Proteasome function is required for biological timing throughout the twenty-four hour cycle.
Proteasome function is required for biological timing throughout the twenty-four hour cycle.
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DOI：
10.1016/j.cub.2011.03.060
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发表时间：
2011-05-24
期刊：
影响因子：
9.2
通讯作者：
Millar, Andrew J.
中科院分区：
文献类型：
--
作者：
van Ooijen, Gerben;Dixon, Laura E.;Troein, Carl;Millar, Andrew J.
Circadian clocks were, until recently, seen as a consequence of rhythmic transcription of clock components, directed by transcriptional/translational feedback loops (TTFLs). Oscillations of protein modification were then discovered in cyanobacteria. Canonical posttranslational signaling processes have known importance for clocks across taxa. More recently, evidence from the unicellular eukaryote Ostreococcus tauri revealed a transcription-independent, rhythmic protein modification shared in anucleate human cells. In this study, the Ostreococcus system reveals a central role for targeted protein degradation in the mechanism of circadian timing. The Ostreococcus clockwork contains a TTFL involving the morning-expressed CCA1 and evening-expressed TOC1 proteins. Cellular CCA1 and TOC1 protein content and degradation rates are analyzed qualitatively and quantitatively using luciferase reporter fusion proteins. CCA1 protein degradation rates, measured in high time resolution, feature a sharp clock-regulated peak under constant conditions. TOC1 degradation peaks in response to darkness. Targeted protein degradation, unlike transcription and translation, is shown to be essential to sustain TTFL rhythmicity throughout the circadian cycle. Although proteasomal degradation is not necessary for sustained posttranslational oscillations in transcriptionally inactive cells, TTFL and posttranslational oscillators are normally coupled, and proteasome function is crucial to sustain both. ► CCA1 protein degradation rate is clock regulated ► Sensitivity of the circadian clock to proteasomal inhibition is phase independent ► Nontranscriptional rhythms only rely on the proteasome while coupled to the TTFL
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影响因子：
11.6
作者：
Baudry, Antoine;Ito, Shogo;Imaizumi, Takato
通讯作者：
Imaizumi, Takato
DOI：
10.1111/j.1742-4658.2009.06985.x
发表时间：
2009-05
期刊：
The FEBS journal
影响因子：
--
作者：
Hall A;Karplus PA;Poole LB
通讯作者：
Poole LB
影响因子：
2.9
作者：
Djouani-Tahri, El Batoul;Motta, Jean-Paul;Corellou, Florence
通讯作者：
Corellou, Florence
影响因子：
9.9
作者：
通讯作者：
--
影响因子：
7.2
作者：
Baier, M;Dietz, KJ
通讯作者：
Dietz, KJ