X-ray crystallographic studies of intr- and inter-cellular transport

进行了三种与运输有关的结构研究。首先是pre-miRNA的核输出机制。二是细胞内携带物质的拱顶结构研究。三是缝隙结通道的结构-功能研究。Exportin-5:RanGTP:Pre-miRNA复合物、Exportin-5:RanGTP复合物和Exportin-5的结构分别在2.9、3.0和3.5 A的分辨率下测定。通过比较三种不同状态下exportin-5s的结构和分析Pre-miRNA与Exportin-5的相互作用，我们阐明了Exportin-5:RanGTP复合物运输Pre-miRNA的机制。除了来自大鼠肝脏的拱顶外，我们还确定了mvp拱顶的39倍对称性。从而证实了拱顶的39倍对称性。基于connexin-26隙结通道的同源性建模和功能分析，阐明了半通道对的对接选择规律。

Three kinds of structural research relating to the transportation were carried out. The first is the nuclear export mechanism of pre-miRNA. The second is structural study of vault that carries materials in the cell. The third is structural-functional studies of gap junction channels.Structures of Exportin-5:RanGTP:Pre-miRNA complex, Exportin-5:RanGTP complex and Exportin-5 were determined at respective 2.9, 3.0 and 3.5 A resolutions. Comparing structures of exportin-5s in three different states and analyzing interactions between Pre-miRNA and Exportin-5, we elucidated Pre-miRNA transportation mechanism by Exportin-5:RanGTP complex. We have determined the 39-fold symmetry for the MVP-vault in addition to the vault from rat liver. Consequently, the 39-fold symmetry of vault was confirmed. We elucidated docking selectivity rules for hemichannel pairs by homology modeling based on the connexin-26 gap junction channel and functional analyses.