基因君官网
2015年6月23日讯 /生物谷BIOON/ –大部分人每天需要7到8小时睡眠时间保证机体正常功能，但也有一些人他们需要的睡眠时间要少得多。这种差别很大程度上是由基因的多样性决定的。在最近一项发表在current biology上的研究中，研究人员在果蝇体内发现一个叫作Taranis的基因对于正常睡眠非常必要。
研究人员首先对许多果蝇突变系进行了筛选，发现一个叫作Taranis的基因发生突变会导致果蝇睡眠时间大大减少。通过一系列遗传学和生化实验，研究人员对Taranis编码的蛋白进行了追踪，观察Taranis是如何与其他蛋白发生相互作用的，结果发现Taranis能够与一个已知的睡眠调控因子–Cyclin A发生结合，这表明Taranis与Cyclin A形成了一个新的分子机制导致cdk1失活，而正常情况下Cdk1能够抑制睡眠，促进觉醒。
先前研究已经证明Cyclin A 只在一小部分神经元细胞中表达。研究人员发现这些神经元细胞位于果蝇大脑的一个区域，相当于人类的下丘脑–下丘脑是人类脑部结构中与睡眠有关的一个中心。当在那一小部分神经元细胞中敲低Taranis基因的表达，神经元细胞发生激活，果蝇的睡眠时间大大减少。研究人员指出，在睡眠过程中Taranis帮助抑制的这些神经元可能是果蝇大脑中负责唤醒的重要区域。
Taranis在人类中有同源蛋白–Trip-Br家族的转录调控因子，但该家族成员是否通过类似的方式参与人类睡眠调节仍未可知。
总得来说，这项研究以果蝇为研究模型发现Taranis能够与Cyclin A结合抑制Cdk1活性，从而保证正常睡眠时间。（基因宝jiyinbao.com）
TARANIS Functions with Cyclin A and Cdk1 in a Novel Arousal Center to Control Sleep in Drosophila
Dinis J.S. Afonso, Die Liu, Daniel R. Machado, Huihui Pan, James E.C. Jepson5, Dragana Rogulja, Kyunghee Koh
Sleep is an essential and conserved behavior whose regulation at the molecular and anatomical level remains to be elucidated. Here, we identify TARANIS (TARA), a Drosophila homolog of the Trip-Br (SERTAD) family of transcriptional coregulators, as a molecule that is required for normal sleep patterns. Through a forward-genetic screen, we isolated tara as a novel sleep gene associated with a marked reduction in sleep amount. Targeted knockdown of tara suggests that it functions in cholinergic neurons to promote sleep. tara encodes a conserved cell-cycle protein that contains a Cyclin A (CycA)-binding homology domain. TARA regulates CycA protein levels and genetically and physically interacts with CycA to promote sleep. Furthermore, decreased levels of Cyclin-dependent kinase 1 (Cdk1), a kinase partner of CycA, rescue the short-sleeping phenotype of tara and CycA mutants, while increased Cdk1 activity mimics the tara and CycA phenotypes, suggesting that Cdk1 mediates the role of TARA and CycA in sleep regulation. Finally, we describe a novel wake-promoting role for a cluster of ?14 CycA-expressing neurons in the pars lateralis (PL), previously proposed to be analogous to the mammalian hypothalamus. We propose that TARANIS controls sleep amount by regulating CycA protein levels and inhibiting Cdk1 activity in a novel arousal center.