The subcellular distribution of nickel in Ni-sensitive and Ni-resistant strains of Saccharomyces cerevisiae.

Examination of the subcellular distribution of nickel in a Ni-resistant strain N08 of Saccharomyces cerevisiae showed that 70% of the nickel is distributed in the vascular fraction, which contains large amounts of histidine. The nickel taken up by cells grown in medium containing a high concentration of histidine was preferentially distributed to the vacuole. Arginine and lysine did not affect the intracellular distribution of Ni. In a Ni-sensitive strain 0605-S6, the distribution of nickel into the vacuole was lower than that observed in strain N08. Strain 0605-S6 exhibited no increase in the histidine content of the vacuolar fraction when grown in a Ni-supplemented medium. The Ni-resistant mechanism appears to involve the sequestration of nickel to the vacuole, and histidine could play an important role in the reduction of free nickel in the vacuole by the formation of histidine-nickel complexes.