PDF(Pubmed)
Abstract：
The nuclear pore complex (NPC) is the sole mediator of nucleocytoplasmic transport. Despite great advances in understanding its conserved core architecture, the peripheral regions can exhibit considerable variation within and between species. One such structure is the cage-like nuclear basket. Despite its crucial roles in mRNA surveillance and chromatin organization, an architectural understanding has remained elusive. Using in-cell cryo-electron tomography and subtomogram analysis, we explored the NPC\'s structural variations and the nuclear basket across fungi (yeast; S. cerevisiae), mammals (mouse; M. musculus), and protozoa (T. gondii). Using integrative structural modeling, we computed a model of the basket in yeast and mammals that revealed how a hub of Nups in the nuclear ring binds to basket-forming Mlp/Tpr proteins: the coiled-coil domains of Mlp/Tpr form the struts of the basket, while their unstructured termini constitute the basket distal densities, which potentially serve as a docking site for mRNA preprocessing before nucleocytoplasmic transport.
摘要：
核孔复合物（NPC）是核-细胞质运输的唯一介质。尽管在理解其保守的核心架构方面取得了巨大的进步，外围区域可以在物种内部和物种之间表现出相当大的差异。一种这样的结构是笼状核篮。尽管它在mRNA监测和染色质组织中起着至关重要的作用，对建筑的理解仍然难以捉摸。使用细胞内低温电子层析成像和层析图分析，我们探索了NPC的结构变异和跨真菌（酵母；酿酒酵母）的核篮，哺乳动物（小鼠；Musculus），和原生动物（T.gondii）。使用综合结构建模，我们计算了酵母和哺乳动物中篮的模型，该模型揭示了核环中Nups的中心如何与形成篮的Mlp/Tpr蛋白结合：Mlp/Tpr的卷曲螺旋结构域形成篮的支柱，虽然它们的非结构化末端构成了篮子的远端密度，在核质转运之前，它可能充当mRNA预处理的对接位点。
