A helical inner scaffold provides a structural basis for centriole cohesion
A helical inner scaffold provides a structural basis for centriole cohesion
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DOI：
10.1126/sciadv.aaz4137
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发表时间：
2020-02-01
期刊：
影响因子：
13.6
通讯作者：
Guichard, Paul
中科院分区：
文献类型：
--
作者：
Le Guennec, Maeva;Klena, Nikolai;Guichard, Paul
微管三联体（MTTs）的九重放射状排列是中心粒的标志，中心粒是一种保守的细胞器，对中心体和纤毛的形成至关重要。虽然MTTs之间的强凝聚力对于抵抗纤毛跳动和有丝分裂纺锤体施加的力至关重要，但中心粒如何保持其结构完整性尚不清楚。使用冷冻电子断层扫描和subtomogram平均的中心粒从四个进化上遥远的物种，我们发现，MTTs绑定在一起的螺旋形内支架覆盖类似的70%的中心粒长度，保持MTTs的凝聚力下的压力。超微结构扩展显微镜（U-ExM）显示POC 5、POC 1B、FAM 161 A和Centrin-2定位于沿着中心粒MTT内壁的支架结构。此外，我们确定这四种蛋白质相互作用形成结合微管的复合物。总之，我们的研究结果提供了一个结构和分子基础的中心粒凝聚力和几何形状。
The ninefold radial arrangement of microtubule triplets (MTTs) is the hallmark of the centriole, a conserved organelle crucial for the formation of centrosomes and cilia. Although strong cohesion between MTTs is critical to resist forces applied by ciliary beating and the mitotic spindle, how the centriole maintains its structural integrity is not known. Using cryo-electron tomography and subtomogram averaging of centrioles from four evolutionarily distant species, we found that MTTs are bound together by a helical inner scaffold covering similar to 70% of the centriole length that maintains MTTs cohesion under compressive forces. Ultrastructure Expansion Microscopy (U-ExM) indicated that POC5, POC1B, FAM161A, and Centrin-2 localize to the scaffold structure along the inner wall of the centriole MTTs. Moreover, we established that these four proteins interact with each other to form a complex that binds microtubules. Together, our results provide a structural and molecular basis for centriole cohesion and geometry.