Mouse double minute 2 homolog–tumor protein p53 interaction (MDM2–p53 interaction)

The **mouse double minute 2 homolog (MDM2)–tumor protein p53 (TP53) interaction** is a central regulatory mechanism controlling the cellular function of p53, the major tumor suppressor transcription factor. MDM2 is a key E3 ubiquitin ligase that binds the transactivation domain of p53, blocks its transcriptional activity, promotes its nuclear export, and targets it for ubiquitin-mediated proteasomal degradation. This interaction forms an autoregulatory negative feedback loop: p53 transcriptionally upregulates MDM2 expression, and MDM2 in turn downregulates p53[1][3][5]. Disruption of this axis, most often by p53 mutation or by MDM2 overexpression, is a frequent event in human cancer. The MDM2–p53 interaction is a validated anticancer therapeutic target where small molecules (such as Nutlin-3, RG7112, and others) or experimental peptide inhibitors can restore p53 function in tumors retaining wild-type p53, leading to tumor cell cycle arrest or apoptosis[2][4]. Clinical targeting of this axis is associated with therapeutic potential but also dose-limiting toxicities, notably myelosuppression[2]. The p53–MDM2 pathway is modulated by several other proteins (e.g., ARF, MDMX, p14[ARF], and caspase-2), and understanding these complex interactions is important for optimizing therapeutic strategies[1].

Other names

MDM2–p53 complexMDM2–TP53 interactionp53–MDM2 binding

Inhibition of MDM2–p53 binding (restores p53 activity); Activation of wild-type p53 pathway by preventing degradation; Induction of p53-mediated cell cycle arrest and apoptosis in tumor cells