Human P53 Expression in Yeast: Investigating Its Apoptotic Effects

Since its discovery in 1979, the tumor suppressor p53 has been widely studied and expressed in various organisms, including yeast. Yeast has proven to be a very informative model and an effective system for studying the roles and functions of this protein and gene. This review is a compilation of our team's studies involving p53 expression in yeast. These researches investigated certain aspects, essentially the apoptotic function of p53. Our main contribution to the study and understanding of the p53 gene in the yeast context is the confirmation of a negative effect of p53 on cell growth in both Saccharomyces cerevisiae and Pichia pastoris strains, which ultimately led to apoptotic cell death. This involves a high dose of p53 and the NLS signal, which enables p53 to target both the mitochondria and the nucleus. Prior to that, obtaining the whole protein required a cDNA without its UTR. Thus, a yeast model was developed, allowing verification of p53 activity. Cancer mutants and their revertants could thereby be assessed. This has evolved into a real antioxidant/anti-apoptotic molecular screening mechanism. Two primary applications were achieved: testing the co-expression with the thioredoxin 2 gene (TRX2) and assessing the impact of Nigella sativa seed extracts. Furthermore, the high yield of yeast P53 production allowed its use in serological cancer diagnosis.