Plk1 Phosphorylates CLIP-170 and Regulates Its Binding to Microtubules for Chromosome Alignment
Plk1 Phosphorylates CLIP-170 and Regulates Its Binding to Microtubules for Chromosome Alignment
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DOI：
10.1247/csf.14001
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发表时间：
2014-01-01
影响因子：
1.5
通讯作者：
Watanabe, Takashi
中科院分区：
文献类型：
--
作者：
Kakeno, Mai;Matsuzawa, Kenji;Watanabe, Takashi
微管（MT）细胞骨架对于细胞形态发生、细胞迁移和细胞分裂是必不可少的。MT组织化主要由多种MT相关蛋白介导。在这些蛋白质中，正末端跟踪蛋白（+TIPs）是进化上保守的因子，选择性地积累在生长的MT正末端。细胞质连接蛋白（CLIP）-170是一个+TIP，与不同的蛋白质相关联，以确定MT末端的行为及其与细胞内结构（包括有丝分裂染色体）的连接。然而，CLIP-170活性如何在空间和时间上受到控制在很大程度上是未知的。在这里，我们表明，在第三个丝氨酸丰富的区域的CLIP-170的Ser 312磷酸化在有丝分裂过程中增加。Polo样激酶1（Plk 1）负责分裂细胞有丝分裂期的磷酸化。使用纯化的CLIP-170 N-末端片段的体外分析表明，Plk 1的磷酸化减少了CLIP-170与MT末端和晶格的结合，而不影响与EB 3的结合。此外，我们证明，在有丝分裂过程中，稳定的动粒/MT附件和随后的染色体排列需要CLIP-170和一个适当的磷酸化/去磷酸化周期Ser 312。我们提出，CLIP-170磷酸化Plk 1调节适当的染色体排列，通过调节CLIP-170和MT之间的相互作用，在有丝分裂细胞和CLIP-170的活性是严格控制其磷酸化状态，这取决于细胞环境。
The microtubule (MT) cytoskeleton is essential for cellular morphogenesis, cell migration, and cell division. MT organization is primarily mediated by a variety of MT-associated proteins. Among these proteins, plus-end-tracking proteins (+TIPs) are evolutionarily conserved factors that selectively accumulate at growing MT plus ends. Cytoplasmic linker protein (CLIP)-170 is a +TIP that associates with diverse proteins to determine the behavior of MT ends and their linkage to intracellular structures, including mitotic chromosomes. However, how CLIP-170 activity is spatially and temporally controlled is largely unknown. Here, we show that phosphorylation at Ser312 in the third serine-rich region of CLIP-170 is increased during mitosis. Polo-like kinase 1 (Plk1) is responsible for this phosphorylation during the mitotic phase of dividing cells. In vitro analysis using a purified CLIP-170 N-terminal fragment showed that phosphorylation by Plk1 diminishes CLIP-170 binding to the MT ends and lattice without affecting binding to EB3. Furthermore, we demonstrate that during mitosis, stable kinetochore/MT attachment and subsequent chromosome alignment require CLIP-170 and a proper phosphorylation/dephosphorylation cycle at Ser312. We propose that CLIP-170 phosphorylation by Plk1 regulates proper chromosome alignment by modulating the interaction between CLIP-170 and MTs in mitotic cells and that CLIP-170 activity is stringently controlled by its phosphorylation state, which depends on the cellular context.