Targeting the Ubiquitin–Proteasome System in Atrial Fibrillation: Mechanistic Insights and Translational Perspectives

Atrial fibrillation (AF) is the most common sustained arrhythmia, and its initiation and progression involve multiple mechanisms, including electrical remodeling, structural remodeling, inflammatory responses, and oxidative stress. In recent years, the ubiquitin–proteasome system (UPS), a central pathway for maintaining intracellular protein homeostasis, has attracted increasing attention in the pathogenesis of AF. By regulating the degradation and expression of ion channel proteins, Ca2+-handling molecules, and pro-fibrotic signaling factors, the UPS plays a pivotal role in key pathological processes such as electrical and structural remodeling. Several E3 ubiquitin ligases (e.g., NEDD4-1/2, MuRF1, WWP1/2, TRAF6), deubiquitinating enzymes (e.g., JOSD2), and immunoproteasome subunits (e.g., β5i) have been shown to exert critical regulatory effects on atrial electrophysiological disturbances, interstitial remodeling, and inflammation. This review provides a comprehensive summary of the regulatory mechanisms of the UPS in AF-associated pathological processes, outlines potential therapeutic targets, and highlights current intervention strategies, including proteasome inhibitors, selective E3 ligase modulators, and natural compounds. Moreover, we discuss the latest advances and future perspectives regarding the application of UPS-based interventions in AF, aiming to provide theoretical foundations and research insights for the mechanistic exploration and innovative therapeutic development of AF.