Puvion-Dutilleul F, Venturini L, Guillemin M C, de Thé H, Puvion E
Laboratoire, Organisation fonctionnelle du Noyau de l'UPR 9044 CNRS, Villejuif, Franc.
Exp Cell Res. 1995 Dec;221(2):448-61. doi: 10.1006/excr.1995.1396.
We investigated the intranuclear distribution of PML and Sp100 in HeLa cells at the ultrastructural level and examined their relocalization in response to herpes simplex virus type 1 (HSV-1) infection. In the absence of infection, we observed that both are components, not only of nuclear bodies, but also of interchromatin granule-associated zones, which suggests a potential role for PML and Sp100 in splicing events. Prolonged HSV-1 infection induced dramatic changes in nuclear organization which consisted of the morphological disappearance of some nuclear structures (nuclear bodies, interchromatin granule-associated zones, coiled bodies) and of the development of a centrally located electron-translucent viral region which pushed the cellular clusters of interchromatin granules to the nuclear border. Concomitantly, dense bodies, concentric arrays of reduplicated inner nuclear membrane, and translucent patches containing a few viral capsids occurred at the nuclear border. PML and Sp100 were exclusively detected over the finely granular material of the viral translucent patches which also contains small amounts of p80-coilin and U1 and U2 snRNAs. An antiserum raised against capsid proteins intensely labeled the viral translucent patches at the level of their finely granular material and enclosed viral capsids. Our data, therefore, suggest that these viral structures, in addition to being the site of accumulation of viral capsid proteins and, possibly, a capsidworks, are also a site of sequestration of cell factors including PML and Sp100. Viral capsid proteins could interfere with and inactivate PML and Sp100 and be implicated in the shutoff of host cell metabolism induced by HSV-1 infection.
我们在超微结构水平上研究了人宫颈癌细胞（HeLa细胞）中早幼粒细胞白血病（PML）蛋白和Sp100蛋白的核内分布，并检测了它们在单纯疱疹病毒1型（HSV-1）感染后的重新定位情况。在未感染的情况下，我们观察到这两种蛋白不仅是核仁的组成成分，也是染色质间颗粒相关区域的组成成分，这表明PML和Sp100在剪接事件中可能发挥作用。HSV-1的长时间感染导致核组织发生显著变化，表现为一些核结构（核仁、染色质间颗粒相关区域、卷曲小体）的形态消失，以及位于细胞核中央的电子透明病毒区域的形成，该区域将染色质间颗粒的细胞簇推向核边缘。与此同时，在核边缘出现了致密小体、重复的内核膜同心阵列以及含有少量病毒衣壳的半透明斑块。PML和Sp100仅在病毒半透明斑块的细颗粒物质上被检测到，这些细颗粒物质还含有少量的p80卷曲螺旋蛋白以及U1和U2小核核糖核酸。一种针对衣壳蛋白产生的抗血清在病毒半透明斑块的细颗粒物质水平以及封闭的病毒衣壳处进行了强烈标记。因此，我们的数据表明，这些病毒结构除了是病毒衣壳蛋白的积累位点以及可能的衣壳装配位点外，也是包括PML和Sp100在内的细胞因子的隔离位点。病毒衣壳蛋白可能会干扰并使PML和Sp100失活，并与HSV-1感染诱导的宿主细胞代谢关闭有关。
