The Rab11 Pathway Is Required for Influenza A Virus Budding and Filament Formation
The Rab11 Pathway Is Required for Influenza A Virus Budding and Filament Formation
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DOI：
10.1128/jvi.00307-10
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发表时间：
2010-06-01
影响因子：
5.4
通讯作者：
Stuart, Amanda D.
中科院分区：
文献类型：
--
作者：
Bruce, Emily A.;Digard, Paul;Stuart, Amanda D.
甲型流感病毒通过顶端质膜出芽，形成有包膜的病毒颗粒，其形状可以是多形性球体或极细长的丝状。对于任何一种病毒粒子，导致病毒和细胞膜分离的因素尚不清楚。我们发现细胞 Rab11（一种参与内吞再循环的小 GTP 结合蛋白）和 Rab11 家族相互作用蛋白 3（[FIP3]，在膜运输和肌动蛋白动力学调节中发挥作用）都是支持丝状病毒体形成所必需的，而 Rab11 还参与球形颗粒的最终出芽步骤。用 Rab11 GTP 循环突变体转染的细胞或通过小干扰 RNA 处理去除 Rab11 或 FIP3 含量的细胞失去了形成病毒丝的能力。 Rab11 的耗竭导致细胞释放的球形病毒滴度降低多达 100 倍。 Rab11 耗尽细胞的扫描电子显微镜显示，高密度的病毒颗粒显然在出芽过程中停滞不前。薄片的透射电子显微镜证实，Rab11 缺失导致大量异常形成的病毒颗粒无法从质膜上夹断。基于这些发现，我们发现 Rab11 介导的途径在流感病毒形态发生和出芽中发挥着明确的作用。
Influenza A virus buds through the apical plasma membrane, forming enveloped virus particles that can take the shape of pleomorphic spheres or vastly elongated filaments. For either type of virion, the factors responsible for separation of viral and cell membranes are not known. We find that cellular Rab11 (a small GTP-binding protein involved in endocytic recycling) and Rab11-family interacting protein 3 ([FIP3] which plays a role in membrane trafficking and regulation of actin dynamics) are both required to support the formation of filamentous virions, while Rab11 is additionally involved in the final budding step of spherical particles. Cells transfected with Rab11 GTP-cycling mutants or depleted of Rab11 or FIP3 content by small interfering RNA treatment lost the ability to form virus filaments. Depletion of Rab11 resulted in up to a 100-fold decrease in titer of spherical virus released from cells. Scanning electron microscopy of Rab11-depleted cells showed high densities of virus particles apparently stalled in the process of budding. Transmission electron microscopy of thin sections confirmed that Rab11 depletion resulted in significant numbers of abnormally formed virus particles that had failed to pinch off from the plasma membrane. Based on these findings, we see a clear role for a Rab11-mediated pathway in influenza virus morphogenesis and budding.