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

高等植物K~+通道KAT1有6个跨膜区。我们的研究数据表明，第三和第四跨膜结构域不是逐个穿透细胞膜，而是以串联和并行的方式穿透细胞膜。首次描述了两个跨膜结构域一起位于膜中的方式。这表明存在未被发现的膜蛋白插入和膜生物发生装置。为了更准确地理解新的膜生物发生造型，还需要进一步的研究。相关实验结果如下：1)实验数据表明，K~(2+)转运体KTR和TrkH具有K~(+)通道的结构。2)蓝藻的KTRK~+转运系统除了KtrA和KtrB外，还需要第三组分KtrE。3)高浓度K~(++)对细菌生长有毒性，尤其是碱性pH。为了存活细胞，需要特殊的K^+挤出系统。结果表明，副溶血性弧菌的K+排出系统为NhaP2。4)大肠杆菌中的Ca~(2+)&lt；(Na~(++))/H~(++)逆向转运蛋白Chaa也具有K~(++)/H~(++)逆向转运蛋白的功能，K~(++)逆其化学梯度排出。5)将Na~+/H~+逆向转运蛋白基因转入光合细菌和水稻中，使其耐Na~+。这对当前的生物技术挑战具有重大意义，例如允许作物在世界上越来越多的土壤盐碱度过高的地区生长。

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.