2002/04/23 by Jose M. G. Vilar, José M. G. Vilar, Hao Yuan Kueh +2 · 2 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Neuroscience · Physics and Astronomy · #Circadian rhythm and melatonin #Gene Regulatory Network Analysis #Light effects on plants #cond-mat #physics.bio-ph #q-bio.MN
paper · pdf · doi:10.1073/pnas.092133899
published as Proc. Natl. Acad. Sci. USA 99, 5988-5992 (2002) · 20 pages, 7 figures
openalex publication_date 2002/04/23 · arxiv created 2002/08/11 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
A wide range of organisms use circadian clocks to keep internal sense of daily time and regulate their behavior accordingly. Most of these clocks use intracellular genetic networks based on positive and negative regulatory elements. The integration of these "circuits" at the cellular level imposes strong constraints on their functioning and design. Here, we study a recently proposed model [Barkai, N. & Leibler, S. (2000) Nature (London), 403, 267-268] that incorporates just the essential elements found experimentally. We show that this type of oscillator is driven mainly by two elements: the concentration of a repressor protein and the dynamics of an activator protein forming an inactive complex with the repressor. Thus, the clock does not need to rely on mRNA dynamics to oscillate, which makes it especially resistant to fluctuations. Oscillations can be present even when the time average of the number of mRNA molecules goes below one. Under some conditions, this oscillator is not only resistant to but, paradoxically, also enhanced by the intrinsic biochemical noise.