Mammalian Cry1 and Cry2 are essential for maintenance of circadian rhythms
Mammalian Cry1 and Cry2 are essential for maintenance of circadian rhythms
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作者：
van der Horst, GTJ;Muijtjens, M;Yasui, A
许多生化、生理和行为过程都表现出昼夜节律，这些节律是由一种称为生物钟的内部计时机制产生的。根据迅速发展的情况。模型中，驱动这个时钟的核心振荡器由一个基于自动调节转录(翻译后)的反馈环组成，涉及一组‘时钟’基因(1-6)。分子码头不会以准确的24小时节律性振荡，但会被光带入太阳的昼夜节律。哺乳动物蛋白Cry1和Cry2是植物蓝光受体(隐色素)和光解酶家族的成员，已被认为是光携带生物钟(7-10)的候选光受体。在这里，我们表明，缺乏Cry1或Cry2蛋白的小鼠表现出运动活动的加速和延迟的自由奔跑周期。引人注目的是，在没有这两种蛋白质的情况下，可以观察到自由奔跑节律性的瞬间和完全丧失。这表明，除了可能的光感受器和拮抗性时钟调节功能外，这两种蛋白质对维持昼夜节律性都是必不可少的。
Many biochemical, physiological and behavioural processes show circadian rhythms which are generated by an internal timekeeping mechanism referred to as the biological clock. According to rapidly developing. models, the core oscillator driving this clock is composed of an autoregulatory transcription-(post) translation-based feedback loop involving a set of 'clock' genes(1-6). Molecular docks do not oscillate with an exact 24-hour rhythmicity but are entrained to solar day/night rhythms by light. The mammalian proteins Cry1 and Cry2, which are members of the family of plant blue-light receptors (cryptochromes) and photolyases, have been proposed as candidate light receptors for photoentrainment of the biological clock(7-10). Here we show that mice lacking the Cry1 or Cry2 protein display accelerated and delayed free-running periodicity of locomotor activity, respectively. Strikingly, in the absence of both proteins, an instantaneous and complete loss of free-running rhythmicity is observed. This suggests that, in addition to a possible photoreceptor and antagonistic clock-adjusting function, both proteins are essential for the maintenance of circadian rhythmicity.