Cheng Hai-Ying Mary, Obrietan Karl
Department of Medical Biophysics, The University Health Network, University of Toronto, 610 University Avenue, Toronto, Ont., Canada M5G 2M9.
Semin Cell Dev Biol. 2006 Jun;17(3):345-51. doi: 10.1016/j.semcdb.2006.03.006. Epub 2006 Apr 3.
Living organisms are endowed with an autonomous timekeeping program that not only maintains circadian rhythms of behaviour and physiology but is reset by cues from the external, cyclic environment. Intracellular signaling events that mediate entrainment of the mammalian circadian clock by photic (light) as well as non-photic inputs are only beginning to be elucidated. Dexras1 is a novel Ras-like G protein that modulates multiple signaling cascades. Genetic ablation of Dexras1 in mice (dexras1(-/-)) results in altered responsiveness of the master circadian clock to photic and non-photic cues. This review will attempt to provide mechanistic insights into the involvement of Dexras1 in biological timing processes based on its role as a modulator of signal transduction.
生物有机体具有自主的计时程序，该程序不仅能维持行为和生理的昼夜节律，还能被来自外部周期性环境的线索所重置。介导哺乳动物生物钟通过光（光照）以及非光输入进行同步的细胞内信号事件才刚刚开始被阐明。Dexras1是一种新型的类Ras G蛋白，可调节多种信号级联反应。小鼠中Dexras1基因的缺失（dexras1(-/-)）会导致主生物钟对光和非光线索的反应性改变。本综述将基于Dexras1作为信号转导调节因子的作用，试图提供其参与生物计时过程的机制性见解
