Integrity of membrane lipid rafts is necessary for the ordered assembly and release of infectious newcastle disease virus particles
Integrity of membrane lipid rafts is necessary for the ordered assembly and release of infectious newcastle disease virus particles
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DOI：
10.1128/jvi.01183-06
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发表时间：
2006-11-01
影响因子：
5.4
通讯作者：
Morrison, Trudy G.
中科院分区：
文献类型：
--
作者：
Laliberte, Jason P.;McGinnes, Lori W.;Morrison, Trudy G.
膜脂筏结构域被认为是许多包膜病毒的组装位点。研究了经典脂筏和与膜细胞骨架相关的脂筏在新城疫病毒（NDV）组装中的作用。脂筏相关蛋白 Caveolin-1、flotillin-2 和肌动蛋白被整合到病毒体中，而非脂筏相关的转铁蛋白受体则被排除。对病毒蛋白在脂筏（由耐去垢剂膜 (DRM) 定义）、非脂筏膜和病毒体中分布的动力学分析显示，HN、F 和 NP 病毒蛋白在合成后早期就在脂筏中积累。随后，这些蛋白质离开 DRM 并在纯化的病毒粒子中定量回收，而这些蛋白质在洗涤剂可溶性细胞组分中的水平保持相对恒定。受感染细胞的胆固醇消耗极大地改变了病毒蛋白与 DRM 的关联，导致病毒颗粒释放增加，感染性降低。传染性的降低并不是由于对随后的病毒进入的影响，因为从完整病毒中提取胆固醇并没有显着降低传染性。从胆固醇耗尽的细胞释放的颗粒具有非常不均匀的密度，并且纳米粒子和糖蛋白的比例发生变化，表明结构异常可能导致其感染性降低。综上所述，这些结果表明脂筏，包括细胞骨架相关的脂筏，是NDV组装的位点，并且这些结构域对于传染性新城疫病毒颗粒的有序组装和释放非常重要。
Membrane lipid raft domains are thought to be sites of assembly for many enveloped viruses. The roles of both classical lipid rafts and lipid rafts associated with the membrane cytoskeleton in the assembly of Newcastle disease virus (NDV) were investigated. The lipid raft-associated proteins caveolin-1, flotillin-2, and actin were incorporated into virions, while the non-lipid raft-associated transferrin receptor was excluded. Kinetic analyses of the distribution of viral proteins in lipid rafts, as defined by detergent-resistant membranes (DRMs), in non-lipid raft membranes, and in virions showed an accumulation of HN, F, and NP viral proteins in lipid rafts early after synthesis. Subsequently, these proteins exited the DRMs and were recovered quantitatively in purified virions, while levels of these proteins in detergent-soluble cell fractions remained relatively constant. Cholesterol depletion of infected cells drastically altered the association of viral proteins with DRMs and resulted in an enhanced release of virus particles with reduced infectivity. Decreased infectivity was not due to effects on subsequent virus entry, since the extraction of cholesterol from intact virus did not significantly reduce infectivity. Particles released from cholesterol-depleted cells had very heterogeneous densities and altered ratios of NP and glycoproteins, demonstrating structural abnormalities which potentially contributed to their lowered infectivity. Taken together, these results indicate that lipid rafts, including cytoskeleton-associated lipid rafts, are sites of NDV assembly and that these domains are important for ordered assembly and release of infectious Newcastle disease virus particles.