Role of the CM2 Protein in the Influenza C Virus Replication Cycle
Role of the CM2 Protein in the Influenza C Virus Replication Cycle
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DOI：
10.1128/jvi.01367-10
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发表时间：
2011-02-01
影响因子：
5.4
通讯作者：
Hongo, Seiji
中科院分区：
文献类型：
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作者：
Furukawa, Takatoshi;Muraki, Yasushi;Hongo, Seiji
CM2是丙型流感病毒的第二膜蛋白。尽管其生化特性、编码策略和作为离子通道的特性已被广泛研究，但CM2在病毒复制周期中的作用仍有待阐明。为了阐明这一作用，在本研究中，我们生成了cm2缺陷型流感C病毒样颗粒（VLPs），并检测了产生vlp的293T细胞、vlp和感染vlp的HMV-II细胞。通过实时荧光定量PCR对VLPs中的病毒RNA （vRNA）进行定量分析，发现cm2缺陷型VLPs中含有的vRNA约为野生型VLPs的三分之一，尽管在vlp产生细胞中病毒成分的表达水平或产生的vlp的数量和形态上没有检测到显著差异。这一发现表明，CM2参与了基因组包装成VLPs的过程。此外，感染cm2缺陷vlp的HMV-II细胞表现出报告基因表达显著降低。尽管cm2缺陷型VLPs可以像野生型VLPs一样有效地内化到HMV-II细胞中，但在cm2缺陷型vlp感染细胞的核部分中检测到的vRNA数量少于野生型vlp感染细胞，这表明感染细胞中cm2缺陷型vlp的剥膜过程并没有以适当的方式进行。综上所述，本研究获得的数据表明，CM2在病毒复制周期的基因组包装和解包衣过程中具有潜在的作用。
CM2 is the second membrane protein of influenza C virus. Although its biochemical characteristics, coding strategy, and properties as an ion channel have been extensively studied, the role(s) of CM2 in the virus replication cycle remains to be clarified. In order to elucidate this role, in the present study we generated CM2-deficient influenza C virus-like particles (VLPs) and examined the VLP-producing 293T cells, VLPs, and VLP-infected HMV-II cells. Quantification of viral RNA (vRNA) in the VLPs by real-time PCR revealed that the CM2-deficient VLPs contain approximately one-third of the vRNA found in wild-type VLPs although no significant differences were detected in the expression levels of viral components in VLP-producing cells or in the number and morphology of the generated VLPs. This finding suggests that CM2 is involved in the genome packaging process into VLPs. Furthermore, HMV-II cells infected with CM2-deficient VLPs exhibited significantly reduced reporter gene expression. Although CM2-deficient VLPs could be internalized into HMV-II cells as efficiently as wild-type VLPs, a smaller amount of vRNA was detected in the nuclear fraction of CM2-deficient VLP-infected cells than in that of wild-type VLP-infected cells, suggesting that the uncoating process of the CM2-deficient VLPs in the infected cells did not proceed in an appropriate manner. Taken together, the data obtained in the present study indicate that CM2 has a potential role in the genome packaging and uncoating processes of the virus replication cycle.