美国圣路易斯华盛顿大学Rui Zhang和哈佛医学院Alan Brown等研究人员合作解析了纤毛的结构。这一研究成果10月24日在线发表于国际学术期刊《细胞》。

研究人员使用单颗粒冷冻电镜可视化并建立天然轴丝双重微管重复结构的原子模型，该模型揭示了38个相关蛋白（包括33个微管内部蛋白）的身份、位置、重复长度和相互作用。该结构证明了这些蛋白质如何建立双重微管的独特结构，如何沿着轴丝保持连贯的周期性，以及如何使微管抵抗由纤毛运动引起的反复机械应力。

这项工作阐明了支撑这种具大重复性真核生物结构的构造原理，并为理解人类纤毛病的病因提供了分子基础。

据介绍，运动纤毛的轴丝是真核细胞最大的大分子机器。在人类中，轴丝功能受损会导致一系列的纤毛病。轴丝的组装、结构和运动性需要径向排列的一组双峰微管，每个微管以重复的形式装饰有非微管蛋白成分。

附：英文原文

Title: Structure of the Decorated Ciliary Doublet Microtubule

Author: Meisheng Ma, Mihaela Stoyanova, Griffin Rademacher, Susan K. Dutcher, Alan Brown, Rui Zhang

Issue&Volume: 2019/10/24

Abstract: The axoneme of motile cilia is the largest macromolecular machine of eukaryotic cells. In humans, impaired axoneme function causes a range of ciliopathies. Axoneme assembly, structure, and motility require a radially arranged set of doublet microtubules, each decorated in repeating patterns with non-tubulin components. We use single-particle cryo-electron microscopy to visualize and build an atomic model of the repeating structure of a native axonemal doublet microtubule, which reveals the identities, positions, repeat lengths, and interactions of 38 associated proteins, including 33 microtubule inner proteins (MIPs). The structure demonstrates how these proteins establish the unique architecture of doublet microtubules, maintain coherent periodicities along the axoneme, and stabilize the microtubules against the repeated mechanical stress induced by ciliary motility. Our work elucidates the architectural principles that underpin the assembly of this large, repetitive eukaryotic structure and provides a molecular basis for understanding the etiology of human ciliopathies.

DOI: 10.1016/j.cell.2019.09.030

Source: https://www.cell.com/cell/fulltext/S0092-8674(19)31081-5