植物表达分泌蛋白的运输及定位

Transport and Localization of the Secretory Protein Expressed in Plant

分泌途径主要由内膜系统构成,内质网和高尔基体对于分泌蛋白的运输及定位具有重要作用。分泌蛋白的运输包括顺行途径和逆行途径。蛋白质通过质流和受体介导的途径运输到小泡中。在植物中,分泌蛋白的运输主要通过小泡和相连的小管来完成。分子伴侣和质量控制不仅能优化新合成蛋白的折叠和组装,而且去除了有折叠缺陷的蛋白。分泌蛋白的定位需要特定的信号肽,而高尔基体固有蛋白以依赖跨膜长度的方式,沿着分泌途径的细胞器分布。本文对植物表达分泌蛋白的分泌途径及定位、相关的分子伴侣和质量控制进行了综述。

The secretory pathway of eukaryotic organelles mainly consists of endomembrane system. The endoplasmic reticulum（ER） and the Golgi apparatus are the key organelles for the secretory protein transport and localization. Anterograde traffic is balanced by retrograde traffic running in the opposite direction. Protein import from the ER occurs via receptor-mediated protein transport or bulk flow. In plant cell, vesicles or direct connections in the form of tubular extensions might mediate protein transport between the two organelles. The ER molecular chaperone machinery and the associated quality control mechanisms not only optimize folding and assembly of newly synthesized secretory proteins but also dispose of defective ones. The localization of proteins to specific organelles within eukaryotic cells depends on discrete targeting signals, but the length of the transmembrane domain is of crucial importance for the retention of proteins within the Golgi. In this review, the recent findings regarding secretory protein transport and localization were summarized, along with the associated quality control mechanisms and molecular chaperone machinery.