哺乳动物的昼夜钟蛋白质形成动态相互作用的微体,与相位分离有所区别
Pancheng Xie1,2, Xiaowen Xie1, Congrong Ye1
1Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390.
概括
内生生日间钟蛋白形成了独特的核微体,而不是过度表达时看到的大型凝聚物. 这表明哺乳动物昼夜钟的类似酶的机制.
科学领域:
- 分子生物学分子生物学
- 时间生物学 时间生物学
- 生物物理学的生物物理.
背景情况:
- 液-液相分离 (LLPS) 对生物过程至关重要,但其对内源蛋白的作用往往不清楚.
- 核心昼夜钟蛋白,如PERIOD (PER),本质上是无序的,并形成复合体,但研究往往使用过度表达系统.
- 了解内源性昼夜蛋白质的LLPS对于破译昼夜时钟的分子机制至关重要.
研究的目的:
- 调查LLPS对内源性昼夜钟蛋白的生理相关性.
- 要区分由过度表达的蛋白质形成的LLPS凝聚物和由内源蛋白质形成的结构.
- 阐明核钟蛋白在哺乳动物昼夜负反循环中的动态相互作用.
主要方法:
- 在细胞中稳定表达Per2转基因,观察LLPS凝结物.
- 超高分辨率显微镜可可视化核微生物体内内内源性PER2.
- 分析细胞和小鼠组织中的微体特征 (扩散,抗治疗) 和与其他钟蛋白 (BMAL1,CRY1) 的相互作用.
主要成果:
- 过度表达的PER2形成了缓慢运动的,依赖酸化的LLPS凝结物.
- 内源的PER2形成了快速扩散的核微生物体,与LLPS凝结物不同,并且耐各种处理.
- 只有很小一部分内源性PER2微体与BMAL1和CRY1暂时相互作用,这表明一种类似酶的机制.
结论:
- 哺乳动物的昼夜时钟机制依赖于核心时钟蛋白的动态相互作用,而不仅仅依赖于大型LLPS凝结物.
- 过度表达研究可能无法准确地反映内源性昼夜蛋白的行为.
- 研究内源性蛋白质对于理解LLPS和昼夜时钟功能至关重要.
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