Circadian clocks and cell division: what's the pacemaker?
Evolution has selected a system of two intertwined cell cycles: the cell division cycle (CDC) and the daily (circadian) biological clock. The circadian clock keeps track of solar time and programs biological processes to occur at environmentally appropriate times. One of these processes is the CDC, which is often gated by the circadian clock. The intermeshing of these two cell cycles is probably responsible for the observation that disruption of the circadian system enhances susceptibility to some kinds of cancer. The core mechanism underlying the circadian clockwork has been thought to be a transcription & translation feedback loop (TTFL), but recent evidence from studies with cyanobacteria, synthetic oscillators and immortalized cell lines suggests that the core circadian pacemaking mechanism that gates cell division in mammalian cells could be a post-translational oscillator (PTO).
Johnson
Carl Hirschie
CH
Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA. carl.h.johnson@vanderbilt.edu
D000818:Animals; D005075:Biological Evolution; D002453:Cell Cycle / Q000502:physiology*; D057906:Circadian Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D056925:Circadian Rhythm Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D000458:Cyanobacteria / Q000166:cytology / Q000502:physiology; D005055:Euglena / Q000166:cytology / Q000502:physiology; D025461:Feedback, Physiological; D006801:Humans; D008027:Light
D056925:Circadian Rhythm Signaling Peptides and Proteins