Mouse double minute 2 homolog (MDM2)-Tumor protein p53 (p53) protein-protein interaction interface (MDM2-p53 PPI)

The MDM2-p53 protein-protein interaction interface is a critical regulatory node in cell cycle control and genome integrity (UniProt: P22301, P04637). MDM2 functions as an E3 ubiquitin ligase that binds to the N-terminal transactivation domain of the p53 tumor suppressor, targeting it for proteasomal degradation and maintaining low p53 levels in unstressed cells. In many human cancers, particularly those retaining wild-type TP53, MDM2 is frequently overexpressed or amplified, effectively silencing the tumor-suppressive activity of p53 (PubMed: 25236395). Therapeutic strategies focus on small molecules that occupy the deep hydrophobic cleft on the surface of MDM2, mimicking the three key p53 residues (Phe19, Trp23, and Leu26) required for binding. By disrupting this interaction, these inhibitors stabilize p53, allowing it to accumulate and trigger transcriptional programs for apoptosis or senescence in malignant cells. Clinical development of these agents primarily targets MDM2-amplified sarcomas and TP53 wild-type hematologic malignancies, though hematological toxicities like thrombocytopenia remain a significant therapeutic challenge (PubMed: 33097836).

Other names

MDM2-p53 interactionHDM2-p53 interactionMDM2-p53 complexMDM2-TP53 interaction

Small molecule inhibitors bind to the p53-binding pocket of MDM2, sterically hindering the interaction between MDM2 and p53. This prevents the MDM2-mediated ubiquitination and subsequent proteasomal degradation of p53, leading to the stabilization and accumulation of wild-type p53 protein, which then activates downstream target genes involved in cell cycle arrest and apoptosis (PubMed: 33097836).