MDM2-p53 complex

The MDM2-p53 complex is a key regulatory assembly formed between the E3 ubiquitin ligase MDM2 and the tumor suppressor protein p53. MDM2 binds directly to the N-terminal transactivation domain of p53 via a deep hydrophobic cleft, principally interacting with p53 residues Phe19, Trp23, and Leu26, which form an amphipathic alpha helix[1][2]. By binding to p53, MDM2 inhibits its transcriptional activity, promotes its nuclear export, and targets it for ubiquitin-mediated proteasomal degradation, thereby functioning as a principal negative regulator of p53 in normal and cancerous cells[2][3][6][7]. Overexpression or amplification of MDM2, frequently observed in several tumor types, inactivates p53 and contributes to oncogenesis[3][2]. The MDM2-p53 interface has been heavily targeted in oncology drug discovery: small-molecule MDM2 antagonists such as Nutlin-3a competitively inhibit this interaction, leading to the reactivation of wild-type p53 signaling and apoptosis in cancer cells harboring functional p53[4]. Therapeutic interventions targeting this complex are primarily in development or clinical trials for cancers with intact p53 and elevated MDM2[4]. Notable therapeutic challenges include hematological and gastrointestinal toxicities, often attributed to broad activation of p53 in normal tissue.

Other names

Mdm2:p53 complexMDM2-p53 protein-protein interactionMDM2-p53 interfaceMDM2-p53 binding

Inhibition of the MDM2-p53 interaction, leading to stabilization and activation of p53; Prevention of p53 ubiquitination and degradation