Fig. 8: Diagram of the mechanism.

RACK1 competitively inhibits β-catenin binding to PSMD2, enhances β-catenin stability, regulates cell cycle progression and facilitates breast cancer progression. PSMD2 is a key component of the proteasome that binds to β-catenin and regulates its degradation through the UPS (left). RACK1 deficiency results in increased ubiquitin-proteasome degradation of β-catenin (right).