人类拓酶IIα通过相变转换促进染色质凝结
Meiling Wu1,2, Curtis Beck3, Joyce H Lee3
1Department of Physics & LASSP, Cornell University, Ithaca, NY 14853, USA.
bioRxiv : the preprint server for biology
|October 28, 2024
概括
人类拓酶IIα (topo IIα) 通过其C端域直接凝结DNA和染色质,独立于催化活性. 这种新功能表明 topo IIαα.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 托波二醇酶II (topo II) 酶可以解决DNA纠.
- 人类有两个topo II同酶,topo IIα和topo IIβ,具有不同的C端域 (CTD).
- 拓IIα对于线粒分裂期间的染色体凝聚至关重要,但其机制尚不清楚.
研究的目的:
- 研究人类TOPO IIα在DNA和染色质凝聚中的作用.
- 确定TOPO IIα的CTD对其凝结功能的贡献.
- 探索Topo IIα的冷凝和催化活动之间的关系.
主要方法:
- 在体外研究中使用净化的人类TOPO IIα和TOPO IIβ.
- 在低蛋白度下进行DNA凝聚试验.
- 在凝结过程中测量DNA张力.
- 评估ATP独立性和催化活性干扰.
主要成果:
- 人类TOPOIIα在低度 (≤100 pM) 通过聚合物-崩相过渡凝结DNA和染色素.
- Topo IIα的C端域 (CTD) 对于凝结至关重要;去除将取消这种功能.
- 托波IIα介导的凝结能够承受高达1.5pN的DNA张力,并且独立于ATP.
- 在凝结过程中,Topo IIβ的效率低于Topo IIα.
- 托波IIα的凝结和催化活性可以同时发生,干扰最小.
结论:
- 人类的TOPO IIα具有一种新的,CTD介导的DNA和染色质凝聚功能.
- 这种非催化凝聚活动对于线粒分裂期间的染色体凝聚至关重要.
- 托波IIα直接参与染色体的组织,独立于其DNA分裂活动.
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