Structural Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
Science. 2012 Jan 27;335(6067):432-6. doi: 10.1126/science.1213274.
Two-pore domain potassium (K(+)) channels (K2P channels) control the negative resting potential of eukaryotic cells and regulate cell excitability by conducting K(+) ions across the plasma membrane. Here, we present the 3.4 angstrom resolution crystal structure of a human K2P channel, K2P1 (TWIK-1). Unlike other K(+) channel structures, K2P1 is dimeric. An extracellular cap domain located above the selectivity filter forms an ion pathway in which K(+) ions flow through side portals. Openings within the transmembrane region expose the pore to the lipid bilayer and are filled with electron density attributable to alkyl chains. An interfacial helix appears structurally poised to affect gating. The structure lays a foundation to further investigate how K2P channels are regulated by diverse stimuli.
双孔钾（K(+)）通道（K2P 通道）控制真核细胞的负静息电位，并通过在质膜上传导 K(+)离子来调节细胞兴奋性。在这里，我们呈现了人类 K2P 通道 K2P1（TWIK-1）的 3.4 埃分辨率晶体结构。与其他 K(+)通道结构不同，K2P1 是二聚体。位于选择性过滤器上方的细胞外帽域形成离子通道，K(+)离子通过侧门流动。跨膜区域内的开口将孔暴露于脂质双层，并充满可归因于烷基链的电子密度。界面螺旋似乎在结构上准备好影响门控。该结构为进一步研究 K2P 通道如何受到各种刺激的调节奠定了基础。
