Molecular components of the Mammalian circadian clock.
Molecular components of the Mammalian circadian clock.
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DOI：
10.1007/978-3-642-25950-0_1
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发表时间：
2013-01-01
影响因子：
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通讯作者：
Takahashi, Joseph S
中科院分区：
文献类型：
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作者：
Buhr, Ethan D;Takahashi, Joseph S
哺乳动物的昼夜活动主要与环境中的光暗周期同步。这是通过将信号传递到下丘脑中的视交叉上核（SCN）的视觉光感受来实现的。来自SCN的信号使整个身体的独立生物钟同步到适当的相位。能够引导这些外围时钟的信号包括体液信号、代谢因素和体温。在单个组织的水平上，通过基于局部转录/抑制的反馈振荡器和系统线索的作用，数千个基因被带到独特的阶段。在这种分子钟中，蛋白质CLOCK和BMAL 1引起基因的转录，这些基因最终反馈并抑制CLOCK和BMAL 1的转录活性。最后，还有其他分子昼夜节律振荡器，它们可以在所有已测试的物种中独立于基于转录的时钟发挥作用。
Mammals synchronize their circadian activity primarily to the cycles of light and darkness in the environment. This is achieved by ocular photoreception relaying signals to the suprachiasmatic nucleus (SCN) in the hypothalamus. Signals from the SCN cause the synchronization of independent circadian clocks throughout the body to appropriate phases. Signals that can entrain these peripheral clocks include humoral signals, metabolic factors, and body temperature. At the level of individual tissues, thousands of genes are brought to unique phases through the actions of a local transcription/translation-based feedback oscillator and systemic cues. In this molecular clock, the proteins CLOCK and BMAL1 cause the transcription of genes which ultimately feedback and inhibit CLOCK and BMAL1 transcriptional activity. Finally, there are also other molecular circadian oscillators which can act independently of the transcription-based clock in all species which have been tested.