Chromate-induced sulfur starvation and mRNA mistranslation in yeast are linked in a common mechanism of Cr toxicity.

Toxicity of the environmental carcinogen chromate is known to involve sulfur starvation and also error-prone mRNA translation. Here we reconcile those facts using the yeast model. We demonstrate that: (i) cysteine and methionine starvation mimic Cr-induced translation errors, (ii) genetic suppression of S starvation suppresses Cr-induced mistranslation, and (iii) mistranslation requires cysteine and methionine biosynthesis. Therefore, Cr-induced S starvation is the cause of mRNA mistranslation. This establishes a single, novel pathway mediating the toxicity of chromate.