Nuclear pore complexes (NPCs) span the nuclear envelope and mediate nucleocytoplasmic exchange. They are a hallmark of eukaryotes and deeply rooted in the evolutionary origin of cellular compartmentalization. NPCs have an elaborate architecture that has been well studied in vertebrates. Whether this architecture is unique or varies significantly in other eukaryotic kingdoms remains unknown, predominantly due to missing in situ structural data. Here, we report the architecture of the algal NPC from the early branching eukaryote Chlamydomonas reinhardtii and compare it to the human NPC. We find that the inner ring of the Chlamydomonas NPC has an unexpectedly large diameter, and the outer rings exhibit an asymmetric oligomeric state that has not been observed or predicted previously. Our study provides evidence that the NPC is subject to substantial structural variation between species. The divergent and conserved features of NPC architecture provide insights into the evolution of the nucleocytoplasmic transport machinery.

中文翻译：

---

藻类核孔复合体的原位结构。


核孔复合物（NPC）跨越核膜并介导核质交换。它们是真核生物的标志，深深植根于细胞区室化的进化起源。 NPC 具有复杂的结构，这已在脊椎动物中得到了充分的研究。这种结构在其他真核生物王国中是否是独特的或显着变化仍然未知，这主要是由于原位结构数据的缺失。在这里，我们报告了来自早期分支真核生物莱茵衣藻的藻类 NPC 的结构，并将其与人类 NPC 进行比较。我们发现衣藻NPC的内环具有出乎意料的大直径，并且外环表现出以前未观察到或预测的不对称寡聚状态。我们的研究提供的证据表明，不同物种之间的 NPC 存在显着的结构差异。 NPC 结构的发散和保守特征为核细胞质运输机制的进化提供了见解。