Quality control at the powerhouse: mitochondrial proteostasis dysfunction and disease.

Intrinsic protein quality control (QC) mechanisms are essential in maintaining mitochondrial health and function. These sophisticated molecular machineries govern protein trafficking and import, processing, folding, maturation and degradation, ensuring the organelle's health. Disruption in mitochondrial protein QC can lead to severe, multisystem disorders with variable age of onset and progression. In this review, we provide a snapshot of the intrinsic molecular protein QC machineries in mitochondria detailing their function, localisation and substrate specificity. We also highlight how dysfunction of these molecular machines contributes to mitochondrial disease. Ultimately, elucidating the consequences of proteostatic failure offers critical insights into the pathogenesis of complex mitochondrial disorders.