Research for function of antiporters and devices for membrane biogenesis using bacteria.

利用细菌进行膜生物发生的逆向转运蛋白和装置的功能研究。

基本信息

批准号：
14572051
负责人：
NAKAMURA Tatsunosuke
金额：
$ 2.11万
依托单位：
Niigata University of Pharmacy and Applied Life Sciences
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

Higher plant K^+ channel, KAT1, has 6 transmembrane domains. Our research data indicate that the third and fourth transmembrane domains do not penetrate membrane one-by-one, but penetrate it tandem and concurrent manner. The manner in which two transmembrane domains are situated in the membrane all together is described for the first time. It suggests the existence of undiscovered devices for membrane protein insertion and membrane biogenesis. Further research is required to understand more precisely the new membrane biogenesis styling. Related experiments are rested below.1)Experimental data indicate that K^+ transporters, Ktr and TrkH, have the structure of K^+ channel. 2)Ktr K^+ transport system of Cyanobacterium requires the third component KtrE in addition to KtrA and KtrB. 3)High concentrations of K^+ are toxic for bacterial growth, especially alkaline pH. To survive cell requires special K^+ extrusion systems. Our data indicate that K+ extrusion system of Vibrio parahaemolyticus is NhaP2. 4)Ca^<2+>(Na^+)/H^+ antiporter ChaA from Escherichia coli also works as a K^+/H^+ antiporter and extrude K^+ against its chemical gradient. 5)Transgenic Na^+/H^+ antiporter genes into photosynthetic bacteria and rice and made them Na^+ tolerant. It is significant for current biotechnological challenges, such as allowing crops to grow in the increasing number of the world's areas that have excessive soil salinity and alkalinity.

高等植物 K^+ 通道 KAT1 有 6 个跨膜结构域。我们的研究数据表明，第三和第四跨膜结构域不是逐一穿透膜，而是串联和并行地穿透膜。首次描述了两个跨膜结构域一起位于膜中的方式。它表明存在未被发现的膜蛋白插入和膜生物发生装置。需要进一步的研究来更准确地了解新的膜生物发生样式。相关实验如下： 1)实验数据表明K^+转运蛋白Ktr和TrkH具有K^+通道结构。 2）Ktr 蓝藻的K^+转运系统除了KtrA和KtrB外还需要第三种成分KtrE。 3）高浓度的K^+对细菌生长有毒，尤其是碱性pH值。为了使细胞存活，需要特殊的 K^+ 挤出系统。我们的数据表明副溶血弧菌的K+挤出系统是NhaP2。 4)来自大肠杆菌的Ca^<2+>(Na^+)/H^+反向转运蛋白ChaA也可作为K^+/H^+反向转运蛋白，并逆其化学梯度挤出K^+。 5)将Na^+/H^+逆向转运基因转入光合细菌和水稻中，使其具有Na^+耐受性。它对于当前的生物技术挑战具有重要意义，例如让农作物在世界上越来越多的土壤盐分和碱度过高的地区生长。