Identification of a novel tetramerization domain in large conductance KCa channels
Identification of a novel tetramerization domain in large conductance KCa channels
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DOI：
10.1016/s0896-6273(01)00444-5
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发表时间：
2001-10-11
期刊：
影响因子：
16.2
通讯作者：
Reinhart, PH
中科院分区：
文献类型：
--
作者：
Quirk, JC;Reinhart, PH
已知有50多个基因编码K+通道单体，并可共同组装形成异四聚体K+通道。然而，只有可能的单体组合的子集聚集在一起形成功能离子通道。合适的通道单体的组装和四聚是由缔合域(ADS)介导的。为了确定人类大电导钙激活的钾通道(HSlo1)中的这些结构域，我们使用酵母双杂交方法筛选了hSlo1结构域的自结合。对可能的ADS在非洲爪哇卵母细胞中进行了功能分析，并进一步通过共沉淀、天然凝胶电泳法和蔗糖密度梯度离心法对其进行了鉴定。这导致了单个细胞内结合结构域的鉴定，该结构域位于通道孔附近，是通道功能所必需的。我们的结论是，这种新的四聚结构域，称为BK-T1，促进了hSlo1单体组装成功能KC通道。
More than 50 genes are known to encode K+ channel monomers and can coassemble to form hetero-tetrameric K+ channels. However, only a subset of possible monomer combinations come together to form functional ion channels. The assembly and tetramerization of appropriate channel monomers is mediated by association domains (ADs). To identify such domains in human large-conductance Ca2(+)-activated K+ channels (hSlo1), we screened hSlo1 domains for self-association using yeast two-hybrid assays. Putative ADs were subjected to functional assays in Xenopus oocytes and further characterized by co precipitation, native gel electrophoresis, and sucrose density gradient centrifugation assays. This led to the identification of a single intracellular association domain localized near the channel pore and required for channel function. We conclude that this novel tetramerization domain, referred to as BK-T1, promotes the assembly of hSlo1 monomers into functional Kc channels.