Proteasome inhibition interferes with Gag polyprotein processing, release, and maturation of HIV-1 and HIV-2
Proteasome inhibition interferes with Gag polyprotein processing, release, and maturation of HIV-1 and HIV-2
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DOI：
10.1073/pnas.97.24.13057
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发表时间：
2000-11-21
影响因子：
11.1
通讯作者：
Yewdell, JW
中科院分区：
文献类型：
--
作者：
Schubert, U;Ott, DE;Yewdell, JW
逆转录病毒组装和成熟涉及病毒蛋白的折叠和运输到病毒组装位点，随后是新生病毒粒子内Gag多蛋白的后续蛋白水解裂解。我们报告说，抑制蛋白酶体严重降低了艾滋病毒的萌芽，成熟和感染性。尽管Env糖蛋白的加工没有改变，但蛋白酶体抑制剂抑制病毒蛋白酶对标签多聚蛋白的加工，而不影响HIV-1病毒蛋白酶本身的活性，如HIV-1标签多聚蛋白Pr 55的体外加工所证明的。此外，这种作用的发生与HIV-1辅助蛋白Vpu的病毒释放功能无关，并且不限于HIV-1，因为蛋白酶体抑制剂也减少HIV-2的病毒释放和标签加工。电子显微镜分析显示，在出芽的病毒粒子的超微结构的变化类似于突变体的后期组装域的p6（gag），一个C-末端结构域的Pr 55所需的有效的病毒成熟和释放。蛋白酶体抑制降低了HIV-1感染细胞中游离泛素的水平，并阻止了p6（gag）的单泛素化。与此一致，PR或p6（gag）突变的病毒对蛋白酶体抑制剂介导的有害作用具有抗性。这些结果表明，在感染性HIV颗粒的释放和成熟中需要活性蛋白酶体/泛素系统，并为干扰逆转录病毒复制提供了潜在的药物策略。
Retrovirus assembly and maturation involve folding and transport of viral proteins to the virus assembly site followed by subsequent proteolytic cleavage of the Gag polyprotein within the nascent virion. We report that inhibiting proteasomes severely decreases the budding, maturation, and infectivity of HIV. Although processing of the Env glycoproteins is not changed, proteasome inhibitors inhibit processing of tag polyprotein by the viral protease without affecting the activity of the HIV-1 viral protease itself, as demonstrated by in vitro processing of HIV-1 tag polyprotein Pr55. Furthermore, this effect occurs independently of the virus release function of the HIV-1 accessory protein Vpu and is not limited to HIV-1, as proteasome inhibitors also reduce virus release and tag processing of HIV-2. Electron microscopy analysis revealed ultrastructural changes in budding virions similar to mutants in the late assembly domain of p6(gag), a C-terminal domain of Pr55 required for efficient virus maturation and release. Proteasome inhibition reduced the level of free ubiquitin in HIV-1-infected cells and prevented monoubiquitination of p6(gag). Consistent with this, viruses with mutations in PR or p6(gag) were resistant to detrimental effects mediated by proteasome inhibitors. These results indicate the requirement for an active proteasome/ubiquitin system in release and maturation of infectious HIV particles and provide a potential pharmaceutical strategy for interfering with retrovirus replication.