Abstract 1967 Metal Toxicity on Organelle Structure and Function in Saccharomyces cerevisiae

The metal lithium has been used as a mood stabilizer for bipolar medication since 1970. Lithium is an inhibitor of GSK-3, preventing these neurological diseases from progressing, and has the potential to be used in Alzheimer's medication. The effects of lithium on general cellular physiology is less well-known but Saccharomyces cerevisiae can be used to clarify this question. We are particularly interested in the effects lithium has on the vacuole organelle because it is generally impacted by cellular responses to metal exposure. The vacuole in S. cerevisiae is similar to the human lysosome in that it takes in the waste of the cell and disposes of it. Our objective is to observe the impact of exposure to lithium, copper, iron, magnesium, and calcium on S. cerevisiae the structure and dynamics vacuoles, in particular to discover if these metals will lead to a block in the process of inheritance that transfers vacuole from mother to bud. We also want to observe whether there is recovery from the inheritance-blocking effects of lithium upon washout. Exposure of the BY4741 VPH1-GFP strain to high concentrations of the metals was conducted. Data analysis included quantifying the percentage of mother bud pairs displaying loss of inheritance. Measurements for vacuole volume and surface area were obtained using a computational algorithm using fluorescence images as input. We observed that high concentrations of lithium chloride had a higher prevalence of a block in vacuolar inheritance. Additionally, vacuole volume and surface area increased along with cell volume with the influx of lithium. With recovery, results suggest vacuole inheritance can resume to normal function. These results can indicate if lithium can cause adverse health effects to humans. This can promote increased research on the medicinal applications of lithium and other metals. I would like to acknowledge San Francisco State University Biology Department, SEO funding: NIH Bridge to Doctorate : Grant No. 5 T32-GM142515-2, NIH funding: NIH SC2-GM118267, Center for Cellular Construction: CCC DBI-1548297, and Genentech: G-7874540.