In eukaryotic cells, about one-third of the synthesized proteins are translocated into the endoplasmic reticulum; they are membrane or lumen resident proteins and proteins direct to the Golgi apparatus. The co-translational translocation takes place through the heterotrimeric protein-conducting channel Sec61 which is associated with the ribosome and many accessory components, such as the heterotetrameric translocon-associated protein (TRAP) complex. Recently, microscopic techniques, such as cryo-electron microscopy and cryo-electron tomography, have enabled the determination of the translocation machinery structure. However, at present, there is a lack of understanding regarding the roles of some of its components; indeed, the TRAP complex function during co-translational translocation needs to be established. In addition, TRAP may play a role during unfolded protein response, endoplasmic-reticulum-associated protein degradation and congenital disorder of glycosylation (ssr4 CDG). In this article, I describe the current understanding of the TRAP complex in the light of its possible function(s).

中文翻译：

---

了解哺乳动物 TRAP 复合体功能。

在真核细胞中，大约三分之一的合成蛋白质被转移到内质网中；它们是膜或腔内驻留蛋白和直接到达高尔基体的蛋白。共翻译易位通过异三聚体蛋白传导通道 Sec61 发生，该通道与核糖体和许多辅助成分（例如异四聚体易位子相关蛋白 (TRAP) 复合物）相关。最近，显微技术，例如冷冻电子显微镜和冷冻电子断层扫描，已经能够确定易位机械结构。然而，目前对其某些组成部分的作用缺乏了解；事实上，需要建立共翻译易位期间的 TRAP 复合体功能。此外，TRAP 可能在未折叠蛋白反应、内质网相关蛋白降解和先天性糖基化障碍 (ssr4 CDG) 过程中发挥作用。在本文中，我根据 TRAP 复合体的可能功能描述了目前对 TRAP 复合体的理解。