Kim Leo A, Furst Johannes, Gutierrez David, Butler Margaret H, Xu Shuhua, Goldstein Steve A N, Grigorieff Nikolaus
Department of Pediatrics, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06535, USA.
Neuron. 2004 Feb 19;41(4):513-9. doi: 10.1016/s0896-6273(04)00050-9.
Regulatory KChIP2 subunits assemble with pore-forming Kv4.2 subunits in 4:4 complexes to produce native voltage-gated potassium (Kv) channels like cardiac I(to) and neuronal I(A) subtypes. Here, negative stain electron microscopy (EM) and single particle averaging reveal KChIP2 to create a novel approximately 35 x 115 x 115 Angstrom, intracellular fenestrated rotunda: four peripheral columns that extend down from the membrane-embedded portion of the channel to enclose the Kv4.2 "hanging gondola" (a platform held beneath the transmembrane conduction pore by four internal columns). To reach the pore from the cytosol, ions traverse one of four external fenestrae to enter the rotundal vestibule and then cross one of four internal windows in the gondola.
调节性KChIP2亚基与形成孔道的Kv4.2亚基以4:4复合物形式组装，以产生天然的电压门控钾（Kv）通道，如心脏I(to)和神经元I(A)亚型。在这里，负染电子显微镜（EM）和单颗粒平均法显示，KChIP2形成了一种新的约35×115×115埃的细胞内有孔圆形结构：四个外围柱从通道嵌入膜的部分向下延伸，包围Kv4.2“悬挂吊篮”（由四个内部柱支撑在跨膜传导孔下方的平台）。为了从细胞质到达孔道，离子穿过四个外部孔之一进入圆形前庭，然后穿过吊篮中的四个内部窗口之一。
