Involvement of Golgin-160 in cell surface transport of renal ROMK channel: Co-expression of Golgin-160 increases ROMK currents
Involvement of Golgin-160 in cell surface transport of renal ROMK channel: Co-expression of Golgin-160 increases ROMK currents
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DOI：
10.1159/000091454
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发表时间：
2006-01-01
影响因子：
--
通讯作者：
Steinmeyer, K
中科院分区：
文献类型：
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作者：
Bundis, F;Neagoe, I;Steinmeyer, K
弱内向整流钾通道 ROMK 对于肾脏中水和盐的重吸收很重要。在这里，我们将 Golgin-160 确定为 ROMK 通道的新型交互伙伴。通过使用酵母双杂交测定和转染细胞的免疫共沉淀，我们证明 Golgin-160 与 ROMK C 末端结合。免疫荧光显微镜证实这两种蛋白质共定位于高尔基体区域。通过非洲爪蟾卵母细胞中共表达的 Golgin-160 增强 ROMK 电流，进一步证实了这种相互作用。 ROMK电流幅度的增加是由于ROMK蛋白的细胞表面密度的增加。 Golgin-160 还刺激相关 Kir2.1 以及电压门控 Kv1.5 和 Kv4.3 通道的电流幅度，但不刺激共表达 HERG 通道的电流幅度。这些结果表明，高尔基体相关的 Golgin-160 识别 ROMK 的细胞质 C 末端，从而促进 ROMK 转运至细胞表面。然而，对关系较远的钾通道活性的刺激作用表明，Golgin-160 在质膜蛋白运输中具有更普遍的作用。版权所有 (c) 2006 S.Karger AG，巴塞尔。
The weak inward rectifier potassium channel ROMK is important for water and salt reabsorption in the kidney. Here we identified Golgin-160 as a novel interacting partner of the ROMK channel. By using yeast two-hybrid assays and co-immunoprecipitations from transfected cells, we demonstrate that Golgin-160 associates with the ROMK C-terminus. Immunofluorescence microscopy confirmed that both proteins are co-localized in the Golgi region. The interaction was further confirmed by the enhancement of ROMK currents by the co-expressed Golgin-160 in Xenopus oocytes. The increase in ROMK current amplitude was due to an increase in cell surface density of ROMK protein. Golgin-160 also stimulated current amplitudes of the related Kir2.1, and of voltage-gated Kv1.5 and Kv4.3 channels, but not the current amplitude of co-expressed HERG channel. These results demonstrate that the Golgi-associated Golgin-160 recognizes the cytoplasmic C-terminus of ROMK, thereby facilitating the transport of ROMK to the cell surface. However, the stimulatory effect on the activity of more distantly-related potassium channels suggests a more general role of Golgin-160 in the trafficking of plasma membrane proteins. Copyright (c) 2006 S.Karger AG, Basel.