Direct Observation of ATP-Induced Conformational Changes in Single P2X4 Receptors

被引：82

作者：

Shinozaki, Youichi ^{[1
]}

Sumitomo, Koji ^{[1
]}

Tsuda, Makoto ^{[2
]}

Koizumi, Schuichi ^{[3
]}

Inoue, Kazuhide ^{[2
]}

Torimitsu, Keiichi ^{[1
]}

机构：

[1] NTT Corp, NTT Basic Res Labs, Kanagawa, Japan

[2] Kyushu Univ, Grad Sch Pharmaceut Sci, Dept Mol & Syst Pharmacol, Fukuoka 812, Japan

[3] Univ Yamanashi, Interdisciplinary Grad Sch Med & Engn, Dept Pharmacol, Yamanashi, Japan

来源：

PLOS BIOLOGY | 2009年 / 7卷 / 05期

基金：

日本科学技术振兴机构;

关键词：

FORCE MICROSCOPY REVEALS; CHANNELS; SURFACE; STOICHIOMETRY; BINDING; SITE;

D O I：

10.1371/journal.pbio.1000103

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The ATP-gated P2X(4) receptor is a cation channel, which is important in various pathophysiological events. The architecture of the P2X(4) receptor in the activated state and how to change its structure in response to ATP binding are not fully understood. Here, we analyze the architecture and ATP-induced structural changes in P2X(4) receptors using fast-scanning atomic force microscopy (AFM). AFM images of the membrane-dissociated and membrane-inserted forms of P2X(4) receptors and a functional analysis revealed that P2X(4) receptors have an upward orientation on mica but lean to one side. Time-lapse imaging of the ATP-induced structural changes in P2X(4) receptors revealed two different forms of activated structures under 0 Ca2+ conditions, namely a trimer structure and a pore dilation-like tripartite structure. A dye uptake measurement demonstrated that ATP-activated P2X(4) receptors display pore dilation in the absence of Ca2+. With Ca2+, the P2X(4) receptors exhibited only a disengaged trimer and no dye uptake was observed. Thus our data provide a new insight into ATP-induced structural changes in P2X(4) receptors that correlate with pore dynamics.

引用

页数：12

共 32 条

[1] A high-speed atomic force microscope for studying biological macromolecules [J].