Dynamics of human DNA topoisomerases IIalpha and IIbeta in living cells.
Dynamics of human DNA topoisomerases IIalpha and IIbeta in living cells.
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DOI：
10.1083/jcb.200112023
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发表时间：
2002-04-01
期刊：
影响因子：
--
通讯作者：
Mielke C
中科院分区：
文献类型：
--
作者：
Christensen MO;Larsen MK;Barthelmes HU;Hock R;Andersen CL;Kjeldsen E;Knudsen BR;Westergaard O;Boege F;Mielke C
DNA拓扑异构酶（topo）II催化许多DNA代谢过程所必需的拓扑基因组变化。它也被认为是间期核基质和有丝分裂染色体支架的结构成分。哺乳动物有两种异构体（α和β），在体外具有相似的特性。在这里，我们研究了它们在活细胞和增殖细胞中的特性，稳定表达人类同工酶的生物荧光嵌合体。Topo IIα和IIβ在间期的行为相似，但在有丝分裂中表现不同，其中只有Topo IIα与染色体的主要部分相关。在间期，这两种同工酶加入核仁重组和积累在核仁中，这似乎不涉及催化DNA周转，因为治疗与替尼泊苷（稳定共价催化DNA中间体的拓扑异构酶II）搬迁的大部分酶从核仁到核质颗粒。光漂白显示，这两种同工酶的整个补体是完全移动的和自由的核亚室之间的间期交换。在染色体中，Topo IIα也是完全移动的，分布均匀。然而，低渗细胞溶解触发了轴向模式。这些观察结果表明，拓扑异构酶II是不是一个固定的，结构组件的染色体支架或间期核骨架，而是一个动态的相互作用的合作伙伴，这样的结构。
DNA topoisomerase (topo) II catalyses topological genomic changes essential for many DNA metabolic processes. It is also regarded as a structural component of the nuclear matrix in interphase and the mitotic chromosome scaffold. Mammals have two isoforms (α and β) with similar properties in vitro. Here, we investigated their properties in living and proliferating cells, stably expressing biofluorescent chimera of the human isozymes. Topo IIα and IIβ behaved similarly in interphase but differently in mitosis, where only topo IIα was chromosome associated to a major part. During interphase, both isozymes joined in nucleolar reassembly and accumulated in nucleoli, which seemed not to involve catalytic DNA turnover because treatment with teniposide (stabilizing covalent catalytic DNA intermediates of topo II) relocated the bulk of the enzymes from the nucleoli to nucleoplasmic granules. Photobleaching revealed that the entire complement of both isozymes was completely mobile and free to exchange between nuclear subcompartments in interphase. In chromosomes, topo IIα was also completely mobile and had a uniform distribution. However, hypotonic cell lysis triggered an axial pattern. These observations suggest that topo II is not an immobile, structural component of the chromosomal scaffold or the interphase karyoskeleton, but rather a dynamic interaction partner of such structures.
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影响因子：
3.3
作者：
Pederson, T
通讯作者：
Pederson, T
影响因子：
4.8
作者：
Kimura, K;Nozaki, N;Kikuchi, A
通讯作者：
Kikuchi, A
拓扑异构酶II在有丝分裂染色体中的定位。
影响因子：
7.8
作者：
Earnshaw, W C;Heck, M M
通讯作者：
Heck, M M
影响因子：
64.5
作者：
ADACHI, Y;LUKE, M;LAEMMLI, UK
通讯作者：
LAEMMLI, UK
影响因子：
64.5
作者：
DELATOUR, EB;LAEMMLI, UK
通讯作者：
LAEMMLI, UK