染色质构造蛋白MeCP2调控染色质高级结构的结构机理研究

Chromatin architectural protein MeCP2 is an important epigenetic regulator and serves as a link between DNA methylation and chromatin dynamics. Dysregulation of MeCP2 cause the neurodevelopment disease known as Rett syndrome which is a severe ASD (autism spectrum disorder). MeCP2 can interact with nucleosomes resulting in the compaction of chromatin in vitro. MeCP2 is a typical intrinsically disordered protein with nine α-MoRFs. Domains with α-MoRFs can form well-defined complex structure with nucleosomes containing linker DNA. So far, there is no crystal structure of MeCP2-nucleosome complex reported. Our group have established a platform for in vitro reconstitution of nucleosomes for crystallization. And solved the X-ray structure of the Sir3-BAH domain binding to the nucleosome. Solving the 3D structures of MeCP2-nucleosome complexs using X-ray and CryoEMs, is essential to reveal the epigenetic regulation of chromatin higher-order structure by MeCP2, and will provide a new clue for understanding the molecular mechanism of ASD .

染色质构造蛋白MeCP2是联系DNA甲基化和染色质重塑等表观遗传信息的重要桥梁，其功能畸变是导致Rett综合征等自闭症谱系障碍发生的主要因素。在体外，MeCP2蛋白能够与核小体相互作用，导致染色质凝聚。MeCP2属典型的天然无序蛋白，其一级结构散布9个α-MoRFs。含有α-MoRFs元件的MeCP2截短蛋白能够结合含有linker-DNA的核小体，形成均一有序的MeCP2-核小体复合体，但是其精细结构目前尚不清楚。申请人所在课题组多年来致力于核小体体外重构技术平台的建立和完善，并于国内首次成功解析了染色质构造蛋白Sir3-BAH结构域与核小体复合体的X射线晶体结构。本项目旨在利用X射线晶体学和冷冻电镜方法，解析MeCP2与单个和多个核小体复合体的精细结构，揭示MeCP2调控染色质高级结构的结构机理，并深刻理解自闭症谱系障碍等神经发育性疾病的表观遗传分子机制。

本项目旨在利用X射线晶体学和冷冻电镜方法，解析MeCP2与单个和多个核小体复合体的精细结构，揭示MeCP2调控染色质高级结构的结构机理，并深刻理解自闭症谱系障碍等神经发育性疾病的表观遗传分子机制。项目在研3年期间，严格按照任务书中所列研究计划开展。围绕MeCP2与单核小体的晶体结构以及MeCP2与多聚核小体的电镜结构解析，展开了大量的筛选和尝试工作。目前已经在MeCP2与多聚核小体的电镜结构解析中取得了很好的进展，研究成果有望近期发表。项目参与者硕士生王景龙获得了双硕士学位。