Institut de Biologie Moléculaire des Plantes du CNRS (UPR 2357), Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg CEDEX, France.
Virus Res. 2012 Dec;170(1-2):34-43. doi: 10.1016/j.virusres.2012.08.005. Epub 2012 Aug 18.
Citrus psorosis (CPsV) and Mirafiori lettuce big-vein virus (MiLBVV) belong to the family Ophioviridae, plant viruses with filamentous nucleocapsids and segmented genomes of negative polarity, causing the worldwide distributed citrus psorosis and lettuce big-vein diseases, respectively. To gain insight into the replication cycle of these viruses, the subcellular localization of the viral coat proteins (CP) was studied. Immunoblot analysis of fractionated extracts derived from natural and experimental infected hosts indicated that the CP of CPsV occurs in the soluble cytoplasmic fraction. The cytoplasmic localization of this protein was confirmed by confocal microscopy of fluorescent protein (FP)-tagged CP following its expression in either CPsV-infected and healthy Citrus sinensis plants or in Nicotiana benthamiana plants. The same localization was observed for FP-tagged CP of MiLBVV. The CPs of CPsV and MiLBBV can undergo homologous and heterologous interactions as revealed by fluorescent lifetime imaging microscopy and co-immunoprecipitation analysis. A putative leucine zipper motif that is conserved among ophiovirus CP sequences may account for these interactions.
柑橘疱症病毒（CPsV）和米拉弗里奥生菜大脉病毒（MiLBVV）属于蛇形病毒科，是具有丝状核衣壳和负链分段基因组的植物病毒，分别导致世界范围内分布的柑橘疱症和生菜大脉病。为了深入了解这些病毒的复制周期，研究了病毒外壳蛋白（CP）的亚细胞定位。从天然和实验感染宿主中分离的提取物的免疫印迹分析表明，CPsV 的 CP 存在于可溶性细胞质部分。通过在 CPsV 感染和健康柑橘属植物或本氏烟植物中表达 FP 标记的 CP 后进行共聚焦显微镜观察，证实了该蛋白的细胞质定位。MiLBVV 的 FP 标记 CP 也观察到相同的定位。CPsV 和 MiLBBV 的 CP 可以发生同源和异源相互作用，如荧光寿命成像显微镜和共免疫沉淀分析所揭示的。在蛇形病毒 CP 序列中保守的假定亮氨酸拉链基序可能解释了这些相互作用。
