Nucleocapsid-independent assembly of coronavirus-like particles by co-expression of viral envelope protein genes.
Nucleocapsid-independent assembly of coronavirus-like particles by co-expression of viral envelope protein genes.
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DOI：
10.1002/j.1460-2075.1996.tb00553.x
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发表时间：
1996-04-15
期刊：
影响因子：
11.4
通讯作者：
Rottier, P J
中科院分区：
文献类型：
--
作者：
Vennema, H;Godeke, G J;Rossen, J W;Voorhout, W F;Horzinek, M C;Opstelten, D J;Rottier, P J
已证明有包膜病毒的出芽是由核衣壳和蛋白脂质膜之间的相互作用驱动的。相比之下，我们在这里描述了独立于核衣壳的病毒包膜的组装。含有冠状病毒包膜蛋白的膜颗粒在动物细胞中组装并释放，这些细胞从转染的质粒中共表达这些蛋白质的基因。在三种病毒膜蛋白中，只有两种是颗粒形成所必需的，即膜糖蛋白（M）和小包膜蛋白（E）。刺突（S）蛋白是可有可无的，但在存在时被掺入。重要的是，核衣壳蛋白（N）既不是必需的，也不是存在时被纳入颗粒中的。最近被认为是结构蛋白的 E 蛋白被证明是一种完整的膜蛋白。通过免疫金标记和电子显微镜发现包膜囊泡形成均匀的球形颗粒群，其大小（直径约 100 nm）和形状与真正的冠状病毒没有区别。它们的密度比病毒颗粒小，并且在蔗糖速度梯度中沉积速度比病毒颗粒稍慢。明显真实的病毒包膜的不依赖于核衣壳的形成代表了一种新的病毒组装模式。
Budding of enveloped viruses has been shown to be driven by interactions between a nucleocapsid and a proteolipid membrane. By contrast, we here describe the assembly of viral envelopes independent of a nucleocapsid. Membrane particles containing coronaviral envelope proteins were assembled in and released from animal cells co-expressing these proteins' genes from transfected plasmids. Of the three viral membrane proteins only two were required for particle formation, the membrane glycoprotein (M) and the small envelope protein (E). The spike (S) protein was dispensable but was incorporated when present. Importantly, the nucleocapsid protein (N) was neither required not taken into the particles when present. The E protein, recently recognized to be a structural protein, was shown to be an integral membrane protein. The envelope vesicles were found by immunogold labelling and electron microscopy to form a homogeneous population of spherical particles indistinguishable from authentic coronavirions in size (approximately 100 nm in diameter) and shape. They were less dense than virions and sedimented slightly slower than virions in sucrose velocity gradients. The nucleocapsid-independent formation of apparently bona fide viral envelopes represents a novel mode of virus assembly.