Crescenzo-Chaigne Bernadette, van der Werf Sylvie, Naffakh Nadia
Unité de Génétique Moléculaire des Virus Respiratoires, URA 1966 CNRS, Institut Pasteur, Paris, France.
Virology. 2002 Nov 25;303(2):240-52. doi: 10.1006/viro.2002.1637.
Using a genetic system that allows the in vivo reconstitution of active ribonucleoproteins, the ability to ensure transcription/replication of a viral-like reporter RNA harboring the G(3) --> A(3), U(5) --> C(5), and C(8) --> U(8) mutations (triple 3-5-8 mutations) in the 3' arm of the promoter was examined with core proteins from human or avian strains of influenza A viruses. The efficiency of transcription/replication of the viral-like RNA with the triple 3-5-8 mutations in COS-1 cells was found to be slightly decreased as compared to the wild-type RNA when the polymerase was derived from a human virus. In contrast, it was found to be considerably increased when the polymerase was derived from an avian virus, in agreement with published observations using the avian A/FPV/Bratislava virus (G. Neumann and G. Hobom, 1995, J. Gen. Virol. 76, 1709-1717). This increase could be attributed to the compensation of the defect in transcription/replication activity in the COS-1 mammalian cell line due to the presence of a glutamic acid at PB2 residue 627, characteristic of avian strains of influenza viruses. Our results thus suggest that PB2 and/or cellular proteins interacting with PB2 could be involved in RNA conformational changes during the process of transcription/replication.
利用一种能在体内重建活性核糖核蛋白的遗传系统，使用来自甲型流感病毒人源或禽源毒株的核心蛋白，检测了确保在启动子3'臂上带有G(3)→A(3)、U(5)→C(5)和C(8)→U(8)突变（3-5-8三联突变）的类病毒报告RNA转录/复制的能力。当聚合酶来源于人病毒时，与野生型RNA相比，在COS-1细胞中带有3-5-8三联突变的类病毒RNA的转录/复制效率略有下降。相反，当聚合酶来源于禽病毒时，其转录/复制效率显著提高，这与使用禽源A/FPV/布拉迪斯拉发病毒的已发表观察结果一致（G.诺伊曼和G.霍博姆，1995年，《普通病毒学杂志》76卷，第1709 - 1717页）。这种提高可归因于由于禽源流感病毒毒株特有的PB2残基627处存在谷氨酸，补偿了COS-1哺乳动物细胞系中转录/复制活性的缺陷。因此，我们的结果表明，PB2和/或与PB2相互作用的细胞蛋白可能参与转录/复制过程中的RNA构象变化。
