Do H, Falcone D, Lin J, Andrews D W, Johnson A E
Department of Medical Biochemistry & Genetics, Texas A&M University Health Science Center, College Station 77843-1114, USA.
Cell. 1996 May 3;85(3):369-78. doi: 10.1016/s0092-8674(00)81115-0.
During the cotranslational integration of a nascent protein into the endoplasmic reticulum membrane, the transmembrane (TM) sequence moves out of an aqueous pore formed by Sec61alpha, TRAM, and other proteins and into the nonpolar lipid bilayer. Photocross-linking reveals that this movement involves the sequential passage of the TM domain through three different proteinaceous environments: one adjacent to Sec61alpha and TRAM and two adjacent to TRAM that place different restrictions on TM domain movement. In addition, the TM sequence is not allowed to diffuse into the bilayer from the final TRAM-proximal site until translation terminates. Cotranslational integration is therefore linked to translation and occurs via an ordered multistep pathway at an endoplasmic reticulum site that is multilayered both structurally and functionally.
在新生蛋白质共翻译整合到内质网膜的过程中，跨膜（TM）序列从由Sec61α、转运体相关膜蛋白（TRAM）和其他蛋白质形成的水相孔中移出，进入非极性脂质双层。光交联显示，这种移动涉及TM结构域依次通过三种不同的蛋白质环境：一种与Sec61α和TRAM相邻，另外两种与TRAM相邻，它们对TM结构域的移动施加了不同的限制。此外，在翻译终止之前，TM序列不被允许从最终的TRAM近端位点扩散到双层中。因此，共翻译整合与翻译相关联，并通过内质网位点上有序的多步途径发生，该位点在结构和功能上都是多层的。
