ISG15 inhibit Ebola VP40VLP budding in an L-domain-dependent manner by blocking Nedd4 ligase activity
ISG15 inhibit Ebola VP40VLP budding in an L-domain-dependent manner by blocking Nedd4 ligase activity
复制标题
DOI：
10.1073/pnas.0710629105
复制
发表时间：
2008-03-11
影响因子：
11.1
通讯作者：
Harty, Ronald N.
中科院分区：
文献类型：
--
作者：
Okumura, Atsushi;Pitha, Paula M.;Harty, Ronald N.
埃博拉病毒出芽是由VP 40基质蛋白介导的。VP 40可以独立于其他病毒蛋白从哺乳动物细胞中出芽，VP 40病毒样颗粒（VLP）的有效释放需要与宿主蛋白（如tsg 101和E3泛素连接酶Nedd 4）相互作用。泛素本身被认为是埃博拉病毒利用，以促进有效的病毒出口。VP 40功能的破坏以及由此病毒出芽仍然是开发新型抗病毒疗法的有吸引力的靶点。在这里，我们研究了ISG 15蛋白对埃博拉病毒VP 40 VLP释放的影响。ISG 15是一种在细菌或病毒感染后表达的IFN诱导的泛素样蛋白。我们的研究结果表明，表达游离ISG 15或ISGylation系统（UbE 1 L和UbcH 8），抑制埃博拉病毒VP 40 VLP的出芽。解决这种抑制的分子机制，我们表明ISG 15与Nedd 4泛素连接酶相互作用，抑制VP 40的泛素化。此外，不与Nedd 4相互作用的VP 40的L结构域缺失突变体（Delta PT/PY）对ISG 15介导的VLP释放抑制不敏感。这些数据提供了ISG 15对埃博拉病毒的抗病毒活性的证据，并提出了涉及Nedd 4、功能和随后的VP 40泛素化的破坏的作用机制。
Ebola virus budding is mediated by the VP40 matrix protein. VP40 can bud from mammalian cells independent of other viral proteins, and efficient release of VP40 virus-like particles (VLPs) requires interactions with host proteins such as tsg101 and Nedd4, an E3 ubiquitin ligase. Ubiquitin itself is thought to be exploited by Ebola virus to facilitate efficient virus egress. Disruption of VP40 function and thus virus budding remains an attractive target for the development of novel antiviral therapies. Here, we investigate the effect of ISG15 protein on the release of Ebola VP40 VLPs. ISG15 is an IFN-inducible, ubiquitin-like protein expressed after bacterial or viral infection. Our results show that expression of free ISG15, or the ISGylation system (UbE1L and UbcH8), inhibits budding of Ebola virus VP40 VLPs. Addressing the molecular mechanism of this inhibition, we show that ISG15 interacts with Nedd4 ubiquitin ligase and inhibits ubiquitination of VP40. Furthermore, the L-domain deletion mutant of VP40 (Delta PT/PY), which does not interact with Nedd4, was insensitive to ISG15-mediated inhibition of VLP release. These data provide evidence of antiviral activity of ISG15 against Ebola virus and suggest a mechanism of action involving disruption of Nedd4, function and subsequent ubiquitination of VP40.