Fomina Svetlana, Howard Tina D, Sleator Olivia K, Golovanova Marina, O'Ryan Liam, Leyland Mark L, Grossmann J Günter, Collins Richard F, Prince Stephen M
University of Manchester, Manchester Interdisciplinary Biocentre, Manchester M1 7DN, UK.
Biochim Biophys Acta. 2011 Oct;1808(10):2374-89. doi: 10.1016/j.bbamem.2011.06.021. Epub 2011 Jul 5.
The interaction of the extra-membranous domain of tetrameric inwardly rectifying Kir2.1 ion channels (Kir2.1NC(4)) with the membrane associated guanylate kinase protein PSD-95 has been studied using Transmission Electron Microscopy in negative stain. Three types of complexes were observed in electron micrographs corresponding to a 1:1 complex, a large self-enclosed tetrad complex and extended chains of linked channel domains. Using models derived from small angle X-ray scattering experiments in which high resolution structures from X-ray crystallographic and Nuclear Magnetic Resonance studies are positioned, the envelopes from single particle analysis can be resolved as a Kir2.1NC(4):PSD-95 complex and a tetrad of this unit (Kir2.1NC(4):PSD-95)(4). The tetrad complex shows the close association of the Kir2.1 cytoplasmic domains and the influence of PSD-95 mediated self-assembly on the clustering of these channels.
利用负染透射电子显微镜研究了四聚体内向整流型Kir2.1离子通道的膜外结构域（Kir2.1NC(4)）与膜相关鸟苷酸激酶蛋白PSD-95的相互作用。在电子显微镜照片中观察到三种类型的复合物，分别对应1:1复合物、大型自封闭四联复合物以及连接通道结构域的延伸链。通过从小角X射线散射实验得到的模型（其中来自X射线晶体学和核磁共振研究的高分辨率结构已定位），单颗粒分析得到的包络可以解析为Kir2.1NC(4):PSD-95复合物以及该单元的四联结构（Kir2.1NC(4):PSD-95）(4)。四联复合物显示了Kir2.1胞质结构域的紧密关联以及PSD-95介导的自组装对这些通道聚集的影响。
