Ziemiecki A, Garoff H, Simons K
J Gen Virol. 1980 Sep;50(1):111-23. doi: 10.1099/0022-1317-50-1-111.
In Semliki Forest virus (SFV)-infected cells, all structural proteins are translated from a 26S mRNA using a single initiation site. The capsid protein which is made first is released into the cytoplasm whereas the two membrane proteins, p62 (the precursor for E2 and E3) and E1, are inserted into the rough endoplasmic reticulum membrane. Based on gradient centrifugation and cross-linking studies, it can be seen that the p62 and E1 polypeptides form a complex immediately after synthesis and migrate to the plasma membrane in the form of a p62-E1 complex. The processing of p62 to E2 and E3 is first seen 25 to 30 min after a 10 min pulse of radioactive amino acids. This cleavage can be inhibited by addition of antisera specific for E1 and E3, thus supporting the view that, as in the case of the related Sindbis virus, this cleavage occurs on the external face of the plasma membrane. Proteolytic digestion of crude vesicle preparations derived from plasma membranes, combined with peptide mapping, indicate that the carboxy-terminal end of E2 spans the cell plasma membrane, there being a portion of mol. wt about 3000 located towards the cytosol.
在感染辛德毕斯病毒（SFV）的细胞中，所有结构蛋白均从26S mRNA利用单一起始位点进行翻译。首先合成的衣壳蛋白释放到细胞质中，而两种膜蛋白，即p62（E2和E3的前体）和E1，则插入糙面内质网膜中。基于梯度离心和交联研究可以看出，p62和E1多肽在合成后立即形成复合物，并以p62-E1复合物的形式迁移到质膜。在用放射性氨基酸脉冲处理10分钟后，最早在25至30分钟时可观察到p62加工成E2和E3。添加针对E1和E3的抗血清可抑制这种切割，从而支持如下观点：与相关的辛德毕斯病毒一样，这种切割发生在质膜的外表面。对源自质膜的粗囊泡制剂进行蛋白水解消化并结合肽图谱分析表明，E2的羧基末端跨细胞质膜，朝向胞质溶胶一侧有一段分子量约为3000的部分。
