Mitochondria contain about 1,000–1,500 proteins that fulfil multiple functions. Mitochondrial proteins originate from two genomes: mitochondrial and nuclear. Hence, proper mitochondrial function requires synchronization of gene expression in the nucleus and in mitochondria and necessitates efficient import of mitochondrial proteins into the organelle from the cytosol. Furthermore, the mitochondrial proteome displays high plasticity to allow the adaptation of mitochondrial function to cellular requirements. Maintenance of this complex and adaptable mitochondrial proteome is challenging, but is of crucial importance to cell function. Defects in mitochondrial proteostasis lead to proteotoxic insults and eventually cell death. Different quality control systems monitor the mitochondrial proteome. The cytosolic ubiquitin–proteasome system controls protein transport across the mitochondrial outer membrane and removes damaged or mislocalized proteins. Concomitantly, a number of mitochondrial chaperones and proteases govern protein folding and degrade damaged proteins inside mitochondria. The quality control factors also regulate processing and turnover of native proteins to control protein import, mitochondrial metabolism, signalling cascades, mitochondrial dynamics and lipid biogenesis, further ensuring proper function of mitochondria. Thus, mitochondrial protein quality control mechanisms are of pivotal importance to integrate mitochondria into the cellular environment.

线粒体包含大约 1,000-1,500 种具有多种功能的蛋白质。线粒体蛋白来自两个基因组：线粒体和核。因此，适当的线粒体功能需要细胞核和线粒体中基因表达的同步，并且需要将线粒体蛋白从细胞质有效导入细胞器。此外，线粒体蛋白质组显示出高可塑性，允许线粒体功能适应细胞需求。维护这种复杂且适应性强的线粒体蛋白质组具有挑战性，但对细胞功能至关重要。线粒体蛋白质稳态的缺陷导致蛋白质毒性损伤并最终导致细胞死亡。不同的质量控制系统监测线粒体蛋白质组。胞质泛素-蛋白酶体系统控制蛋白质跨线粒体外膜的转运并去除受损或错误定位的蛋白质。同时，许多线粒体伴侣蛋白和蛋白酶控制蛋白质折叠并降解线粒体内受损的蛋白质。质量控制因素还调节天然蛋白质的加工和周转，以控制蛋白质输入、线粒体代谢、信号级联、线粒体动力学和脂质生物发生，进一步确保线粒体的正常功能。因此，线粒体蛋白质质量控​​制机制对于将线粒体整合到细胞环境中至关重要。许多线粒体伴侣蛋白和蛋白酶控制蛋白质折叠并降解线粒体内受损的蛋白质。质量控制因素还调节天然蛋白质的加工和周转，以控制蛋白质输入、线粒体代谢、信号级联、线粒体动力学和脂质生物发生，进一步确保线粒体的正常功能。因此，线粒体蛋白质质量控​​制机制对于将线粒体整合到细胞环境中至关重要。许多线粒体伴侣蛋白和蛋白酶控制蛋白质折叠并降解线粒体内受损的蛋白质。质量控制因素还调节天然蛋白质的加工和周转，以控制蛋白质输入、线粒体代谢、信号级联、线粒体动力学和脂质生物发生，进一步确保线粒体的正常功能。因此，线粒体蛋白质质量控​​制机制对于将线粒体整合到细胞环境中至关重要。