Murti K G, Porter K R, Goorha R, Ulrich M, Wray G
Exp Cell Res. 1984 Sep;154(1):270-82. doi: 10.1016/0014-4827(84)90686-4.
We have described the structure of virus assembly sites in frog virus 3-infected tissue culture cells based on an examination of sectioned and whole cells by conventional and high voltage (1 000 kV) electron microscopy (HVEM), respectively. We have also attempted to identify the cellular and viral components within the assembly sites using immunofluorescence and a combination of DNase digestion and EM autoradiography. Immunofluorescence studies showed that the sites do not contain tubulin, vimentin, actin, or myosin, confirming EM and HVEM studies which showed the absence of these cytoskeletal filaments from these sites. Enzymatic digestion and autoradiographic studies identified viral DNA in clumps of electron-dense material which are suspended within the matrix of the assembly site. Examination of whole, virus-infected cells by HVEM revealed that the matrix of the assembly site appears as a compaction of the cytoplasmic matrix and appears to be continuous with it. The fine strands of cytomatrix, equated with the microtrabeculae of other cells, are covered with or contain granules measuring 6-8 nm; similar granules also populate the virus assembly sites. Disruption of purified FV 3 with chloroform yielded capsomeres measuring 6-8 nm. Based on all these observations, we postulate that the virus assembly sites are regions of the cytomatrix specialized for virus assembly and that the viral components are transported along the cytomatrix to the assembly sites.
我们分别通过传统电子显微镜和高压（1000 kV）电子显微镜（HVEM）对蛙病毒3感染的组织培养细胞进行切片检查和全细胞检查，描述了病毒装配位点的结构。我们还试图利用免疫荧光以及DNA酶消化和电子显微镜放射自显影相结合的方法，鉴定装配位点内的细胞和病毒成分。免疫荧光研究表明，这些位点不含微管蛋白、波形蛋白、肌动蛋白或肌球蛋白，这证实了电子显微镜和高压电子显微镜的研究结果，即这些位点不存在这些细胞骨架丝。酶消化和放射自显影研究在悬浮于装配位点基质中的电子致密物质团块中鉴定出病毒DNA。通过高压电子显微镜对整个病毒感染细胞的检查显示，装配位点的基质表现为细胞质基质的致密化，并且似乎与之连续。等同于其他细胞微梁的细胞基质细纤维上覆盖着或含有直径为6 - 8纳米的颗粒；类似的颗粒也存在于病毒装配位点。用氯仿破坏纯化的FV 3可产生直径为6 - 8纳米的衣壳粒。基于所有这些观察结果，我们推测病毒装配位点是细胞基质中专门用于病毒装配的区域，并且病毒成分沿着细胞基质被运输到装配位点。
