Respiratory syncytial virus assembly occurs in GM1-rich regions of the host-cell membrane and alters the cellular distribution of tyrosine phosphorylated caveolin-1
Respiratory syncytial virus assembly occurs in GM1-rich regions of the host-cell membrane and alters the cellular distribution of tyrosine phosphorylated caveolin-1
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DOI：
10.1099/0022-1317-83-8-1841
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发表时间：
2002-08-01
影响因子：
3.8
通讯作者：
Sugrue, RJ
中科院分区：
文献类型：
--
作者：
Brown, G;Rixon, HWM;Sugrue, RJ
我们以前已经表明，呼吸道合胞病毒（RSV）的装配发生在宿主细胞表面膜的区域内，这些区域富含蛋白质caveolin-1（cav-1）。在这份报告中，我们采用免疫荧光显微镜进一步检查RSV组装过程。我们的研究结果表明，RSV成熟的细胞表面的区域，除了cav-1，富含脂筏神经节苷脂GM 1。此外，通过共聚焦显微镜比较模拟感染和RSV感染的细胞，发现磷酸小窝蛋白-1（pcav-1）的细胞分布发生了显着变化。在模拟感染的细胞中，pcav-1位于与细胞外基质相互作用的细胞区域，称为粘着斑（FA）。与此相反，RSV感染的细胞表现出与FA和pcav-1的外观，后者是在模拟感染的细胞中不存在的pcav-1的水平下降。这些胞质囊泡在感染后9 - 18 h清晰可见，与RSV丝状体的形成一致，尽管我们没有观察到pcav-1与成熟病毒的直接关联。此外，我们注意到pcav-1和生长激素受体结合蛋白-7（Grb 7）之间在这些胞质囊泡内存在强烈的共定位，而在模拟感染的细胞中未观察到。总的来说，这些发现表明RSV组装过程发生在宿主细胞质膜上的专门的脂筏结构内，诱导pcav-1的细胞再分布，并导致形成含有pcav-1和Grb 7的细胞质囊泡。
We have previously shown that respiratory syncytial virus (RSV) assembly occurs within regions of the host-cell surface membrane that are enriched in the protein caveolin-1 (cav-1). In this report, we have employed immunofluorescence microscopy to further examine the RSV assembly process. Our results show that RSV matures at regions of the cell surface that, in addition to cav-1, are enriched in the lipid-raft ganglioside GM1. Furthermore, a comparison of mock-infected and RSV-infected cells by confocal microscopy revealed a significant change in the cellular distribution of phosphocaveolin-1 (pcav-1). In mock-infected cells, pcav-1 was located at regions of the cell that interact with the extracellular matrix, termed focal adhesions (FA). In contrast, RSV-infected cells showed both a decrease in the levels of pcav-1 associated with FA and the appearance of pcav-1 containing cytoplasmic vesicles, the latter being absent in mock-infected cells. These cytoplasmic vesicles were clearly visible between 9 and 18 h post-infection and coincided with the formation of RSV filaments, although we did not observe a direct association of pcav-1 with mature virus. In addition, we noted a strong colocalization between pcav-1 and growth hormone receptor binding protein-7 (Grb7), within these cytoplasmic vesicles, which was not observed in mock-infected cells. Collectively, these findings show that the RSV assembly process occurs within specialized lipid-raft structures on the host-cell plasma membrane, induces the cellular redistribution of pcav-1 and results in the formation of cytoplasmic vesicles that contain both pcav-1 and Grb7.