COVER: Mitochondria are essential organelles that are involved in ATP production, various metabolic pathways, innate immune response, and apoptosis. Although mitochondria are continuously exposed to damaging conditions, autophagy, ubiquitin-proteasomes, and internal proteases maintain mitochondrial quality and integrity. In addition to processing incoming precursors through translocator complexes, mitochondrial proteases localized in different sub-compartments also regulate metabolic reactions, half-lives of mitochondrial proteins, and gene transcription. Impaired mitochondrial qualities are known to be associated with various pathologies including cancer, neurodegenerative disorders, and mitochondrial disease. The cover illustrates mitochondrial quality control mechanisms regulated by autophagy (upper left), proteasomes (upper right), and internal proteases (middle). Yamano, K., Kinefuchi, H., Kojima W. (2024) Mitochondrial quality control via organelle and protein degradation. J. Biochem. 175, 487-494