黄瓜花叶病毒2b蛋白自身互作结构域的研究

Determination of self-interaction functional domain of cucumber mosaic virus 2b protein

黄瓜花叶病毒（Cucumber mosaic virus,CMV）寄主范围广,在全球分布广泛,可为害多种蔬菜和园艺作物,造成重大经济损失。CMV株系或分离物被划分为亚组IA、IB和亚组II。CMV 2b蛋白是重要的致病因子,也是最早被鉴定的RNA沉默抑制子之一,CMV亚组I株系的2b蛋白在植物体内能发生自身互作。通过双分子荧光互补试验发现亚组II株系LS-CMV编码的2b蛋白在植物体内不能发生自身互作;进一步通过重叠PCR技术对编码Fny 2b和LS 2b蛋白的基因序列进行片段重组交换,利用双分子荧光互补技术初步明确,2b蛋白发生自身互作的关键结构域位于N端的第13~37位氨基酸序列。

Cucumber mosaic virus（CMV） has a very wide host range and a world-wide distribution; it can cause sig- nificant economic losses in many vegetables and horticultural crops. CMV strains or isolates could be classified into subgroups IA, IB and Ⅱ. CMV 2b protein was an important virulence factor and one of the firstly identified RNA-si- lencing suppressors, and the 2b proteins encoded by subgroup I CMV strains could interact itself in planta. Howev- er, it remains unknown whether the 2b proteins encoded by subgroup II strains could interact itself in planta. Results from the bi-molecular fluorescence complement （BiFC） experiments showed that 2b protein encoded by subgroup II strain LS did not interact itself. Subsequently, we exchanged sequences between Fny2b and LS2h, then found that the N-terminal 13-37amino-acid sequence of CMV 2b was the key functional domain, which was associated with the self-interaction of CMV 2b protein.