The membrane trafficking protein calpactin forms a complex with bluetongue virus protein NS3 and mediates virus release
The membrane trafficking protein calpactin forms a complex with bluetongue virus protein NS3 and mediates virus release
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DOI：
10.1073/pnas.192432299
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发表时间：
2002-10-01
影响因子：
11.1
通讯作者：
Roy, P
中科院分区：
文献类型：
--
作者：
Beaton, AR;Rodriguez, J;Roy, P
蓝舌病毒是环状病毒属的一种虫媒病毒，在昆虫和哺乳动物细胞中感染和复制。然而，细胞病变效应（cpe）对每一个主机是非常不同的。哺乳动物细胞表现出大量的cpe，很可能是病毒释放机制的结果，而昆虫细胞表现出很少的cpe，似乎在没有细胞裂解的情况下释放病毒。每种感染细胞类型的表达分析显示一种蛋白质，非结构（NS）蛋白NS 3，在不同的细胞类型中差异表达，这表明它可能在病毒外出途径中起作用。然而，这种相互作用的分子基础一直不清楚。在这里，通过使用酵母双杂交分析，我们表明，NS 3与细胞蛋白丸（calpactin轻链），膜联蛋白11复合物的一部分，参与胞吐作用的相互作用。我们将NS 3与p11相互作用的区域映射到在蛋白质的N末端发现的13个残基的肽，并显示它有效地与p36（膜联蛋白11重链）竞争p11配体结合。此外，我们发现NS 3的C-末端结构域与VP 2相互作用，VP 2是完全组装的病毒颗粒的最外层蛋白，这表明NS 3形成了一个桥接分子，将组装的病毒与细胞输出机制联系起来。我们的数据描述了第一个参与环状病毒外出的宿主蛋白，并为理解虫媒病毒与宿主的相互作用提供了新的见解。
Bluetongue virus, an arbovirus of the Orbivirus genus, infects and replicates in both insect and mammalian cells. However, the cytopathic effect (cpe) on each host is very different. Mammalian cells show substantial cpe, most likely a result of the mechanism of virus release, whereas insect cells show little cpe and appear to release virus without cell lysis. Expression analysis of each infected cell type shows one protein, the nonstructural (NS) protein NS3, to be differentially expressed in the different cell types, suggesting it may act in the virus egress pathway. The molecular basis of such an interaction, however, has never been clear. Here, by using yeast two-hybrid analysis, we show that NS3 interacts with a cellular protein pill (calpactin light chain), part of the annexin 11 complex that is involved in exocytosis. We map the NS3 region of interaction with p11 to a 13-residue peptide found at the N terminus of the protein and show it effectively competes with p36 (annexin 11 heavy chain) for p11 ligand binding. Further, we show that the C-terminal domain of NS3 interacts with VP2, the outermost protein of the fully assembled virus particle, suggesting that NS3 forms a bridging molecule that draws assembled virus into contact with the cellular export machinery. Our data describe the first host protein involvement in orbivirus egress and provide new insights into understanding arbovirus interactions with their hosts.