Cloning and functional expression of a new aquaporin (AQP9) abundantly expressed in the peripheral leukocytes permeable to water and urea, but not to glycerol
Cloning and functional expression of a new aquaporin (AQP9) abundantly expressed in the peripheral leukocytes permeable to water and urea, but not to glycerol
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DOI：
10.1006/bbrc.1998.8252
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发表时间：
1998-03-06
影响因子：
3.1
通讯作者：
Sasaki, S
中科院分区：
文献类型：
--
作者：
Ishibashi, K;Kuwahara, M;Sasaki, S
利用PCR技术从人白细胞中同源克隆到一个水通道蛋白家族的新成员（AQP 9）。通过对人肝cDNA文库的筛选，获得了一个全长克隆。AQP 9编码295个氨基酸的蛋白质，其氨基酸序列与AQP 3（48%）、AQP 7（45%）和其它水通道蛋白（类似于30%）相同，表明AQP 3、AQP 7和AQP 9属于水通道蛋白家族的亚家族。将AQP 9-cRNA注射到非洲爪蟾卵母细胞中，以低活化能（4.2 kcal/mol）刺激渗透水渗透性7倍，0.3 mM氯化汞抑制48%。AQP 9也促进尿素转运4倍。然而，与AQP 3和AQP 7相反，AQP 9不刺激甘油渗透性，表明独特的渗透性特征。北方印迹分析显示，3.5 kb信使在外周血白细胞>>肝>肺=脾中高表达，但在胸腺中不表达。AQP 9在白细胞免疫功能中的可能作用是令人感兴趣的，并且具有独特渗透性的AQP 9的鉴定可能扩展我们对体内水和小溶质转运的理解。(C)北京：科学出版社.
A new member (AQP9) of the aquaporin family was identified from human leukocytes by homology cloning using PCR. A full length clone was obtained by screening human liver cDNA library. AQP9 encodes a 295-amino-acid protein with the amino acid sequence identity with AQP3 (48%), AQP7 (45%), and other aquaporins (similar to 30%), suggesting that AQP3, AQP7, and AQP9 belong to a subfamily of the aquaporin family. injection of AQP9-cRNA into Xenopus oocytes stimulated the osmotic water permeability 7-folds with a low activation energy (4.2 kcal/mol) which was inhibited by 0.3 mM mercury chloride by 48 %. AQP9 also facilitated urea transport 4-folds. However, in contrast to AQP3 and AQP7, AQP9 did not stimulate the glycerol permeability, suggesting a unique permeability character. Northern blot analysis revealed the high expression of 3.5-kb messages in peripheral leukocytes >> liver > lung = spleen, but not in thymus. T-he possible role of AQP9 in the immunological function of leukocytes is intriguing and the identification of AQP9 with unique permeability profile may expand our understanding of water and small solute transport in the body. (C) 1998 Academic Press.