[Circadian rhythms and systems biology].
Cellular rhythms represent a field of choice for studies in system biology. The examples of circadian rhythms and of the cell cycle show how the experimental and modeling approaches contribute to clarify the conditions in which periodic behavior spontaneously arises in regulatory networks at the cellular level. Circadian rhythms originate from intertwined positive and negative feedback loops controlling the expression of several clock genes. Models can be used to address the dynamical bases of physiological disorders related to dysfunctions of the mammalian circadian clock. The cell cycle is driven by a network of cyclin-dependent kinases (Cdks). Modeled in the form of four modules coupled through multiple regulatory interactions, the Cdk network operates in an oscillatory manner in the presence of sufficient amounts of growth factor. For circadian rhythms and the cell cycle, as for other recently observed cellular rhythms, periodic behavior represents an emergent property of biological systems related to their regulatory structure.
Goldbeter
Albert
A
Unité de chronobiologie théorique, Université Libre de Bruxelles, Campus Plaine, CP 231, B-1050 Bruxelles, Belgique. agoldbet@ulb.ac.be
Gérard
Claude
C
Leloup
Jean-Christophe
JC
D056930:ARNTL Transcription Factors / Q000502:physiology; D000818:Animals; D001001:Anura / Q000196:embryology / Q000502:physiology; D056926:CLOCK Proteins / Q000235:genetics / Q000502:physiology; D002453:Cell Cycle / Q000502:physiology; D021081:Chronobiology Disorders / Q000235:genetics / Q000503:physiopathology; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D018844:Cyclin-Dependent Kinases / Q000502:physiology; D016213:Cyclins / Q000502:physiology; D003624:Darkness; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology; D006801:Humans; D008027:Light; D008322:Mammals / Q000235:genetics / Q000502:physiology; D016200:Maturation-Promoting Factor / Q000502:physiology; D008954:Models, Biological; D056950:Period Circadian Proteins / Q000235:genetics / Q000502:physiology; D049490:Systems Biology
D056930:ARNTL Transcription Factors; C538960:BMAL1 protein, human; D016213:Cyclins; D056950:Period Circadian Proteins; D056926:CLOCK Proteins; D018844:Cyclin-Dependent Kinases; D016200:Maturation-Promoting Factor