APC and EB1 function together in mitosis to regulate spindle dynamics and chromosome alignment
APC and EB1 function together in mitosis to regulate spindle dynamics and chromosome alignment
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DOI：
10.1091/mbc.e05-03-0259
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发表时间：
2005-10-01
影响因子：
3.3
通讯作者：
Kaplan, KB
中科院分区：
文献类型：
--
作者：
Green, RA;Wollman, R;Kaplan, KB
最近，我们已经表明，在腺瘤性息肉病结肠癌（APC）（APC（1-1450））截短的癌症主要干扰有丝分裂纺锤体功能，这表明APC调节微管动力学在有丝分裂。在这里，我们研究APC突变体干扰EB 1功能的可能性，EB 1是一种与APC相互作用的正末端微管结合蛋白，是正常微管动力学所必需的。我们发现，siRNA介导的抑制APC，EB 1，或APC和EB 1一起引起类似的缺陷，在有丝分裂纺锤体和染色体排列没有逮捕细胞在有丝分裂;相反，抑制CLIP 170或LIS 1导致不同的纺锤体缺陷和有丝分裂逮捕。我们表明，ApC（1-1450）作为一个显性负的形成一个异源寡聚体与全长APC，并阻止它与EB 1，这是一致的APC和EB 1之间的功能关系。表达EB 1-GFP的有丝分裂细胞的活体成像表明APC（1-1450）损害了EB 1-彗星的动力学，增加了EB 1-GFP暂停的频率。这些数据一起提供了新的见解APC如何调节有丝分裂纺锤体功能，以及如何在肿瘤细胞中容忍染色体分离的错误。
Recently, we have shown that a cancer causing truncation in adenomatous polyposis coli (APC) (APC(1-1450)) dominantly interferes with mitotic spindle function, suggesting APC regulates microtubule dynamics during mitosis. Here, we examine the possibility that APC mutants interfere with the function of EB1, a plus-end microtubule-binding protein that interacts with APC and is required for normal microtubule dynamics. We show that siRNA-mediated inhibition of APC, EB1, or APC and EB1 together give rise to similar defects in mitotic spindles and chromosome alignment without arresting cells in mitosis; in contrast inhibition of CLIP170 or LIS1 cause distinct spindle defects and mitotic arrest. We show that ApC(1-1450) acts as a dominant negative by forming a hetero-oligomer with the full-length APC and preventing it from interacting with EB1, which is consistent with a functional relationship between APC and EB1. Live-imaging of mitotic cells expressing EB1-GFP demonstrates that APC(1-1450) compromises the dynamics of EB1-comets, increasing the frequency of EB1-GFP pausing. Together these data provide novel insight into how APC may regulate mitotic spindle function and how errors in chromosome segregation are tolerated in tumor cells.