Electron tomography of nascent herpes simplex virus virions
Electron tomography of nascent herpes simplex virus virions
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DOI：
10.1128/jvi.02571-06
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发表时间：
2007-03-01
影响因子：
5.4
通讯作者：
Marko, Michael
中科院分区：
文献类型：
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作者：
Baines, Joel D.;Hsieh, Chyong-Ere;Marko, Michael
用单纯疱疹病毒1型（HSV-1）感染的细胞常规包埋或高压冷冻后冷冻置换，并用乙酸双氧铀染色。电子断层扫描的衣壳附着或经历在内核膜（INNI），衣壳内的细胞质囊泡附近的核膜，和细胞外的病毒粒子的附着或经历的附着揭示了以下现象。(i)核衣壳在INNI或邻接INM的B衣壳处经历包裹，通过长8至19 nm和宽55 nm的纤维连接到INM的增厚的斑块。纤维接触核衣壳的五重对称顶点（五邻体）和六重对称面（六邻体），尽管相对于衣壳中这些亚基的各自频率，纤维接合五邻体比六邻体更频繁。(ii)在核周病毒体中，类似尺寸的纤维桥接病毒体包膜和核衣壳表面。(iii)核周病毒体的被膜比细胞外病毒体的被膜密度小得多;在前一种情况下观察到连接纤维，但在后者中没有。(iv)从细胞外病毒体的包膜发出的突出的外部刺突在核周病毒体中不存在。(v)核周病毒粒子的病毒粒子包膜较细胞外病毒粒子更致密、更厚。(vi)囊泡附近，但显然是不同的，核膜在单节来自扩展核周空间中看到的电子断层扫描。这些观察结果表明，与核周病毒体相比，细胞外的被膜和包被机制非常不同，并且与将最终被膜应用于与核周空间不同的隔室中的无包膜核衣壳一致。
Cells infected with herpes simplex virus type 1 (HSV-1) were conventionally embedded or freeze substituted after high-pressure freezing and stained with uranyl acetate. Electron tomograms of capsids attached to or undergoing envelopment at the inner nuclear membrane (INNI), capsids within cytoplasmic vesicles near the nuclear membrane, and extracellular virions revealed the following phenomena. (i) Nucleocapsids undergoing envelopment at the INNI, or B capsids abutting the INM, were connected to thickened patches of the INM by fibers 8 to 19 nm in length and :55 nm in width. The fibers contacted both fivefold symmetrical vertices (pentons) and sixfold symmetrical faces (hexons) of the nucleocapsid, although relative to the respective frequencies of these subunits in the capsid, fibers engaged pentons more frequently than hexons. (ii) Fibers of similar dimensions bridged the virion envelope and surface of the nucleocapsid in perinuclear virions. (iii) The tegument of perinuclear virions was considerably less dense than that of extracellular virions; connecting fibers were observed in the former case but not in the latter. (iv) The prominent external spikes emanating from the envelope of extracellular virions were absent from perinuclear virions. (v) The virion envelope of perinuclear virions appeared denser and thicker than that of extracellular virions. (vi) Vesicles near, but apparently distinct from, the nuclear membrane in single sections were derived from extensions of the perinuclear space as seen in the electron tomograms. These observations suggest very different mechanisms of tegumentation and envelopment in extracellular compared with perinuclear virions and are consistent with application of the final tegument to unenveloped nucleocapsids in a compartment(s) distinct from the perinuclear space.