SynthSys, University of Edinburgh, The Kings Buildings, Mayfield Road, EH9 3JD, Edinburgh, UK.
Trends Biochem Sci. 2012 Nov;37(11):484-92. doi: 10.1016/j.tibs.2012.07.006. Epub 2012 Aug 20.
Circadian clocks have evolved as an adaptation to life on a rotating planet, and orchestrate rhythmic changes in physiology to match the time of day. For decades, cellular circadian rhythms were considered to solely result from feedback between the products of rhythmically expressed genes. These transcriptional/translational feedback loops (TTFLs) have been ubiquitously studied, and explain the majority of circadian outputs. In recent years, however, non-transcriptional processes were shown to be major contributors to circadian rhythmicity. These key findings have profound implications on our understanding of the evolution and mechanistic basis of cellular circadian timekeeping. This review summarises and discusses these results and the experimental and theoretical evidence of a possible relation between non-transcriptional oscillator (NTO) mechanisms and TTFL oscillations.
生物钟作为一种适应旋转星球的产物而进化，协调生理节律的变化以适应一天中的时间。几十年来，细胞生物钟节律被认为仅源自节律表达基因产物之间的反馈。这些转录/翻译反馈环（TTFLs）已被广泛研究，并解释了大多数生物钟输出。然而，近年来，非转录过程被证明是生物钟节律的主要贡献者。这些关键发现对我们理解细胞生物钟计时的进化和机制基础具有深远的影响。本综述总结并讨论了这些结果，以及非转录振荡器（NTO）机制与 TTFL 振荡之间可能存在关系的实验和理论证据。
