信号肽与蛋白质的分选转运

The Mechanisms of Protein Sorting and Translocation Regulated by Signal Peptides

蛋白质一般在位于细胞质中的核糖体内合成,但是它们发挥生理功能的地点却分布在细胞的不同区域,这些区域通常由蛋白质所不能自由透过的脂膜所包裹。因此,细胞质中新合成的蛋白质必须进行准确的定向运输才能保证各项生命活动的正常运行。研究发现,一般情况下,新生蛋白通常在位于其N端的信号肽的指引下到达细胞特定区域,并由其介导跨膜转运。本文重点介绍信号肽的结构、功能及作用机制等的研究成果。

Proteins are primarily synthesized in the ribosomes while their physiological functions are performed in various subcellular compartments, which are separated by lipid membranes that are not freely permeable to proteins. Therefore, once synthesized in the cytoplasm, proteins must be sorted and targeted to proper functional compartments to ensure fine-tuning of essential physiological processes. Accumulating evidences have demonstrated that signal peptides, which are frequently localized at the N-terminus of nascent proteins, play an essential role in this process. The current review will summarize research progress on the structure and function of signal peptides, and focus on the mechanisms of protein sorting and translocation regulated by signal peptides.