USP10 strikes down β-catenin by dual-wielding deubiquitinase activity and phase separation potential

Wnt/β-catenin signaling is a conserved pathway crucially governing development, homeostasis, and oncogenesis. Discoveries of its regulators hold great values in both basic and translational research. Through screening, we identified a deubiquitinase, USP10, as a critical modulator of β-catenin. Mechanistically, USP10 binds to key scaffold Axin1 via conserved motifs and stabilizes Axin1 through K48-linked deubiquitination. Surprisingly, USP10 physically tethers Axin1 and β-catenin and promotes the phase separation for β-catenin suppression regardless of the enzymatic activity. Function-wise, USP10 enzymatic activity preferably regulates embryonic development and both the enzymatic activity and physical function jointly control intestinal homeostasis by antagonizing β-catenin. In colorectal cancer, USP10 substantially represses cancer growth mainly through physical promotion of phase separation and correlates with Wnt/β-catenin magnitude clinically. Collectively, we discovered USP10 functioning in multiple biological processes against β-catenin and unearthed the enzyme-dependent and -independent "dual-regulating" mechanism. These two functions of USP10 work in parallel and are context dependent.