Robust daily rhythms of RNA and protein expression occur in “clockless” cells For several decades, researchers have studied the molecular mechanisms underlying circadian rhythms, the daily oscillations ubiquitous in biology. This basic clockwork is well understood in animal cells: Conserved clock proteins form a transcription-translation feedback loop that drives circadian oscillations of gene expression and downstream processes. These cellular clocks in peripheral tissues are hierarchically synchronized by a “master clock” in the brain [the suprachiasmatic nucleus (SCN) in mammals] responding to daylight, and also by other physiological signals such as feeding. On page 800 of this issue, Ray et al. (1) demonstrate that many circadian oscillations—in transcription, translation, and protein phosphorylation—can continue in mouse cells in the absence of an essential circadian clock gene, Bmal1 (brain and muscle ARNT-like 1). Thus, there might be other unknown clocks that also control circadian gene expression.

中文翻译：

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走向另一个时钟

RNA 和蛋白质表达的稳健日常节律发生在“无时钟”细胞中 几十年来，研究人员研究了昼夜节律的分子机制，即生物学中普遍存在的日常振荡。这种基本的发条机制在动物细胞中得到了很好的理解：保守的时钟蛋白形成了一个转录-翻译反馈回路，驱动基因表达和下游过程的昼夜节律振荡。外周组织中的这些细胞时钟由大脑中的“主时钟”[哺乳动物中的视交叉上核 (SCN)] 响应日光以及其他生理信号（例如进食）进行分级同步。在本期的第 800 页，Ray 等人。(1) 证明许多昼夜节律振荡——在转录、翻译、和蛋白质磷酸化——在缺乏必需的生物钟基因 Bmal1（大脑和肌肉 ARNT 样 1）的情况下，可以在小鼠细胞中继续存在。因此，可能还有其他未知的时钟也控制着昼夜节律基因的表达。