FIG. 4.

Comparison of first start codon selection by DENV2 cHP to selection by improved start codon context. (A) Schematic diagram of constructs used to test the efficiency of first start codon selection by the cHP or by initiation context. (B) Anti-FLAG immunoblot of C-FLAG-transfected Hep3B cells at 4 h posttransfection. The efficiency of codon usage is expressed as a ratio of the higher-molecular-weight C-FLAG isoform (1st AUG) to the lower-molecular-weight isoform (2nd AUG). The error bars indicate SDs; the data are derived from five experiments. (C) Anti-FLAG immunoblot of transfected C6/36 cells at 24 h posttransfection as in panel B. The graph is as in panel B; the data represent the averages of four experiments. *, P < 0.05 relative to wt; **, P < 0.01 relative to −3G/HPmut.