Li Ge, Poulsen Melissa, Fenyvuesvolgyi Csaba, Yashiroda Yoko, Yoshida Minoru, Simard J Marc, Gallo Robert C, Zhao Richard Y
Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201.
RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan.
Proc Natl Acad Sci U S A. 2017 Jan 17;114(3):E376-E385. doi: 10.1073/pnas.1619735114. Epub 2017 Jan 3.
The Zika virus (ZIKV) causes microcephaly and the Guillain-Barré syndrome. Little is known about how ZIKV causes these conditions or which ZIKV viral protein(s) is responsible for the associated ZIKV-induced cytopathic effects, including cell hypertrophy, growth restriction, cell-cycle dysregulation, and cell death. We used fission yeast for the rapid, global functional analysis of the ZIKV genome. All 14 proteins or small peptides were produced under an inducible promoter, and we measured the intracellular localization and the specific effects on ZIKV-associated cytopathic activities of each protein. The subcellular localization of each ZIKV protein was in overall agreement with its predicted protein structure. Five structural and two nonstructural ZIKV proteins showed various levels of cytopathic effects. The expression of these ZIKV proteins restricted cell proliferation, induced hypertrophy, or triggered cellular oxidative stress leading to cell death. The expression of premembrane protein (prM) resulted in cell-cycle G1 accumulation, whereas membrane-anchored capsid (anaC), membrane protein (M), envelope protein (E), and nonstructural protein 4A (NS4A) caused cell-cycle G2/M accumulation. A mechanistic study revealed that NS4A-induced cellular hypertrophy and growth restriction were mediated specifically through the target of rapamycin (TOR) cellular stress pathway involving Tor1 and type 2A phosphatase activator Tip41. These findings should provide a reference for future research on the prevention and treatment of ZIKV diseases.
寨卡病毒（ZIKV）可导致小头畸形和吉兰-巴雷综合征。关于ZIKV如何引发这些病症，或者哪种ZIKV病毒蛋白导致相关的ZIKV诱导的细胞病变效应，包括细胞肥大、生长受限、细胞周期失调和细胞死亡，目前所知甚少。我们利用裂殖酵母对ZIKV基因组进行快速、全面的功能分析。所有14种蛋白质或小肽均在诱导型启动子的控制下产生，我们测定了每种蛋白质的细胞内定位及其对ZIKV相关细胞病变活性的特定影响。每种ZIKV蛋白的亚细胞定位总体上与其预测的蛋白质结构一致。5种结构蛋白和2种非结构蛋白表现出不同程度的细胞病变效应。这些ZIKV蛋白的表达限制了细胞增殖、诱导了肥大，或引发了导致细胞死亡的细胞氧化应激。前膜蛋白（prM）的表达导致细胞周期G1期积累，而膜锚定衣壳蛋白（anaC）、膜蛋白（M）、包膜蛋白（E）和非结构蛋白4A（NS4A）导致细胞周期G2/M期积累。一项机制研究表明，NS4A诱导的细胞肥大和生长受限是通过雷帕霉素靶蛋白（TOR）细胞应激途径特异性介导的，该途径涉及Tor1和2A型磷酸酶激活剂Tip41。这些发现应为未来寨卡病毒疾病的防治研究提供参考。
