Cd 2+ binds to Atx1 and affects the physical interaction between Atx1 and Ccc2 in Saccharomyces cerevisiae

The ATX1 deletion strain of Saccharomyces cerevisiae is more resistant to Cd 2+ than the wild-type. To investigate the function of Atx1 in Cd 2+ toxicity, we used a metal-binding assay to study the interaction between Atx1 and Cd 2+ in vitro. Using circular dichroism and two-hybrid analyses, we found that Atx1 can bind Cd 2+ specifically and that Cd 2+ binding to Atx1 affects the physical interaction between Atx1 and Ccc2. These results imply that Atx1 delivers Cd 2+ to Ccc2 and that this delivery is, at least in part, responsible for Cd 2+ toxicity in S. cerevisiae .