Fig. 7.

Model showing HAUSP-mediated deubiquitination in normal versus cancer cells determining the fate of Rb. The equilibrium is biased towards Rb stabilization under normal conditions while in cancer, when the MDM2 load in the cells increases, the balance shifts to destabilize Rb, which deregulates the normal cell cycle and helps in enhanced proliferation of cells. Hence, showing MDM2 level to be the critical factor for regulation of HAUSP activity on Rb.