Adenomatous polyposis coli in cell extensions can promote with or without EB1
Adenomatous polyposis coli in cell extensions can promote with or without EB1
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DOI：
10.1091/mbc.e05-06-0498
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发表时间：
2006-05-01
影响因子：
3.3
通讯作者：
Waterman-Storer, CM
中科院分区：
文献类型：
--
作者：
Kita, K;Wittmann, T;Waterman-Storer, CM
在间期细胞中，腺瘤性结肠息肉病（APC）蛋白在细胞突起中的微管（MT）的一个小子集上积累，这表明APC可以调节这些MT的动力学。我们comicroinjected非扰动荧光标记的单克隆抗体和标记微管蛋白，同时可视化动态的内源性APC和MT活细胞。与非APC修饰的MT相比，APC修饰的MT花费更多的时间生长并且具有降低的灾难频率。内源性APC与MT缩短短暂相关。为了确定APC及其结合伴侣EB 1之间的关系，我们在活细胞中同时监测了EB 1-绿色荧光蛋白和内源性APC。只有一小部分EB 1与APC共定位。APC缺陷细胞和EB 1小干扰RNA显示，EB 1和APC定位在MT末端独立。EB 1的耗尽没有改变APC对MT+末端的生长稳定作用。此外，APC仍然与用低浓度诺考达唑稳定的MT结合，而EB 1则没有。因此，我们证明，协会的内源性APC与MT结束直接与他们的增长稳定性增加，这可以独立于其与13131协会，APC和EB 1可以与MT加上结束不同的机制。
In interphase cells, the adenomatous polyposis coli (APC) protein accumulates on a small subset of microtubules (MTs) in cell protrusions, suggesting that APC may regulate the dynamics of these MTs. We comicroinjected a nonperturbing fluorescently labeled monoclonal antibody and labeled tubulin to simultaneously visualize dynamics of endogenous APC and MTs in living cells. MTs decorated with APC spent more time growing and had a decreased catastrophe frequency compared with non-APC-decorated MTs. Endogenous APC associated briefly with shortening MTs. To determine the relationship between APC and its binding partner EB1, we monitored EB1-green fluorescent protein and endogenous APC concomitantly in living cells. Only a small fraction of EB1 colocalized with APC at any one time. APC-deficient cells and EB1 small interfering RNA showed that EB1 and APC localized at MT ends independently. Depletion of EB1 did not change the growth-stabilizing effects of APC on MT plus ends. In addition, APC remained bound to MTs stabilized with low nocodazole, whereas EB1 did not. Thus, we demonstrate that the association of endogenous APC with MT ends correlates directly with their increased growth stability, that this can occur independently of its association with 13131, and that APC and EB1 can associate with MT plus ends by distinct mechanisms.