New Regulator of Tumor Suppressor Found
Tumor suppressor proteins such as p53 play a role in suppressing tumor growth. In particular, p53 expression is increased in response to DNA damage and then, through a series of cellular events, prevents the cell from dividing. However, to play this important biological role, the activity of p53 has to be tightly regulated.
In this study, the investigators aimed to determine the role of the protein PHF20 as a potential p53 regulator. To meet their aim, the investigators employed a number of biochemical, biophysical, and cellular approaches in the laboratory to determine the role of PHF20 as a potential regulator of p53.
The investigators observed that PHF20 binds very tightly to two specific sites that have been methylated on p53. The association between these two proteins promotes stabilization and activation of p53 by protecting it from modification and eventual degradation by another cellular protein, Mdm2. The most important observation made in this study was that PHP20 contributes to the increased expression of p53 that occurs in response to DNA damage.
Based on these findings, the investigators concluded that PHF20 effects the methylation of p53 that leads to its eventual stabilization and activation.