Abstract Mitochondrial precursor proteins with amino-terminal presequences are imported via the presequence pathway, utilizing the TIM23 complex for inner membrane translocation. Initially, the precursors pass the outer membrane through the TOM complex and are handed over to the TIM23 complex where they are sorted into the inner membrane or translocated into the matrix. This handover process depends on the receptor proteins at the inner membrane, Tim50 and Tim23, which are critical for efficient import. In this review, we summarize key findings that shaped the current concepts of protein translocation along the presequence import pathway, with a particular focus on the precursor handover process from TOM to the TIM23 complex. In addition, we discuss functions of the human TIM23 pathway and the recently uncovered pathogenic mutations in TIM50.

中文翻译：

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从 TOM 到 TIM23 复合体——前体的移交

摘要 具有氨基末端前序列的线粒体前体蛋白通过前序列途径导入，利用 TIM23 复合物进行内膜易位。最初，前体通过外膜穿过 TOM 复合物，并被移交给 TIM23 复合物，在那里它们被分类到内膜或转移到基质中。这一交接过程取决于内膜上的受体蛋白 Tim50 和 Tim23，它们对于有效导入至关重要。在这篇综述中，我们总结了沿着前序列输入途径形成蛋白质易位的当前概念的关键发现，特别关注从 TOM 到 TIM23 复合体的前体移交过程。此外，我们讨论了人类 TIM23 通路的功能和最近发现的 TIM50 致病突变。