Protein quality control in mitochondria.

Mitochondria are crucial for both life and death of eukaryotic cells. Compromised mitochondrial integrity has severe cellular consequences and is linked to senescence and neurodegenerative disorders in humans. To maintain the functionality of proteins in mitochondria, quality-control mechanisms including signal transduction pathways counteracting mitochondrial stress have evolved. A network of molecular chaperones and proteases monitors protein integrity and prevents accumulation of damaged proteins. In this review, the current knowledge of elaborate defence strategies within mitochondria is summarized.