Identification of an apical Cl-/HCO-3 exchanger in the small intestine
Identification of an apical Cl-/HCO-3 exchanger in the small intestine
复制标题
DOI：
10.1152/ajpgi.00338.2001
复制
发表时间：
2002-03-01
影响因子：
4.5
通讯作者：
Soleimani, M
中科院分区：
文献类型：
--
作者：
Wang, ZH;Petrovic, S;Soleimani, M
HCO 3-分泌是十二指肠对酸损伤最重要的防御机制。然而，在十二指肠中介导顶端HCO 3-分泌的转运蛋白的身份仍然未知。最近已经鉴定了一个阴离子交换剂家族，其包括在腺瘤中下调的阴离子交换剂（pendrin或SLC 26 A3）、pendrin（PDS或SLC 26 A4）和推定的阴离子转运体（PAT 1或SLC 26 A6）。Pendrin和pendrin介导Cl-/碱基交换;然而，PAT 1（SLC 26 A6）的功能特性和分布尚不清楚。在这些研究中，我们研究了PAT 1的功能特性、组织分布和膜定位。在非洲爪蟾卵母细胞中的表达研究表明，PAT 1的功能在Cl-/HCO 3-交换模式。组织分布研究表明，PAT 1的表达在小肠中是高度丰富的，但在结肠中是低的，与小肠的模式相反。在胃和心脏中也大量检测到PAT 1。免疫印迹分析研究表明，PAT 1是一种与十二指肠中90 kDa蛋白相似的蛋白。免疫组织化学研究定位于十二指肠绒毛细胞刷状缘膜的PAT 1。我们建议，PAT 1是一个顶端的Cl-/HCO 3-交换在小肠。
HCO3- secretion is the most important defense mechanism against acid injury in the duodenum. However, the identity of the transporter(s) mediating apical HCO3- secretion in the duodenum remains unknown. A family of anion exchangers, which include downregulated in adenoma (DRA or SLC26A3), pendrin (PDS or SLC26A4), and the putative anion transporter (PAT1 or SLC26A6) has recently been identified. DRA and pendrin mediate Cl-/base exchange; however, the functional identity and distribution of PAT1 (SLC26A6) is not known. In these studies, we investigated the functional identity, tissue distribution, and membrane localization of PAT1. Expression studies in Xenopus oocytes demonstrated that PAT1 functions in Cl-/HCO3- exchange mode. Tissue distribution studies indicated that the expression of PAT1 is highly abundant in the small intestine but is low in the colon, a pattern opposite that of DRA. PAT1 was also abundantly detected in stomach and heart. Immunoblot analysis studies identified PAT1 as a similar to90 kDa protein in the duodenum. Immunohistochemical studies localized PAT1 to the brush border membranes of the villus cells of the duodenum. We propose that PAT1 is an apical Cl-/HCO3- exchanger in the small intestine.