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

开展了与交通相关的三种结构研究。第一个是前miRNA的核出口机制。二是细胞内承载材料的拱顶结构研究。分别在2.9、3.0和3.5A分辨率下测定了Exportin-5：RanGTP：Pre-miRNA复合体、Exportin-5：RanGTP复合体和Exportin-5的结构。通过比较Exportin-5s在三种不同状态下的结构，以及分析前miRNA与Exportin-5的相互作用，我们阐明了Exportin-5：RanGTP复合体转运Pre-miRNA的机制。除了大鼠肝脏的拱顶外，我们还确定了MVP-拱顶的39倍对称性。因此，证实了拱顶的39次对称性。我们通过基于间隙连接蛋白-26缝隙连接通道的同源建模和功能分析来阐明半通道对的对接选择性规则。

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.