The inner junction complex of the cilia is an interaction hub that involves tubulin post-translational modifications
The inner junction complex of the cilia is an interaction hub that involves tubulin post-translational modifications
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DOI：
10.7554/elife.52760
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发表时间：
2020-01-17
期刊：
影响因子：
7.7
通讯作者：
Khanh Huy Bui
中科院分区：
文献类型：
--
作者：
Khalifa, Ahmad Abdelzaher Zaki;Ichikawa, Muneyoshi;Khanh Huy Bui
微管是参与细胞稳定性、运输和组织的细胞骨架结构。结构单元，α-和β-微管蛋白异源二聚体，形成原丝，侧向结合到中空微管中。微管也以高度稳定的双线微管形式存在于纤毛中，纤毛跳动和功能需要稳定性。双联体微管通过在其A-和B-微管相遇的内外连接处的相互作用来保持其稳定性。在这里，使用冷冻电子显微镜，生物信息学和质谱的双重莱茵衣藻和嗜热四膜虫，我们确定了两个新的内部连接蛋白，FAP 276和FAP 106，和内部连接相关的蛋白，FAP 126，从而提出了完整的答案的内部连接的身份和定位。我们的双重结构的研究表明，内部连接作为一个相互作用的枢纽，涉及微管蛋白的翻译后修饰。这些相互作用有助于双联体的稳定性，从而有助于正常的纤毛运动。
Microtubules are cytoskeletal structures involved in stability, transport and organization in the cell. The building blocks, the alpha- and beta-tubulin heterodimers, form protofilaments that associate laterally into the hollow microtubule. Microtubule also exists as highly stable doublet microtubules in the cilia where stability is needed for ciliary beating and function. The doublet microtubule maintains its stability through interactions at its inner and outer junctions where its A-and B-tubules meet. Here, using cryo-electron microscopy, bioinformatics and mass spectrometry of the doublets of Chlamydomonas reinhardtii and Tetrahymena thermophila, we identified two new inner junction proteins, FAP276 and FAP106, and an inner junction-associated protein, FAP126, thus presenting the complete answer to the inner junction identity and localization. Our structural study of the doublets shows that the inner junction serves as an interaction hub that involves tubulin post-translational modifications. These interactions contribute to the stability of the doublet and hence, normal ciliary motility.