Andrews D W, Johnson A E
Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada.
Trends Biochem Sci. 1996 Oct;21(10):365-9.
In eukaryotes, the vast majority of secreted and integral membrane proteins are targeted to the membrane of the endoplasmic reticulum (ER) early during translation. These polypeptides are then either transported across or inserted into the ER membrane at sites termed translocons. As protein translocation occurs through an aqueous pore, the minimal requirement for a translocon is a passive structure that provides a passage-way across the membrane. However, recent data suggest that the translocon is a complex structure that orchestrates the localization, orientation, maturation and possibly degradation of nascent chains.
在真核生物中，绝大多数分泌蛋白和整合膜蛋白在翻译早期就被靶向运输到内质网（ER）膜。这些多肽随后要么被转运穿过内质网膜，要么在内质网膜上称为易位子的位点插入内质网膜。由于蛋白质转运是通过一个水相孔进行的，因此易位子的最低要求是一个提供跨膜通道的被动结构。然而，最近的数据表明，易位子是一个复杂的结构，它协调新生肽链的定位、方向、成熟以及可能的降解。
