Knowledge Bank

Chromium (III) is a trace nutrient that is considered essential for human life. However, its biological roles in the body are largely unknown. A few studies indicate that Cr3+ may enhance the effects of insulin and help the body maintain healthy glucose levels, but to date, clinical trials testing its effectiveness have mostly been inconclusive. As yeast is known to contain particularly high amounts of chromium, the purpose of this study was to use the fission yeast Schizosaccharomyces pombe as a model system to gain a better understanding of the mechanisms by which chromium is imported and stored. We have found that S. pombe survives on plates supplemented with Cr3+ up to a concentration of approximately 3 mM. We have also found that S. pombe accumulates Cr3+ from its environment, much like brewer’s yeast, Saccharomyces cerevisiae. To identify genes involved in chromium uptake, we have set up a genetic screen to isolate mutants which are able to survive in the presence of 3.5 mM Cr3+. Our ongoing studies are characterizing a number of these mutants, investigating why they have increased chromium tolerance, and determining whether genes involved in chromium accumulation are conserved between yeast and humans.