Aim: p53 is one of the important tumor suppressor proteins in humans and plays a role in many biological functions such as cell cycle arrest, DNA repair, and apoptosis. The aim of this research was to examine the activity of methionine and the methionine sulfoxide reductase (Msr) enzyme on oxidized p53.
Methods: Shuttle vectors that can replicate in both yeast cells and bacterial cells were used in the research. A high copy of the human p53 protein was created by Gateway cloning technology. Escherichia coli bacteria were used for the plasmid DNA transformation. The isolation experiment was then completed. The accuracy of the process was checked by a run-on experiment in gel electrophoresis. In addition, the β-Galactosidase assay was performed in the study.
Results: Mutants lacking the Methionine Sulfoxide Reductase genes had higher p53-dependent Lac-Z activity compared to the control cells. However, overexpression of Msr genes did not cause a change in p53 activity. Differences in p53 activity were observed upon treatment of mutants with 1mM hydrogen peroxide. Specifically, cells lacking both the Msra and Msrb genes were found to have less p53 activity.
Conclusions: The loss of activity in p53 in oxidative stress was concluded to be protected against and controlled by the Msr enzymes.