Plant mitochondria operate as the powerhouses for cellular energy production by using the combined functions of both imported and organelle-synthesised proteins. Homeostasis of mitochondrial proteins is controlled by both synthesis and degradation processes which together define protein turnover in this organelle. Better understanding of plant mitochondrial protein turnover will provide information on protein quality control inside these organelles and its importance for proper function and regulation of mitochondrial machinery. This review discusses methods used for measurement of turnover rates of plant mitochondrial proteins and presents our current understanding of these rates for key mitochondrial proteins and protein complexes. The assembly and maintenance of mitochondrial OXPHOS complexes, in particular Complexes I and V, will be discussed in detail based on the evidence for differential protein turnover rates of the same protein subunits in different mitochondrial fractions. The impact of the loss of specific plant mitochondrial proteases on proteolysis events and rates of mitochondrial protein turnover will be highlighted. The challenges and future directions for investigation of plant mitochondrial protein turnover are also discussed.

中文翻译：

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植物线粒体中的蛋白质周转率

植物线粒体通过使用进口蛋白质和细胞器合成蛋白质的综合功能，作为细胞能量产生的动力源。线粒体蛋白质的稳态受合成和降解过程的控制，这两个过程共同定义了该细胞器中的蛋白质周转。更好地了解植物线粒体蛋白质周转将提供有关这些细胞器内蛋白质质量控​​制及其对线粒体机器正常功能和调节的重要性的信息。本综述讨论了用于测量植物线粒体蛋白质周转率的方法，并介绍了我们目前对关键线粒体蛋白质和蛋白质复合物的这些速率的理解。线粒体 OXPHOS 复合物的组装和维持，特别是复合物 I 和 V，将根据不同线粒体部分中相同蛋白质亚基的不同蛋白质周转率的证据详细讨论。将强调特定植物线粒体蛋白酶的损失对蛋白水解事件和线粒体蛋白质周转率的影响。还讨论了研究植物线粒体蛋白质周转的挑战和未来方向。