USP20

USP20 (ubiquitin-specific peptidase 20) is a cysteine protease deubiquitinase that regulates protein stability by removing ubiquitin chains from specific substrates and thereby controls multiple signaling pathways involved in cellular homeostasis^[1]. Mechanistically, USP20 modulates key biological processes through substrate-specific deubiquitination, including regulation of TNFα-induced NF-κB signaling, autophagy initiation, receptor trafficking, and protein quality control^[2][3]. In the TNFα signaling pathway, USP20 directly binds and stabilizes the scaffold protein p62 by removing K48-linked polyubiquitin chains, promoting NF-κB activation and supporting cell survival responses^[2]. Consistent with this mechanism, depletion of USP20 disrupts formation of the PKCζ-RIPK1-p62 signaling complex and enhances apoptosis in cellular models exposed to TNFα-mediated stress^[2]. USP20 also contributes to autophagy regulation through stabilization of ULK1 and participates in protein homeostasis by deubiquitinating tail-anchored membrane proteins after endoplasmic reticulum insertion^[1][3]. In disease contexts, altered USP20 expression has been associated with multiple cancer models, where USP20 regulates the stability of proteins involved in proliferation, migration, invasion, and tumor progression^[1]. Compared with the closely related deubiquitinase USP33, which shares substantial sequence homology, USP20 exhibits overlapping functions in receptor recycling and membrane protein quality-control pathways but displays distinct substrate interactions and signaling outputs depending on cellular context^[3][4]. Currently, selective pharmacological modulators of USP20 remain limited, and most studies employ genetic depletion or overexpression approaches to investigate USP20-dependent signaling mechanisms and disease phenotypes^[1].