在真核细胞中，mRNA降解是调节基因表达的一个重要步骤，在动物细胞增殖、组织分化、机体发育、获得性免疫系统的建立以及压力应答等过程中均发挥着十分重要的作用。研究真核mRNA降解对转录后基因表达的调控机制是当前生命科学领域的一个研究热点。5'端脱帽反应是mRNA降解的一个关键步骤，涉及到脱帽酶以及许多调节脱帽反应的细胞内因子和复合物。明确脱帽酶的催化和调节机理及其偶联其他参与mRNA降解的复合体的分子基础是mRNA降解领域的一个重要研究内容。本项目利用X-射线晶体衍射技术作为主要研究手段，配合其他生物化学、生物物理、分子和细胞生物学的方法，系统地开展一系列参与mRNA脱帽过程的蛋白-RNA复合物，蛋白-蛋白复合物的结构与功能研究。在分子水平上，揭示mRNA脱帽及调控的分子机制，为进一步阐明mRNA降解的分子机理奠定坚实的基础。

In eukaryotic cells, degradation of mRNA is a key step in gene expression regulation and plays a crucial role in animal development, cell proliferation, differentiation, stress response, and the establishment of adaptive immune system. Studying the mechanism of post-transcriptional regulation of gene expression is one of the hot research topics in the current field of life sciences. Removal of the 5' cap structure (decapping)is a critical step in the 5'-3' mRNA decay pathway, which involves the decapping enzyme and many cellualr protein factors that regulate this process. In the field of mRNA decay, an important area of research is to elucidate the mechanism by which the decapping reaction is catalyzed and regulated as well as the molecular basis underlying the link between decpping proteins and other protein complexes involved in mRNA decay. In this project, X-ray crystallography will be primarily used in conjunction with other biophysical and biochemical techniques, as well as molecular and cell biology methods to study a series of protein-RNA and protein-protein complexes involved in mRNA decapping. These studies will unravel the molecular mechanism governing mRNA decapping and lay a solid foundation for further mechanistic study on eukaryotic mRNA decay.