Laboratoire de Virologie Moléculaire et Structurale, Centre de Recherche de Gif, CNRS (UPR 3296), Avenue de la Terrasse, 91198, Gif sur Yvette Cedex, France.
Viruses. 2012 Jan;4(1):117-39. doi: 10.3390/v4010117. Epub 2012 Jan 18.
Rhabdoviruses enter the cell via the endocytic pathway and subsequently fuse with a cellular membrane within the acidic environment of the endosome. Both receptor recognition and membrane fusion are mediated by a single transmembrane viral glycoprotein (G). Fusion is triggered via a low-pH induced structural rearrangement. G is an atypical fusion protein as there is a pH-dependent equilibrium between its pre- and post-fusion conformations. The elucidation of the atomic structures of these two conformations for the vesicular stomatitis virus (VSV) G has revealed that it is different from the previously characterized class I and class II fusion proteins. In this review, the pre- and post-fusion VSV G structures are presented in detail demonstrating that G combines the features of the class I and class II fusion proteins. In addition to these similarities, these G structures also reveal some particularities that expand our understanding of the working of fusion machineries. Combined with data from recent studies that revealed the cellular aspects of the initial stages of rhabdovirus infection, all these data give an integrated view of the entry pathway of rhabdoviruses into their host cell.
狂犬病毒通过内吞作用进入细胞，随后在内涵体的酸性环境中与细胞膜融合。受体识别和膜融合都是由单个跨膜病毒糖蛋白（G）介导的。融合是通过低 pH 值诱导的结构重排触发的。G 是一种非典型的融合蛋白，因为其在融合前和融合后构象之间存在 pH 依赖性平衡。阐明水疱性口炎病毒（VSV）G 的这两种构象的原子结构表明，它与先前表征的 I 类和 II 类融合蛋白不同。在这篇综述中，详细介绍了融合前和融合后的 VSV G 结构，表明 G 结合了 I 类和 II 类融合蛋白的特征。除了这些相似之处，这些 G 结构还揭示了一些特殊性，扩展了我们对融合机制工作原理的理解。结合最近研究揭示的狂犬病毒感染初始阶段的细胞方面的数据，所有这些数据为狂犬病毒进入宿主细胞的进入途径提供了一个综合的视角。
