Chronobiology and Molecular Endocrinology Lab, Department of Zoology, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, India.
Chronobiol Int. 2023 Jul 3;40(7):970-981. doi: 10.1080/07420528.2023.2231081.
Circadian rhythms are generated by intrinsic 24-h oscillations that anticipate the extrinsic changes associated with solar day. A conserved transcriptional-translational feedback loop generates these molecular oscillations of clock genes at the organismal and the cellular levels. One of the recently discovered outputs of circadian clock is Nocturnin (Noct) or Ccrn4l. In mice, mRNA is broadly expressed in cells throughout the body, with a particularly high-amplitude rhythm in liver. NOCT belongs to the EEP family of proteins with the closest similarity to the CCR4 family of deadenylases. Multiple studies have investigated the role of Nocturnin in development, adipogenesis, lipid metabolism, inflammation, osteogenesis, and obesity. Further, mice lacking Noct ( KO or Noct) are protected from high-fat diet-induced obesity and hepatic steatosis. Recent studies had provided new insights by investigating various aspects of Nocturnin, ranging from its sub-cellular localization to identification of its target transcripts. However, a profound understanding of its molecular function remains elusive. This review article seeks to integrate the available literature into our current understanding of the functions of Nocturnin, their regulatory roles in key tissues and to throw light on the existing scientific lacunae.
昼夜节律是由内在的 24 小时振荡产生的，这些振荡可以预测与太阳日相关的外在变化。一个保守的转录-翻译反馈环在机体和细胞水平上产生这些生物钟基因的分子振荡。最近发现的昼夜节律的一个输出产物是 Nocturnin（Noct）或 Ccrn4l。在小鼠中，mRNA 在全身的细胞中广泛表达，在肝脏中表现出特别高振幅的节律。NOCT 属于 EEP 蛋白家族，与 CCR4 家族的脱腺苷酸酶具有最接近的相似性。多项研究调查了 Nocturnin 在发育、脂肪生成、脂质代谢、炎症、成骨和肥胖中的作用。此外，缺乏 Noct（KO 或 Noct）的小鼠可以防止高脂肪饮食诱导的肥胖和肝脂肪变性。最近的研究通过研究 Nocturnin 的各个方面提供了新的见解，范围从亚细胞定位到鉴定其靶转录本。然而，对其分子功能的深刻理解仍然难以捉摸。这篇综述文章旨在将现有的文献整合到我们对 Nocturnin 功能的当前理解中，以及它们在关键组织中的调节作用，并阐明现有的科学空白。
