Sip18 hydrophilin prevents yeast cell death during desiccation stress

For this study, we performed a genetic screen of S. cerevisiae's deletion library for mutants sensitive to dehydration stress, with which we aimed to discover cell dehydration-tolerant genes.

We used a yeast gene deletion set (YGDS) of 4850 viable mutant haploid strains to perform a genome-wide screen for the identification of desiccation stress modifiers. SIP18 is among the genes identified as essential for cells surviving to drying/rehydration process. Deletion of SIP18 promotes the accumulation of reactive oxygen species and enhances apoptotic and necrotic cell death in response to dehydration/rehydration process.

SIP18p acts as an inhibitor of apoptosis in yeast under dehydration stress, as suggested by its antioxidative capacity through the ROS accumulation reduction after an H(2) O(2) attack.

To our knowledge, this is the first systematic screen for the identification of putative genes essential to overcoming cell dehydration process. A broad range of identified genes could help to understand why some strains of high biotechnological interest cannot cope with the drying and rehydration treatments. Dehydration sensitivity makes these strains not suitable to be commercialized by yeast manufactures.