Cas9感知CRISPRRNA丰度以调节CRISPR间隔器的获取
Xufei Zhou1, Rucheng Diao2, Xin Li1
1Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
Nature
|September 3, 2025
概括
在没有RNA伴侣的情况下,Neisseria apoCas9增强了CRISPR免疫记忆. 这种蛋白质起到传感器的作用,促进新的免疫记忆形成,并通过调节间隔器的获取来预防自身免疫.
科学领域:
- 微生物学
- 分子生物学
- 遗传学
背景情况:
- Prokaryotes 使用 CRISPR-Cas 系统进行适应性免疫,将外来 DNA 存储在 CRISPR 阵列中作为间隔器.
- 包括Cas9在内的II型CRISPR-Cas系统对于防御入侵核酸至关重要.
- Cas9通常与crRNA和tracrRNA一起指导DNA向.
研究的目的:
- 独立于其RNA合作伙伴,研究Cas9的生物作用.
- 了解Cas9是如何根据细胞条件调节间隔器的.
- 阐明控制CRISPR-Cas适应性免疫力的反机制.
主要方法:
- 在crRNA和/或tracrRNA耗尽后研究Neisseria apoCas9的活性.
- 评估了不同CRISPR阵列长度和crRNA水平对间隔器获取的影响.
- 检查了Cas9核酶叶和全长蛋白在调节获取中的作用.
- 分析了Cas9在II-C类型中调节功能的进化保存.
主要成果:
- 在crRNA和tracrRNA的独立性下,Neisseria apoCas9刺激了间隔器获取效率.
- 在CRISPR阵列较短的细胞中,Cas9感知到低crRNA水平,从而调节了获取.
- 随着数组的扩大而增加的crRNA丰富性降低了apoCas9的可用性,抑制了获取.
- 单独Cas9的核酶叶刺激了获取,但全长的Cas9调节了对crRNA水平的反应.
- 这种调节活性在多种类型II-C Cas9 正态中保持不变.
结论:
- 建立了一种用于CRISPR免疫力的自补反机制.
- 证明了Cas9作为crRNA传感器和间隔器获取的调节器的双重作用.
- 突出了Cas9在保护CRISPR免疫深度和预防自身免疫的功能.
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