Involvement of PHO80 and PHO85 genes in Saccharomyces cerevisiae ion tolerance

PHO85 is a versatile gene in Saccharomyces cerevisiae, which is involved in metabolism of inorganic phosphate and usage of carbon source, accumulation of glycogen, regulation of protein stability and cell cycle control. The viability of wild type budding yeast strain YPH499 and its derivative pho85Δ mutant, pho80Δ mutant, and pap1 (pcl7)Δ mutant in different cations were investigated and their tolerance to the cations(LC₅₀) was measured. The results showed that the deletion of PHO85 or PHO80 gene both increased sensibility of Sacchromyces cerevisiae to ions K⁺, Mg²⁺, Zn²⁺, Ca²⁺ and Mn²⁺, while the deletion of pap1 (pcl7) gene did not lead to such phenotype. The difference between the patterns of relative growth curve of the mutants and wild type strain in the above ions also implied that PHO80 was the unique PCLs in complex with PHO85 CDK, that were contributed to K⁺ and Mg²⁺ ion homeostasis control and there were some other PCLs besides PHO80 that were involved in Zn²⁺, Ca²⁺ and Mn²⁺ tolerance regulation as cyclin of PHO85 CDK. Furthermore, the amount of the total cellular calcium of pho85Δ mutant, pho80Δ mutant and YPH499 indicated that the ability of calcium accumulation of pho85Δ mutant and pho80Δ mutant was impaired.