FIG 6.

Properties of chimeric SFV and SINV harboring heterologous nsP4. (A) Schematic presentation of chimeric SFV (left) and SINV (right) genomes. Swapped nsP4 regions are color-codes. The modified junction region between ns- and structural ORFs, including the codon-altered region of nsP4 (Table 1), is shown below the drawing of chimeric SFV genomes. The arrow indicates the transcription start site of the SG promoter of the virus. The red X indicates inactivation of the SG promoter by synonymous mutations introduced into the sequence encoding the C-terminal region of nsP4. (B) The lysates of the BHK-21 cells transfected with icDNA plasmids of SFV and its chimeras (left panels) or with in vitro transcripts of icDNA of SINV and its chimeras (right panels) and lysate from mock-transfected control cells were subjected to SDS-PAGE and immunoblot analysis with antibodies against the corresponding nsP2 and capsid proteins. β-actin is shown as a loading control. The top panels show lysates of transfected cells that were incubated at 37°C, while the bottom panels show lysates of transfected cells that were incubated at 28°C. The experiment was repeated twice with similar results; the data from one experiment are shown.