USP14 Protein, Human

USP14, a proteasome-associated deubiquitinase, emerges as a crucial player in cellular processes, particularly in the dynamic regulation of ubiquitin at the proteasome. Functioning as a reversibly associated subunit of the proteasome, USP14 ensures the release of ubiquitin from ubiquitinated proteins targeted for degradation, facilitating the regeneration of ubiquitin within the cellular environment. Beyond its role in proteasome-mediated protein turnover, USP14 plays a pivotal role in diverse physiological contexts. It is involved in the degradation of the chemokine receptor CXCR4, a critical event for CXCL12-induced cell chemotaxis. Additionally, USP14 serves as a physiological inhibitor of endoplasmic reticulum-associated degradation (ERAD) under non-stressed conditions, interacting with ERN1 and modulating the degradation of unfolded endoplasmic reticulum proteins. Furthermore, USP14 contributes to synaptic development and function at neuromuscular junctions (NMJs) and participates in the innate immune defense against viruses by stabilizing the viral DNA sensor CGAS, thereby impeding its autophagic degradation.