AQP水通道的结构生物学研究进展

Recent advances in structural studies of Aquaporins

水通道(AQP)广泛存在于原核和真核生物中,主要负责水分子的跨膜运输,具有重要的生理功能。其家族成员大都是四聚体,每个单体都具有独立的孔区,可以允许水分子通过。利用X射线晶体学,电子晶体学和单颗粒冷冻电镜等方法,至今已经解析了70余个水通道的结构;基于这些高分辨结构,已有较多的研究探讨其快速转运水分子的机制,探究其在转运水的同时又阻止质子的通透的原因;然而水通道四聚体中心孔区的作用一直存在争议。另一方面,水通道单体及四聚体形式的结构功能研究较多,而对其形成更高聚合状态的探讨相对较少。本文重点聚焦于水通道四聚体中心孔区及其形成更高级空间结构的最新研究,希望从一个新的角度探讨水通道的结构生物学研究进展。

Aquaporins(AQP)are water channels that are widely distributed in prokaryotes and eukaryotes.They are responsible for water transport across a membrane.Four AQPs are assembled into tetramers in a structure.Each of the monomer has a dependent pore which allows the passage of water molecules.More than 70 structures of AQPs have been resolved using X⁃ray diffraction,electron crystallography,and single⁃particle Cryo⁃electron microscopy.Based on these high⁃resolution structures,extensive studies have been focused on the detailed mechanism for the fast transport of water molecules by AQPs.However,little is known about the central pore of AQP tetramers.In this short review,we focus on the central pore of AQP tetramers and the study of higher oligomer formation of AQPs,discussing the recent advances in structural studies of AQP channels from a new perspective.