- Abstract:
-
The main function of the cell clock is to separate in time incompatible biochemistry. No amphibolic cell energy metabolism can produce ATP unless it is controlled by the organizing oscillations of the clock. The long oscillation period of the clock is due to the participation of storage metabolites in the clockwork. The theoretically predicted "metabolic see-saw" is operative in cyanobacteria, making concentrations of carbohydrate and amino acid storage compounds oscillate out of phase. The immediate cause of oscillations generated by the clock is a set of positive feedbacks in the redox metabolism. These feedbacks generate a nearly ideal square waveform required for the efficient suppression of the incompatibility. Such a waveform is easy to observe in synchronous cyanobacterial populations. The master positive feedbacks do not involve a de novo protein synthesis. However, gene expression control mechanisms and metabolic negative feedbacks maintain a general homeostasis and contribute to the stability of the oscillation period. The clock ticks in nondividing cells and gates the cell divisions. In cyanobacteria, the divisions can occur once or twice per one clock period. In the second case, the divisions are gated within very short time gaps (less than 10 min each) at the end of subjective light and dark phases. Mathematical modeling of a large number of cell clocks, interacting via a common extracellular medium, demonstrates a set of different population dynamic behaviors. This set cannot be easily extrapolated into the intracellular behavior and the underlying mechanisms. From the nearly sine waveform, often observed experimentally in loosely synchronized cell populations, one cannot draw any conclusion about the waveform generated by the individual clock.
- Links To Paper
- No links available
- Bibtex format
- @InProceedings{EDI-INF-RR-1160,
- author = {
Evgeni Selkov, Sr.
and Evgeny Selkov
and Dmitry Karpeev
and David DeHorn
and Mike Minkov
and Evgeni Nikolaev
and Yulya Poluektova
},
- title = {Metabolic theory of the cell clock and its experimental verification with sequenced cyanobacteria},
- book title = {Plant Biology 2003, Abstract #779},
- publisher = {American Society of Plant Biologists},
- year = 2003,
- month = {Jul},
- }
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