KChAP as a chaperone for specific K+ channels
KChAP as a chaperone for specific K+ channels
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DOI：
10.1152/ajpcell.2000.278.5.c931
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发表时间：
2000-05-01
影响因子：
5.5
通讯作者：
Wible, BA
中科院分区：
文献类型：
--
作者：
Kuryshev, YA;Gudz, TI;Wible, BA
K+频道的陪伴者概念是新的。最近，我们发现了一种新型分子伴侣 KChAP，它通过与 Kv2.1 氨基末端的瞬时相互作用增加爪蟾卵母细胞中的 Kv2.1 总蛋白和功能通道。在这里，我们报告 KChAP 是 Kv1.3 和 Kv4.3 的伴侣。 KChAP 增加了 Kv1.3 和 Kv4.3 电流的幅度，而不影响动力学或电压依赖性，但对 Kv1.1、1.2、1.4、1.5、1.6 和 3.1 或 Kir2.2、HERG 或 KvLQT1 没有这种影响。尽管 KChAP 属于与转录因子相互作用的蛋白质家族，但转录抑制剂放线菌素 D 不会阻断通道电流的上调。KChAP 的 98 个氨基酸片段与通道结合，在增强 Kv4.3 电流和蛋白质水平方面与 KChAP 没有区别。使用 KChAP 抗体，我们将 KChAP 与来自心脏的 Kv2.1 和 Kv4.3 共免疫沉淀。我们认为 KChAP 是特定 Ky 通道的伴侣，并且可能在心肌细胞中具有此功能，其中 Kv4.3 产生瞬时外向电流 I-to。
The concept of chaperones for K+ channels is new. Recently, we discovered a novel molecular chaperone, KChAP, which increased total Kv2.1 protein and functional channels in Xenopus oocytes through a transient interaction with the Kv2.1 amino terminus. Here we report that KChAP is a chaperone for Kv1.3 and Kv4.3. KChAP increased the amplitude of Kv1.3 and Kv4.3 currents without affecting kinetics or voltage dependence, but had no such effect on Kv1.1, 1.2, 1.4, 1.5, 1.6, and 3.1 or Kir2.2, HERG, or KvLQT1. Although KChAP belongs to a family of proteins that interact with transcription factors, upregulation of channel currents was not blocked by the transcription inhibitor actinomycin D. A 98-amino acid fragment of KChAP binds to the channel and is indistinguishable from KChAP in its enhancement of Kv4.3 current and protein levels. Using a KChAP antibody, we have coimmunoprecipitated KChAP with Kv2.1 and Kv4.3 from heart. We propose that KChAP is a chaperone for specific Ky channels and may have this function in cardiomyocytes where Kv4.3 produces the transient outward current, I-to.