Date of Completion
P53 is a tumor suppressor protein, which functions in maintaining the cell cycle. When p53 loses its function, cells may multiply at an uncontrolled rate and form tumors. This loss of function is linked to over fifty percent of human cancers. This investigation aims to explore the possible link between p53 aggregation and tumorigenesis. There is a possibility that p53, especially in mutant form, will aggregate beyond its normal tetrameric conformation and lose its function, leading to tumor formation. Wild-type p53 and six mutants, R175H, R175C, R248Q, R248W, R273C, and R273H (six of the most common mutations found in human cancers), were purified from E. coli using Ni-NTA agarose resin. Aggregation rates were monitored for the wild-type and each mutant by Thioflavin-T binding assays. Atomic force microscopy was used to visualize each of the p53 mutants pre-incubation and at time points that Thioflavin-T binding suggested the presence of aggregates. Utilizing this data, each mutant was characterized for its relative speed of aggregation; this suggests which mutants are more aggregation-prone. Combined with cell viability results, our data indicates that p53 aggregation of mutated variants is a contributing factor to tumorigensis. Those mutants with the greatest propensity to aggregate also appear to be those with the greatest ability to become immortal.
Arhar, Taylor A., "Aggregation Characterization of Wild-Type p53 and Six Common p53 Mutants" (2015). Honors Thesis. 2.