Mitochondria are essential organelles because they have key roles in cellular energy metabolism and many other metabolic pathways. Several quality control systems have evolved to ensure that dysfunctional mitochondria are either repaired or eliminated. The activities of these pathways are crucial for cellular health because they maintain functional mitochondria. In addition, the cytosolic ubiquitin–proteasome system (UPS) and the mitochondria-associated degradation pathway (MAD) share some of their core components, are functionally tightly interconnected, and mutually modulate their activities. Thus, the mitochondrial outer membrane (MOM) actively supports quality control systems in extramitochondrial compartments. Furthermore, mitochondrial quality surveillance systems also act on cytosolic or endoplasmic reticulum (ER) substrates and modulate immune responses. Therefore, mitochondria contribute to cellular quality control and homeostasis on several levels.

线粒体是必需的细胞器，因为它们在细胞能量代谢和许多其他代谢途径中起关键作用。已经开发出几种质量控制系统，以确保修复或消除功能异常的线粒体。这些途径的活动对于细胞健康至关重要，因为它们维持功能性线粒体。此外，胞质泛素-蛋白酶体系统（UPS）和线粒体相关的降解途径（MAD）共享它们的一些核心成分，在功能上紧密相连，并相互调节其活性。因此，线粒体外膜（MOM）积极支持线粒体外隔室中的质量控制系统。此外，线粒体质量监控系统还作用于细胞质或内质网（ER）底物并调节免疫反应。因此，线粒体在几个水平上有助于细胞质量控制和体内稳态。