Department of Cell Biology, University of Alberta, Edmonton, Canada T6G 2H7.
Virology. 2012 Nov 10;433(1):226-35. doi: 10.1016/j.virol.2012.08.011. Epub 2012 Aug 25.
Although flaviviruses encode their own helicases, evidence suggests that cellular helicases are also required for replication and/or assembly of these viruses. By and large, the mechanisms of action for viral and cellular helicases are not known. Moreover, in some cases, enzymatic activity is not even required for their roles in virus biology. Recently, we showed that expression of the host nucleolar helicase DDX56 is important for infectivity of West Nile virus (WNV) particles. In the present study, we demonstrate that the helicase activity of this enzyme is essential for its role in assembly of infectious WNV virions. Over-expression of the capsid-binding region of DDX56 also reduces infectivity of WNV suggesting that interaction of DDX56 and capsid protein is an important step in the virion assembly pathway. To our knowledge, this is the first study showing that enzymatic activity of a cellular helicase is critical for infectivity of flaviviruses.
虽然黄病毒编码它们自己的解旋酶，但有证据表明，细胞解旋酶也需要参与这些病毒的复制和/或组装。总的来说，病毒和细胞解旋酶的作用机制尚不清楚。此外，在某些情况下，它们在病毒生物学中的作用甚至不需要酶活性。最近，我们表明宿主核仁解旋酶 DDX56 的表达对西尼罗河病毒 (WNV) 颗粒的感染性很重要。在本研究中，我们证明了该酶的解旋酶活性对其组装感染性 WNV 病毒粒子的作用至关重要。DDX56 的衣壳结合区的过表达也降低了 WNV 的感染性，这表明 DDX56 和衣壳蛋白的相互作用是病毒组装途径中的一个重要步骤。据我们所知，这是第一项表明细胞解旋酶的酶活性对黄病毒感染性至关重要的研究。
