Interconnected feedback loops in the Neurospora circadian system
Interconnected feedback loops in the Neurospora circadian system
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DOI：
10.1126/science.289.5476.107
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发表时间：
2000-07-07
期刊：
影响因子：
56.9
通讯作者：
Dunlap, JC
中科院分区：
文献类型：
--
作者：
Lee, K;Loros, JJ;Dunlap, JC
在粗糙脉孢菌中，白色项圈1（WC-1），转录激活因子和正时钟元件，从wc-1转录物的非节律性稳态池中有节律地表达，与转录后调节的节律性一致。frq的突变影响WC-1表达的水平和周期性，并且驱动的FRQ表达不仅抑制其自身的内源性水平，而且以约8小时的延迟正向调节WC-1合成，该延迟类似于在野生型时钟中所见。因此，FRQ在脉孢菌生物钟中起着双重作用，从而与WC-1形成了第二个反馈回路，这将促进该昼夜节律系统的鲁棒性和稳定性。果蝇和小鼠生物钟中也存在互锁环，这表明这种互锁环可能是昼夜节律计时系统的一个保守方面。
In Neurospora crassa, white collar 1 (WC-1), a transcriptional activator and positive clock element, is rhythmically expressed from a nonrhythmic steady-state pool of wc-1 transcript, consistent with posttranscriptional regulation of rhythmicity. Mutations in frq influence both the level and periodicity of WC-1 expression, and driven FRQ expression not only depresses its own endogenous levels, but positively regulates WC-1 synthesis with a lag of about 8 hours, a delay similar to that seen in the wild-type clock. FRQ thus plays dual roles in the Neurospora clock and thereby, with WC-1, forms a second feedback loop that would promote robustness and stability in this circadian system. The existence also of interlocked loops in Drosophila melanogaster and mouse clocks suggests that such interlocked loops may be a conserved aspect of circadian timing systems.