Biocentre, Johannes Gutenberg-University Mainz, Mainz, Germany.
Institute of Molecular Biology, Mainz, Germany.
Elife. 2020 Jul 21;9:e55963. doi: 10.7554/eLife.55963.
Nucleocytoplasmic transport is tightly regulated by the nuclear pore complex (NPC). Among the thousands of molecules that cross the NPC, even very large (>15 nm) cargoes such as pathogens, mRNAs and pre-ribosomes can pass the NPC intact. For these cargoes, there is little quantitative understanding of the requirements for their nuclear import, especially the role of multivalent binding to transport receptors via nuclear localisation sequences (NLSs) and the effect of size on import efficiency. Here, we assayed nuclear import kinetics of 30 large cargo models based on four capsid-like particles in the size range of 17-36 nm, with tuneable numbers of up to 240 NLSs. We show that the requirements for nuclear transport can be recapitulated by a simple two-parameter biophysical model that correlates the import flux with the energetics of large cargo transport through the NPC. Together, our results reveal key molecular determinants of large cargo import in cells.
核质转运受到核孔复合体 (NPC) 的严格调控。在穿过 NPC 的数千种分子中，即使是非常大的（>15nm）货物，如病原体、mRNA 和前核糖体，也可以完整地穿过 NPC。对于这些货物，人们对其核输入的要求几乎没有定量的了解，特别是多价结合通过核定位序列（NLS）运输受体的作用以及大小对输入效率的影响。在这里，我们基于大小范围为 17-36nm 的四个衣壳样颗粒，检测了 30 种大型货物模型的核输入动力学，其NLS 数量可调高达 240 个。我们表明，通过一个简单的双参数生物物理模型可以再现核运输的要求，该模型将输入通量与通过 NPC 运输大型货物的能量相关联。总之，我们的结果揭示了细胞中大型货物输入的关键分子决定因素。
