Active heterodimers are formed from human DNA topoisomerase II alpha and II beta isoforms
Active heterodimers are formed from human DNA topoisomerase II alpha and II beta isoforms
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DOI：
10.1073/pnas.93.16.8288
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发表时间：
1996-08-06
影响因子：
11.1
通讯作者：
Andersen, AH
中科院分区：
文献类型：
--
作者：
Biersack, H;Jensen, S;Andersen, AH
DNA拓扑异构酶II是染色体动力学和DNA代谢所必需的核酶。在哺乳动物细胞中，存在两种遗传和生物化学上不同的拓扑异构酶II形式，其被命名为拓扑异构酶II α和拓扑异构酶II β。在我们对人类拓扑异构酶II的研究中，我们发现该酶的很大一部分在HeLa细胞中以α/β异二聚体形式存在。当人拓扑异构酶II α和II β在酵母中共表达时，形成异二聚体的能力得到了验证，并在二聚化测定中进行了研究。纯化的异二聚体的分析表明，这些酶保持拓扑异构酶II的特异性催化活性，拓扑异构酶II的活性异二聚体亚类的天然存在值得关注，每当拓扑异构酶II α和II β的功能，定位和细胞周期调控进行了研究。
DNA topoisomerase II is a nuclear enzyme essential for chromosome dynamics and DNA metabolism. In mammalian cells, two genetically and biochemically distinct topoisomerase II forms exist, which are designated topoisomerase II alpha and topoisomerase II beta. In our studies of human topoisomerase II, we have found that a substantial fraction of the enzyme exists as alpha/beta heterodimers in HeLa cells. The ability to form heterodimers was verified when human topoisomerases II alpha and II beta mere coexpressed in yeast and investigated in a dimerization assay. Analysis of purified heterodimers shows that these enzymes maintain topoisomerase II specific catalytic activities, The natural existence of an active heterodimeric subclass of topoisomerase II merits attention whenever topoisomerases II alpha and II beta function, localization, and cell cycle regulation are investigated.