Nuclear assembly of polyomavirus capsids in insect cells expressing the major capsid protein VP1
Nuclear assembly of polyomavirus capsids in insect cells expressing the major capsid protein VP1
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DOI：
10.1128/jvi.65.9.4991-4998.1991
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发表时间：
1991-09
影响因子：
5.4
通讯作者：
L. Montross;Simon C Watkins;R. Moreland;H. Mamon;D. Caspar;R. Garcea
中科院分区：
文献类型：
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作者：
L. Montross;Simon C Watkins;R. Moreland;H. Mamon;D. Caspar;R. Garcea
多瘤病毒通常在受感染小鼠细胞的细胞核中组装。通过电子显微镜检查表达多瘤病毒主要衣壳蛋白VP1的Sf9昆虫细胞。在细胞核中发现了尺寸明显均匀的衣壳状颗粒。免疫金电子显微镜显示细胞质中有丰富的VP1，但未组装成任何可识别的高级结构。用钙离子载体离子霉素处理细胞后，细胞质 VP1 组装。负染色和冷冻电子显微镜显示纯化的 VP1 聚集体主要由类似于空 T = 7 病毒衣壳的颗粒组成。因此，多瘤病毒VP1可以在体内组装成独立于其他病毒蛋白或DNA的衣壳。核组装可能是由于该亚细胞区室中可用钙的增加所致。
Polyomavirus normally assembles in the nucleus of infected mouse cells. Sf9 insect cells expressing the polyomavirus major capsid protein VP1 were examined by electron microscopy. Capsidlike particles of apparently uniform size were found in the nucleus. Immunogold electron microscopy demonstrated abundant VP1 in the cytoplasm which was not assembled into any recognizable higher-order structure. Cytoplasmic VP1 assembled after the cells were treated with the calcium ionophore ionomycin. Purified VP1 aggregates were shown by negative staining and cryoelectron microscopy to consist predominantly of particles similar to the empty T = 7 viral capsid. Thus, polyomavirus VP1 can assemble in vivo into capsids independent of other viral proteins or DNA. Nuclear assembly may result from increased available calcium in this subcellular compartment.