A Model of Regulation

Science's STKE  25 Oct 2005:
Vol. 2005, Issue 307, pp. tw378
DOI: 10.1126/stke.3072005tw378

It is becoming possible to recognize basic principles of regulatory circuits that control biological processes. Brandman et al. (see the Perspective by Bornholdt) compared three distinct biological regulatory systems and note that all contain multiple positive feedback loops with fast and slow time courses. They used mathematical models of the systems to show that these characteristics allow the systems to be relatively insensitive to fluctuations in signal input and allow for the kinetics of activation and inactivation to be adjusted independently to best fit the physiological requirements of the system.

O. Brandman, J. E. Ferrell Jr., R. Li, T. Meyer, Interlinked fast and slow positive feedback loops drive reliable cell decisions. Science 310, 496-498 (2005). [Abstract] [Full Text]

S. Bornholdt, Less is more in modeling large genetic networks. Science 310, 449-451 (2005). [Summary] [Full Text]