Department of Plant Pathology, University of California, Davis, CA 95616, USA.
Virology. 2010 Jul 20;403(1):67-77. doi: 10.1016/j.virol.2010.04.006. Epub 2010 May 5.
The Crinivirus, Lettuce infectious yellows virus (LIYV) has a bipartite, positive-sense ssRNA genome. LIYV RNA 1 encodes replication-associated proteins while RNA 2 encodes proteins needed for other aspects of the LIYV life cycle. LIYV RNA 1 ORF 2 encodes P34, a trans enhancer for RNA 2 accumulation. Here we show that P34 is a sequence non-specific ssRNA-binding protein in vitro. P34 binds ssRNA in a cooperative manner, and the C-terminal region contains the RNA-binding domain. Topology predictions suggest that P34 is a membrane-associated protein and the C-terminal region is exposed outside of the membrane. Furthermore, fusions of P34 to GFP localized to the perinuclear region of transfected protoplasts, and colocalized with an ER-specific dye. This localization was of interest since LIYV RNA 1 replication (with or without P34 protein) induced strong ER rearrangement to the perinuclear region. Together, these data provide insight into LIYV replication and possible functions of P34.
菜豆黄花叶病毒（LIYV）是一种具有二分体、正链 ssRNA 基因组的 Crinivirus。LIYV RNA1 编码与复制相关的蛋白，而 RNA2 编码 LIYV 生命周期其他方面所需的蛋白。LIYV RNA1 ORF2 编码 P34，它是 RNA2 积累的转增强子。本文中，我们证明 P34 是体外序列非特异性 ssRNA 结合蛋白。P34 以合作方式结合 ssRNA，其 C 末端区域包含 RNA 结合结构域。拓扑预测表明 P34 是一种膜相关蛋白，其 C 末端区域暴露在膜外。此外，P34 与 GFP 的融合蛋白定位于转染原生质体的核周区，并与 ER 特异性染料共定位。这一定位很有趣，因为 LIYV RNA1 复制（有无 P34 蛋白）诱导 ER 强烈向核周区重排。这些数据为 LIYV 复制和 P34 可能的功能提供了深入了解。
