Trichoplein controls microtubule anchoring at the centrosome by binding to Odf2 and ninein
Trichoplein controls microtubule anchoring at the centrosome by binding to Odf2 and ninein
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DOI：
10.1242/jcs.075705
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发表时间：
2011-03-15
影响因子：
4
通讯作者：
Inagaki, Masaki
中科院分区：
文献类型：
--
作者：
Ibi, Miho;Zou, Peng;Inagaki, Masaki
角蛋白细胞骨架在上皮细胞中发挥多种功能，并为支架蛋白(包括毛发蛋白)提供受调控的相互作用部位。以前，我们发现Trichoplein定位于分化良好的未分化上皮中的角蛋白中间丝和桥粒上。在此，我们报道了Trichoplein在上皮和非上皮细胞中广泛表达，并在中心体蛋白Ninein的正确定位中起主要作用。免疫细胞化学分析还表明，该蛋白集中在母体和子体中心粒的近远端至内侧区。Trichoplein与中心体蛋白Odf2和Ninein结合，这两个蛋白定位于母中心粒的远端到近端。Trichoplein的缺失取消了Ninein的招募，但没有取消Odf2，特别是在亚远端。然而，Odf2的缺失抑制了毛滴蛋白向母中心粒的募集，而九肽的缺失则没有。此外，每个分子的耗尽都会损害MT在中心体的锚定。这些结果表明，三环素可能通过与Odf2和Ninein形成复合体，在增殖细胞中心体的MT锚定活性中发挥关键作用。
The keratin cytoskeleton performs several functions in epithelial cells and provides regulated interaction sites for scaffold proteins, including trichoplein. Previously, we found that trichoplein was localized on keratin intermediate filaments and desmosomes in well-differentiated, non-dividing epithelia. Here, we report that trichoplein is widely expressed and has a major function in the correct localization of the centrosomal protein ninein in epithelial and non-epithelial cells. Immunocytochemical analysis also revealed that this protein is concentrated at the subdistal to medial zone of both mother and daughter centrioles. Trichoplein binds the centrosomal proteins Odf2 and ninein, which are localized at the distal to subdistal ends of the mother centriole. Trichoplein depletion abolished the recruitment of ninein, but not Odf2, specifically at the subdistal end. However, Odf2 depletion inhibited the recruitment of trichoplein to a mother centriole, whereas ninein depletion did not. In addition, the depletion of each molecule impaired MT anchoring at the centrosome. These results suggest that trichoplein has a crucial role in MT-anchoring activity at the centrosome in proliferating cells, probably through its complex formation with Odf2 and ninein.