识别RACK1和蛋白激酶Calpha作为哺乳动物昼夜钟的组成部分
Maria S Robles1, Cyril Boyault, Darko Knutti
1Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
概括
昼夜时钟是指昼夜的时间表.
科学领域:
- 分子生物学分子生物学
- 时间生物学 时间生物学
- 生物化学 生物化学
背景情况:
- 哺乳动物的昼夜时钟依赖于一个涉及CLOCK-BMAL1转录因子的负反循环.
- 了解这种反循环的分子机制对于破译昼夜节律调节至关重要.
研究的目的:
- 在昼夜反阶段研究与BMAL1相关的蛋白质复合体.
- 阐明受体对激活的C激酶-1 (RACK1) 和蛋白激酶C-α (PKCalpha) 在哺乳动物昼夜钟中的作用.
主要方法:
- 对含有BMAL1.1.的小鼠核蛋白复合物的分析.
- 在纤维细胞中研究RACK1和PKCalpha的过度表达和耗尽.
- 在体外酸化试验以评估PKCalpha.的BMAL1修饰.
主要成果:
- 在核BMAL1复合体内,RACK1和PKCalpha被以昼夜依赖的方式鉴定出来.
- 过度表达RACK1和PKCalpha抑制了CLOCK-BMAL1的转录活性.
- 在体外,RACK1增强了PKCalpha介导的BMAL1酸化.
- RACK1或PKCalpha的耗尽导致纤维细胞的昼夜周期缩短.
结论:
- 蛋白激酶C (PKC) 信号通路在昼夜时钟内被动态调节.
- RACK1和PKCalpha是哺乳动物昼夜反循环的组成部分,影响时钟振荡.
- 该PKC通路由内部细胞过程节奏激活,而不仅仅是外部刺激,有助于昼夜节律.
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