Huang Gaoxingyu, Zhan Xiechao, Zeng Chao, Liang Ke, Zhu Xuechen, Zhao Yanyu, Wang Pan, Wang Qifan, Zhou Qiang, Tao Qinghua, Liu Minhao, Lei Jianlin, Yan Chuangye, Shi Yigong
Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China.
Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China.
Cell Res. 2022 May;32(5):451-460. doi: 10.1038/s41422-022-00633-x. Epub 2022 Mar 18.
Nuclear pore complex (NPC) mediates nucleocytoplasmic shuttling. Here we present single-particle cryo-electron microscopy structure of the inner ring (IR) subunit from the Xenopus laevis NPC at an average resolution of 4.2 Å. A homo-dimer of Nup205 resides at the center of the IR subunit, flanked by two molecules of Nup188. Four molecules of Nup93 each places an extended helix into the axial groove of Nup205 or Nup188, together constituting the central scaffold. The channel nucleoporin hetero-trimer of Nup62/58/54 is anchored on the central scaffold. Six Nup155 molecules interact with the central scaffold and together with the NDC1-ALADIN hetero-dimers anchor the IR subunit to the nuclear envelope and to outer rings. The scarce inter-subunit contacts may allow sufficient latitude in conformation and diameter of the IR. Our structure reveals the molecular basis for the IR subunit assembly of a vertebrate NPC.
核孔复合体（NPC）介导核质穿梭。在此，我们展示了非洲爪蟾NPC内环（IR）亚基的单颗粒冷冻电子显微镜结构，平均分辨率为4.2埃。Nup205的同型二聚体位于IR亚基的中心，两侧是两个Nup188分子。四个Nup93分子各自将一个延伸的螺旋插入Nup205或Nup188的轴向凹槽中，共同构成中央支架。Nup62/58/54通道核孔蛋白异源三聚体锚定在中央支架上。六个Nup155分子与中央支架相互作用，并与NDC1-ALADIN异源二聚体一起将IR亚基锚定到核膜和外环上。亚基间稀少的接触可能使IR在构象和直径上有足够的自由度。我们的结构揭示了脊椎动物NPC的IR亚基组装的分子基础。
