Figure 5.

mRNA mistranslation causes chromium toxicity. Exponential phase cells were sub-cultured in 300 μl volumes of YEPD in 48-well plates, and growth (OD₆₀₀) was subsequently monitored at 30°C with continuous shaking in a plate reader. (a) Growth of S. cerevisiae BY4743 in unsupplemented medium (control; open circles), or in medium supplemented with 0.1 mM Cr (filled circles), or 100 μg ml^-1 of the ribosome-targeting drug paromomycin (open squares), or 0.1 mM Cr + 100 μg ml^-1 paromomycin (filled squares). (b) Growth of S. cerevisiae L1494 (wild type; circles), L1583 (error-prone translation; squares) and L1597 (high translational fidelity; triangles) strains in the absence (open symbols) or presence (filled symbols) of 0.1 mM CrO₃. Typical results from one of three independent experiments are shown.