FIG 5.

Codon usage deoptimization in enhanced green fluorescent protein (eGFP) decreases the abundance of its mRNA. (A) The codon usage is represented using the Graphical Codon Usage Analyzer (GCUA) available online at http://gcua.schoedl.de/, as was done for v-FLIP in Fig. 2. The upper panel shows the (optimized) eGFP, the middle panel shows the mutant with deoptimization of the 5′ 180 nt, and the bottom panel shows eGFP, whose codon usage has been completely deoptimized. (B) Northern blot (using probe against FLAG tag) of total RNA from HEK293 cells transfected with recombinant FLAG-tagged eGFP and mutants.