水稻条纹病毒调控抗性蛋白remorin棕榈酰化修饰的分子机制

Rice stripe virus (RSV) is the pathogen of rice stripe disease that causing serious yield and quality loss in East Asia. Our previous researches revealed that remorin is a negative regulator of RSV cell-to-cell movement and unveiled a new strategy used by RSV to overcome remorin-mediated plant defense: RSV encodes the viral NSvc4 protein that can interact with remorin and interfere with the remorin S-acylation. The disruption of remorin S-acylation affects its targeting to the PM microdomain, and the resulting accumulation of non-targeted remorin is subjected to autophagic degradation, facilitating virus rapid cell-to-cell movement. However, the mechanism of RSV regulating S-acylation is still unknown. Based on our preliminary results, this project will utilize protein interaction test and in vitro enzyme activity assay to identify the palmitoyl acyltransferase (PAT) that is responsible for the S-acylation modification of remorin. Illustrating the model and biological role of the interaction between RSV capsid protein (CP) and PAT based on PAT knock-out/overexpression and CP overexpression transgenic plants. Finally, all above will decipher the molecular mechanism of RSV regulating S-acylation of remorin, providing a scientific basis for rice stripe disease control.

由水稻条纹病毒（Rice Stripe Virus，RSV）引发的水稻条纹叶枯病严重危害我国及周边国家的水稻产量和品质。我们前期研究揭示了植物remorin蛋白是RSV细胞间移动的负调控因子，而RSV的运动蛋白NSvc4与remorin互作干扰remorin的棕榈酰化修饰，导致remorin细胞膜定位减弱并进入自噬降解，以利于RSV在细胞间快速移动。但RSV调控植物棕榈酰化的详细机制仍未知，本项目拟从水稻及本氏烟的棕榈酰基转移酶（Palmitoyl Acyltransferase，PAT）着手，通过蛋白互作及体外酶活性测定等生化手段，鉴定催化remorin棕榈酰化修饰的PAT。结合PAT敲除、过表达和CP过表达等遗传学材料，解析RSV外壳蛋白CP与PAT的互作模式和生物学意义。最终阐明RSV调控植物抗性蛋白remorin棕榈酰化修饰的分子机制，为控制水稻条纹叶枯病害的发生提供科学理论依据。

由水稻条纹病毒（Rice Stirpe Virus，RSV）引发的水稻条纹叶枯病严重危害我国水稻生产。我们前期研究揭示了植物NbREM1.1蛋白是RSV细胞间移动的负调控因子，NbREM1.1的棕榈酰化修饰是其抑制RSV细胞间移动的必要条件，但是NbREM1.1蛋白棕榈酰化修饰的酶学机制尚不清楚，我们前期还发现RSV侵染会抑制NbREM1.1的棕榈酰化修饰，但是其抑制的分子机制有待解析。本项目从本氏烟棕榈酰基转移酶（Palmitoyl Acyltransferase，PAT）着手，通过蛋白互作、体外棕榈酰基转移酶活性测定等生化手段，鉴定到催化NbREM1.1棕榈酰化修饰的PAT。通过胼胝体染色、病毒的细胞间移动分析等方法发现PAT具有调控细胞胞间连丝口径胼胝体积累并调控胞间连丝通透性的能力，PAT是病毒细胞间移动的负调控因子，具有抗病毒育种的应用潜力。进一步研究发现RSV病毒可以通过编码外壳蛋白CP干扰PAT对病毒细胞移动的抑制作用，减轻植物对病毒细胞移动的防御反应。揭示了RSV病毒与寄主植物棕榈酰化修饰关键蛋白PAT及胞间连丝通透性调控蛋白NbREM1.1互作的分子机制，为植物抗病毒育种提供了新思路。