Folding of rabies virus glycoprotein: Epitope acquisition and interaction with endoplasmic reticulum chaperones
Folding of rabies virus glycoprotein: Epitope acquisition and interaction with endoplasmic reticulum chaperones
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DOI：
10.1128/jvi.71.5.3742-3750.1997
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发表时间：
1997-05-01
影响因子：
5.4
通讯作者：
Gaudin, Y
中科院分区：
文献类型：
--
作者：
Gaudin, Y
使用四种针对狂犬病病毒糖蛋白 (G) 的特性良好的单克隆抗体 (MAb) 来研究体内 G 折叠。其中两个 MAb 能够免疫沉淀不完全氧化的折叠中间体，另外两个仅在折叠完成后识别 G。通过使用这些 MAb，还研究了 G 在折叠过程中经历低 pH 诱导的构象变化的能力，似乎某些结构域在折叠完成之前获得了这种能力。此外，仅分析了未折叠的 G 与一些分子伴侣之间的相互作用。未折叠的 G 与 BiP 和钙联蛋白相关，与 BiP 的关联是脉冲后立即达到最大，而与钙连接蛋白的关联在追踪 5 至 10 分钟后达到最大。还研究了衣霉素和栗精胺对分子伴侣结合和折叠的影响，在两种药物存在下，钙连接蛋白结合减少，与钙连接蛋白特异性识别单葡萄糖基化寡糖的观点一致，但仍然观察到一些残留的结合，表明钙连接蛋白也识别多肽链。在两种药物存在下，与BiP的结合增加并延长，折叠受损。然而，药物的整体效果不同，因为折叠在栗精胺的存在比衣霉素的存在要好。综上所述，这些结果为绘制狂犬病病毒糖蛋白折叠示意图提供了基础。
Four well-characterized monoclonal antibodies (MAbs) directed against rabies virus glycoprotein (G) were used to study G folding in vivo. Two of the MAbs were able to immunoprecipitate incompletely oxidized folding intermediates, The two others recognized G only after folding was completed, By using these MAbs, the ability of G to undergo low-pH-induced conformational changes during folding was also investigated, It appeared that some domains acquire this ability before folding is completed, In addition, interactions between unfolded G and some of the molecular chaperones mere analyzed, Unfolded G was associated with BiP and calnexin, Association with BiP was maximal immediately after the pulse, whereas association with calnexin was maximal after 5 to 10 min of chase. The effects of tunicamycin and castanospermine on chaperone binding and folding were also studied, In the presence of both drugs, calnexin binding was reduced, consistent with the view that calnexin specifically recognizes monoglucosylated oligosaccharides, but some residual binding was still observed, indicating that calnexin also recognizes the polypeptide chain, In the presence of both drugs, association with BiP was increased and prolonged and folding was impaired, However, the global effects of the drugs were different, since folding was much more efficient in the presence of castanospermine than in the presence of tunicamycin. Taken together, these results provide the basis to draw a schematic view of rabies virus glycoprotein folding.