Abstract Mitochondrial protein import is one of the key processes during mitochondrial biogenesis that involves a series of events necessary for recognition and delivery of nucleus-encoded/cytosol-synthesized mitochondrial proteins into the organelle. The past research efforts have mainly unraveled how membrane translocases ensure the correct protein sorting within the different mitochondrial subcompartments. However, early steps of recognition and delivery remain relatively uncharacterized. In this review, we discuss our current understanding about the signals on mitochondrial proteins, as well as in the mRNAs encoding them, which with the help of cytosolic chaperones and membrane receptors support protein targeting to the organelle in order to avoid improper localization. In addition, we discuss recent findings that illustrate how mistargeting of mitochondrial proteins triggers stress responses, aiming to restore cellular homeostasis.

中文翻译：

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从细胞质到线粒体：蛋白质之旅的开始

摘要 线粒体蛋白输入是线粒体生物发生过程中的关键过程之一，涉及识别和传递核编码/胞质溶胶合成的线粒体蛋白到细胞器中所必需的一系列事件。过去的研究工作主要揭示了膜转位酶如何确保不同线粒体亚室中正确的蛋白质分选。然而，识别和交付的早期步骤仍然相对没有特征。在这篇综述中，我们讨论了我们目前对线粒体蛋白信号以及编码它们的 mRNA 的理解，这些信号在胞质伴侣和膜受体的帮助下支持蛋白质靶向细胞器，以避免不正确的定位。此外，