Regulation of the Voltage Gated K+ Channel Kv1.3 by Recombinant Human Klotho Protein
Regulation of the Voltage Gated K+ Channel Kv1.3 by Recombinant Human Klotho Protein
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DOI：
10.1159/000368472
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发表时间：
2014-01-01
影响因子：
2.8
通讯作者：
Lang, Florian
中科院分区：
文献类型：
--
作者：
Almilaji, Ahmad;Honisch, Sabina;Lang, Florian
背景/目的：Klotho 是一种主要在肾脏中产生并释放到循环血液中的蛋白质，有助于负调节 1,25(OH)(2)D-3 的形成，因此是矿物质代谢的强大调节剂。作为 β-葡萄糖醛酸酶，α Klotho 蛋白进一步调节质膜中几种载体和通道的稳定性，从而调节通道和转运蛋白的活性。因此，α Klotho 蛋白参与调节看似与矿物质代谢无关的多种功能，包括淋巴细胞功能。本研究探讨了 α Klotho 蛋白对电压门控 K+ 通道 K-v1.3 的影响。方法：将编码 K-v1.3 (KCNA3) 的 cRNA 注射到爪蟾卵母细胞中，并利用双电极电压钳测定表达 K-v1.3 的爪蟾卵母细胞中去极化诱导的外向电流。在不存在或存在β-葡萄糖醛酸酶抑制剂D-糖二酸-1,4-内酯（DSAL，10μM）的情况下，在没有或预先用重组人Klotho蛋白（50ng/ml，24小时）处理的情况下进行实验。此外，在不加或加重组人Klotho蛋白（50ng/ml，24小时）孵育24小时后，通过全细胞膜片钳测定Jcam淋巴瘤细胞中的电压门控K+电流。利用流式细胞术中的荧光抗体测定 Jcam 细胞中的 K-v1.3 蛋白丰度。结果：在表达 K-v1.3 的非洲爪蟾卵母细胞中，用重组人 Klotho 蛋白（50 ng/ml，24 小时）处理后，K-v1.3 电流和 K-v1.3 蛋白丰度均显着增强，而 DSAL 的存在逆转了这种效应。此外，重组人 Klotho 蛋白处理增加了 Jcam 细胞中的 K-v 电流和 K-v1.3 蛋白丰度。结论：Alpha Klotho 蛋白增强质膜中 K-v1.3 通道丰度和 K-v1.3 电流，其效果取决于其 β-葡萄糖醛酸酶活性。版权所有 (C) 2014 S. Karger AG，巴塞尔
Background/Aims: Klotho, a protein mainly produced in the kidney and released into circulating blood, contributes to the negative regulation of 1,25(OH)(2)D-3 formation and is thus a powerful regulator of mineral metabolism. As beta-glucuronidase, alpha Klotho protein further regulates the stability of several carriers and channels in the plasma membrane and thus regulates channel and transporter activity. Accordingly, alpha Klotho protein participates in the regulation of diverse functions seemingly unrelated to mineral metabolism including lymphocyte function. The present study explored the impact of alpha Klotho protein on the voltage gated K+ channel K-v1.3. Methods: cRNA encoding K-v1.3 (KCNA3) was injected into Xenopus oocytes and depolarization induced outward current in K-v1.3 expressing Xenopus oocytes determined utilizing dual electrode voltage clamp. Experiments were performed without or with prior treatment with recombinant human Klotho protein (50 ng/ml, 24 hours) in the absence or presence of a beta-glucuronidase inhibitor D-saccharic acid-1,4-lactone (DSAL, 10 mu M). Moreover, the voltage gated K+ current was determined in Jcam lymphoma cells by whole cell patch clamp following 24 hours incubation without or with recombinant human Klotho protein (50 ng/ml, 24 hours). K-v1.3 protein abundance in Jcam cells was determined utilising fluorescent antibodies in flow cytometry. Results: In K-v1.3 expressing Xenopus oocytes the K-v1.3 currents and the protein abundance of K-v1.3 were both significantly enhanced after treatment with recombinant human Klotho protein (50 ng/ml, 24 hours), an effect reversed by presence of DSAL. Moreover, treatment with recombinant human Klotho protein increased K-v currents and K-v1.3 protein abundance in Jcam cells. Conclusion: Alpha Klotho protein enhances K-v1.3 channel abundance and K-v1.3 currents in the plasma membrane, an effect depending on its beta-glucuronidase activity. Copyright (C) 2014 S. Karger AG, Basel