An RNase-sensitive particle containing Drosophila melanogaster DNA topoisomerase II.
An RNase-sensitive particle containing Drosophila melanogaster DNA topoisomerase II.
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RNase敏感的粒子，其中包含果蝇Melanogaster DNA拓扑异构酶II。
DOI：
10.1083/jcb.126.6.1331
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发表时间：
1994-09
期刊：
影响因子：
--
通讯作者：
Fisher PA
中科院分区：
文献类型：
--
作者：
Meller VH;McConnell M;Fisher PA
在0-2小时龄的果蝇胚胎的无细胞提取物中，大多数DNA拓扑异构酶II（topo II）似乎是无核的，并且在低速离心（10，000 g）后保留在上清液中。几乎所有这些明显可溶的拓扑异构酶II都是沉降系数为67 S的颗粒。在果蝇KC组织培养细胞、16-19小时胚胎和非洲爪蟾雌甾酮成熟卵母细胞提取物中检测到类似的含拓扑异构酶II的颗粒。含有果蝇topo II的颗粒对EDTA、Triton X-100和DNA酶I不敏感，但可被0.3 M NaCl或RNA酶A孵育破坏。在任一破坏性处理后，topo II在9 S下沉淀。含拓扑异构酶II的颗粒也对微球菌核酸酶敏感。化学交联的结果证实了离心分离得到的结果。免疫印迹分析表明，含有拓扑异构酶II的颗粒缺乏大量核纤层蛋白、核孔复合物蛋白gp 210、增殖细胞核抗原、RNA聚合酶II亚单位、组蛋白、卷曲蛋白和核仁蛋白.北方印迹分析表明，含有拓扑异构酶II的颗粒缺乏U RNA。因此，目前的数据支持的概念，非核果蝇topo II含有颗粒主要由topo II和一个未知的RNA分子（S）。
Most DNA topoisomerase II (topo II) in cell-free extracts of 0-2-h old Drosophila embryos appears to be nonnuclear and remains in the supernatant after low-speed centrifugation (10,000 g). Virtually all of this apparently soluble topo II is particulate with a sedimentation coefficient of 67 S. Similar topo II-containing particles were detected in Drosophila Kc tissue culture cells, 16-19-h old embryos and extracts of progesterone-matured oocytes from Xenopus. Drosophila topo II- containing particles were insensitive to EDTA, Triton X-100 and DNase I, but could be disrupted by incubation with 0.3 M NaCl or RNase A. After either disruptive treatment, topo II sedimented at 9 S. topo II- containing particles were also sensitive to micrococcal nuclease. Results of chemical cross-linking corroborated those obtained by centrifugation. Immunoblot analyses demonstrated that topo II- containing particles lacked significant amounts of lamin, nuclear pore complex protein gp210, proliferating cell nuclear antigen, RNA polymerase II subunits, histones, coilin, and nucleolin. Northern blot analyses demonstrated that topo II-containing particles lacked U RNA. Thus, current data support the notion that nonnuclear Drosophila topo II-containing particles are composed largely of topo II and an unknown RNA molecule(s).