Redox cycling of intracellular thiols: State variables for ultradian, cell division cycle and circadian cycles?

Since the pioneering work of Rapkine (1931) the hypothesis that many rhythmic life processes may involve cyclic interconversion of dithiols to disulphides provides a central theme that unifies ultradian, cell division cycle and circadian rhythm research. We have shown that in an autonomously-oscillating continuous culture of Saccharomyces cerevisiae ultradian (τ = 40 min) cycles between high and low respiratory states are accompanied by redox cycling of nicotinamide nucleotide(s) and glutathione. This system may provide insights into regulation of rhythmic processes with longer periods