کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6266589 | 1294915 | 2013 | 9 صفحه PDF | دانلود رایگان |
The biochemical basis of circadian timekeeping is best characterized in cyanobacteria. The structures of its key molecular players, KaiA, KaiB, and KaiC are known and these proteins can reconstitute a remarkable circadian oscillation in a test tube. KaiC is rhythmically phosphorylated and its phospho-status is a marker of circadian phase that regulates ATPase activity and the oscillating assembly of a nanomachine. Analyses of the nanomachines have revealed how their timing circuit is ratcheted to be unidirectional and how they stay in synch to ensure a robust oscillator. These insights are likely to elucidate circadian timekeeping in higher organisms, including how transcription and translation could appear to be a core circadian timer when the true pacemaker is an embedded biochemical oscillator.
⺠A biochemical circadian oscillator can be reconstituted with three proteins and ATP. ⺠The biochemical oscillator drives a Transcription/Translation Feedback Loop in vivo. ⺠Activities of the core protein include ATPase, kinase and phospho-transferase. ⺠Structural insights explain unidirectionality, synchrony, robustness, and entrainment.
Journal: Current Opinion in Neurobiology - Volume 23, Issue 5, October 2013, Pages 732-740