E3 ubiquitin-protein ligase Mdm2 (MDM2)

E3 ubiquitin-protein ligase that mediates ubiquitination of p53/TP53, resulting in its degradation by the proteasome. Inhibits p53/TP53- and p73/TP73-mediated cell cycle arrest and apoptosis by binding its transcriptional activation domain.

Also functions as a ubiquitin ligase E3 toward itself and ARRB1. Permits the nuclear export of p53/TP53.