SUMOylation in Mitochondrial Quality Control: Mechanisms and Implications for Neurodegenerative Disease.

Mitochondria, as the primary energy-generating organelles in neurons, play a pivotal role in regulating cellular metabolism. Given the post-mitotic nature and long lifespan of neurons, they are particularly vulnerable to the cumulative burden of mitochondrial damage. In response to various physiological and stress signals, a sophisticated mitochondrial quality control (MQC) system has evolved, which encompasses mitochondrial biogenesis, dynamics (fission and fusion), and mitophagy. This coordinated network acts as a critical surveillance mechanism to eliminate damaged components and maintain a healthy mitochondrial pool. The small ubiquitin-like modifier (SUMO) pathway, involving reversible SUMOylation and deSUMOylation, has emerged as a key regulator of MQC by directly modifying its core components. Dysregulation of the SUMO pathway disrupts mitochondrial homeostasis, and the resulting mitochondrial dysfunction is increasingly recognized as a central pathogenic mechanism in neurodegenerative diseases. This review systematically examines the role of the SUMO pathway in regulating MQC and its implications in the pathogenesis of Alzheimer's disease, Parkinson's disease, and Huntington's disease. Finally, we discuss the therapeutic potential and translational challenges of targeting the SUMO pathway for the treatment of neurodegenerative diseases.