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Unity and diversity of ion transport mechanisms and regulation of Na+/H+ antiporters

离子转运机制的统一性和多样性以及Na /H反向转运蛋白的调节

基本信息

批准号：
13142207
负责人：
KANAZAWA Hiroshi
金额：
$ 54.21万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13142207/
关键词：
intracellular ion homeostasis Na+H+ exchangers pH regulation salinity resistance active transporters molecular structure of membrane proteins intracellular localization of membrane proteins molecular biological approach 細胞内イオン恒常性膜蛋白質

项目摘要

Regulation of intracellular pH, Na^+ concentration, and osmolality are the most important factors for cell survival. These regulations are performed mainly by Na^+/H^+ exchangers named NhaA or NHE on the cytoplasmic as well as endocytic membranes. In this project we aimed to elucidate molecular structure-function relationship and functional regulation of these antiporters including intracellular localization of these molecules for these molecules from bacteria, yeast and mammalian cells. As a result, following achievement was performed. (1) For H pylori NhaA membrane integral domains essential for the ion transport were identified. Further the residues important or essential for Na^+ and H^+ binding were estimated and their hydrophobic environment within the membranes were elucidated. A new detection system of conformational change of NhaA during the ion transport was set up. (2) For yeast Nhalp essential or important residues for the ion transport were identified. Function of the hydrophilic C terminal half domain which seems to be similar to the mammalian NHE were analyzed. A membrane jaxta-positional 16 amino acid residues and its flanking 38 amino acid residues were found to be essential for destination of Nhalp to the cytoplasmic membrane, and binding Cos3p, a noble protein capable enhancing the ion exchange, respectively. (3) For mammalian NHE, we identified two new isoforms, NHE8 and 9. The isoforms NHE 6 to 9 were found to be in the membranes of various endocytic vesicles and function as K+/H+ antipoter rather than Na^+/H^+ antiporter, leading to regulate pH within endocytic vesicles. CHP capable binding NHE1-5 found by us was found to bind other proteins, DRAK2 (apoptotic protein kinase) and KIFIB□ (Kinesin isoform). The present findings will contribute to understand the function and structure relation ship and the regulations of these proteins as well as for elucidating diversity and unity of Na+/H+ antoporters among various organs and species.

细胞内 pH 值、Na^+ 浓度和渗透压的调节是细胞生存的最重要因素。这些调节主要由细胞质膜和内吞膜上名为 NhaA 或 NHE 的 Na^+/H^+ 交换剂执行。在这个项目中，我们的目的是阐明这些反向转运蛋白的分子结构-功能关系和功能调节，包括这些来自细菌、酵母和哺乳动物细胞的分子的细胞内定位。结果，取得了以下成果。 (1)对于幽门螺杆菌，鉴定了离子转运所必需的NhaA膜积分结构域。此外，还估计了对Na^+和H^+结合重要或必需的残基，并阐明了它们在膜内的疏水环境。建立了离子转运过程中NhaA构象变化的新检测体系。 (2)对于酵母Nhalp，鉴定了离子运输必需的或重要的残基。分析了与哺乳动物NHE类似的亲水性C末端半结构域的功能。发现膜 jaxta 位置的 16 个氨基酸残基及其侧翼 38 个氨基酸残基分别对于 Nhalp 到达细胞质膜和结合 Cos3p（一种能够增强离子交换的高贵蛋白）至关重要。 (3)对于哺乳动物NHE，我们鉴定了两种新的异构体NHE8和9。NHE 6至9被发现存在于各种内吞囊泡的膜中，并且作为K+/H+反向转运蛋白而不是Na^+/H^+反向转运蛋白发挥作用，从而调节内吞囊泡内的pH。我们发现的能够结合 NHE1-5 的 CHP 也能结合其他蛋白质：DRAK2（凋亡蛋白激酶）和 KIFIB□（驱动蛋白亚型）。本研究结果将有助于理解这些蛋白质的功能和结构关系以及调控，并有助于阐明不同器官和物种之间Na+/H+前向转运蛋白的多样性和统一性。

项目成果

期刊论文数量（120）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The murine genome contains one functional gene and two Pseudogene coding for the 16 kDa proteolipid subunit of vacuolar H+-ATPase

小鼠基因组包含 1 个功能基因和 2 个编码液泡 H -ATP 酶 16 kDa 蛋白脂质亚基的假基因

DOI：
发表时间：
2001
期刊：
Gene 273
影响因子：
0
作者：
Suzuki N.;et al.;Keiko Hayami
通讯作者：
Keiko Hayami

Hiroki Inoue, Yutaka Nakamura, Mana Nagita, Tomoyo Takai, Miho Masuda, Norihio Nakamura, Hiroshi Kanazawa: "Calcineurin homologous protein isoform 2 (CHP2),Na^+/H^+ exchangers-binding protein, is expressed in intestinal epithelium"Biol.Pharm.Bull.. 26. 14

Hiroki Inoue、Yutaka Nakamura、Mana Nagita、Tomoyo Takai、Miho Masuda、Norihio Nakamura、Hiroshi Kanazawa：“钙调磷酸酶同源蛋白亚型 2 (CHP2)，Na^ /H^ 交换器结合蛋白，在肠上皮中表达”Biol.Pharm