Live cell dynamics of promyelocytic leukemia nuclear bodies upon entry into and exit from mitosis
Live cell dynamics of promyelocytic leukemia nuclear bodies upon entry into and exit from mitosis
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DOI：
10.1091/mbc.e08-01-0035
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发表时间：
2008-07-01
影响因子：
3.3
通讯作者：
Spector, David L.
中科院分区：
文献类型：
--
作者：
Chen, Yi-Chun M.;Kappel, Constantin;Spector, David L.
早幼粒细胞白血病核小体（PML NBs）被认为参与肿瘤抑制、病毒防御、DNA修复和/或转录调控。为了研究PML NBs在有丝分裂过程中的动态，我们培养了几种U2OS细胞系，这些细胞系稳定地与其他个体标记蛋白共同表达PML增强的青色荧光蛋白。利用三维延时活细胞成像和四维粒子跟踪，我们定量地证明了PML NBs在细胞从前期向中期发展时表现出高比例的定向运动。这种增加的动态运动发生在细胞周期蛋白B1进入细胞核之前或之后，但在核膜破裂之前。我们的数据表明，进入前期导致染色质区域和PML NBs之间的拴系丧失，导致它们的动力学增加。有丝分裂结束后，Sp100和Fas死亡结构域相关蛋白（Daxx）在功能性核膜重组后进入子核。然而，这些蛋白向PML NB的募集被延迟，并与新生PML NB形成的时间相关。总之，这些结果为有丝分裂期间与PML NBs相关的动态变化提供了见解。
Promyelocytic leukemia nuclear bodies (PML NBs) have been proposed to be involved in tumor suppression, viral defense, DNA repair, and/ or transcriptional regulation. To study the dynamics of PML NBs during mitosis, we developed several U2OS cell lines stably coexpressing PML-enhanced cyan fluorescent protein with other individual marker proteins. Using three-dimensional time-lapse live cell imaging and four-dimensional particle tracking, we quantitatively demonstrated that PML NBs exhibit a high percentage of directed movement when cells progressed from prophase to prometaphase. The timing of this increased dynamic movement occurred just before or upon nuclear entry of cyclin B1, but before nuclear envelope breakdown. Our data suggest that entry into prophase leads to a loss of tethering between regions of chromatin and PML NBs, resulting in their increased dynamics. On exit from mitosis, Sp100 and Fas death domain-associated protein (Daxx) entered the daughter nuclei after a functional nuclear membrane was reformed. However, the recruitment of these proteins to PML NBs was delayed and correlated with the timing of de novo PML NB formation. Together, these results provide insight into the dynamic changes associated with PML NBs during mitosis.