Protective roles of two aluminum (Al)-induced genes, HSP150 and SED1 of Saccharomyces cerevisiae, in Al and oxidative stresses.

We isolated two yeast cDNA clones whose transcripts are induced by aluminum (Al) metal stress. Partial nucleotide sequencing showed that one is the HSP150 gene encoding a secreted heat shock protein, and the other corresponds to the SED1 gene encoding a putative membrane protein. To clarify the biological functions of these genes, we analyzed the sensitivity of gene-disrupted mutants to Al stress and to oxidative stresses. The Al tests indicated that the HSP150 protein served a basal protective role in Al stress, but SED1 did not; both of the genes had protective roles for oxidative stresses. The results for the HSP150 gene suggest that there is an overlap between Al ion stress, oxidative stress and heat shock stress in yeast.