World Library  

Add to Book Shelf
Flag as Inappropriate
Email this Book

Plos Biology : Coupling of a Core Post-translational Pacemaker to a Slave Transcription, Volume 8

By Merrow, Martha

Click here to view

Book Id: WPLBN0003940811
Format Type: PDF eBook :
File Size:
Reproduction Date: 2015

Title: Plos Biology : Coupling of a Core Post-translational Pacemaker to a Slave Transcription, Volume 8  
Author: Merrow, Martha
Volume: Volume 8
Language: English
Subject: Journals, Science, Biology
Collections: Periodicals: Journal and Magazine Collection (Contemporary), PLoS Biology
Publication Date:
Publisher: Plos


APA MLA Chicago

Merrow, M. (n.d.). Plos Biology : Coupling of a Core Post-translational Pacemaker to a Slave Transcription, Volume 8. Retrieved from

Description : Cyanobacteria are the only model circadian clock system in which a circadian oscillator can be reconstituted in vitro. The underlying circadian mechanism appears to comprise two subcomponents : a post-translational oscillator (PTO) and a transcriptional/translational feedback loop (TTFL). The PTO and TTFL have been hypothesized to operate as dual oscillator systems in cyanobacteria. However, we find that they have a definite hierarchical interdependency—the PTO is the core pacemaker while the TTFL is a slave oscillator that quickly damps when the PTO stops. By analysis of overexpression experiments and mutant clock proteins, we find that the circadian system is dependent upon the PTO and that suppression of the PTO leads to damped TTFL-based oscillations whose temperature compensation is not stable under different metabolic conditions. Mathematical modeling indicates that the experimental data are compatible with a core PTO driving the TTFL: the combined PTO/TTFL system is resilient to noise. Moreover, the modeling indicates a mechanism by which the TTFL can feed into the PTO such that new synthesis of clock proteins can phase-shift or entrain the core PTO pacemaker. This prediction was experimentally tested and confirmed by entraining the in vivo circadian system with cycles of new clock protein synthesis that modulate the phosphorylation status of the clock proteins in the PTO. In cyanobacteria, the PTO is the self-sustained core pacemaker that can operate independently of the TTFL, but the TTFL damps when the phosphorylation status of the PTO is clamped. However, the TTFL can provide entraining input into the PTO. This study is the first to our knowledge to experimentally and theoretically investigate the dynamics of a circadian clock in which a PTO is coupled to a TTFL. These results have important implications for eukaryotic clock systems in that they can explain how a TTFL could appear to be a core circadian clockwork when in fact the true pacemaker is an embedded biochemical oscillator.


Click To View

Additional Books

  • Plos Biology : Did Pterosaurs Feed by Sk... (by )
  • Plos Biology : Gal4 Gets Genes to Loosen... (by )
  • Plos Biology : Usf Binding Sequences fro... (by )
  • Plos Biology : Hairy Transcriptional Rep... (by )
  • Plos Biology : Structure of a Classical ... (by )
  • Plos Biology : Reinvigorating the Role o... (by )
  • Plos Biology : Mitotic Spindle Assembly ... (by )
  • Plos Biology : a Neural Computation for ... (by )
  • Plos Biology : Neural Substrates of Moun... (by )
  • Plos Biology : an Unbiased Cell Morpholo... (by )
  • Plos Biology : Sperm Sociality ; Coopera... (by )
  • Plos Biology : Neural Mechanisms Underly... (by )
Scroll Left
Scroll Right


Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.