H11/HSPB8 Restricts HIV-2 Vpx to Restore the Anti-Viral Activity of SAMHD1.
H11/HSPB8 Restricts HIV-2 Vpx to Restore the Anti-Viral Activity of SAMHD1.
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DOI：
10.3389/fmicb.2016.00883
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发表时间：
2016
影响因子：
5.2
通讯作者：
Ryo A
中科院分区：
文献类型：
--
作者：
Kudoh A;Miyakawa K;Matsunaga S;Matsushima Y;Kosugi I;Kimura H;Hayakawa S;Sawasaki T;Ryo A
病毒-宿主相互作用在病毒复制和病毒诱导的发病机制中起着至关重要的作用。病毒完全依靠宿主细胞繁殖后代病毒；然而，宿主因子通过与病毒蛋白的相互作用积极或消极地调节病毒的复制。病毒-宿主蛋白相互作用的阐明不仅有助于更好地理解宿主细胞对抗病毒感染的分子机制，而且有助于开发新的抗病毒治疗方法。鉴定相关宿主因子需要能够全面表征病毒-宿主蛋白相互作用的技术。在这项研究中，我们开发了一种蛋白质组学方法来系统地鉴定与病毒蛋白有效相互作用的人类蛋白激酶。为此，我们使用小麦无生殖细胞蛋白合成系统合成了412个全长人蛋白激酶，并使用扩增发光接近均质法（AlphaScreen）筛选它们与病毒蛋白的关联。利用该系统，我们试图发现一种针对HIV-2病毒蛋白X （Vpx）的强大抗病毒宿主限制机制。筛选发现H11/HSPB8为Vpx结合蛋白，负向调控Vpx的稳定性和功能。事实上，H11/HSPB8的过表达通过泛素-蛋白酶体途径促进Vpx的降解，并抑制其与SAMHD1的相互作用，SAMHD1是一种负责阻断HIV复制的宿主限制因子。相反，在通常表达高水平Vpx蛋白的人滋养细胞中，靶向敲低H11/HSPB8，恢复Vpx的表达和功能，使细胞对病毒复制高度敏感。这些结果表明，我们的蛋白质组学方法是揭示传统方法尚未发现的病毒-宿主相互作用的有力工具。此外，我们发现H11/HSPB8可能是一个潜在的宿主调节因子，可以预防妊娠期间胎盘感染HIV-2。
Virus–host interactions play vital roles in viral replication and virus-induced pathogenesis. Viruses rely entirely upon host cells to reproduce progeny viruses; however, host factors positively or negatively regulate virus replication by interacting with viral proteins. The elucidation of virus–host protein interaction not only provides a better understanding of the molecular mechanisms by which host cells combat viral infections, but also facilitates the development of new anti-viral therapeutics. Identification of relevant host factors requires techniques that enable comprehensive characterization of virus–host protein interactions. In this study, we developed a proteomic approach to systematically identify human protein kinases that interact potently with viral proteins. For this purpose, we synthesized 412 full-length human protein kinases using the wheat germ cell-free protein synthesis system, and screened them for their association with a virus protein using the amplified luminescent proximity homogenous assay (AlphaScreen). Using this system, we attempted to discover a robust anti-viral host restriction mechanism targeting virus protein X (Vpx) of HIV-2. The screen identified H11/HSPB8 as a Vpx-binding protein that negatively regulates the stability and function of Vpx. Indeed, overexpression of H11/HSPB8 promoted the degradation of Vpx via the ubiquitin–proteasome pathway and inhibited its interaction with SAMHD1, a host restriction factor responsible for blocking replication of HIV. Conversely, targeted knockdown of H11/HSPB8 in human trophoblast cells, which ordinarily express high levels of this protein, restored the expression and function of Vpx, making the cells highly susceptible to viral replication. These results demonstrate that our proteomic approach represents a powerful tool for revealing virus–host interaction not yet identified by conventional methods. Furthermore, we showed that H11/HSPB8 could be a potential host regulatory factor that may prevent placental infection of HIV-2 during pregnancy.