Ninein is essential for apico-basal microtubule formation and CLIP-170 facilitates its redeployment to non-centrosomal microtubule organizing centres.
Ninein is essential for apico-basal microtubule formation and CLIP-170 facilitates its redeployment to non-centrosomal microtubule organizing centres.
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DOI：
10.1098/rsob.160274
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发表时间：
2017-02
期刊：
影响因子：
5.8
通讯作者：
Mogensen MM
中科院分区：
文献类型：
--
作者：
Goldspink DA;Rookyard C;Tyrrell BJ;Gadsby J;Perkins J;Lund EK;Galjart N;Thomas P;Wileman T;Mogensen MM
柱状上皮细胞的分化涉及微管和中心体成分的戏剧性重组，形成不再锚定在中心体的顶基阵列。相反，MTS的负端锚定在顶端非中心体微管组织中心(n-MTOCs)。N-MTOCs的形成是至关重要的，因为它们决定了MTS的空间组织，进而影响细胞的形状和功能。然而，人们对它们是如何形成的知之甚少。我们先前已经证明，中心体锚定蛋白Ninein从中心体释放，以微管依赖的方式移动，并在上皮分化过程中积聚在n-MTOCs处。在这里，我们使用耗竭和敲除(KO)的方法，报告了Ninein的表达对于根尖基底层阵列的形成和上皮的延长是必不可少的，并且Clip-170是其重新部署到n-MTOCs所必需的。功能抑制还表明，IQGAP1和活性的rac1与CLIP-170协同作用，促进微管+端皮质靶向和九肽的重新部署。分别缺失编码CLIP-170和CLIP-115基因的Clip1/CLIP2双KO小鼠的肠道组织和体外有机物证实，尽管Ninein在n-MTOCs中丢失，但CLIP-170仍需要CLIP-170将其重新募集到n-MTOCs中，并可能被其他锚定因子如p150Glued和CAMSAP2所补偿，以确保尖基微管的形成。
Differentiation of columnar epithelial cells involves a dramatic reorganization of the microtubules (MTs) and centrosomal components into an apico-basal array no longer anchored at the centrosome. Instead, the minus-ends of the MTs become anchored at apical non-centrosomal microtubule organizing centres (n-MTOCs). Formation of n-MTOCs is critical as they determine the spatial organization of MTs, which in turn influences cell shape and function. However, how they are formed is poorly understood. We have previously shown that the centrosomal anchoring protein ninein is released from the centrosome, moves in a microtubule-dependent manner and accumulates at n-MTOCs during epithelial differentiation. Here, we report using depletion and knockout (KO) approaches that ninein expression is essential for apico-basal array formation and epithelial elongation and that CLIP-170 is required for its redeployment to n-MTOCs. Functional inhibition also revealed that IQGAP1 and active Rac1 coordinate with CLIP-170 to facilitate microtubule plus-end cortical targeting and ninein redeployment. Intestinal tissue and in vitro organoids from the Clip1/Clip2 double KO mouse with deletions in the genes encoding CLIP-170 and CLIP-115, respectively, confirmed requirement of CLIP-170 for ninein recruitment to n-MTOCs, with possible compensation by other anchoring factors such as p150Glued and CAMSAP2 ensuring apico-basal microtubule formation despite loss of ninein at n-MTOCs.