Progress in regulation of activity and stability of ubiquitin protein ligase MDM2

The ubiquitin protein ligase (E3) MDM2 (Murine double minute 2) possesses oncogenic activities. Overexpression of this protein enhances degradation and inactivation of the tumor suppressor p53. At least 7% of all human tumors exhibit inappropriate amplification of mdm2, whereas p53 gene remains in its wild-type configuration. This indicates that MDM2 may function in the p53-independent manner to promote tumorigenesis. Considering the critical role of MDM2, this review summarizes the current mechanisms and progress on MDM2 regulation in levels of gene control, mRNA transcription, post-translational modification, and interaction proteins.