Investigation of the effect of oxidative stress on the protein stability of insulin transcription factor, MafA

Type II diabetes, which is characterized by chronic hyperglycemia, is one of the most common diseases in the United States. A primary cause of elevated blood glucose level is decreased insulin production. Previous research by Robertson and associates using a mammalian pancreatic cell line (HIT‐T15) has shown that levels of MafA, a transcription factor needed for insulin production, is dramatically decreased after chronic culture in high glucose. Furthermore, co‐culture with antioxidants has been shown to inhibit the degradation of MafA protein. Although oxidative stress is hypothesized to cause the degradation of MafA, little is known about the role of antioxidant enzymes in determining MafA stability at the molecular level. Saccharomyces cerevisiae , a system in which protein degradation has been thoroughly characterized, will serve as a model to investigate the stability of MafA protein. An expression vector has been designed to express the MafA gene in yeast. Preliminary investigations will include assessment of MafA protein stability in yeast and use of yeast deletion mutants to examine the role of endogenous antioxidants enzymes. This research is funded by the Henry Luce Foundation.