中文摘要：

Ⅳ型膜蛋白是一种特殊的尾部锚定的膜蛋白,如囊泡运输相关的Syb2、负责蛋白转运的SRP受体和Sec61、调节细胞凋亡的Bcl-2等,在细胞中发挥了重要的作用。同大部分膜蛋白的翻译同步转运机制相比,Ⅳ型膜蛋白插入内质网膜的过程属于翻译后转运机制。Ⅳ型膜蛋白从核糖体中翻译结束并释放后,经过一系列的多分子协同作用转运到内质网膜上,再由内质网上的通道蛋白或整合酶整合转运进入内质网。近年来,基于体外翻译与重组实验的不断创新,鉴定出了一些非常重要的转运分子,如TRC复合物的40KD亚基,为了解这类特殊膜蛋白的合成转运机制提供了大量可靠的证据,但仍然有许多关键的内容与机制需要进一步的探索与发现。

英文摘要：

Tail-Anchored （TA） membrane proteins are an important and specific class of membrane proteins, which include the SNARE proteins Syb2 involved in vesicle trafficking, as well as Bcl-2 family involved in apoptosis, and several subunits of the mitochondrial and endoplasmic reticulum （ER） protein translocation channels （SRP receptor and Sec61）, play a key role in cell functions, compared with classic co-translational translocation of type Ⅱ membrane proteins, TA proteins belong to post-translational translocation. When the nascent TA proteins was fully translated and released from ribosome, then translocated by assistance of multi-molecular cooperation and inserted into ER membrane. Recently, based on the translation and reconstitution system in vitro, several important proteins were identified to regulate the translocation of TA proteins, like the 40 kD subunit of TRC complex, which would provide strong foundation for introduction of post-translational translocation. But some crucial element and mechanism are still unknown and needs discoverying and researching.