流感病毒在脂筏上组装与出芽

Influenza Virus Assembly and Budding in Lipid Rafts

流感病毒造成的季节性流行性疾病给全世界带来沉重的健康负担.近年来,甲型流感病毒的变种H5N1、H7N9给各国带来了很大危害.流感病毒属于正黏附病毒科,它的遗传物质由多个节段的负链RNA组成,其组装和出芽剪切生殖是一个涉及到多种病毒因子,多步骤、复杂的生化过程.流感病毒会使用宿主的细胞膜上的"脂筏"区域作为病毒出芽位点.首先病毒的两种糖蛋白NA蛋白、HA蛋白会在脂筏区域聚集,造成脂筏区膜变形弯曲,并且发动出芽的过程.接着,流感病毒基质蛋白M1的C端与HA、NA结合,其自身在脂筏区域开始多聚化并使膜向外弯曲形成原始病毒体的内部结构,接着招募病毒的核糖核蛋白复合物(VRNP)与M2蛋白,使组装的过程进一步完成.最后,M2蛋白会富集在原始病毒体的底部,完成膜的剪切和病毒体的释放.

Influenza A virus causes annual epidemics, and occasional pandemics that bring a significant global health threat. Influenza virus, which belongs to the Orthomyxoviridae family, is an enveloped virus that contains a segmented and negative-sense RNA genome. The assembly and budding of progeny influenza is a complicated and multi-step process involving many viral factors. Influenza budding occurs in lipid raft domains of cells membrane. Firstly, two viral glycoproteins HA and NA, concentrate in lipid rafts to initiate the budding process by causing membrane enlargement and curvature. Secondly Matrix protein 1 （M1）, which forms the inner virion matrix, is then recruited to the budding site followed by the incorporation of viral VPNPs and M2 proteins. In the later stages of budding, M2 is concentrated to the bottom of the budding virion at the lipid rafts boundary, resulting in viral scission and virion release.