Matrix protein and another viral component contribute to induction of apoptosis in cells infected with vesicular stomatitis virus
Matrix protein and another viral component contribute to induction of apoptosis in cells infected with vesicular stomatitis virus
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DOI：
10.1128/jvi.75.24.12169-12181.2001
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发表时间：
2001-12-01
影响因子：
5.4
通讯作者：
Lyles, DS
中科院分区：
文献类型：
--
作者：
Kopecky, SA;Willingham, MC;Lyles, DS
水泡性口炎病毒（VSV）感染引起宿主细胞凋亡是一种重要的细胞病变效应。病毒基质（M）蛋白负责几个重要的细胞病变效应，包括抑制宿主基因表达和诱导细胞变圆的VSV感染的细胞。这就提出了M蛋白是否也参与诱导细胞凋亡的问题。用M mRNA转染HeLa或BHK细胞，以确定在不存在其他病毒组分的情况下表达M蛋白时是否诱导细胞凋亡。M蛋白的表达诱导细胞凋亡的形态学变化和激活的caspase-3在两种细胞类型，表明M蛋白诱导细胞凋亡的情况下，其他病毒成分。一个M蛋白含有一个点突变，使其在抑制宿主基因表达（M51 R突变）激活很少，如果有的话，半胱天冬酶-3，而缺失突变体缺乏氨基酸4至21是有缺陷的病毒组装功能，但在抑制宿主基因表达的功能是有效的野生型（wt）M蛋白激活半胱天冬酶-3。为了确定在病毒感染的情况下M蛋白是否影响细胞凋亡的诱导，通过使用重组感染性cDNA克隆（rM 51 R-M病毒）将M51 R M蛋白突变掺入野生型背景中。将rM 51 R-M病毒诱导细胞凋亡的时间与相应的重组wt（rwt）病毒和tsO 82病毒（最初鉴定M51 R突变的突变病毒）诱导细胞凋亡的时间进行比较。在HeLa细胞中，rwt病毒诱导凋亡的速度比rM 51 R-M病毒，证明了M蛋白在诱导凋亡中的作用。与HeLa细胞的结果相反，rwt病毒诱导的细胞凋亡比rM 51 R-M病毒在BHK细胞中更慢。这表明除了M蛋白以外的病毒组分有助于诱导BHK细胞中的细胞凋亡，并且wt M蛋白起到延迟其他病毒组分诱导细胞凋亡的作用。tsO_（82）病毒诱导HeLa和BHK细胞凋亡的速度均快于rM_（51）R-M病毒。这两种病毒在其M蛋白中含有相同的点突变，这表明除了M蛋白的基因序列差异外，其他基因的序列差异影响其诱导凋亡的速率。
The induction of apoptosis in host cells is a prominent cytopathic effect of vesicular stomatitis virus (VSV) infection. The viral matrix (M) protein is responsible for several important cytopathic effects, including the inhibition of host gene expression and the induction of cell rounding in VSV-infected cells. This raises the question of whether M protein is also involved in the induction of apoptosis. HeLa or BHK cells were transfected with M mRNA to determine whether M protein induces apoptosis when expressed in the absence of other viral components. Expression of M protein induced apoptotic morphological changes and activated caspase-3 in both cell types, indicating that M protein induces apoptosis in the absence of other viral components. An M protein containing a point mutation that renders it defective in the inhibition of host gene expression (M51R mutation) activated little, if any, caspase-3, while a deletion mutant lacking amino acids 4 to 21 that is defective in the virus assembly function but fully functional in the inhibition of host gene expression was as effective as wild-type (wt) M protein in activating caspase-3. To determine whether M protein influences the induction of apoptosis in the context of a virus infection, the M51R M protein mutation was incorporated onto a wt background by using a recombinant infectious cDNA clone (rM51R-M virus). The timing of the induction of apoptosis by rM51R-M virus was compared to that by the corresponding recombinant wt (rwt) virus and to that by tsO82 virus, the mutant virus in which the M51R mutation was originally identified. In HeLa cells, rwt virus induced apoptosis faster than did rM51R-M virus, demonstrating a role for M protein in the induction of apoptosis. In contrast to the results obtained with HeLa cells, rwt virus induced apoptosis more slowly than did rM51R-M virus in BHK cells. This indicates that a viral component other than M protein contributes to induction of apoptosis in BHK cells and that wt M protein acts to delay induction of apoptosis by the other viral component. tsO82 virus induced apoptosis more rapidly than did rM51R-M virus in both HeLa and BHK cells. These two viruses contain the same point mutation in their M proteins, suggesting that sequence differences in genes other than that for M protein affect their rates of induction of apoptosis.