Sulfate is essential for normal cellular function. The kidney plays a major role in sulfate homeostasis. Sulfate is freely filtered and then undergoes net reabsorption in the proximal tubule. The apical membrane Na(+)/sulfate cotransporter NaS1 (SLC13A1) has a major role in mediating proximal tubule sulfate reabsorption, as demonstrated by the findings of hyposulfatemia and hypersulfaturia in Nas1-null mice. The anion exchanger SAT1 (SLC26A1), the founding member of the SLC26 sulfate transporter family, mediates sulfate exit across the basolateral membrane to complete the process of transtubular sulfate reabsorption. Another member of this family, CFEX (SLC26A6), is present at the apical membrane of proximal tubular cells. It also can transport sulfate by anion exchange, which probably mediates backflux of sulfate into the lumen. Knockout mouse studies have demonstrated a major role of CFEX as an apical membrane Cl(-)/oxalate exchanger that contributes to NaCl reabsorption in the proximal tubule. Several additional SLC26 family members mediate sulfate transport and show some level of renal expression (e.g., SLC26A2, SLC26A7, SLC26A11). Their roles in mediating renal tubular sulfate transport are presently unknown. This paper reviews current data available on the function and regulation of three sulfate transporters (NaS1, SAT1, and CFEX) and their physiological roles in the kidney.

中文翻译：

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肾脏硫酸盐转运蛋白的特异性和调控。

硫酸盐对于正常细胞功能至关重要。肾脏在硫酸盐稳态中起主要作用。硫酸盐被自由过滤，然后在近端小管中进行净重吸收。根尖膜Na（+）/硫酸盐共转运蛋白NaS1（SLC13A1）在介导近端肾小管硫酸盐重吸收中起主要作用，这在Nas1无效的小鼠体内发生了低硫酸盐血症和高血尿症。阴离子交换剂SAT1（SLC26A1）是SLC26硫酸盐转运蛋白家族的创始成员，介导硫酸盐通过基底外侧膜流出，从而完成跨管硫酸盐重吸收的过程。该家族的另一个成员CFEX（SLC26A6）存在于近端肾小管细胞的顶膜。它也可以通过阴离子交换转运硫酸盐，这可能会将硫酸盐的反流介导到管腔中。敲除小鼠研究表明，CFEX作为心尖膜Cl（-）/草酸酯交换剂的主要作用，它有助于近端小管中NaCl的重吸收。其他几个SLC26家族成员介导硫酸盐转运并显示一定水平的肾脏表达（例如SLC26A2，SLC26A7，SLC26A11）。它们在介导肾小管硫酸盐转运中的作用目前未知。本文综述了有关三种硫酸盐转运蛋白（NaS1，SAT1和CFEX）的功能和调节及其在肾脏中的生理作用的现有数据。它们在介导肾小管硫酸盐转运中的作用目前未知。本文综述了有关三种硫酸盐转运蛋白（NaS1，SAT1和CFEX）的功能和调节及其在肾脏中的生理作用的现有数据。它们在介导肾小管硫酸盐转运中的作用目前未知。本文综述了有关三种硫酸盐转运蛋白（NaS1，SAT1和CFEX）的功能和调节及其在肾脏中的生理作用的现有数据。