Santangelo Philip J, Bao Gang
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA.
Nucleic Acids Res. 2007;35(11):3602-11. doi: 10.1093/nar/gkm246. Epub 2007 May 7.
The final step in the maturation of paramyxoviruses, orthomyxoviruses and viruses of several other families, entails the budding of the viral nucleocapsid through the plasma membrane of the host cell. Many medically important viruses, such as influenza, parainfluenza, respiratory syncytial virus (RSV) and Ebola, can form filamentous particles when budding. Although filamentous virions have been previously studied, details of how viral filaments bud from the plasma membrane remain largely unknown. Using molecular beacon (MB)-fluorescent probes to image the viral genomic RNA (vRNA) of human RSV (hRSV) in live Vero cells, the dynamics of assembled viral filaments was observed to consist of three primary types of motion prior to egress from the plasma membrane: (i) filament projection and rotation, (ii) migration and (iii) non-directed motion. In addition, from information gained by imaging the 3D distribution of cellular vRNA, observing and characterizing vRNA dynamics, imaging vRNA/Myosin Va colocalization, and studying the effects of cytochalasin D (actin depolymerizing agent) exposure, a model for filamentous virion egress is presented.
副粘病毒、正粘病毒和其他几个病毒家族的病毒成熟的最后一步，是病毒核衣壳通过宿主细胞的质膜出芽。许多具有医学重要性的病毒，如流感病毒、副流感病毒、呼吸道合胞病毒（RSV）和埃博拉病毒，在出芽时可形成丝状颗粒。尽管此前已对丝状病毒粒子进行过研究，但病毒丝如何从质膜出芽的细节仍基本未知。利用分子信标（MB）荧光探针在活的非洲绿猴肾细胞（Vero细胞）中对人呼吸道合胞病毒（hRSV）的病毒基因组RNA（vRNA）进行成像，观察到组装好的病毒丝在从质膜释放之前的动态变化主要包括三种类型的运动：（i）丝的伸出和旋转，（ii）迁移，以及（iii）无定向运动。此外，通过对细胞vRNA的三维分布进行成像、观察和表征vRNA动态变化、对vRNA/肌球蛋白Va共定位进行成像以及研究细胞松弛素D（肌动蛋白解聚剂）暴露的影响所获得的信息，提出了一个丝状病毒粒子释放的模型。
