Centro Nacional de Biotecnología. Darwin 3, Cantoblanco, 28049 Madrid, Spain.
Cell Microbiol. 2011 Dec;13(12):1894-906. doi: 10.1111/j.1462-5822.2011.01679.x. Epub 2011 Sep 30.
The influenza virus establishes close functional and structural connections with the nucleus of the infected cell. Thus, viral ribonucleoproteins (RNPs) are closely bound to chromatin components and the main constituent of viral RNPs, the nucleoprotein (NP) protein, interacts with histone tails. Using a yeast two-hybrid screening, we previously found that the PA influenza virus polymerase subunit interacts with the CHD6 protein, a member of the CHD family of chromatin remodelers. Here we show that CHD6 also interacts with the viral polymerase complex and colocalizes with viral RNPs in the infected cells. To study the relationships between RNPs, chromatin and CHD6, we have analysed whether NP and CHD6 binds to peptides representing trimethylated lysines of histone 3 tails that mark transcriptionally active or inactive chromatin. Upon infection, NP binds to marks of repressed chromatin and, interestingly an important recruitment of CHD6 to these heterochromatin marks occurs in this situation. Silencing experiments indicate that CHD6 acts as a negative modulator of influenza virus replication. Hence, the CHD6 association with inactive chromatin could be part of a process where the influenza virus triggers modifications of chromatin-associated proteins that could contribute to the pathogenic events used by the virus to induce host cell shut-off.
流感病毒与感染细胞的核建立了密切的功能和结构联系。因此，病毒核糖核蛋白（RNP）与染色质成分紧密结合，而病毒 RNP 的主要成分核蛋白（NP）蛋白与组蛋白尾部相互作用。我们之前使用酵母双杂交筛选发现，流感病毒聚合酶亚基 PA 与染色质重塑体 CHD 家族的成员 CHD6 蛋白相互作用。在这里，我们表明 CHD6 也与病毒聚合酶复合物相互作用，并在感染细胞中与病毒 RNP 共定位。为了研究 RNP、染色质和 CHD6 之间的关系，我们分析了 NP 和 CHD6 是否与代表组蛋白 3 尾部三甲基化赖氨酸的肽结合，这些赖氨酸标记转录活跃或失活的染色质。感染后，NP 与被抑制的染色质标记结合，有趣的是，CHD6 在这种情况下被重要招募到这些异染色质标记。沉默实验表明，CHD6 作为流感病毒复制的负调节剂发挥作用。因此，CHD6 与失活染色质的关联可能是流感病毒触发与染色质相关蛋白修饰的过程的一部分，这些修饰可能有助于病毒诱导宿主细胞关闭的致病事件。
