subgenomic replicon, as well as a full-length infectious clone of the lineage II WN strain, which appeared surprisingly stable compared to other flavivirus infectious clones. This infectious clone was used to investigate effects of 5'- and 3'-nonrelated sequences on virus replication and infectivity of synthetic RNA. While a long nonrelated sequence at the 3'-end delayed but did not prevent establishment of the productive infectious cycle, a much shorter extra sequence at the 5'-end completely abrogated virus replication. Replacement of the conserved 5'-adenosine residue substantially delayed, but did not prevent, establishment of virus infection. In all cases, the recovered virus had restored its authentic 5'- and 3'-end genome sequences. However, the presence of extensive nonrelated sequences at both 5'- and 3'-ends could not be repaired.
Yamshchikov
V F
VF
Department of Internal Medicine, University of Virginia, Charlottesville, Virginia 22908, USA. vfy9e@virginia.edu
Wengler
G
G
Perelygin
A A
AA
Brinton
M A
MA
Compans
R W
RW
D020413:3' Untranslated Regions / Q000235:genetics; D020121:5' Untranslated Regions / Q000235:genetics; D002460:Cell Line; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D016679:Genome, Viral; D012093:Replicon; D014158:Transcription, Genetic; D014162:Transfection; D014779:Virus Replication / Q000235:genetics; D014902:West Nile virus / Q000235:genetics* / Q000472:pathogenicity
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions