Isolation and Characterization of Salt Street Signaling Components from Yeast Saccharomyces cerevisiae

Isolation and Characterization of Salt Street Signaling Components from Yeast Saccharomyces cerevisiae

To identify novel components involved in the salt stress signaling pathway of yeast cells, we used mTn3-mediated transposon tagging library and screened mutants displaying enhanced tolerance to NaCl. Southern blot analysis indicated that more than 80% of the sre (salt resistant) mutants possessed only one insertion of the tagged transposon, suggesting that the NaCl resistant phenotype was mediated by a single gene in the majority of the mutants. To define the role of SRE genes in the salt stress signaling pathway, we introduced NaCl stress-inducible ENA1::LacZ construct into the sre mutants and examined the expression of ${\beta}$-galactosidase activity. Interestingly, we could detect high level of ${\beta}$-galactosidase activity without any NaCl treatment in the sre-3, 4, 6 and 7 mutants. These results indicate that SRE-3, 4, and 7 gene are components of salt stress signaling pathway of yeast cells.