Max Perutz Labs, Vienna Biocenter Campus, University of Vienna and Medical University of Vienna, Vienna, Austria.
Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria.
Nat Cell Biol. 2024 Sep;26(9):1504-1519. doi: 10.1038/s41556-024-01484-x. Epub 2024 Aug 13.
The nuclear basket attaches to the nucleoplasmic side of the nuclear pore complex (NPC), coupling transcription to mRNA quality control and export. The basket expands the functional repertoire of a subset of NPCs in Saccharomyces cerevisiae by drawing a unique RNA/protein interactome. Yet, how the basket docks onto the NPC core remains unknown. By integrating AlphaFold-based interaction screens, electron microscopy and membrane-templated reconstitution, we uncovered a membrane-anchored tripartite junction between basket and NPC core. The basket subunit Nup60 harbours three adjacent short linear motifs, which connect Mlp1, a parallel homodimer consisting of coiled-coil segments interrupted by flexible hinges, and the Nup85 subunit of the Y-complex. We reconstituted the Y-complex•Nup60•Mlp1 assembly on a synthetic membrane and validated the protein interfaces in vivo. Here we explain how a short linear motif-based protein junction can substantially reshape NPC structure and function, advancing our understanding of compositional and conformational NPC heterogeneity.
核篮附着在核孔复合体(NPC)的核质侧,将转录与 mRNA 质量控制和输出偶联。在酿酒酵母中,核篮通过绘制独特的 RNA/蛋白质相互作用组,扩展了一组 NPC 的功能谱。然而,核篮如何与 NPC 核心对接仍然未知。通过整合基于 AlphaFold 的相互作用筛选、电子显微镜和膜模板重建,我们揭示了核篮和 NPC 核心之间的膜锚定三联体连接。核篮亚基 Nup60 含有三个相邻的短线性基序,它们连接 Mlp1,这是一个由卷曲螺旋片段组成的平行同源二聚体,中间有柔性铰链,以及 Y 复合物的 Nup85 亚基。我们在合成膜上重建了 Y 复合物•Nup60•Mlp1 组装体,并在体内验证了蛋白质界面。在这里,我们解释了基于短线性基序的蛋白质连接如何实质性地重塑 NPC 结构和功能,从而推进了我们对组成和构象 NPC 异质性的理解。