中文摘要：

生物钟作为内源的分子机器调控生物体的生化反应、生理及行为各层面的活动。真核生物生物钟运行的分子机制非常保守,都是由正调因子和负调因子构成的基于转录/翻译的负反馈调控环来控制。泛素—蛋白酶体途径引发的生物钟蛋白降解是生物钟调控的重要步骤。从真菌、动物到植物,基于磷酸化的生物钟蛋白的泛素化及降解是决定生物钟周期长短的主要调控方式。尽管各物种进化出的生物钟蛋白差异较大,它们都有效地利用了细胞中进化上非常保守的组分,如蛋白激酶、磷酸酶、泛素连接酶、去泛素酶以及蛋白酶体等来调控生物钟的运行。

英文摘要：

Circadian clocks are endogenous molecular machineries that control a large number of biochemical, physiological and behavioral activities in most eukaryotic organisms. The eukaryotic clocks are regulated by transcription-translation negative feedback loops containing positive and negative elements. The ubiquitinproteasome pathway is an essential component of eukaryotic clocks by controlling the degradation rates of clock proteins. From fungi, animals to plants, phosphorylation-dependent ubiquitination and degradation of clock proteins play a major role in period determination in eukaryotes. Although eukaryotic organisms evolved different clock proteins, they adapted the conserved components, such as kinases, phosphatases, ubiquitin ligases, deubiquitinases and proteasome, to regulate the oscillation of circadian clocks.