玉米组蛋白H2B及其泛素化在甘蔗花叶病毒侵染形成圆柱状内含体及致病中的作用机制

甘蔗花叶病毒（sugarcane mosaic virus, SCMV）等马铃薯Y病毒属（Potyvirus）成员在侵染过程中产生典型的细胞病理学特征：圆柱状内含体（横切面为风轮状）。圆柱状内含体在potyviruses侵染早期即形成，表明其在病毒侵染中发挥重要作用。近来发现圆柱状内含体在病毒细胞间移动中发挥关键作用。过去虽然对圆柱状内含体的形态等做了大量工作，但其所含有的寄主蛋白种类及功能未知。本项目在前期研究中通过分离鉴定SCMV侵染的玉米叶片中圆柱状内含体蛋白成分的基础上，深入研究组蛋白H2B及其泛素化对圆柱状内含体形成、与SCMV编码的CI蛋白互作、以及在病毒复制增殖和移动中的功能及作用机制。本项目聚焦重要病害发生过程中细胞病理学成因，研究结果将为揭示马铃薯Y病毒属成员侵染形成圆柱状内含体的机制及其在病毒致病中的功能提供重要数据，为研究病毒—寄主互作和发展抗病毒新策略提供新思路。

Cylindrical inclusions are the typical cellular pathology characterizations of potyviruses infection including sugarcane mosaic virus (SCMV). Pinwheels would arise from cross sections of the cylindrical inclusions. Previous studies showed that cylindrical inclusions are formed from early infection stage, suggesting their importance for virus infection. Recent work indicated that cylindrical inclusions play key roles for viral cell-to-cell movement. Though lot of studies had been for shape and structure of cylindrical inclusions, little is known for the components, especially the included host proteins and functions in the cylindrical inclusions. Based on our preliminary work on the isolation and identification of protein components in the cylindrical inclusions, we found that Histone H2B was hijacked to the cylindrical inclusions and become ubiquitination. Further, knock-down or overexpression assay verified that H2B could promote virus replication and multiplication. In this proposal, we will focus on the role and the mechanism of H2B and its ubiquitination for cylindrical inclusions formation, interaction with SCMV-encoded CI protein, and for viral replication, multiplication and movement. Our proposal concentrates on the cause of the cytopathology of important disease, and the research results will provide vital data to dissect the mechanism for the formation of cylindrical inclusions and their roles in viral pathogenicity, and also will produce novel idea for research on virus-host interaction and developing new strategies for virus control.