Insights to the activation of Sod1: Determining if Over Expressing CCS wt, C231S, C229S and C229-231S rescues Sod1 Growth in Saccharomyces cerevisiae

Paige Finley

Abstract

Saccharomyces cerevisiae, a common yeast, is used to study gene interactions. The lack of various genes can produce certain physical characteristics such as impaired growth in various conditions, which allows for a change in growth when another gene is inserted or deleted from a yeast cell. One common stressful condition for yeast and humans is oxidative stress, which is brought on by various free radicals and reactive oxygen species such as Superoxide. Organisms have developed complex mechanisms such as antioxidant enzymes to combat oxidative stress. The antioxidant enzyme, copper and zinc loaded superoxide dismutase (Sod1) functions to catalyze the disproportionation of superoxide into the less damaging molecules, dioxygen and hydrogen peroxide. In order for Sod1 to be activated copper and zinc must be inserted and a bond must form within the structure of the protein. The Copper Chaperone for Superoxide dismutase (CCS) is thought to catalyze two of these steps and has been found to be necessary for Sod1 activity. Four of the genes associated with CCS whose absence leads to decreased growth as well as decreased Sod1 activity include CCS wt, C231S, C229S and C229-231S. Excess copper and excess Sod1 can rescue yeast cells lacking CCS so the purpose of this work is to see if the reverse can happen where excess amounts of CCS will rescue cells lacking Sod1.