Fig. 7

TRIM28 possesses an intrinsic E3 ubiquitin ligase activity (RING domain) and subsequently directs p53 for proteasomal degradation. TRIM28 directly interacts with MDM2 through its’ coiled-coil (CC) region within RBCC domain and cooperates with MDM2 to promote p53 polyubiquitination and degradation in the proteasome. MDM2 - E3 ubiquitin-protein ligase, major regulator of the p53 tumor suppressor; p53 – tumor suppressor, guardian of the genome, tetrameric in active conformation