Polo-like kinase is necessary for flagellum inheritance in Trypanosoma brucei
Polo-like kinase is necessary for flagellum inheritance in Trypanosoma brucei
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DOI：
10.1242/jcs.101162
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发表时间：
2012-07-01
影响因子：
4
通讯作者：
de Graffenried, Christopher L.
中科院分区：
文献类型：
--
作者：
Ikeda, Kyojiro N.;de Graffenried, Christopher L.
类Polo蛋白在哺乳动物细胞的多种有丝分裂过程中发挥着重要作用，从中心粒分离、染色体聚集到脱落。为了完成这些角色，随着细胞周期的进展，Polo样激酶同源物移动到不同的细胞位置，从中心体开始，到纺锤体两极，然后是中体。在布鲁氏锥虫的原生寄生虫中，单一的Polo-like激酶同源蛋白T.brucei PLK(TbPLK)是细胞质分裂所必需的，也是正确复制含有中心素的细胞骨架结构所必需的。我们发现TbPLK在细胞周期中具有动态的定位模式。该激酶定位于鞭毛的核基体，然后依次定位于调节鞭毛与细胞体的位置和附着的一系列细胞骨架结构。当这些结构进行复制时，该激酶定位于每一个结构。TbPLK与一组特殊的微管联系在一起，称为微管四元组，它可能在其迁移过程中运输激酶。TbPLK的耗尽会导致基本体分离的缺陷，并阻止定位鞭毛的调节器的复制，这表明TbPLK在这些结构上的存在可能是这些结构正常生物发生所必需的。在布氏毛虫中，TbPLK在整个细胞内迁移，但它所针对的特定位置及其功能是针对一个正确定位和附着的鞭毛的遗传。
Polo-like kinases play an important role in a variety of mitotic events in mammalian cells, ranging from centriole separation and chromosome congression to abscission. To fulfill these roles, Polo-like kinase homologs move to different cellular locations as the cell cycle progresses, starting at the centrosome, progressing to the spindle poles and then the midbody. In the protist parasite Trypanosoma brucei, the single polo-like kinase homolog T. brucei PLK (TbPLK) is essential for cytokinesis and is necessary for the correct duplication of a centrin-containing cytoskeletal structure known as the bilobe. We show that TbPLK has a dynamic localization pattern during the cell cycle. The kinase localizes to the basal body, which nucleates the flagellum, and then successively localizes to a series of cytoskeletal structures that regulate the position and attachment of the flagellum to the cell body. The kinase localizes to each of these structures as they are duplicating. TbPLK associates with a specialized set of microtubules, known as the microtubule quartet, which might transport the kinase during its migration. Depletion of TbPLK causes defects in basal body segregation and blocks the duplication of the regulators that position the flagellum, suggesting that its presence on these structures might be necessary for their proper biogenesis. TbPLK migrates throughout the cell in T. brucei, but the specific locations to which it targets and its functions are geared towards the inheritance of a properly positioned and attached flagellum.